Abstract: In a hollow cathode lamp comprising, in a bulb having a light exit port, a hollow cathode and an anode opposed to the light exit port, which comprises a tubular hood having a tubular shape, having one open end connected to the hollow cathode, having another open end opposed to the light exit port, and having an opening formed in a peripheral side face thereof, and an electron supply disposed at a position to front on the opening, discharge making use of thermoelectrons is implemented between the electron supply and the anode.

Abstract: In order to meet various requirements for discharge tubes for use as light sources, including easiness of production, stability of discharge, long lifetime, etc. without any contradiction between them, a discharge tube of the present invention involves an improvement in the discharge tube for use as a light source constructed to effect arc discharge in a discharge gas atmosphere between a cathode 2, having a cathode tip portion 22 fixed to a lead rod 21, and an anode 3 opposed thereto while keeping the cathode and anode enclosed in the gas. The cathode tip portion has a cusp pointed toward the anode and consists of a refractory metal substrate 221 of an impregnated type or a sintered type containing an electron-emissive material, and a refractory metal coating 222 covering the surface except at the tip portion of the cusp.

Abstract: While a power supply line from a main power section to a light-emitting section in a xenon flash lamp is provided with a diode in order to prevent a current from flowing into the main power section, there has been a problem that the diode generates heat due to a large current passing therethrough upon power supply at the time of light emission and breaks. When diodes are connected in parallel, the large current can be dispersed, whereby the diodes can be restrained from raising temperature in excess.

Abstract: In a hollow cathode lamp comprising, in a bulb having a light exit port, a hollow cathode and an anode opposed to the light exit port, which comprises a tubular hood having a tubular shape, having one open end connected to the hollow cathode, having another open end opposed to the light exit port, and having an opening formed in a peripheral side face thereof, and an electron supply disposed at a position to front on the opening, discharge making use of thermoelectrons is implemented between the electron supply and the anode.

Abstract: An ultraviolet detector comprises a metal tubular member which hermetically encloses an anode and a cathode therein and is filled with a discharged gas introduced therein from a metal exhaust tube. After the anode and the cathode are enclosed within the tubular member, the ultraviolet detector can be made without being subjected to any glass fusing process. Accordingly, the inside of the sealed vessel V1 can be prevented from being contaminated with fluorine, whereby the ultraviolet detector with stable characteristics can be provided.

Abstract: A gas discharge tube having an outer envelope in which deuterium gas is filled. In the envelope, an anode, a cathode and a first shield cover for surrounding these electrodes are disposed. A second shield cover is disposed within the first shield cover and at a position adjacent the anode to divide an internal space defined by the first shield cover into a first chamber in which the anode is positioned and a second chamber in which a cathode is positioned. A plasma arc generating portion is positioned at the second shield cover. A plasma arc generated on the plasma arc generating portion provides an optical axis extending linearly toward the outer envelope through an opening of the first shield cover. The cathode is disposed at a position offset from the optical axis for providing a flow line of electrons from the cathode to the anode in a direction obliquely with respect to the optical axis.

Abstract: A gaseous-discharge lamp has a valve defining an interior of the lamp in which an inert gas, such as xenon, is confined. A cup-shaped reflector is disposed in the interior of the lamp, whose inner surface cross-section is preferably a hyperbola or an ellipse so that a collimated light spot is projected outwardly of the lamp or a focused light beam is available. The reflector has a larger-diameter opening facing a light projection window formed on one face of the valve and a bottom portion formed with a hole. An anode and a cathode are disposed in confrontation with each other in a space surrounded by the reflector. A trigger probe electrode intervenes between the anode and the cathode. A sparker electrode is disposed outside of the reflector and in the vicinity of the hole formed in the bottom portion thereof. By the provision of the reflector in the interior of the lamp, light of high radiation intensity is produced from the lamp without increasing the size of the lamp.

Abstract: A discharge tube has a sealed envelope filled with a gas; an anode, cathode and shielding electrode built in the sealed envelope; and electrode holding pins. At least eight electrode holding pins penetrate a button stem so as to be arranged at predetermined intervals on a circle coaxial with the button stem, and, of at least eight electrode holding pins, at least three hold the cathode, at least three hold the shielding electrode, and at least two hold the anode.

Abstract: A gas discharge tube comprises an indirectly heated cathode structure including a hot cathode into which a heater is incorporated. During discharging, the heater is supplied with a discharge current so as to generate Joule heat which is used as a heat source for the hot cathode. To this end, in a drive circuit in which the heater is preheated with a heater power source to initiate the discharging and to light up the discharge tube, followed by supply of discharging power from a discharging maintaining power source, a preheating switch is inserted between the heater and heater power source, and is opened at a start of the discharging and kept opened thereafter.

Abstract: An improved composite light source utilizing light from an arc discharge in a deuterium gas atmosphere and that from a tungsten lamp. The composite light source comprises a sealed envelope having a light emitting window made of quartz, in which deuterium gas is filled, an electrode structure to cause an arc discharge in the deuterium gas atmosphere to occur, and a tungsten lamp. The light emitting window, an aperture of a focusing plate for forming an arc discharge, an aperture of the anode, and the filament of the tungsten lamp are sequentially arranged in line at their centers. The composite light source has the optical means to focus the light beam emitted from the tungsten lamp onto the aperture of the focusing plate for forming the arc discharge. In the present invention, useless power consumption to elevate the temperature within the tungsten lamp can be reduced. It extends the life of the light source improving the efficiency of light emission.

Abstract: A tungsten double coil covered with cathode material made from a paste of carbonate mixed with organic solvent. The coil is mounted around a molybdenum cylinder having a cavity in which a heater is installed.

Abstract: An ultraviolet detector comprises a metal tubular member which hermetically encloses an anode and a cathode therein and is filled with a discharged gas introduced therein from a metal exhaust tube. After the anode and the cathode are enclosed within the tubular member, the ultraviolet detector can be made without being subjected to any glass fusing process. Accordingly, the inside of the sealed vessel V1 can be prevented from being contaminated with fluorine, whereby the ultraviolet detector with stable characteristics can be provided.