Matsushita Electronics Corporation

Matsushita Electric Industrial Co., Ltd.

Yoshiro Ogata

Haruo Yamazaki

Hidezoh Akutsu

Takashi Ikeda

Yasuhiro Shimada

Kazuhiko Ito

Koichi Wani

Takashi Katsura

Masataka Ozawa

Kazutaka Koyama

Hidehito Kawahara

Tadaaki Miki

A laser apparatus includes an optical resonator having a laser medium and generating a laser light. A wavelength selection element selects a given wavelength of the laser light. The selected wavelength resides within a gain bandwidth of the laser medium. A sealed container houses the wavelength selection element. The sealed container may be filled with a gas. A density of the gas within the sealed container may be changed to vary the selected wavelength.

Laser apparatus

A high-pressure sodium lamp is connected to a d.c. power supply through a ballast, to operate it with a current containing a d.c. component. The relation between the ratio l/d of the inter-electrode distance l (mm) to the inner diameter d (mm) of the arc tube of the high-pressure sodium lamp and the sodium vapor pressure P.sub.Na (kPa) in the arc tube is maintained at P.sub.Na .gtoreq.6.0 (l/d-5.8), thus making it possible to operate the high-pressure sodium lamp with a current containing a d.c. component without causing a significant color separation which otherwise might be the result of cataphoresis.

Discharge lamp operation apparatus

In a fluorescent lamp of the type in which a lamp envelope comprises an outer bulb having generally a spherical or a partially spherical or a cylindrical configuration and an inner bulb inserted into the outer bulb in predetermined nested relationship; either of the inner surface of the outer bulb or the outer surface of the inner bulb is formed with a groove which defines a zig-zag discharge path between the outer and inner bulbs; a phosphor is formed at least over the wall surfaces of the groove; electrodes are disposed at the ends, respectively, of the discharge path and a uv (ultraviolet) radiation-emitting discharge gas consisting of mercury vapor and a rare gas or a rare gas mixture is filled in the discharge path, both the open end portions of the outer and inner bulbs are flared radially outwardly and inwardly respectively, or either of the open end portion of the outer or inner bulb is flared radially outwardly or inwardly so that glass frit can be filled into the annular space defined between the open end portions of the outer and inner bulbs both or either of which is flared. When glass frit is heated and then solidified, not only the open ends of the outer and inner bulbs can be gas-tightly sealed together but also lead-wires which also support the electrodes at the ends of the discharge path are also gas-tightly sealed.

Fluorescent lamp and process for fabricating the same

A high-pressure sodium lamp in which the inner diameter of an arc envelope is largest at the midpoint between the ends thereof and the inner and outer diameters thereof in the vicinity of the ends at which are air-tightly fitted electrodes and their associated parts are reduced gradually relative to the inner diameter of the midpoint thereof. When the arc envelope is turned on, the following conditions are satisfied:

High-pressure sodium lamp

A high-pressure sodium lamp in which the ends of an arc tube which is made of transparent single-crystal alumina and which contains sodium are sealed with feed-throughs each having an electrode extended from the inner end thereof. Each feed-through is directly sealed to the inner wall surface of each end of the arc tube. In addition, each feed-through is formed with an enlarged-diameter portion which is directly sealed to the inner wall surface at each end of the arc tube and a reduced-diameter portion which is spaced apart from the inner wall surface at each end of the arc tube.

Each of the electrodes at the ends of an arc tube filled with a buffer gas, metal and sodium comprises an electrode core, an electrode coil wound around the core, an electron-emitting means disposed in the annular space between the electrode core and electrode coil and a shielding means disposed in said annular space in such a way that the electron-emitting means is shielded from exposure to the discharge space in the arc tube. The ratio h/d is determined such that 0.8.ltoreq.h/d.ltoreq.5.4, where h is the length in mm of the portion of the electrode core extended beyond the inner end of the shielding means or the innermost coil of the electrode coil; and d is the diameter in mm of the electrode core. The arc spots can be held to remain on the end faces of the electrode cores during lamp operation so that variations in electrical and optical characteristics can be almost eliminated.

A high pressure sodium vapor discharge lamp,

High pressure sodium vapor discharge lamp

A metal vapor laser discharge tube comprising an anode, a laser capillary, a metal reservoir at one end of the laser capillary, a cathode disposed in coaxial relation with and around the laser capillary, and an air-tight envelope enclosing the cathode and the laser capillary. For prolonging the life of the metal vapor laser discharge tube, the laser further includes a condenser installed in a discharge path between the laser capillary and the cathode and may comprise discharge guiding members.

Growing community of inventors

Osaka, Japan

Yoshiro Ogata