Abstract: Provided is a light-bulb type LED lamp 10 including a plurality of LEDs 67-78, a base 12, a lighting circuit unit that converts commercial power provided through the base 12 into power for lighting the LEDs 67-78, and a heat radiation member 16 that includes a bowl-shaped portion 42. Two stages 46 and 48, extending inwards from an inner circumferential surface 44 of the bowl-shaped portion 42, are provided in a direction of a central axis X of the bowl-shaped portion 42. The LEDs 67-78 are mounted on the stages 46 and 48 in a circumferential direction around the central axis X.

Abstract: To aim to provide a lighting apparatus that is compact yet easy in lamp replacement. A lighting apparatus 1 comprises: a lamp 6 including an outer tube 13 and an arc tube 15 provided inside the outer tube 13; and an opening-type lighting fixture 3 having a mirror part 11 having a concave reflective surface 9 inside which the lamp 6 is disposed. The mirror part 11 reflects light emitted from the lamp 6 at the reflection surface 9 such that the reflected light is emitted through an opening 10 of the mirror part 11. Relational expressions 22?r?28, R?130, and 3.5?R/r are satisfied, with r denoting a maximum outer diameter [mm] of the outer tube 13, and R denoting an opening diameter [mm] of the mirror part 11.

Abstract: Provided is a light-bulb type LED lamp 10 including a plurality of LEDs 67-78, a base 12, a lighting circuit unit that converts commercial power provided through the base 12 into power for lighting the LEDs 67-78, and a heat radiation member 16 that includes a bowl-shaped portion 42. Two stages 46 and 48, extending inwards from an inner circumferential surface 44 of the bowl-shaped portion 42, are provided in a direction of a central axis X of the bowl-shaped portion 42. The LEDs 67-78 are mounted on the stages 46 and 48 in a circumferential direction around the central axis X.

Abstract: To aim to provide a lighting apparatus that is compact yet easy in lamp replacement. A lighting apparatus 1 comprises: a lamp 6 including an outer tube 13 and an arc tube 15 provided inside the outer tube 13; and an opening-type lighting fixture 3 having a mirror part 11 having a concave reflective surface 9 inside which the lamp 6 is disposed. The mirror part 11 reflects light emitted from the lamp 6 at the reflection surface 9 such that the reflected light is emitted through an opening 10 of the mirror part 11. Relational expressions 22?r?28, R?130, and 3.5?R/r are satisfied, with r denoting a maximum outer diameter [mm] of the outer tube 13, and R denoting an opening diameter [mm] of the mirror part 11.

Abstract: A metal halide lamp according to the present invention includes: a main tube (6) made of a light-transmitting ceramic and forming a part of an arc tube; a first thin tube (7a) coupled to a first end of the main tube (6); a second thin tube (7b) coupled to a second end of the main tube (6); a pair of electrodes (5a, 5b), which are inserted into the first and second thin tubes (7a, 7b), respectively, such that the far ends thereof face each other inside the main tube (1); and a first metal halide enclosed in the arc tube. A second metal halide, which has a lower vapor pressure than that of the first metal halide, is further enclosed in the arc tube. And the main tube (6) has portions, of which the inside diameter decreases monotonically toward the ends.

Abstract: A high pressure discharge lamp includes an outer tubular bulb whose inner space is exhausted to a vacuum; an arc tube contained in the outer tubular bulb; and a voltage reducing switching element for reducing a voltage applied to the arc tube. The voltage reducing switching element includes a heat sensitive switching element and a starting-voltage reducing element which are connected in series. During a period in which the heat sensitive switching element has a predetermined temperature or higher, the heat sensitive switching element is closed to electrically connect the arc tube and the voltage reducing switching element in parallel, so that the starting-voltage reducing element is operated. During a period in which the heat sensitive switching element has a temperature lower than the predetermined temperature, the heat sensitive switching element is opened so that the starting-voltage reducing element is not operated.

Abstract: A metal halide lamp of the present invention has an arc tube formed of ceramic and a pair of opposing electrodes. This lamp includes a Pr (praseodymium) halide, a Na (sodium) halide, and a Ca (calcium) halide enclosed within the arc tube. The Pr halide content Hp [mol], the Na halide content Hn [mol], and the Ca halide content Hc [mol] satisfy the relationships of 0.4?Hc/Hp?15.0 and 3.0?Hn/Hp?25.0.

Abstract: Disclosed is a lighting system capable of preventing damage to an outer-tube resulting from an outer-tube discharge that often occurs at the end of useful life of a lamp. The lighting system includes: a metal halide lamp having an arc tube housed within an outer tube; and a lamp .lighting device for operating the metal halide lamp. The lamp lighting device includes: a power supply unit operable to supply an electric power to the metal halide lamp; a detecting unit operable to detect an electrical property of the metal halide lamp; a judging unit operable to judge, based on the detected electrical property, whether a currently occurring discharge is an outer-tube discharge; and an instructing unit operable to instruct the power supply unit to suspend or reduce the electric power supply to the metal halide lamp upon a judgment that the currently occurring discharge is an outer-tube discharge. The detection unit detects a lamp voltage.

Abstract: he present invention aims at providing a metal halide lamp having a configuration to achieve the following goals: to prevent the lamp from burning out during the life due to a rise in lamp voltage; and to obtain high luminous efficiency at the same time. The metal halide lamp 1 comprises: an arc tube 4 made of translucent ceramic and having a main tube part 6 in which a pair of electrodes 14 is disposed; and an outer tube 3 housing the arc tube 4 therein. 4.0?L/D?10.0, where L (mm) is a length of a space between the electrodes 14 and D (mm) is an internal diameter of the main tube part 6. R/r ?3.4, where R (mm) is an internal diameter of the outer tube 3 and r (mm) is an external diameter in the main tube part 6 of the arc tube 4, within a region positionally corresponding to, in a radial direction of the outer tube and the arc tube, the space between the electrodes 14, on a cross-sectional surface where an outer circumference of the arc tube 4 comes closest to an inner circumference of the outer tube 3. M?4.

Abstract: A metal halide lamp according to the present invention includes a discharge tube (3) having an envelope (18) that is formed of a translucent ceramic and has a main tube portion (16), a first slender tube portion (17a) and a second slender tube portion (17b) respectively formed in both end portions of this main tube portion (16), and a first electrode lead-in member (21) and a second electrode lead-in member (22) having a first electrode portion (25a) and a second electrode portion (25b) formed in their respective tip portions. The individual electrode lead-in members (21, 22) are inserted in the respective slender tube portions (17a, 17b), and a gap (23) is formed respectively between the slender tube portion (17a, 17b) and the electrode lead-in member (21, 22).

Abstract: The present invention aims at providing a metal halide lamp that (i) prevents a decline in the lumen maintenance and a deterioration of quality in appearance due to the coloring of a casing tube surrounding the arc tube, and at the same time (ii) achieves high luminous efficiency. A metal halide lamp (1) has a pair of electrodes (20a&b) placed in an arc tube (3) made of translucent ceramic, and a sodium halide is enclosed therein. The metal halide lamp (1) satisfies L/D 4, where L (mm) is the length of the space between the electrodes (20a&b) and D (mm) is the internal diameter of the arc tube (3). The metal halide lamp (1) has a casing tube (2) surrounding the arc tube (3), at least around a portion between the electrodes (20a&b). Here, R/r 3.

Abstract: he present invention aims at providing a metal halide lamp having a configuration to achieve the following goals: to prevent the lamp from burning out during the life due to a rise in lamp voltage; and to obtain high luminous efficiency at the same time. The metal halide lamp 1 comprises: an arc tube 4 made of translucent ceramic and having a main tube part 6 in which a pair of electrodes 14 is disposed; and an outer tube 3 housing the arc tube 4 therein. 4.0?L/D?10.0, where L (mm) is a length of a space between the electrodes 14 and D (mm) is an internal diameter of the main tube part 6. R/r ?3.4, where R (mm) is an internal diameter of the outer tube 3 and r (mm) is an external diameter in the main tube part 6 of the arc tube 4, within a region positionally corresponding to, in a radial direction of the outer tube and the arc tube, the space between the electrodes 14, on a cross-sectional surface where an outer circumference of the arc tube 4 comes closest to an inner circumference of the outer tube 3. M?4.

Abstract: A metal halide lamp of the present invention has an arc tube formed of ceramic and a pair of opposing electrodes. This lamp includes a Pr (praseodymium) halide, a Na (sodium) halide, and a Ca (calcium) halide enclosed within the arc tube. The Pr halide content Hp [mol], the Na halide content Hn [mol], and the Ca halide content Hc [mol] satisfy the relationships of 0.4?Hc/Hp?15.0 and 3.0?Hn/Hp?=25.0.

Abstract: A metal halide lamp according to the present invention includes: a main tube 6 made of a light-transmitting ceramic and forming a part of an arc tube; a first thin tube 7a coupled to a first end of the main tube 6; a second thin tube 7b coupled to a second end of the main tube 6; a pair of electrodes 5a, 5b, which are inserted into the first and second thin tubes 7a, 7b, respectively, such that the far ends thereof face each other inside the main tube 1; and a first metal halide enclosed in the arc tube. A second metal halide, which has a lower vapor pressure than that of the first metal halide, is further enclosed in the arc tube. And the main tube 6 has portions, of which the inside diameter decreases monotonically toward the ends.