Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Panasonic Photo & Lighting Co., Ltd.

Toshihiro Terada

Hirofumi Yamashita

Haruo Yamazaki

Shinji Kihara

Masanobu Murakami

Taizou Ono

Yusuke Mori

Takashi Maniwa

Hideki Wada

Tomokazu Matsuura

Shigeru Ido

Kazuhiro Matsuo

Takenori Shibata

Koji Takasaki

Shingo Tsutsumi

Mitsuharu Kawasaki

Hiroyuki Arata

Yuko Habuta

A low-pressure discharge lamp () is provided that includes a glass tube () having an inner diameter in a range of 1 to 5 mm and a pair of electrodes () disposed at end portions in the glass tube (). The pair of electrodes () contain at least one transition metal selected from transition metals of Groups IV to VI. Mercury and a rare gas containing argon and neon are sealed in an inner portion of the glass tube (). A relationship between a cathode glow discharge density J and a composition index &#x3b1; of the sealed rare gas of the low-pressure discharge lamp () satisfies the following expression&#x3b1;&#x2266;/()&#x2266;1.5&#x3b1;(where S represents an effective discharge surface area (mm) of an electrode, I represents a RMS lamp current (mA), P represents a pressure (kPa) of a sealed rare gas, and &#x3b1; represents a composition index of a sealed rare gas that is a constant expressed by &#x3b1;=(90.5A+3.4N)&#xd7;10when a total of a composition ratio A of argon and a composition ratio N of neon is expressed by A+N=1).

Low-pressure discharge lamp and back light device using the same

A cold-cathode fluorescent lamp including a glass bulb and a pair of electrodes which are cylindrical and respectively inserted in two ends of the glass bulb. Two end portions of the glass bulb are substantially circular in transverse cross section, the two end portions respectively corresponding to the inserted pair of electrodes in length. At least part of a middle portion of the glass bulb is flat in transverse cross section, the middle portion corresponding to a space in the glass bulb between the pair of electrodes.

Cold-cathode fluorescent lamp and backlight unit

A fluorescent lamp including a glass bulb that is in a shape of a tube. External electrodes are formed as conductive layers each of which covers an outer surface of the glass bulb at an end thereof. Metal members in a shape of a cap are respectively connected to the external electrodes by covering at least part of the external electrodes. The metal members are formed such that rims of the metal members recede from a center of the glass bulb in the tube axis direction a distance L than rims of the external electrodes.

Fluorescent lamp, backlight unit, and liquid crystal television for suppressing corona discharge

A backlight unit has an external electrode fluorescent lamp in an housing. The external electrode fluorescent lamp includes a glass bulb having a discharge space inside, and electrodes around both ends of the glass bulb. A protective layer and a phosphor layer are formed on an internal surface of the glass bulb in this order. The glass bulb is made of soda glass, and sodium oxide precipitated from this soda glass appears on part of the internal surface of the glass bulb where the protective layer is not formed, so as to be exposed to the discharge space.

Fluorescent lamp for use in a backlight unit and liquid crystal display device

A discharge lamp includes a glass bulb and a pair of electrodes provided at both ends of the glass bulb. At least one of the electrodes is an external electrode formed on an outer surface of the glass bulb as a thin layer whose maximum thickness is 70 &#x3bc;m or less, and an end portion of the external electrode becomes smaller in thickness towards an end of the external electrode.

Discharge lamp provided with external electrodes, production method of the discharge lamp, backlight unit provided with the discharge lamp, and liquid crystal display apparatus

Low-pressure discharge lamp and back light device using same

A backlight unit that includes: an outer container; a curved fluorescent lamp that is contained in the outer container and includes two electrodes and a glass bulb that has (i) a folded portion and (ii) two straight portions that extend in parallel with each other from the folded portion, and the two electrodes being respectively attached to two ends of the glass bulb; and an inverter operable to supply power for lighting to the curved fluorescent lamp. The inverter is disposed outside the outer container, and the curved fluorescent lamp is arranged so that the electrodes are at low positions and the folded portion is at a high position in the outer container when the backlight unit is erected vertically in use.

Backlight unit including curved fluorescent lamp, and liquid crystal display apparatus including the backlight unit

The present invention has an object to provide a cold-cathode fluorescent lamp which can suppress sputtering caused by electric discharge and reduce consumption of mercury so as to achieve a longer lifetime even if a lamp current is large and a lighting tube has a small diameter. The cold-cathode fluorescent lamp according to the present invention is characterized in that a distance between the inner surface of the lighting tube and the outer surface of a cylindrical electrode is set such that electric discharge develops mainly on the inner surface of the cylindrical electrode. When the lighting tube has an inside diameter Dof 1 to 6 mm and the maximum lamp current is 5 mA or more, an outside diameter Dof the cylinder electrode is preferably set at D&#x2212;0.4 [mm]&#x2266;D&#x3c;D

Cold-cathode fluorescent lamp

The present invention has an object to provide a cold-cathode discharge lamp which can suppress sputtering on a lead-in wire and reduce consumption of mercury so as to achieve a longer lifetime without increasing an amount of applied mercury. The cold-cathode discharge lamp of the present invention is characterized in that a lead-in wire connected to a cylindrical electrode in a lighting tube is made of a material same as a material that forms the cylindrical electrode. It is possible to suppress concentration negative glow discharge shifted to the lead-in wire and to allow the electrode to be covered with even negative glow discharge. Thus, it is possible to reduce mercury consumed by excessive sputtering on the outer surface of the internal lead-in wire and to achieve a longer lifetime of the cold-cathode discharge lamp.

Cold-cathode discharge lamp and lamp device having reduced sputtering on internal lead-in wire

The present invention has an object to provide a cold-cathode fluorescent lamp which can suppress sputtering caused by electric discharge and reduce consumption of mercury so as to achieve a longer lifetime even if a lamp current is large and a lighting tube has a small diameter. The cold-cathode fluorescent lamp according to the present invention is characterized in that a distance between the inner surface of the lighting tube and the outer surface of a cylindrical electrode is set such that electric discharge develops mainly on the inner surface of the cylindrical electrode. When the lighting tube has an inside diameter D of 1 to 6 mm and the maximum lamp current is 5 mA or more, an outside diameter D of the cylinder electrode is preferably set at D &minus;0.4 &lsqb;mm&rsqb;&lE;D D

A fluorescent lamp includes an arc tube made of a glass, a holder made of a heat-resistant resin for supporting the arc tube, and a case having a base and combined with the holder. The glass of the arc tube has light transmittance of 70% or less with respect to a wavelength of 340 nm, 50% or less with respect to 330 nm, and 15% or less with respect to 310 nm. The glass suppresses vaporization of the resin of the holder due to heat and ultraviolet ray emitted from the arc tube, thereby preventing adhesion of scattered resin to the inner surface of a globe of a lighting fixture.

Growing community of inventors

Amagasaki, Japan

Toshihiro Terada