Matsushita Electric Industrial Co., Ltd.

Matsushita Electronics Corporation

Panasonic Corporation

Matsushita Electrical Industrial Co., Ltd.

Shiro Iida

Takeshi Matsumura

Hiroki Kitagawa

Kenji Itaya

Noriyuki Uchida

Masayoshi Kato

Yasushige Tomiyoshi

Yoshinori Kakuno

Tatsuhiro Yabuki

Kenji Nakano

Akiko Nakanishi

Masashi Sangen

Toyokazu Amano

Nobuharu Hata

Shoichi Kamizono

Katsushi Seki

Masayoshi Gyoten

Hiroki Nakagawa

Toshiaki Tsuruha

Hidezoh Akutsu

Tetsuya Tahara

Kazuhiko Itou

Kenji Fujiwara

Fumiyuki Sato

Yuji Tsuneto

Takashi Ueda

Tetsuo Matsuba

Shinichiro Ishitsuka

Junichi Takahashi

Kohhei Iwase

Kouhei Iwase

Toshikatsu Kotaki

Masaru Oyaizu

Masao Yukawa

Takayuki Iwasaki

A lamp includes an arc tube and a lighting unit for lighting the arc tube. The lighting unit includes a rectifier circuit, a smoothing circuit for partial smoothing, and an inverter circuit having a pair of switching elements. The smoothing circuit smoothes portions of the output voltage of the rectifier circuit below the first voltage value and outputs a voltage that falls between the first voltage value and the second voltage value. The discharge sustaining voltage of the arc tube is set to fall between the first and second values of the voltage Vdc output from the smoothing circuit.

Visible indication of mistaken lamp use

An arc tube is composed of an arc tube body that is formed by winding a straight glass tube. Two portions of the straight glass tube are spirally wound around an imaginary conical surface. The spiraled portions of the glass tube are sandwiched between a pair of movable fixed plates. The spiraled portions of the glass tube are heated to a temperature equal to or higher than a point at which the glass tube is deformable and yet lower than the softening point of the glass tube. The spiraled portions are flattened by the movable plate moving downwardly under its own weight.

Manufacturing method of an arc tube formed from a glass tube and having a spirally wound section within one plane

Fluorescent lamp

A lamp including an arc tube and a holder is provided. The arc tube includes a pair of electrodes respectively at both tube ends, and forms, between the pair of electrodes, a discharge path which turns in a double spiral substantially on one plane. The holder holds the arc tube in a state of fixing the tube ends of the arc tube and at least one part of the arc tube between the tube ends.

Lamp having an arc tube protected from breakage

A low-pressure mercury discharge lamp includes: an arc tube made by winding a glass tube into double spiral configuration; a holding member that is in a form of a cylinder with a closed bottom and is for holding the arc tube; an electronic ballast for lighting the arc tube; a case in a cone form for covering the electronic ballast by being fit to a circumferential wall of the holding member; and a globe covering the arc tube. When an inner diameter of the arc tube is represented as Di mm, and tube wall loading of the arc tube is represented as L W/cm, rectangular coordinates (Di, L) are confined within a range defined by points of: (2.5, 0.31), (4.0, 0.35), (5.5, 0.30), (6.5, 0.19), and (2.5, 0.01).

Small arc tube and low-pressure mercury discharge lamp

An arc tube is formed by turning a glass tube at a substantially middle thereof and winding the glass tube from the middle to its both ends around an axis to form a double spiral, and sealing electrodes at both ends of the glass tube. The spiral pitch of a spiral part in a vicinity of one of the ends and an adjacent spiral part in the direction of the axis is set larger than the spiral pitch of other adjacent spiral parts, to widen a gap between the one end and the adjacent spiral part.

Arc tube with shortened total length, manufacturing method for arc tube, and low-pressure mercury lamp

Disclosed is a compact self-ballasted fluorescent lamp with higher luminous efficiency than conventional lamps and improved luminous flux rising characteristics at lamp startup equivalent to those of general fluorescent lamps. The compact self-ballasted fluorescent lamp () includes an arc tube () formed by a bent glass tube () covered with a globe (). The glass tube () has a turning part substantially in the middle between its both ends, a first spiral part starting from one end and wound around an axis toward the turning part, and a second spiral part starting from the turning part and wound around the axis toward the other end. The arc tube () has mercury enclosed therein in a single form. The glass tube () has a substantially circular-shaped cross section and an inner diameter of 7.4 mm. The turning part is connected to the globe () via a heat-conductive member ().

Fluorescent lamp and manufacturing method for arc tube

Arc tube formed from a glass tube and having a spirally wound section within one plane

A mandrel has a main body having a substantially-cone-shape. The main body has, on its circumferential surface, a spiral-shaped groove at which the glass tube to be wound is held. The groove, in cross section, has a contact range in which the glass tube's circumferential surface is in contact. One end of the contact range corresponds to a circumference part of the glass tube in wound state which is closest to the axis of the main body of the mandrel, a part of the groove that extends from the circumference part towards the apex of the main body is parallel to the axis of the mandrel, and the pitch of the groove in the axial direction of the mandrel is formed smaller than the outer diameter of the glass tube. The glass tube wound on the mandrel is easily removed from the main body by lowering the mandrel. In the arc tube formed in such a way, any two glass tube portions, which are adjacent to each other in the axial direction of the arc tube, overlap with each other.

Small arc tube, low-pressure mercury lamp, lighting apparatus, mandrel for forming the arc tube, and production method of the arc tube

Growing community of inventors

Kyoto, Japan

Shiro Iida