Patent ID: 7804234

Claim:
A compact fluorescent lamp comprising a discharge tube arrangement, said discharge tube arrangement being formed of at least one discharge tube made of glass, enclosing a discharge volume filled with a discharge gas, and having a fluorescent phosphor coating disposed on the inner surface of the tube, the tube forming a continuous arc path and further being provided with electrodes disposed at each end of the arc path; a ballast circuit mounted on a printed circuit board for controlling current in the tube and being connected to the electrodes by lead-in wires and to a supply voltage by lead-out wires; a bulb-shaped outer envelope comprising a substantially spherical portion enclosing the discharge tube arrangement, and an elongated end portion enclosing the ballast circuit and having a circumferential groove with an inside surface of the groove being in contact with the printed circuit board of the ballast circuit; the end portion of the outer envelope having a neck portion with an open end for receiving a base shell; the open end of the neck portion being closed and terminated by a closing and neck reinforcing means of a material compatible with the material of the outer envelope; and the closing and neck reinforcing means comprising a substantially circular opening, through which the lead-out wires are led to a base for connecting said lamp to said supply voltage through a socket.