CN2879420Y - High optical efficiency low working voltage outer electrode fluorescent lamp - Google Patents

Abstract

The utility model relates to a high optical efficiency low working voltage outer electrode fluorescent lamp comprising a lamp glass housing sealed at two ends, a fluorescent layer is provided on an inner wall of the lamp glass housing, outer electrodes is provided on outer surfaces of two ends of the lamp glass housing which is filled with discharging gas, a high quadratic electron emitting material medium layer is provided at an inner surface of two ends of the lamp glass housing. The basic theory of the utility model is forming a medium layer having a high quadratic emitting coefficient on the inner surface of two ends of the present outer electrodes fluorescent lamp, increasing number of electrons which perform ionizing collision in a gas discharging region so as to increase the irradiance efficiency, in addition, the utility model also has an advantage of low work voltage.

Description

High Luminous Efficiency Low Working Voltage External Electrode Fluorescent Lamp

technical field

The utility model relates to an external electrode fluorescent lamp tube with high light efficiency and low working voltage.

Background technique

Cold cathode fluorescent lamp is a new type of light source that does not require cathode filament heating and can be made very thin (generally below 10mm, such as 1.8mm). There are two types of cold cathode fluorescent lamps, namely internal electrode fluorescent lamps (CCFL) and external electrode Fluorescent lamp (EEFL). The electrons and ions required for gas discharge in cold cathode fluorescent lamps are composed of gas ionization process and secondary emission of electrodes, which is different from the gas discharge formed by hot cathode fluorescent lamps (HCFL) through thermionic emission of hot cathodes. Internal electrode fluorescent lamps have high luminous efficiency, small outer diameter, no need for heating, and long life, so they are widely used in places where the volume of the light source is particularly small, such as liquid crystal display backlight, household appliances (refrigerators) lighting, etc. However, internal electrode fluorescent lamps also have some disadvantages, such as high discharge voltage (150-500v), and luminous efficiency is about 30% lower than that of hot cathode fluorescent lamps. In recent years, with the development of liquid crystal displays and LCD TVs, the demand for internal electrode fluorescent lamps is increasing. Large-size LCD TVs, such as 34-inch LCD TVs, require high brightness and must reach the brightness level of current picture tube TVs. Each TV needs about 100 lamps to meet the requirements. Therefore, a large part of the cost of LCD TVs is on the backlight. To reduce the cost of LCD backlight, it is necessary to improve the luminous efficiency of cold cathode fluorescent lamps, reduce the use of lamps or reduce the cost of each lamp. Since each lamp needs to be equipped with an inverter power supply to maintain the normal operation of the lamp tube, and the cost of the inverter power supply has a great relationship with its working voltage, so reducing the working voltage of the lamp tube can effectively reduce the cost of the inverter. Compared with internal electrode fluorescent lamps, external electrode fluorescent lamps have higher brightness and longer lifespan. At the same time, multiple lamp tubes (such as 20 lamp tubes) can be used to share one inverter to reduce the cost of backlight.

Existing external electrode fluorescent lamps (EEFL), which have a larger diameter and require a higher voltage for gas discharge, are now being applied to LCD TVs as backlight sources, and it can be expected that the application of these cold cathode fluorescent lamps will develop rapidly. Facing The problem is also to reduce the operating voltage and improve the luminous efficiency.

Contents of the invention

The utility model provides a high luminous efficiency and low working voltage external electrode fluorescent tube with high luminous efficiency and low working voltage.

The fluorescent lamp described in the utility model adopts the following technical solutions:

A fluorescent tube with high luminous efficiency and low working voltage external electrode that can be used as a liquid crystal backlight source or lighting. It includes a lamp tube glass bulb with both ends closed. External electrodes are arranged on the outer surfaces of both ends of the lamp tube, discharge gas is filled in the glass bulb of the lamp tube, and a medium layer of high secondary electron emission material is arranged on the inner surfaces of both ends of the glass bulb of the lamp tube. The above-mentioned fluorescent lamp technical solution is also suitable for curved, spiral or other shaped fluorescent lamps.

Compared with the prior art, the utility model has the following advantages:

The basic idea of the utility model is to make a dielectric layer with a high secondary emission coefficient on the inner surface of the two ends of the existing external electrode fluorescent lamp tube, and use the high secondary electron emission coefficient of the dielectric material to increase the number of electrons ionized and collided in the gas discharge area. number, thereby increasing the luminous efficiency.

In the utility model, a medium layer with a high secondary electron emission coefficient is made on the inner surface of the two ends of the outer electrode fluorescent lamp tube with an exhaust pipe, and then the inner surface of the outer electrode fluorescent lamp tube is coated with phosphor powder, and then the glass tube of the fluorescent lamp is exhausted. . After exhausting, fill the fluorescent lamp glass tube with inert gas and mercury discharge gas, and then seal the tube. The coating made of conductive material is used as the discharge electrode on the outer surface of both ends of the fluorescent lamp glass tube. When working, the AC voltage generated by the inverter is applied to the discharge electrodes at both ends, and the electrons move in the fluorescent lamp glass tube under the action of the electric field. , due to the high secondary electron emission coefficient of the material on the inner surface at both ends of the lamp tube, the number of secondary electrons is greatly increased and ionized collisions occur with the gas molecules in the tube, and the gas in the tube is discharged. Since the discharge space is large enough, it can form a high luminous efficiency. Discharge in the positive column area, the discharge excites the mercury to emit ultraviolet light, and the ultraviolet light excites the phosphor to emit visible light to make it a light source. So as to improve the luminous efficiency and reduce the working voltage.

The utility model makes a dielectric layer on the inner surfaces of both ends of the cold cathode fluorescent lamp, such as a dielectric layer with a high secondary electron emission coefficient material (such as magnesium oxide, aluminum oxide, etc.), and it is expected that the external electrode fluorescent lamp will have a low working voltage. Features of high luminous efficiency. The cost of supporting circuits can be effectively reduced, and the service life of the lamp tube can be prolonged.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Fig. 2 is a schematic diagram of the structure where one end of the tail is not completely covered by the coating.

Fig. 3 is a schematic structural view of the cover of the external electrode fluorescent lamp tube.

Fig. 4 is a structural schematic diagram of a ring-shaped lamp tube.

Fig. 5 is a schematic diagram of the external structure of the lamp tube in a spiral shape.

Detailed ways

A fluorescent tube with high luminous efficiency and low working voltage external electrode that can be used as a liquid crystal backlight source or lighting. It includes a lamp tube glass bulb 2 with both ends closed. External electrodes 4 are arranged on the outer surfaces of both ends of the tube glass bulb 2, discharge gas 3 is filled in the lamp tube glass bulb 2, and a high secondary electron emission material dielectric layer is arranged on the inner surfaces of both ends of the lamp tube glass bulb 2 5. The above-mentioned high secondary electron emission material dielectric layer 5 is a magnesium oxide layer, an aluminum oxide layer or a magnesium aluminate layer. The high secondary electron emission material dielectric layer 5 can also be other high secondary electron emission materials. The above-mentioned lamp tube glass bulb 2 Can be straight, curved, spiral or other shapes.

Claims (2)

1, a kind of liquid crystal backlight or illuminating external electrode fluorescent lamp tube with high light optical effect low operating voltage of can be used as, the tube glass shell (2) that comprises closed at both ends, on the inwall of tube glass shell (2), be provided with phosphor powder layer (1), on the two ends outer surface of tube glass shell (2), be provided with outer electrode (4), in tube glass shell (2), be filled with discharge gas (3), it is characterized in that on the two ends inner surface of tube glass shell (2), being provided with high secondary electron emission material dielectric layer (5).

2, external electrode fluorescent lamp tube with high light optical effect low operating voltage according to claim 1 is characterized in that high secondary electron emission material dielectric layer (5) is magnesium oxide layer, alumina layer or magnesium aluminate layer.

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