Abstract: A method of initiating lighting of a discharge lamp is provided including applying to the discharge lamp to be lighted an initiating voltage resulting from superimposition of a step-up pulse voltage of 1,000 to 3,000 V onto a voltage of 500 to 1,500 V which is continuously applied to the discharge lamp. Also provided is a circuit for lighting a discharge lamp, including a ballast for lighting the discharge lamp, and a low-voltage igniter connected to the ballast for initiating lighting of the lamp, the low-voltage igniter comprising: a lighting diode having an input side connected to an output side of the ballast and an output side connected to the discharge lamp; and a step-up device for superimposing step-up pulses onto the output of the lighting diode via a step-up pulse supply branch line connected to the output side of the lighting diode in initiating lighting of the discharge lamp.

Abstract: There is provided an improved method of lighting an ultra-high pressure discharge lamp in which a pair of electrodes are disposed confronting each other with a spacing of not more than 1.5 mm therebetween in an arc tube forming part of an envelope of quartz glass, the arc tube encapsulating mercury in an amount of 0.15 mg/mm3, the method including the steps of: reducing a lamp power supplied to the pair of electrodes to a degree such as not to stop arc discharge in a transition state from a lighting state to extinction; keeping the lamp power thus reduced for a predetermined time period; and shutting down the supply of current to the electrodes.

Abstract: A method of initiating lighting of a discharge lamp is provided including applying to the discharge lamp to be lighted an initiating voltage resulting from superimposition of a step-up pulse voltage of 1,000 to 3,000 V onto a voltage of 500 to 1,500 V which is continuously applied to the discharge lamp. Also provided is a circuit for lighting a discharge lamp, including a ballast for lighting the discharge lamp, and a low-voltage igniter connected to the ballast for initiating lighting of the lamp, the low-voltage igniter comprising: a lighting diode having an input side connected to an output side of the ballast and an output side connected to the discharge lamp; and a step-up device for superimposing step-up pulses onto the output of the lighting diode via a step-up pulse supply branch line connected to the output side of the lighting diode in initiating lighting of the discharge lamp.

Abstract: Improved method and device for lighting a high pressure discharge lamp are provided which prevent arc jump and inhibit deterioration of lamp voltage and luminance. The method includes the step of: alternately repeating a superposition operation for superposing a pulse current on a lamp current applied to the high pressure discharge lamp for a predetermined time period and a superposition stopping operation for stopping the superposition of the pulse current for a predetermined time period.

Abstract: An ultra-high pressure discharge lamp is provided having seal portions of a structure capable of realizing a pressure resistance of 100 atm or higher while ensuring a higher yield. The ultra-high pressure discharge lamp includes: a pair of mounts each comprising a metal foil having one end welded to an associated electrode and an opposite end welded to an associated external lead pin, and a preseal glass member embedding the metal foil therein; and a quartz envelope having an arc tube portion provided with a pair of seal portions on opposite sides thereof, the electrodes associated with the respective mounts being disposed opposite to each other in the arc tube portion, the preseal glass member being hermetically sealed in a respective one of the seal portions, wherein the preseal glass member has a portion fused to an inner peripheral surface of the respective seal portion over an entire circumference thereof.

Abstract: There is provided a novel method of lighting an ultra-high pressure discharge lamp (A1) having a discharge bulb (1) made of quartz glass in which a pair of electrodes (2) and (3) are disposed facing each other, the method including: lighting the lamp with alternating current; and providing a time period of at least one second for which the alternating current assumes a lighting frequency of 5 Hz or lower during a period for which the lamp lights, wherein the electrodes (2) and (3) each have a current withstanding capability against a current 1.5 times or more as high as a current value at which the lamp lights stably. This method enables the ultra-high pressure discharge lamp to have a longer life and exhibit a higher luminance.

Abstract: An ultra-high pressure discharge lamp is provided having seal portions of a structure capable of realizing a pressure resistance of 100 atm or higher while ensuring a higher yield. The ultra-high pressure discharge lamp includes: a pair of mounts each comprising a metal foil having one end welded to an associated electrode and an opposite end welded to an associated external lead pin, and a preseal glass member embedding the metal foil therein; and a quartz envelope having an arc tube portion provided with a pair of seal portions on opposite sides thereof, the electrodes associated with the respective mounts being disposed opposite to each other in the arc tube portion, the preseal glass member being hermetically sealed in a respective one of the seal portions, wherein the preseal glass member has a portion fused to an inner peripheral surface of the respective seal portion over an entire circumference thereof.

Abstract: It is an object of the present invention to assuredly prevent occurrence of minute cracks in a seal portion of a lamp for improvement of the pressure resistance and service life of the lamp. To achieve the object, there is provided a seal structure of a lamp including: (a) a lamp envelope having a light emitting tube and a seal portion; (b) a metal foil embedded in the seal portion of the lamp envelope; (c) a light emitting element attached to one of opposite ends of the metal foil and disposed in the light emitting tube; and (d) an outer lead rod attached to the other end of the metal foil and led out of the seal portion, the seal structure comprising a separable layer interposed between the seal portion and a portion of the light emitting element embedded in the seal portion.

Abstract: A discharge lamp is provided which employs a higher-pressure and higher-wattage lamp body 1 and is capable of effectively preventing the scattering of broken pieces of the lamp body 1 at explosion of the lamp body 1. The discharge lamp comprises a lamp body 1, a reflector 2 having the lamp body 1, and a front glass fitted on a front portion of the reflector 2, wherein the reflector 2 has vent holes 4 in which mesh sheets 6 or perforated plates 5 are fitted.

Abstract: There is provided an improved method of lighting an ultra-high pressure discharge lamp in which a pair of electrodes are disposed confronting each other with a spacing of not more than 1.5 mm therebetween in an arc tube forming part of an envelope of quartz glass, the arc tube encapsulating mercury in an amount of 0.15 mg/mm3, the method including the steps of: reducing a lamp power supplied to the pair of electrodes to a degree such as not to stop arc discharge in a transition state from a lighting state to extinction; keeping the lamp power thus reduced for a predetermined time period; and shutting down the supply of current to the electrodes.

Abstract: There is provided a novel method of lighting an ultra-high pressure discharge lamp (A1) having a discharge bulb (1) made of quartz glass in which a pair of electrodes (2) and (3) are disposed facing each other, the method including: lighting the lamp with alternating current; and providing a time period of at least one second for which the alternating current assumes a lighting frequency of 5 Hz or lower during a period for which the lamp lights, wherein the electrodes (2) and (3) each have a current withstanding capability against a current 1.5 times or more as high as a current value at which the lamp lights stably. This method enables the ultra-high pressure discharge lamp to have a longer life and exhibit a higher luminance.

Abstract: A method of initiating lighting of a discharge lamp is provided including applying to the discharge lamp to be lighted an initiating voltage resulting from superimposition of a step-up pulse voltage of 1,000 to 3,000 V onto a voltage of 500 to 1,500 V which is continuously applied to the discharge lamp. Also provided is a circuit for lighting a discharge lamp, including a ballast for lighting the discharge lamp, and a low-voltage igniter connected to the ballast for initiating lighting of the lamp, the low-voltage igniter comprising: a lighting diode having an input side connected to an output side of the ballast and an output side connected to the discharge lamp; and a step-up device for superimposing step-up pulses onto the output of the lighting diode via a step-up pulse supply branch line connected to the output side of the lighting diode in initiating lighting of the discharge lamp.

Abstract: An electric discharge lamp is provided comprising; a lamp envelop including a first and a second sealing tubes both of which are sealed and a light-emitting portion located between the sealing tubes; a pier of electrodes disposed in the light-emitting portion; and a filler substance encapsulated within the lamp envelop, one of the sealing tubes having a seal-cut trace of a tip tube that has been used for introducing the filler substance into the lamp envelop therethrough.

Abstract: A metal halide lamp includes a pair of electrodes with a spacing of 0.5 to 1.5 mm therebetween, an envelope enclosing the pair of electrodes, and at least one metal halide, other than a mercury halide, that is encapsulated in the envelope in an amount of from 0.04 to 0.3 mg/cc, wherein the metal halide lamp operates in a power range from 75 to 270 watts per millimeter across the spacing between the pair of electrodes.

Abstract: A halogen lamp with reflector which allows a pinch seal portion to be fitted onto a lamp mount portion of a reflector simply by inserting a lamp body with a pinch seal support and a lead rod support into the lamp mount portion, thrashes the cost and prevents an inorganic adhesive from contaminating a concave reflecting section of the reflector, and is suitable for achieving high wattage. An insulating lead rod support (5) is mounted to lead rods (1b), and a pinch seal support (4) is mounted to the pinch seal portion (1a). The lead rod support (5) is inserted into a bottom aperture (3b) of the lamp mount portion (3). The pinch seal support (4) includes an insertion hole (4d) for passing the pinch seal portion (1b) therethrough, pinch seal abutting pieces (4b), reflector abutting pieces (4a), and an opening closing portion (4c) closing the front opening (6). An adhesive (8) is injected into a gap between the pinch seal portion (1b) and the lamp mount portion (3).

Abstract: A direct current discharge lamp includes: a bulb portion 1a containing therein an anode 2b and a cathode 2a; a first seal portion 5 outwardly extending from the bulb portion 1a on the anode side; a second seal portion 4 outwardly extending from the bulb portion 1a on the cathode side; a pair of feeder elements 3 respectively inserted through the first and second seal portions 5 and 4 for feeding electricity to the anode 2b and cathode 2a; and an extended tube portion 6 interconnecting the bulb portion 1a and the first seal portion 5.