Abstract: A display device 1 includes light emitting sections 36, 37 of different luminous colors disposed between anode and cathode electrodes, current control units 34, 35 for controlling currents supplied to the light emitting sections 36, 37 to desired current levels, respectively, and an emergency power supply for supplying a current to the current control units 34, 35 in an emergency in which a commercial power source does not perform a desired function. When operated by the emergency power supply, the current control units turn on and off the light emitting sections 36, 37 of different luminous colors such that they are turned on during different periods of time. When the emergency power supply is used, the display device 1 controls turning on of the planar light emitting element using an organic EL light emitting element depending on luminous colors thereof, thereby suppressing the power consumption of the emergency power supply.

Abstract: The electrodeless discharge lamp comprises: a bulb provided with a substantially-spherical spherical portion and a neck portion extending from the spherical portion; a base connected to the neck portion; a protrusion formed at an apex of the spherical portion; and an induction coil that causes light emission by discharge developed in the bulb. The electrodeless discharge lamp satisfies the formula below: t?6?10959×X+25?t+6??(Formula) where X=(B×S)/(L×A), B=W/(4×?×(D/20)2), S=?×(d/20)2, L=?×(d/10), W (W) denotes the lamp input power, D (mm) denotes the diameter of the spherical portion, d (mm) denotes the diameter of a portion at a joint surface between the neck portion and the base, and A (mm) denotes the distance from a largest-diameter portion of the spherical portion to the joint surface, and t is the temperature (° C.) at the tip of the protrusion during downward stable lighting of the electrodeless discharge lamp.

Abstract: A display device 1 includes light emitting sections 36, 37 of different luminous colors disposed between anode and cathode electrodes, current control units 34, 35 for controlling currents supplied to the light emitting sections 36, 37 to desired current levels, respectively, and an emergency power supply for supplying a current to the current control units 34, 35 in an emergency in which a commercial power source does not perform a desired function. When operated by the emergency power supply, the current control units turn on and off the light emitting sections 36, 37 of different luminous colors such that they are turned on during different periods of time. When the emergency power supply is used, the display device 1 controls turning on of the planar light emitting element using an organic EL light emitting element depending on luminous colors thereof, thereby suppressing the power consumption of the emergency power supply.

Abstract: An electrodeless discharge lamp has a bulb into which a discharge gas and a mercury, which is controlled at a temperature of a coldest spot are filled. A power coupler generates a high frequency electromagnetic field. A ferrule couples the bulb and the power coupler. The bulb is configured as a substantially spherical barrel formed of a transparent material and has an opening. A sealing member is welded to the opening of the barrel having a substantially cylindrical cavity. A protrusion, which becomes the coldest spot when the lamp is lit in a state that the ferrule is disposed upward, is formed at an apex of the bulb. A protruding portion is formed in a vicinity just above the ferrule of the bulb, that is, in a bulb neck portion, so that the bulb neck portion becomes the coldest spot when the lamp is lit in a state that the ferrule is disposed downward. Thereby, a constant optical output is obtained, regardless of a posture of installation of the electrodeless discharge lamp.

Abstract: The electrodeless discharge lamp of the present invention comprises: a bulb 1 provided with a substantially-spherical spherical portion 1a and a neck portion 1b extending from the spherical portion; a base 15 connected to the neck portion; a protrusion 4 formed at an apex of the spherical portion; and an induction coil 11a that causes light emission by discharge developed in the bulb. When defining the relations B=W/(4×p×(D/20)2), S=p×(d/20)2, L=p×(d/10), X=(B×S)/(L×A), where W (W) denotes the lamp input power, D (mm) denotes the diameter of the spherical portion, d (mm) denotes the diameter of a portion at a joint surface between the neck portion and the base, and A (mm) denotes the distance from a largest-diameter portion of the spherical portion to the joint surface, then the electrodeless discharge lamp satisfies the formula below: t?6=10959×X+25=t+6 ??(Formula) where t is the temperature (° C.) at the tip of the protrusion 4 during downward stable lighting of the electrodeless discharge lamp.

Abstract: In an electrodeless discharge lamp (1) which is lit with PWM light control, a discharge gas including krypton is filled in a bulb (10), so that restriking voltage can be decreased and thus, and oscillation of the ferrite core (22) which is inserted inside of a cavity (5) of the bulb (10) can be decreased, and thus, occurrence of undesired sound can be restrained.

Abstract: In an electrodeless discharge lamp 1 comprising a bulb 10 into which discharge gas and mercury which is controlled at a temperature of a coldest spot are filled, a power coupler 20 generating high frequency electromagnetic field, and a ferrule 15 for coupling the bulb 10 and the power coupler 20, the bulb 10 is configured of a substantially spherical barrel 14 formed of a transparent material and having an opening, and a sealing member 11 welded to the opening of the barrel 14 and having a substantially cylindrical cavity 5; a protrusion 4, which becomes a coldest spot when the lamp is lit in a state that the ferrule 15 is disposed upward, is formed at an apex of the bulb 10; and a protruding portion 17 is formed in a vicinity of just above the ferrule 15 of the bulb 10, that is, in a bulb neck portion 19 so that the bulb neck portion 19 becomes the coldest spot when the lamp is lit in a state that the ferrule 15 is disposed downward.