Patents Assigned to Matsushita Electric Works Research & Development Labratory
  • Patent number: 6064155
    Abstract: A compact fluorescent lamp is designed to imitate an incandescent lamp in size, shape and luminosity. The lamp includes a bulbous envelope (14) having an external shape of an incandescent lamp (10) on a standard Edison-type base (11) that enables it to be substituted for standard 60, 75 and 100 W incandescent lamps. A low-pressure fluorescent lamp (18) having a coiled tubular envelope with an outer diameter less than about 7 mm, an inner diameter between about 1 and 5 mm, and a length between about 50 and 100 cm is wound in a coil around the axis of the bulbous envelope (14) and is disposed within the bulbous envelope. The tubular envelope is formed of soft glass and has a fluorescent phosphor coating disposed on the inner surfaces. Electrodes (14) with external electrical contacts are disposed at each end of the envelope. A ballast (12) is disposed within the bulbous envelope. The ballast is electrically connected to the lamp (15), whereby to control current in the fluorescent lamp.
    Type: Grant
    Filed: May 4, 1998
    Date of Patent: May 16, 2000
    Assignee: Matsushita Electric Works Research and Development Labratory Inc
    Inventors: Jakob Maya, Edward K. Shapiro, Frank D. Mellen
  • Patent number: 5726523
    Abstract: An electrodeless fluorescent lamp and fixture is disclosed which operates at radio frequencies and contains a bifilar coil to reduce RF voltage between the plasma and the coil and a metallic cylinder (10) to remove heat from a said bifilar coil. The bifilar coil consists of two windings. The primary (induction) winding (6) is used to generate RF electrical azimuthal field in the bulb volume needed to maintain the inductively-coupled RF plasma. The second (bifilar) winding (18) has essentially the same number of turns and is wound on the inductive winding (6), but in the direction opposite to that of the primary (inductive) winding. The RF current flowing in the inductive winding (6) induces an RF voltage of the opposite polarity in the bifilar winding (18), so two adjacent turns of both windings have equal (or nearly equal) but of opposite sign RF potentials with respect to the plasma.
    Type: Grant
    Filed: May 6, 1996
    Date of Patent: March 10, 1998
    Assignee: Matsushita Electric Works Research & Development Labratory
    Inventors: Oleg Popov, Jakob Maya, Jagannathan Ravi
  • Patent number: 5698951
    Abstract: An electrodeless fluorescent lamp containing a fill of a rare gas and mercury and a flag (14) disposed therein at a predetermined location in the lamp for increasing the rate of luminous development in the lamp. The flag (14) includes a pair of spaced-apart metallic foil sections (31) and a metallic mesh substrate (30) disposed between the foil sections (31) whereby to be shielded from ion bombardment of the discharge. A coating (30a) of indium which is adapted to amalgamate with the mercury is disposed on the mesh (30). The sections are joined together by spot-welding (32) to enable migration of mercury into and out of the space between the sections thereby enable the atoms to form an amalgam with the indium and be rapidly released therefrom.
    Type: Grant
    Filed: May 6, 1996
    Date of Patent: December 16, 1997
    Assignee: Matsushita Electric Works Research & Development Labratory
    Inventors: Jakob Maya, Oleg Popov, Edward K. Shapiro