(Fuzhou Xie Telai Lighting Co., Ltd., Fuzhou 350014)
Abstract: LED refers to light-emitting diodes, LEDs have inorganic light-emitting diodes (ILEDs), organic light-emitting diodes (OLEDs), and ILEDs and OLEDs are collectively referred to as solid-state light-emitting diodes. GLED refers to gas light-emitting diodes with a new wick structure and working mechanism.
Key words positive halo discharge hollow cathode discharge GLED
1 Introduction
People always want to use fluorescent lamps like incandescent lamps. This makes it possible to make straight fluorescent lamps into H, U, spiral and other patterns; on the other hand, small discharge lamps with the appearance of incandescent lamps have been developed.
Fig. 1 shows a small discharge lamp disclosed in Japanese Patent Laid-Open Publication No. SHO-63-234976. The anode and cathode are arranged at close distances and are parallel to each other. The wick will cause a short circuit of the arc and the cathode decomposition is difficult to complete; a uniform electric field is formed in the discharge space, so that the discharge falls into the mode of the positive column discharge, the electrode position drops greatly, and the anode rod is red hot (tube current 300 mA, anode rod) 800 ° C or more). In order to solve the problem of red heat of the anode rod, the patentee took five cooling measures on the anode rod. This makes the structure of the lamp complicated and the cost performance is low.
Similar technical solutions include U.S. Patent No. 3,243,632 and the like.
Figure 2 shows another small-sized discharge lamp that appears on the domestic and international markets, using a V-shaped filament as the electrode. The lighting is achieved by energizing the filament to reach the hot spot operating temperature, and discharges at both ends of the filament to form radiation; obviously, the lamp utilizes the principle of glow decomposition of the cathode. In order to maintain the discharge at both ends, the application of the electronic powder can only be limited to a short range at both ends of the filament, the life of the lamp is about 2000 hours, and the power is difficult to enlarge. In order to meet the needs of the market and enable people to truly obtain incandescent fluorescent lamps, it is necessary to explore new wick structures and working mechanisms.
2 positive halo discharge
The so-called positive halo discharge means that the cathode and the anode are not arranged in parallel, and the non-uniform electric field is distributed between the electrodes, and the ratio of the effective radius of the cathode to the effective radius of the anode is greater than the natural constant e. This kind of discharge will produce an anode corona near the anode. The main part of the discharge is the anode corona layer. The anode rod only acts as a conduction current, which effectively alleviates the red heat problem of the anode rod; the anode corona of this discharge The thickness of the layer is proportional to the discharge current, the discharge exhibits a positive resistance characteristic, and the discharge is stable.
3 hollow cathode discharge
If the cathode is formed into a pattern having a cavity structure in which the anode resides in the center of the cathode cavity, such discharge has the characteristics of a hollow cathode discharge. After the electrons emerge from the hot spot, the velocity direction of most electrons does not point to the anode due to the non-uniform electric field. They will follow the parabolic orbital: the electric field is accelerated in the space toward the anode, and the electric field is decelerated in the space away from the anode. As a result, the anode will reciprocate around the anode, which will lead to an increase in the number of collisions of electrons with the working gas, and the effect of excitation and ionization is greatly enhanced. This discharge has a very low electrode drop and a large discharge current density.