Flash tubes for photographic use, in particular, a flash tube is adapted to provide a light output adapted to FP-sync, Flat Peak. The flash tube includes a length of glass tubing enclosing a gas for use in the flash tube, a cathode inside a first end part of glass tubing and an anode inside a second end part of glass tubing. The cathode includes an element that helps to ionize the gas that is wound around the cathode, such that a spark stream starts from the upper part of the cathode and is prevented from spreading down wards on the cathode and changing the arc length during the light output adapted to FP-sync.

A flash irradiation device includes: a light-emitting tube sealing a light-emitting gas inside; a pair of discharging electrodes being arranged distant from each other in the first direction; a reflecting member that is disposed on an opposite side of the light-emitting tube from the workpiece; a pair of trigger electrodes on an outer wall surface of the light-emitting tube or in a vicinity of the light-emitting tube, the pair of the trigger electrodes being arranged distant from each other in the first direction; a lighting circuit connected to the pair of the discharging electrodes, the lighting circuit being configured to supply electric power between the pair of the discharging electrodes; and a trigger circuit connected to the pair of the trigger electrodes, the trigger circuit configured to apply a voltage for starting lighting across the pair of the trigger electrodes.

A flash irradiation device includes: a light-emitting tube sealing a light-emitting gas inside; a pair of discharging electrodes being arranged distant from each other in the first direction; a reflecting member that is disposed on an opposite side of the light-emitting tube from the workpiece; a pair of trigger electrodes on an outer wall surface of the light-emitting tube or in a vicinity of the light-emitting tube, the pair of the trigger electrodes being arranged distant from each other in the first direction; a lighting circuit connected to the pair of the discharging electrodes, the lighting circuit being configured to supply electric power between the pair of the discharging electrodes; and a trigger circuit connected to the pair of the trigger electrodes, the trigger circuit configured to apply a voltage for starting lighting across the pair of the trigger electrodes.

A photoionization detector comprised of a gas discharge lamp that ionizes molecules of interest to create ionized molecules and electrons and a sensor having at least one opening for UV light to pass through and electrically conductive patterns on the top and bottom surfaces of the plate. A negative electrical potential pattern can be on one of the top or the bottom surface and can include an interior portion that is at least a first distance away from every edge of the at least one opening. An electron collecting electrode pattern can be on the other of the top or the bottom surface and can substantially fill an area surrounding the opening such that the negative electrical potential pattern and the electron collecting electrode pattern are offset relative to each other. The ionized molecules are collectable by a bias electrode and electrons are collectable by a collector electrode.

A photoionization detector comprised of a gas discharge lamp that ionizes molecules of interest to create ionized molecules and electrons and a sensor having at least one opening for UV light to pass through and electrically conductive patterns on at least one of the top and bottom surfaces of the plate, including at least a negative electrical potential pattern and an electron collecting electrode pattern. The ionized molecules are collectable by a bias electrode and electrons are collectable by a collector electrode. The negative electrical potential pattern includes a linear portion and a polarization plate. The electron collecting electrode pattern includes a wire suspended across the at least one opening and a linear portion on the surface opposite the wire. The electrically conductive patterns can further include a grounded potential conductive pattern having a first portion on the top surface and a second portion on the bottom surface.

The excimer lamp includes: a discharge container having a substantially quadrangular shape with a cross section, the discharge container having a pair of flat walls extending in a longitudinal direction and a pair of side walls connecting the flat walls; a pair of external electrodes facing each other disposed on outer surfaces of the pair of flat walls, respectively; a first internal electrode disposed inside the discharge container so as to extend toward inner surfaces of the pair of flat walls; and a second internal electrode disposed inside the discharge container at a position spaced apart from the first internal electrode in the longitudinal direction so as to extend toward the inner surfaces of the pair of flat walls. The first internal electrode and the second internal electrode are respectively disposed at positions between end parts and central parts of the external electrodes in the longitudinal direction.

Flash tubes for photographic use, in particular a flash tube is adapted to provide a light output adapted to FP-sync, Flat Peak. The flash tube includes a length of glass tubing enclosing a gas for use in the flash tube, a cathode inside a first end part of glass tubing and an anode inside a second end part of glass tubing. The cathode includes an element that helps to ionize the gas that is wound around the cathode, such that a spark stream starts from the upper part of the cathode and is prevented from spreading down wards on the cathode and changing the arc length during the light output adapted to FP-sync.

There is provided a light-emitting device capable of suppressing a decrease in a light emission amount. A light-emitting device including a container member including a ceramic package provided with a depressed portion serving as a discharge space, and a light transmitting member which is attached to the ceramic package via a joining layer formed of a joining material so as to close the depressed portion; an inert gas encapsulated inside the discharge space; and a couple of discharge electrodes which are disposed in the depressed portion of the ceramic package so as to be spaced from each other, the joining material including glass exhibiting a white color, and oxide ceramic powder.

An ultraviolet light emitting device comprises: a first substrate having a main surface; a second substrate facing the main surface of the first substrate; a gas in a space between the first substrate and the second substrate; electrodes directly or indirectly on the main surface of the first substrate; a dielectric layer that is located directly or indirectly on the main surface of the first substrate and covers the electrodes; and a first light-emitting layer. The first light-emitting layer is located directly or indirectly on the dielectric layer and emits ultraviolet light in the gas due to electrical discharge between the electrodes. The first light-emitting layer is thicker in first regions on the dielectric layer than in second regions. The second regions include at least part of regions directly above the electrodes.

There is provided a light-emitting device capable of suppressing a decrease in a light emission amount. A light-emitting device including a container member including a ceramic package provided with a depressed portion serving as a discharge space, and a light transmitting member which is attached to the ceramic package via a joining layer formed of a joining material so as to close the depressed portion; an inert gas encapsulated inside the discharge space; and a couple of discharge electrodes which are disposed in the depressed portion of the ceramic package so as to be spaced from each other, the joining material including glass exhibiting a white color, and oxide ceramic powder.