Abstract: This lighting circuit comprises a current source and a thermal sensing element. The thermal sensing element senses the temperature of a semiconductor light source. The current source generates a drive current that shows a positive correlation with the temperature when the temperature is in a normal range and that shows a negative correlation with the temperature when the temperature falls within a temperature range higher than the normal range.

Abstract: This lighting circuit comprises a current source and a thermal sensing element. The thermal sensing element senses the temperature of a semiconductor light source. The current source generates a drive current that shows a positive correlation with the temperature when the temperature is in a normal range and that shows a negative correlation with the temperature when the temperature falls within a temperature range higher than the normal range.

Abstract: A vehicle lamp includes: a first light source; a second light source; a first input terminal that receives a first turn-on instruction signal of the first light source; a second input terminal that receives a pulsed second turn-on instruction signal of the second light source; and a turn-on circuit that drives the first light source and the second light source based on the first turn-on instruction signal and the second turn-on instruction signal. The turn-on circuit includes: a drive circuit that becomes active based on the first turn-on instruction signal and the second turn-on instruction signal, and outputs a constant drive current from an output terminal; and a distribution circuit that forms a current path such that the drive current flows to the second light source, and forms a current path such that the drive current flows to the first light source.

Abstract: A vehicle lamp includes: a first light source; a second light source; a first input terminal that receives a first turn-on instruction signal of the first light source; a second input terminal that receives a pulsed second turn-on instruction signal of the second light source; and a turn-on circuit that drives the first light source and the second light source based on the first turn-on instruction signal and the second turn-on instruction signal. The turn-on circuit includes: a drive circuit that becomes active based on the first turn-on instruction signal and the second turn-on instruction signal, and outputs a constant drive current from an output terminal; and a distribution circuit that forms a current path such that the drive current flows to the second light source, and forms a current path such that the drive current flows to the first light source.

Abstract: An arc tube for a discharge bulb includes: an electrode assembly that has an electrode bar and a molybdenum foil, wherein an overlapping portion of an end portion of the electrode bar and a molybdenum foil is joined by spot welding; a pinch seal portion that seals a part of the electrode assembly, the part including at least the molybdenum foil; and a closed glass bulb, into which a tip of the electrode bar protrudes, the closed glass bulb forming a discharge light-emitting portion, wherein the size of a recess, which is a weld mark, in the molybdenum foil on the side opposite to a joint portion, at which the molybdenum foil and the electrode bar are joined with each other, is within a range from 0.07 mm2 to 0.25 mm2.

Abstract: A vehicular discharge lamp includes a pair of electrodes including sealed portions sealed in a pair of pinch seal portions of a light emitting tube, wherein each of the sealed portions is segmented into: a first intermediate region positioned in the middle of the electrode in an axial direction; two end regions configured as both end portions of the sealed portion in the axial direction; and two second intermediate regions positioned between the first intermediate region and the end regions, respectively, wherein concave or convex fabrication portions are formed in the second intermediate regions, and wherein a ratio of formation area of the fabrication portions to an area of an outer peripheral surface of the first intermediate region is set to be smaller than that of the formation area of the fabrication portions to an area of outer peripheral surfaces of the second intermediate regions.

Abstract: An arc tube for a discharge bulb includes: an electrode assembly that has an electrode bar and a molybdenum foil, wherein an overlapping portion of an end portion of the electrode bar and a molybdenum foil is joined by spot welding; a pinch seal portion that seals a part of the electrode assembly, the part including at least the molybdenum foil; and a closed glass bulb, into which a tip of the electrode bar protrudes, the closed glass bulb forming a discharge light-emitting portion, wherein the size of a recess, which is a weld mark, in the molybdenum foil on the side opposite to a joint portion, at which the molybdenum foil and the electrode bar are joined with each other, is within a range from 0.07 mm2 to 0.25 mm2.

Abstract: A vehicle discharge lamp is provided with an outer tube, an arc tube disposed within the outer tube, and a pair of electrodes disposed within the arc tube. The arc tube includes a light emitting portion, and a pair of pinch seal portions. Molybdenum foils are sealed in the respective pinch seal portions. Each of the electrodes includes a sealed portion sealed within the pinch seal portion, a projecting portion projecting into the light emitting portion, and a welding portion welded to the molybdenum foil. A concavo-convex part is formed on the sealed portion.

Abstract: A vehicular discharge lamp includes a pair of electrodes including sealed portions sealed in a pair of pinch seal portions of a light emitting tube, wherein each of the sealed portions is segmented into: a first intermediate region positioned in the middle of the electrode in an axial direction; two end regions configured as both end portions of the sealed portion in the axial direction; and two second intermediate regions positioned between the first intermediate region and the end regions, respectively, wherein concave or convex fabrication portions are formed in the second intermediate regions, and wherein a ratio of formation area of the fabrication portions to an area of an outer peripheral surface of the first intermediate region is set to be smaller than that of the formation area of the fabrication portions to an area of outer peripheral surfaces of the second intermediate regions.

Abstract: In a discharge lamp device, the arc tube body is configured by welding and integrating shroud glass with an arc tube so as to enclose a discharging portion, and a rearward elongating portion of the arc tube that elongates in the rear of the shroud glass is inserted and held into an opening of an insulating plug which is made of synthetic resin. A UV blocking film is formed on the outer surface of the rearward elongating portion of the arc tube. UV components of leakage light from the rearward elongating portion are cut off, and the amount of ultraviolet rays to which the resin layer in the opening is exposed is reduced. The UV blocking film is in the opening, and hence cannot be seen through a front lens.

Abstract: In a discharge lamp device, the arc tube body is configured by welding and integrating shroud glass with an arc tube so as to enclose a discharging portion, and a rearward elongating portion of the arc tube that elongates in the rear of the shroud glass is inserted and held into an opening of an insulating plug which is made of synthetic resin. A UV blocking film is formed on the outer surface of the rearward elongating portion of the arc tube. UV components of leakage light from the rearward elongating portion are cut off, and the amount of ultraviolet rays to which the resin layer in the opening is exposed is reduced. The UV blocking film is in the opening, and hence cannot be seen through a front lens.

Abstract: An electric discharge lamp apparatus which incorporates an arc tube 10 structured such that an enclosed glass bulb 12 of an arc tube body 11 is enclosed in an ultraviolet-ray shielding globe 20 and having a front end which is supported by a metal lead support 36 forwards extending from an insulating plug 30 provided with a focusing ring 34 and made of synthetic resin and which has a structure that a rear end of the globe 20 of the arc tube 10 is supported by a metal support member 50 secured to the insulating plug 30, wherein the metal support member 50 is constituted by a metal base plate 51 secured to the insulating plug 30 and forming a reference plane f2 running parallel to the focusing ring 34 on the front surface of the insulating plug and a metal vertically-holding member 60 (a slide plate 61 and an arc-tube holding band 71) integrally joined to the metal base plate 51 and arranged to vertically hold an electrically-discharge axis L of the held arc tube 10 with respect to reference plane f2 of the meta

Abstract: An electric discharge lamp apparatus incorporates: a metal lead support 36 which projects over the front surface of an insulating plug 30 made of synthetic resin, which supports the leading end of an arc tube 10 and which serves as a passage for electric power arranged to be supplied to the arc tube 10; and an insulating sleeve 38 which is made of ceramics formed into a pipe shape and through which the lead support 36 is inserted, wherein a predetermined gap S2 is provided between the insulating sleeve 38 and the lead support 36. Thus, insertion of the lead support 36 into the insulating sleeve 38 can easily be performed, and a dimension error of the insulating sleeve 38 can be absorbed. Since a bent portions 36a is provided for a portion of the lead support 36 into which the insulating sleeve is inserted, the insulating sleeve 38 and the lead support 36 can hermetically integrated with each other. Thus, rattle of the insulating sleeve 38 with respect to the lead support 36 can be prevented.

Abstract: An insulating plug for an electric discharge lamp apparatus, includes: a front portion includes an outer cylindrical portion and an inner cylindrical portion, the inner cylindrical portion having a substantially unique thickness and an opening to receive an arc tube of an electric discharge lamp; a focusing ring extending from the outer cylindrical portion of the front portion; and a rear portion having a rear-end cylindrical portion and a center portion. The front portion, the focusing ring and the rear portion are integrally molded by injecting a synthetic resin into a mold from a gate of the mold, the gate facing the rear-end cylindrical portion of the rear porition of the insulating plug. Furthermore, the electric discharge lamp apparatus in which an arc tube is inserted into the opening of the insulating plug described above.