Toshiba Lighting & Technology Corporation

Kabushiki Kaisha Toshiba

Katsuhide Misono

Hisashi Honda

Taketo Kamei

Shinichi Tsunekawa

Yoichi Hattori

Kazuhisa Ogishi

A fluorescent lamp device comprises an oblate section type fluorescent lamp having an oblate cross section and provided with a luminous surface illuminating in one direction and with a back plate and a lighting circuit means attached to the back plate and adapted to light the fluorescent lamp. The fluorescent lamp is electrically connected to and integrally assembled with the lighting means including the lighting circuit board by the bendable leads and the terminal pieces capable of having various shapes. In addition, a fluorescent lamp device comprises a fluorescent lamp body which includes a front plate, a back plate and a spacer which is provided between the front plate and the back plate and which defines the oblate sectioned bulb of the fluorescent lamp. The bulb airtightly containing at least a pair of cold cathodes and rare gases, the flourescent lamp device being so designed that the discharge current density, which is the ratio of the discharge current between the pair of cold cathodes to the area of the oblate section of the bulb, is 0.30 mA/mm.sup.2 or less and that the flatness F, which is the ratio of the length in the longitudinal direction of the oblate section of the bulb to the length in the lateral direction of the same, and the pressure P (torr) of the rare gases satisfy at least one of the following inequalities (1) and (2):

Fluorescent lamp device

A fluorescent lamp of a hot cathode type which is operated with a lamp current of 50 mA or less comprises an outer tube as an envelop, a gas filled in the envelop and a pair of electrodes disposed at both ends of the outer tube in an opposing fashion, at least one of the electrodes being operated in a hot cathode mode. With the fluorescent lamp of the type described, a following relationship is established, p.d.gtoreq.13, where d represents an inner diameter (cm) of the envelop and p represents an inner pressure (Torr) of the gas filled in the envelop. When the relationship V.sub.k .ltoreq.15, where V.sub.k represents a cathode fall voltage, is further satisfied, the life time of the fluorescent lamp can be elongated.

Fluorescent lamp having low cathode fall voltage

The discharge space of a flat type fluorescent lamp in which a pair of electrodes are oppositely positioned for producing discharge therebetween establishes a predetermined elongated width W along the pair of electrodes and a prescribed height H in a direction perpendicular to the discharge direction. A fill including argon is sealed in the discharge space at a target pressure F (torr) which satisfies the following relationship when an aspect ratio F defined by the ratio of the predetermined elongated width W to the prescribed height H is equal to or greater than four and is equal to or less than eight: 10.ltoreq.P.ltoreq.-5/2 (F-4)+40; and the following relationship when the aspect ratio F is equal to or greater than eight and is equal to or less than eighteen: 10.ltoreq.P.ltoreq.30.

Flat type low pressure gas discharge lamp

Fluorescent lamp tube

A fluorescent lamp apparatus according to the present invention comprises a base member, a fluorescent lamp, and lighting means. The base member is a hollow member having a threaded base which can be screwed into the same type of socket as is used in ordinary incandescent lamps. It has a partition wall, and is divided thereby into a circuit chamber and an air chamber. The circuit chamber is located close to the base, and the air chamber communicates with the atmosphere. The lamp is attached to the base member, and comprises a tubular envelope, a pair of electrodes, and a mercury-vapor pressure adjusting means. The envelope is bent in shape, thus forming a discharge passage of a predetermined configuration, is sealed in an airtight fashion, and has both ends located close to the base member. The electrodes are contained within the end portions of the envelope. The mercury-vapor pressure control means incorporates a quantity of amalgam which is held within the air chamber of the base member, and is designed to supply mercury vapor into the envelope. The lighting means is located with the circuit chamber of the base member and is electrically connected to the electrodes of the fluorescent lamp, for lighting the lamp.

Growing community of inventors

Yokohama, Japan

Katsuhide Misono