Abstract: A light source unit includes a light distribution lens configured to guide light emitted from an LED disposed behind the light distribution lens, and a reflector arranged to surround the light distribution lens. Illuminance unevenness can be more suitably reduced, and effective light is not blocked even if a pinhole device is used for glare prevention, thereby avoiding illuminance unevenness and illuminance reductions. The light distribution lens has a columnar part that extends in the optical axis direction, and a conical recess is formed in the distal end of the columnar part. The conical recess is constituted by a reflective surface that fully reflects, in the circumferential direction, light incident on the light distribution lens. The reflector reflects light emitted from a cylindrical side surface of the columnar part such that the reflected light becomes converging light.

Abstract: A light source unit includes a light distribution lens configured to guide light emitted from an LED disposed behind the light distribution lens, and a reflector arranged to surround the light distribution lens. Illuminance unevenness can be more suitably reduced, and effective light is not blocked even if a pinhole device is used for glare prevention, thereby avoiding illuminance unevenness and illuminance reductions. The light distribution lens has a columnar part that extends in the optical axis direction, and a conical recess is formed in the distal end of the columnar part. The conical recess is constituted by a reflective surface that fully reflects, in the circumferential direction, light incident on the light distribution lens. The reflector reflects light emitted from a cylindrical side surface of the columnar part such that the reflected light becomes converging light.

Abstract: Disclosed are a plant growth lighting apparatus capable of forming a lighting region having a high degree of illuminance uniformity in the array direction of a light-emitting element array as well as a plant hydroponic cultivation apparatus and a plant hydroponic cultivation method capable of growing a plant with high growth efficiency even in a large cultivation region. A plurality of light-emitting element units, each including a first light-emitting element and a second light-emitting element having an emission peak wavelength different from that of the first light-emitting element, are arranged side by side along one direction to form a light-emitting element array. The light-emitting element unit is constituted by two second light-emitting elements disposed so as to be spaced apart from each other in the one direction and one first light-emitting element disposed between the two second light-emitting elements.

Abstract: A halogen lamp of a 12V type including: a glass part, a portion of which is a light emitting portion having a space therein and the rest of which is a sealing portion, both portions being made of quartz glass; an infrared reflective coating formed to cover an outer surface of the glass part; a filament which, supported by the sealing portion, is provided in the inner space of the light emitting portion; a molybdenum foil which is embedded in the sealing portion and is electrically connected to the filament; and a power supply line, one end of which is connected to the molybdenum foil, the other end exposed to outside. The halogen lamp satisfies 450 mm2?Sb?650 mm2 and Se??0.35Sb+520, where Sb and Se designate outer surface areas of the light emitting portion and the sealing portion, respectively.

Abstract: A halogen lamp of a 12V type including: a glass part, a portion of which is a light emitting portion having a space therein and the rest of which is a sealing portion, both portions being made of quartz glass; an infrared reflective coating formed to cover an outer surface of the glass part; a filament which, supported by the sealing portion, is provided in the inner space of the light emitting portion; a molybdenum foil which is embedded in the sealing portion and is electrically connected to the filament; and a power supply line, one end of which is connected to the molybdenum foil, the other end exposed to outside. The halogen lamp satisfies 450 mm2≦Sb<650 mm2 and Se≧−0.35Sb+520, where Sb and Se designate outer surface areas of the light emitting portion and the sealing portion, respectively.