Hamamatsu-Photonics K.k.

Hamamatsu Protonics K.k.

Yoshinobu Ito

Ryotaro Matui

Tomoyuki Ikedo

Koji Matsushita

Masaki Ito

Kouzou Adachi

Koji Kawai

Kazuo Ueno

Tsuyoshi Minamizawa

Takamasa Tanaka

A discharge lamp includes a housing including a dielectric portion having a light transmission area formed of a dielectric material and transmitting light, and a main body portion forming a discharge-gas-filled space together with the dielectric portion, the discharge-gas-filled space being filled with a discharge gas; an electron emission source disposed in the discharge-gas-filled space to face the light transmission area; a discharge path limiting member separating the electron emission source and the light transmission area, in the discharge-gas-filled space, and including an electron passage hole that transmits electrons emitted from the electron emission source; and an external electrode disposed at an outer side of the housing to face the electron emission source across the dielectric portion, and including an opening that passes the light transmitted through the light transmission area.

Discharge lamp and light source device

At an initial stage of a discharge start, a shield electrode is connected to a ground potential via a bidirectional voltage trigger switch. Thereafter, when an electrical charge within the shield electrode flows to the ground potential, by being triggered with this potential, both terminals of the bidirectional voltage trigger switch are disconnected therebetween. Thus, at an initial stage of discharge, charging of the shield electrode is suppressed to suppress a decline in discharge, and in a sustained discharge, destabilization due to an unwanted discharge from the shield electrode to the anode can be suppressed, and using such an electrode automatically allows improving the lighting performance of a discharge lamp.

Light source device, discharge lamp and its control method

A control circuit for a discharge lamp, which can improve the lighting performance of the discharge lamp while realizing low power consumption, and a light source device are provided. The resistance value of the variable resistor (R, R) is not switched to the low resistance (R) for steady discharge at the fourth time tbut is switched to the low resistance (R) at the fifth time tafter lowering of power supply to the filament. With such control, a change in the lamp impedance is absorbed sufficiently by the variable resistor while power supply to the filament is being lowered and, therefore, destabilization of discharge is reduced and the lighting performance is improved.

Controller for discharge lamp and light source device

The present invention relates to a deuterium lamp with a structure to enable high-accuracy positioning with respect to a mounting object such as an analyzer. The deuterium lamp comprises a sealed container in which a light-emitting portion to emit a discharge light in a predetermined direction is stored. The sealed container is constituted by a hollow body portion in which the light-emitting portion is stored and a hollow guide portion which guides a discharge light from the light-emitting portion to a light exit window provided at its front end. The deuterium lamp further comprises an axis adjusting member fixed to the hollow guide portion while storing at least a part of the hollow guide portion and a sealing layer for fixing the hollow guide portion and the axis adjusting member to each other. In particular, the sealing layer makes it possible to fix the axis adjusting member to the hollow guide portion with the center axis of the axis adjusting member being made coincident with the emitting direction of a discharge light. Thereby, even when misalignment has occurred between the center axis of the hollow guide portion and the emitting direction of a discharge light due to a manufacturing error in manufacturing of the container, since the axis adjusting member itself is directly fixed to the mounting object, it becomes possible to fix said deuterium lamp to an analyzer or the like with the optical axis aligned at a high accuracy.

Deuterium lamp

A gas discharge tubeincluding a sealed containerin which a gas is sealed, an anode disposed within the sealed container, a cathodewhich is spaced from the anodein the sealed containerand generates discharge between the cathodeand the anode, a conductive partrestricting a discharge path, the conductive partbeing disposed between the anodeand the cathodeand narrowing the discharge path, wherein by providing a cathode coverwhich is made of ceramics, encloses the cathode, and has an openingat least on an electron emission side, the cathode coverincreases the heat retaining effect of the cathode, makes it easy to keep the temperature of the cathode, and reduces power consumption.

Gas discharge tube having cathode cover made of ceramics

A gas discharge tube which generates discharge between an anodeand a cathodedisposed within a sealed containerin which a gas is sealed, includes a cylindrical partrestricting the discharge path, the cylindrical part being disposed between the anode and the cathode and having a through holefor narrowing the discharge path between the anode and the cathode, and a discharge shielding partwhich is disposed so as to cover a surrounding of the part restricting the discharge path and is electrically insulated from the part restricting the discharge path, wherein the part restricting the discharge path has a cathode side end projecting by a predetermined projecting amount more than a surface on the cathode side of the discharge shielding part and an anode side end projecting into a spaceon the side where the anode is positioned so that a high-density electron region is formed only in a part on the cathode side of the through hole of the part restricting the discharge path to reliably generate starting discharge, preferably perform heat radiation of the anode, and reduce evaporated products from the anode.

Gas discharge tube

In a gas discharge tube there is carried out narrowing of the discharge path with cooperation of the first openingand second openingin order to obtain higher luminance of light. Further, in order to maintain excellent starting-properties of a lamp even if the discharge path is narrowed, a predetermined voltage is applied to a second discharge path limit portionexternally. Thereby, a positive or active starting discharge is produced in such a manner as to pass through the first opening. Further, the second openingis comprised of not only a straight sectionextending in a direction of an optical axis Y, but also a spread sectionextending from an end portion of the straight sectiontoward the first opening.

Gas discharge tube with discharge path limiting means

The present invention relates to a gas discharge tube or the like having a structure for enabling the maintenance of discharge startability and the prevention of the shortening of the life of an anode section and for increasing the amount of visible light from a visible light source passing through a discharge path restricting section. The gas discharge tube comprises a sealed vessel in which gas is encapsulated. A cathode section and anode section for generating discharge are arranged in the sealed vessel. Furthermore, a discharge path restricting section for narrowing a discharge path is arranged between the cathode section and the anode section. In particular, an opening portion is formed in the anode section, and the cross section of the opening portion has a non-circular shape where the maximum opening width in a first direction is different from that in a second direction orthogonal to the first direction. Thus, the amount of the visible light passing through the opening portion of the anode section in the gas discharge tube from the visible light source can be increased by making the maximum opening width in one direction of the first and second directions longer than that in the other direction. The maintenance of the discharge startability and the prevention of the shortening of the life of the anode section can be attained by making the maximum opening width in the other direction shorter than that in one direction.

Gas discharge tube light source apparatus and liquid chromatograph

A gas discharge tubeof the present invention generates an electric discharge between an anode partand a cathode partdisposed inside a sealed containerin which gas has been sealed. The gas discharge tubeincludes an electric discharge path restricting partwhich is cylindrical and disposed between the anode part and the cathode part, and which has a throughholefor narrowing an electric discharge path between the anode part and the cathode part; and a supporting partwhich supports the electric discharge path restricting part and which is electric insulating. The electric discharge path restricting part is provided at its tip portion with a projecting partwhich is cylindrical and projects toward the cathode part side. Letting the outer diameter and height of the projecting partbe 'D' and 'H,' respectively, then D/H is in the range of 0.5 to 2.0. With this structure, it is possible to generate an intense electric field in the vicinity of the tip of the projecting part. This can decrease a startup voltage, thereby ensuring the generation of an electric discharge.

In a gas discharge tube, a first discharge path-induction portion is arranged between a first discharge path-limit portion and a second discharge path-limit portion. A voltage is applied to the first discharge path-induction portion from the outside. As a result, an active starting discharge capable of passing through a first opening of the first discharge path-limit portion is produced between a cathode portion and the first discharge path-induction portion. As a consequence, there is facilitated the discharge at a starting time to pass through a second opening. As a consequence, there is achieved a rapid starting of discharge between the cathode portion and an anode portion. Therefore, in order to achieve further enhancement of brightness, there can be carried out with ease a further miniaturization pertaining to the openings, in terms of its area size, of the discharge path-limit portion while the starting properties being kept excellent, without any increase in a voltage at the starting time of the lamp so much.

High-luminance gas discharge tube with diaphragm elements within discharge path

A gas discharge tubeof the present invention generates an electric discharge between an anode partand a cathode partdisposed inside a sealed containerin which gas has been contained. The gas discharge tubecomprises an electric discharge path restricting partwhich is cylindrical and disposed between the anode part and the cathode part, and which has a throughholefor narrowing an electric discharge path between the anode part and the cathode part; and an electric discharge shielding partwhich is disposed to surround the electric discharge path restricting part so as to restrict an electric discharge from the outer peripheral surface of the electric discharge path restricting part to the cathode part, and which is electrically isolated from the electric discharge path restricting part. The end part of the electric discharge path restricting part on the cathode part side projects beyond a surface of the electric discharge shielding part on the cathode side by a predetermined amount 'P' of projection. With this structure, a high density electron region is formed exclusively in a part of the throughhole of the electric discharge path restricting part on the cathode side, thereby ensuring the generation of a startup discharge.

The gas discharge tube in accordance with the present invention comprises at least two electrically conductive aperture members disposed within a thermoelectron transmission path between a cathode and an anode, and an insulator for electrically insulating the electrically conductive aperture members from each other, thereby being able to emit light with a high luminance. Its startability at the time of emitting light can be enhanced in particular when the aperture area of the electrically conductive aperture member on the downstream side in the thermoelectron transmission path is set favorably.

Gas discharge tube having insulator between aperture members

In order to obtain light of a high luminance in a gas discharge tube of the present invention, a discharge path is narrowed by a first openingand a second openingin collaboration. Further, in order to provide favorable startability in a lamp even when the discharge path is narrowed, a predetermined voltage is applied from the outside to first and second discharge path limiting portionsAs a result, an active starting discharge which is capable of passing through the first and second openings is produced between a cathode portionand the first and second discharge path limiting portionsand thus discharge between the cathode portionand an anode portionis started speedily. Further, the anode portion, cathode portion, first discharge path limiting portion, and second discharge path limiting portion are housed within a light-emitting portion assemblyand electrically connected by first through fourth stem pinsA toD, and the stem pins are utilized effectively to support the light-emitting portion assembly.

Gas discharge tube having multiple stem pins

In a gas discharge tubeof the present invention, a focusing electrode portionand a discharge limiting portionare electrically insulated, and the discharge limiting portioncomprises a discharge limiting openingwhich opposes an arc ball shaping concave portion. Thus the formation of a discharge path from a cathode portionto the concave portionis ensured and a starting discharge can be reliably generated. Further, by means of the discharge limiting openingwhich opposes the concave portion, an arc ball S can be continuously maintained in an appropriate shape even when a lamp is illuminated, and thus the arc ball S can be shaped with stability, thereby stabilizing the luminance and light quantity.

A flange portion is integrally formed with a stem which forms a sealing envelope for a gas discharge tube. Accordingly, operation for building and fixing the flange portion is not necessary, so that lamp assembly operation is simplified, and mass production is facilitated. In addition, when a gas discharge tube is to be fixed to an external stem setting portion, lamp setting is enabled at higher precision by utilizing positioning holes formed in the flange portion in advance.

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Hamamatsu, Japan

Yoshinobu Ito