Stanley Electric Co., Ltd

Toshiyuki Nagahara

Yoshifumi Takao

Masayuki Kanechika

Shinya Omori

Masaaki Muto

Naoyuki Matsubara

Isamu Sato

Kazuhiro Miyamoto

Mitsunari Yoshida

Junji Matsuda

Yasuhisa Yaguchi

Koji Kikuchihara

Hiroharu Shimada

Masatoshi Hirohashi

Shigeru Shibayama

The disclosed subject matter includes a filament electrode that can include a filament coil connected with a pair of lead wires with confidence. It is possible for a fluorescent lamp using the filament electrode to emit light with a wider range while located in a thin tube. The filament electrode can include a pair of connecting pipes, a pair of lead wires located parallel to each other, and a filament coil including two connecting parts. Each of the two connecting parts of the filament coil can attach to respective ends of the pair of lead wires via the pair of connecting pipes via pressure bonding so as not to contact the connecting parts of the filament coil with the ends of the pair of lead wires located in the pair of connecting pipes and so as to align the structures. Thus, the filament electrode can be used even in a thin glass or quartz tube and can provide an effective heat-shield operation.

Filament electrode and fluorescent lamp

A method for manufacturing a hot cathode fluorescent lamp can ensure or facilitate stable initial luminous intensity and provide improved product life characteristics even when the hot cathode fluorescent lamp employs a glass tube with an outer diameter of less than 7 mm&#x3c6;. One end of a glass tube can be sealed with a glass bead of a mount structure. The other opening end of the glass tube can be welded with an opening end of an exhaust pipe with bent portions of lead wires being sandwiched between the opening ends of the glass tube and the exhaust pipe. After evacuating a vacuum system that is constituted by the inner spaces of the glass tube and the exhausted pipe communicating with each other, the bent portions of the lead wires which extrude outside the vacuum system can be clamp-connected to power source lines extending from an external power source. The emitter of the filaments can be activated by the generated heat of the filament. After supplying mercury and a rare gas into the glass tube, the glass bead can be sealed, and unnecessary portions of the glass tube, the exhaust pipe, and the lead wires can be removed to complete the hot cathode fluorescent lamp, in accordance with one aspect of the disclosed subject matter.

Method for manufacturing hot cathode fluorescent lamp

A high pressure discharge lamp can be used in a vehicle lighting device as a light source in place of a halogen lamp, and can be driven with a reduced starting voltage while being miniaturized. A gas is filled in a space between an arc tube and an outer tube of the high pressure discharge lamp, the gas being capable of dielectric barrier discharge, to reduce the starting voltage. A metal conductor is arranged in the space between the arc tube and the outer tube to stabilize the starting voltage and perform other functions. The metal conductor can also serve as a lead line. Accordingly, high voltage portions of the lamp are not exposed outside of the outer tube. This can reduce the entire size of the high pressure discharge lamp such that a housing for a headlight using a halogen lamp can be used for this type of high pressure discharge lamp.

High pressure discharge lamp

A discharge lamp can be configured to include a glass tube bulb; a pair of discharge electrodes arranged within the glass tube bulb; and metal foils enclosed within sealing portions at both axial ends of the glass tube bulb so as to connect the discharge electrodes and externally extending lead wires. The metal foils can be provided with cuts and/or holes of various shapes and sizes acting as a stress alleviating portion for alleviating stress due to temperature variations.

Discharge lamp and method of making same

The invention provides an arc tube with improved chromaticity and start-up characteristics that does not contain mercury, and provides a vehicle headlamp equipped with a metal halide lamp that contains no mercury in the arc tube. Among other improvements, the evaporation of low melting point metal halides is promoted and the start-up characteristics of the arc tube are improved.

Discharge lamp

A metal halide lamp and a method for making the same, in which one end of each electrode projects into a discharge chamber to form a light-emitting portion and the other end thereof is supported by a pinch-sealed portion. A coil is wound around at least the pinch-sealed portion of the electrode to absorb gaseous impurities caused by the heat generated during the operation of the metal halide lamp and to prevent cracking, at the pinch-sealed portion, of bulb. A coil, made of high melting point material and gaseous impurities absorption material, is wound around at least the pinch-sealed portion of the electrode and the combination is disposed into the bulb. The diameter of the coil, the internal diameter of a circle made by the coil, and the pitch of the coil are fixed within specific values in connection with the diameter of the electrode.

Metal halide lamp

A metal halide headlamp comprising an electrode and a coil wrapping around said electrode to prevent the occurrence of cracks in a sealing portion, in which the diameter d.sub.0 of said electrode, the cross-section S of said electrode including said coil, the inner diameter ID of said coil, the pitch P of said coil, the distance L between an end of said coil and a metal foil, and the amount of metal halides with a NaI-to-ScI.sub.3 ratio are specifically limited. Thereby, the prior art problems, i.e., changes in the lamp characteristics, the degradation of durability, and so on, can be solved.

Growing community of inventors

Tokyo, Japan

Toshiyuki Nagahara