Neodymium plasma light source

Abstract

The invention discloses a neodymium plasma light source, and belongs to the technical field of plasma light sources, and the neodymium plasma light source comprises a magnetron which is used for generating microwaves; the microwave resonant cavity is in a semi-elliptic cylinder shape, a reflective mirror and an electrodeless discharge lamp tube are arranged in the microwave resonant cavity, and the electrodeless discharge lamp tube is filled with neodymium halide, tin halide, sodium halide and starting gas; one end of the waveguide tube is connected with the magnetron, and the other end of the waveguide tube is connected with the microwave resonant cavity; the color rendering index of the neodymium plasma light source is better than 95, the correlated color temperature is about 6000 K, and a spectrum curve is characterized in that a peak value appears around 480 nm and is similar to a solar spectrum.

Description

Technical Field

[0001] This invention relates to the field of plasma light source technology, and in particular to a neodymium plasma light source. Background Technology

[0002] To date, three major categories of microwave light sources have been developed in the field of microwave plasma lighting: microwave sulfur lamps, microwave metal halide lamps, and LEP lamps.

[0003] Among them, patent document WO9208240A1 discloses a microwave sulfur lamp technology that achieves a luminous efficacy of over 80 lm / W and a color rendering index of approximately 82. The spectral characteristics of microwave sulfur lamps include producing a very strong green light around 550 nm, which causes discomfort to the human eye. Furthermore, microwave bulbs require an external motor for high-speed rotation, increasing the cost of the lamps. Due to these factors, microwave sulfur lamps have gradually disappeared from the market.

[0004] Patent WO03071581A1 discloses a microwave metal halide lamp technology, a light source using a binary system of praseodymium triiodide and sodium iodide as filler, which achieves a good result of luminous efficacy of over 150 lm / W, with a linear emission spectrum and a color rendering index of 74. Such light sources often contain a large amount of mercury in the lamp tube, which is unpopular, and no such light source products have appeared on the market to date.

[0005] LEP lamps are still in use today. Their biggest problem is the dielectric resonator, which uses alumina ceramic as the dielectric. Due to high dielectric loss, the luminous efficacy is not high. Furthermore, LEP bulbs typically contain trace amounts of mercury and radioactive 85Kr. This type of light source currently has a luminous efficacy of around 85 lm / W and a color rendering index of around 80. Coupled with its high price, market promotion is difficult.

[0006] Patent EP1119021A1 discloses another type of microwave metal halide lamp that emits a continuous spectrum. One type uses a binary system of aluminum triiodide and tin diiodide as the filler light source, and its color rendering index is as high as 97. However, since the peak wavelength of the emission spectrum of aluminum is around 530nm, it is still somewhat different from the solar spectrum. Summary of the Invention

[0007] The purpose of this invention is to provide a neodymium plasma light source to solve the above-mentioned problems.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A neodymium plasma light source, the neodymium plasma light source comprising: Magnetrons are used to generate microwaves; A microwave resonant cavity, which is semi-elliptical cylindrical, contains a reflector and an electrodeless discharge lamp. The electrodeless discharge lamp is filled with a filler material, which consists of neodymium halide, tin halide, sodium halide, and starting gas; the neodymium halide is selected from one of neodymium triiodide, neodymium tribromide, and neodymium trichloride, and the tin halide is selected from one of tin diiodide, tin dibromide, and tin dichloride; A waveguide, one end of which is connected to the magnetron and the other end of which is connected to the microwave resonant cavity.

[0009] As a preferred technical solution, the neodymium halide content is 2-4 mg / cm³. 3 .

[0010] As a preferred technical solution, the molar ratio of neodymium halide: tin halide: sodium halide is 1:(0.6~1.5):(1.0~1.5).

[0011] As a preferred technical solution, the waveguide is horn-shaped.

[0012] As a preferred technical solution, the microwave resonant cavity adopts a high-Q microwave resonant cavity with a resonant frequency of 2480MHz when unloaded.

[0013] As a preferred technical solution, the starting gas is xenon gas at a pressure of 300 Torr.

[0014] Compared with the prior art, the advantages of the present invention are as follows: 1) This invention uses a mixture of neodymium halide, tin halide and sodium halide as the filler of the lamp tube. Specifically, this invention uses neodymium halide with an emission wavelength of around 480nm, tin halide with an emission wavelength of around 530nm and sodium halide that emits yellow and red light. The three are organically combined in an appropriate ratio to obtain a color rendering index and correlated color temperature similar to sunlight. 2) This invention employs a high-Q, semi-elliptical cylindrical microwave resonant cavity. The cavity consists of an aluminum shell with five sides and an aluminum shielding mesh on one side. Compared with commonly used resonant cavities, this structure has a higher Q value. At the same time, all five sides of the resonant cavity are made of highly reflective, mirror-like aluminum. This allows for efficient excitation of the filling material inside the lamp tube to emit light, while also effectively transmitting the light excited inside the cavity to the external space. The neodymium plasma light source of this invention has a color rendering index (CRI) higher than 95 and a correlated color temperature (CBT) of around 6000K. Its spectral curve is characterized by a peak around 480nm, which is very similar to the solar spectrum. Its spectral composition is close to natural light, and its high CRI is beneficial for accurately reproducing object colors, making it particularly suitable for applications requiring high color accuracy, such as museum lighting and high-end commercial lighting. Furthermore, its spectrum is located in the blue-green light region, where the human eye's visual function (photopic vision) is highly sensitive, providing high visual brightness at lower power, improving luminous efficiency, and reducing visual fatigue, making it suitable for environments requiring prolonged lighting. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the neodymium plasma light source device of the present invention; Figure 2 This is a top view of the neodymium plasma light source device structure of the present invention; Figure 3 The spectrum is for a filling material of neodymium triiodide + sodium iodide; Figure 4 The spectrum is for a filling material of tin diiodide; Figure 5 The spectrum is for a filling material of neodymium triiodide + tin diiodide + sodium iodide; In the diagram, 10 is a magnetron; 11 is a waveguide; 12 is a microwave resonant cavity; 13 is a shielding mesh; 14 is a magnetron antenna; 15 is a reflector; 16 is a screw; 17 is an electrodeless discharge lamp; 18 is a left strip slit; 19 is a right strip slit; 20 is a left end cap aluminum plate; and 21 is a right end cap aluminum plate. Detailed Implementation

[0016] To explain the technical content, objectives, and effects of the present invention in detail, the following specific embodiments further illustrate the content of the present invention. However, the content of the present invention is far more than the following embodiments.

[0017] A neodymium plasma light source, reference Figure 1 and Figure 2 The neodymium plasma light source includes: Magnetron 10 is used to generate microwaves; The microwave resonant cavity 12 is semi-elliptical cylindrical and is fixed as a closed cavity by screws 16. The microwave resonant cavity 12 is provided with a reflector 15 and an electrodeless discharge lamp 17. The electrodeless discharge lamp 17 is filled with neodymium halide and / or tin halide and / or sodium halide, and also contains starting gas. Waveguide 11, one end of which is connected to the magnetron 10, and the other end of which is connected to the microwave resonant cavity 12; In this embodiment, the magnetron 10 is powered by a transformer to generate microwave energy at a frequency of 2.45 GHz. A magnetron antenna 14 is provided on the magnetron 10 to transmit microwaves outward. The waveguide 11 is horn-shaped, and the cross-section of the horn-shaped waveguide 11 is rectangular, with a front end of 80mm×80mm, a rear end of 80mm×90mm, and a length of 130mm. It is made of aluminum, with the front end connected to the magnetron 10 and the rear end welded to the microwave resonant cavity 12. The microwave resonant cavity 12 is composed of a reflector 15, a left end plate 20, a right end plate 21, and a shielding mesh 13, which is made of aluminum. The reflector 15 is made of an elliptical surface and forms a semi-elliptical column with the shielding mesh 13. The cross-section is semi-elliptical, with the following dimensions: a=52mm, b=43mm, c=30mm. Two strip-shaped slits of the same size are symmetrically opened on the surface of the reflector 15, namely the left strip-shaped slit 18 and the right strip-shaped slit 19. The slits are both 13.6mm wide and 60mm long, and the two strip-shaped slits are 61.2mm apart. The microwave resonant cavity 12 resonates at 2480MHz when unloaded. The electrodeless discharge lamp 17 is placed at the focal point of the elliptical surface of the microwave resonant cavity 12. It is a quartz glass tube with a length of 50 mm and a diameter of 20 mm. The wall thickness of the electrodeless discharge lamp 17 is 2 mm. The electrodeless discharge lamp 17 is filled with neodymium halide and / or tin halide and / or sodium halide. The specific filler and its filling amount are as shown in Examples 1, 2 and 3 below. The starting gas xenon pressure is 300 Torr. The microwave energy generated by the magnetron 10 is coupled to the microwave resonant cavity 12 through the left strip slit 18 and the right strip slit 19 via the horn-shaped waveguide 11, and then excites the filler in the electrodeless discharge lamp tube 17 to discharge and emit light.

[0018] Example 1 In this embodiment, neodymium triiodide and sodium iodide are used as metal halides filled inside the lamp tube.

[0019] The filler consists of 30 mg of neodymium triiodide and 8.7 mg of sodium iodide, the starting gas is xenon, the pressure is 300 Torr, the internal volume of the lamp tube is 10 cubic centimeters, and the microwave power is 900W. The parameters of the lamp in this embodiment are as follows: Color rendering index Ra = 80.6, correlated color temperature T = 5030K, spectral distribution curve as shown in the figure. Figure 3 As shown.

[0020] Example 2 In this embodiment, tin diiodide is used as the metal halide filled inside the lamp tube.

[0021] The filler is 15 mg of tin diiodide, the starting gas is 300 Torr, the internal volume of the lamp tube is 10 cubic centimeters, and the microwave power is 800W. The parameters of the lamp in this embodiment are as follows: Color rendering index Ra = 80.5, correlated color temperature T = 3600K; spectral distribution curve as shown in the figure. Figure 4 As shown.

[0022] Example 3 In this embodiment, neodymium triiodide, tin diiodide, and sodium iodide are used as metal halides to fill the lamp tube.

[0023] The filling materials include: 30 mg of neodymium triiodide, 23 mg of tin diiodide, 8.7 mg of sodium iodide, 300 Torr of xenon gas for starting, 10 cubic centimeters of lamp tube volume, and 1000 W of microwave power. The parameters of the lamp in this embodiment are: color rendering index Ra=97, correlated color temperature T=5987K; the spectral distribution curve is as follows. Figure 5 As shown.

[0024] Compare Figure 3 , Figure 4 and Figure 5 It can be seen that only tin diiodide exhibits a trough in its spectral curve around 530 nm, thus yielding... Figure 4 The shape of the spectral curve. This can be compensated for by adjusting the filler content, as shown below. Figure 5 In that way, the spectral curve with a peak of 480 nm gradually weakens and tends to approximate the solar spectrum.

[0025] Table 1 shows the relationship between different filler contents and color rendering index for an 800W lamp tube with an internal volume of 5 cubic centimeters. The filler unit in the table is milligrams.

[0026] Table 1. Relationship between color rendering index and filler content , As can be seen from Table 1, for a certain power and a certain volume inside the lamp tube, a set of filler content and expected data can always be obtained.

[0027] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A neodymium plasma light source, characterized in that The neodymium plasma light source comprises: a magnetron for generating microwaves; a microwave resonant cavity, which is semi-elliptic cylindrical, and has a mirror and a non-polar discharge lamp tube arranged therein; the non-polar discharge lamp tube is filled with a filling material, which is composed of neodymium halide, tin halide, sodium halide and starting gas; the neodymium halide is selected from one of neodymium triiodide, neodymium tribromide and neodymium trichloride, and the tin halide is selected from one of tin diiodide, tin dibromide and tin dichloride; a waveguide, which is connected to the magnetron at one end and to the microwave resonant cavity at the other end.

2. A neodymium plasma light source as claimed in claim 1, characterized in that The filling amount of the neodymium halide is 2-4 mg / cm 3 .

3. A neodymium plasma light source as defined in claim 1, characterized in that The molar ratio of the neodymium halide, tin halide and sodium halide is 1:(0.6-1.5):(1.0-1.5).

4. A neodymium plasma light source as defined in claim 1, characterized in that The starting gas is xenon gas, and the pressure is 300 Torr or more.

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