Abstract: A dual tube type fluorescent lamp including a luminescence tube. The luminescence tube has a long and slender airtight glass bulb with a nonlinear form part, a pair of electrodes and a phosphor layer formed on the inside surface of the glass bulb. A gap is formed between the circumference of the luminescence tube and an outside glass tube. The luminescence tube encloses an electric discharge medium coating mercury and a rare gas. An inorganic substance layer is formed at least at the nonlinear form part either on the outer surface of the luminescence tube, on the inner surface of the outside glass tube, or both. The inorganic substance layer has a softening point higher than the softening point of the glass.

Abstract: A lamp voltage detecting section detects the lamp voltage of the high-pressure discharge lamp and transmits it to a current calculating section. A lamp current detecting section detects the lamp current of the high-pressure discharge lamp and transmits it to a differential amplification circuit. A target power value to be supplied to the high-pressure discharge lamp is input to the current calculating section from a target setting device. The current calculating section divides the target power value by the lamp voltage detected by the lamp voltage detecting section to calculate a target current value, and transmits the target current value to the differential amplification circuit. A control section controls the chopping operation of a semiconductor switch so as to make the target current value approximate to the lamp current value.

Abstract: Provided is an apparatus for controlling the power supplied to a discharge lamp by detecting the voltage and current of the lamp's electric supply line. A microcomputer monitors power consumption of the discharge lamp by multiplying the voltage and current detected in the supple line to determine the input power and produces a representative control signal. The actual input power is compared with a preset input power, based upon the signal, and the power consumption of the discharge lamp is controlled in accordance with the results of the comparison.

Abstract: An electrodeless discharge lamp unit includes an electrodeless discharge lamp that has a luminescent tube with an excitation coil wound round and an auxiliary tube, a high-tension applying circuit to apply pulse voltage of a peak value that is able to dielectric break the discharge space in the luminescent tube and a current injection circuit to apply voltage, that is able to maintain non-ring shaped discharge formed in the luminescent tube by applying pulse voltage by a high-tension applying circuit even when the application of pulse voltage is suspended, to the end of the auxiliary tube.

Abstract: An ion generating device according to the present invention has a substrate having at least one insulating surface. A pair of electrodes is separately formed on the substrate to generate a corona discharge therebetween for ionizing gas floating in the atmosphere around the device. A protective layer having a thickness between 0.5 .mu.m and 10 .mu.m is limitedly coated on an exposed surface of the electrode.

Abstract: A discharge lamp lighting apparatus of the present invention includes an inverter to convert input DC voltage into high frequency voltage and supply the converted high frequency voltage to a discharge lamp having filaments, a preheating circuit to preheat the filaments of the discharge lamp, filament voltage detecting circuits to detect voltage applied between both ends of the filaments of the discharge lamp, and an output control circuit to control the inverter to stop or lower the output of high frequency voltage when the detected result of the filament voltage detecting circuit exceeds a specified value.

Abstract: A fluorescent lamp includes a light-transmitting envelope, means for generating a discharge within envelope, a discharge sustaining fill contained in envelope for emitting ultraviolet rays during the lamp operation and a phosphor layer coated on an inner surface of envelope. The phosphor layer converts the ultraviolet rays into visible light and ultraviolet radiation within a wavelength range of 320 nm to 410 nm so as to have radiant flux ratio of ultraviolet radiation of 5 to 50 percent of the entire radiant flux of the lamp.

Abstract: A lamp device includes a mirror reflector having a cylindrical, hollow lamp mounting portion at a rear end portion of a reflector body having a curved suface, a lamp housed in the mirror reflector and having an end with a sealing portion into which the lamp mounting portion is inserted, and an adhesive, filled between the outer surface of the sealing portion and the inner surface of the lamp mounting portion while the lamp sealing portion is inserted into the lamp mounting portion of the reflector body, for bonding the mirror reflector to the lamp. A space region is formed inside the lamp mounting portion and is surrounded by the inner surface of the lamp mounting portion, the outer surface of the sealing portion, and the adhesive filled therebetween. The end of the space region on the side of the curved surface is open, and the space region prevents heat conduction between the lamp mounting portion and the sealing portion.