Kabushiki Kaisha Toshiba

Toshiba Lighting & Technology Corporation

Masami Takagi

Shinichi Tsunekawa

Kenji Ohkubo

Kiyoshi Nishimura

Ariyoshi Ishizaki

Naoki Tsutsui

Toshiharu Yagi

Masuo Shibuya

Shinji Mochimaru

Masahiko Aoyagi

Hidehiko Noguchi

Kunio Yuasa

Masao Kawaziri

Miho Saito

A low-pressure mercury vapor-filled discharge lamp has a glass arc tube and a glass outer tube disposed coaxially with the arc tube forming a space therebetween. A gas is disposed in the space. The arc tube contains a gas and is coated with a phosphor. A first seal hermetically seals the inner tube. A second seal seals the inner tube to the outer tube. The inner tube further contains a pair of cathodes coupled to Dumet wires extending from the interior of the inner tube to the outside of the lamp structure. The pressure in the space is set at not more than 1 Pa, which is nearly high vacuum. The longer the radial dimension of the space, the greater the heat retaining capacity and the better the temperature characteristics which can be obtained. However, by setting the pressure of the space at 1 Pa or less, the optimum heat retaining capacity can be obtained while reducing the diameter of the low-pressure mercury vapor filled discharge lamp 1.

Low-pressure mercury vapor-filled discharge lamp, luminaire and display

A low pressure gas discharge lamp comprises an elongated tube filled with a discharge gas. An inner electrode is disposed in a first end portion of the tube and an outer electrode is formed on an outer surface of the tube. The outer electrode has a belt shaped portion formed on the outer surface of the tube along an axial direction of the tube between the first end portion and a second end portion of the tube and a ring shaped portion formed on the outer surface of the tube around the second end portion of the tube. The ring shaped portion is connected to the belt shaped portion. The discharge is generated between the inner electrode and the outer electrode. The ring shaped portion of the outer electrode prevents the discharge from shifting from a central axis of the tube, and thus makes the lamp have an even brightness distribution along the axis of the tube.

Low pressure gas discharge lamp

This invention relates to a fluorescent lamp unit which comprises a fluorescent lamp, and fluorescent-lamp mounting members mounted at end portions of the fluorescent lamp and for fixing the fluorescent lamp to other members. Between the fluorescent-lamp mounting members and the end portions of the fluorescent lamp, there are provided elastic means mounted so that the fluorescent-lamp mounting members can rotate by an angle not less than 1.degree. relative to the fluorescent lamp, or elastic means mounted so that the fluorescent-lamp mounting means can deflect by not less than 0.1 mm in a longitudinal direction of the fluorescent lamp. The elastic means may be layers of an adhesive. The fluorescent-lamp mounting members may also include screwing means.

Fluorescent lamp unit

A low pressure gas discharge lamp includes a bulb with a pair of closed ends, and a pair of bases attached to the ends of the bulb, respectively. Each base has a cylindrical base body into which the end of bulb is inserted, and a pair of receiving terminals electrically connected to an electrode in the bulb and protruding from the base body in a direction perpendicular to the axis of the bulb. Each terminal has a pair of mutually parallel flat faces and is secured to the base body such that these flat faces are located on planes perpendicular to the axis of the bulb, and a part of at least one flat face is in contact with a bottom wall of the base body.

Low pressure discharge lamp with flat-plate terminal

A low-pressure discharge lamp includes a bulb and a pair of bases attached to the end portions of the bulb, respectively. Each base has a base body fixed to the end of the bulb and a pair of terminals attached to the periphery of the base body. The terminals have contact portions which project from the periphery of the base body and include contact surfaces extending parallel to the axis of the bulb and facing the same direction. The contact surfaces are located so as to contact a common plane.

Low-pressure discharge lamp and electrical base structure

A rare-gas arc lamp includes a pair of coil filaments disposed at the opposite ends of an elongated bulb for increasing an area of a positive column produced between the coil filament pair in a direction perpendicular to the elongated axis of the bulb, and a rare-gas mainly including xenon gas and having substantially no mercury therein sealed in the bulb at a prescribed pressure selected from the range between 20 Torr and 200 Torr. The combination of the coil filament pair and the xenon gas sealed in the bulb at a prescribed pressure in the range of 20 Torr to 200 Torr may reduce visible changes in a luminance distribution of the lamp when the positive column fluctuates during the operation of the lamp.

Rare gas arc lamp having hot cathode

A fluorescent lamp includes a bulb defining a discharge channel, and a pair of discharge electrodes provided at both ends of the bulb. Each electrode has a pair of leads, a filament mounted between the leads, and rod-like auxiliary electrodes protruding from the leads, respectively. Each auxiliary electrode extends beyond the filament in the electron discharge direction of the discharge electrodes. Each auxiliary electrode is constructed so as to satisfy the following equation Q/I.sub.L .gtoreq.1.0.times.10.sup.-2, where Q is heat capacity of the auxiliary electrode and I.sub.L is lamp current.

Growing community of inventors

Yokohama, Japan

Masami Takagi