CN1106671C - Metal halide lamp - Google Patents

Abstract

A highly efficient discharge lamp has a color rendering index greater than 75, alumens per watt rating greater than 90, a correlated color temperature of between 3500 and 4040 DEG K, and a wall loading greater than 17 W/cm2. The lamp comprises an outer glass envelope and a pair of electrical conductors extending thereinto. A quartzdischarge tube is disposed within the outer envelope and includes a pair of spaced electrodes which are electrically connected to the electrical conductors for creating an electrical discharge during operation of the lamp. The discharge tube has an arcchamber or arc cavity with the configuration of a prolate spheroid having a major meter and a given arc distance as measured by the linear distance between the interior terminations of the electrodes, the ratio of the major diameter to the arc distance being less than 1 and greater than 0.9. An arc generating and sustaining medium within the arc chamber comprises the halides of sodium, scandium, lithium, thulium, and a thallium amalgam. A fill gas selected from argon and xenon, and a given quantity of mercury.

Description

Metal halide lamp

The present invention relates to the high brightness metal halide lamp, particularly have more dynamical high brightness metal halide lamp.

The high brightness metal halide lamp is one of at present available the most effective light source.When the mercury lamp of invention for the first time in 1934, this light fixture has the arc length of a 158mm, and the aperture is 33mm, and power is input as 400W, and the power loading of generation is 2W/cm ²Effect is about 40 lumen per watts (LPW) and colour rendering index (CRI) less than 20.

Along with the introducing of nineteen thirty-nine quartz arc tube, the aperture is reduced to 22mm and arc length is 70mm.Input power load for 400W reaches 6W/cm ²Effect is 50LPW, and the life-span is increased to 6000 hours.

At the initial stage sixties, by the improvement to quartzy production technology, metal halide is introduced becomes possibility, to increase rare hg spectrum.(sparse mercury spectrum)。This has produced with scandium and sodium is the lamp of additive.It has 80LPW under the input of 400W power and CRI is 65.The aperture of this lamp is that 20mm and arc length are that 45mm is to satisfy the evaporation requirement of metal halide additive.Power loading is increased to 12W/cm under the 400W input power ²

The development of upgrading in this field has comprised the development of lithium iodide, and it has promoted scandium-Sodium chemistry industry (seeing as U.S. Patent number 5,057,743, people such as keeffe).This lamp has further improved in correlated colour temperature (CCT) under the 3200K, and CRI reaches 75, LPW be 85 and under low-power mean wall load be 15.5W/cm ²

This lamp grows because of its life-span and good colour rendering property causes people's attention.It comprises wherein contains metal halide, the quartzy electric arc metal halide lamp housing of the composite filled thing of mercury and inert gas.The arc discharge chamber is contained in the alumina silicate Bohemian glass shell that for example has a good ultraviolet line absorption characteristic usually.Yet, in the high energy consumption epoch, provide a kind of have better and more efficiently the metal halide high-intensity discharge lamp of the characteristics of luminescence be necessary.

Therefore, an object of the present invention is to eliminate the defective of prior art.

Another object of the present invention provides a kind of metal halide high-intensity discharge lamp, and its colour rendering index is greater than 75, effect greater than 90LPW and correlated colour temperature between 3500～4040K.

These purposes can realize that this discharge lamp comprises having the glass shell that the pair of conductive body inserts into the inner portion by a kind of metal halide high-intensity discharge lamp is provided.Quartz discharge tube is arranged on enclosure and this quartz discharge tube comprises a pair of electrode on the electric conductor, separately that is connected to, and is used for discharging at the lamp duration of work.Discharge tube has the arc chamber of a long ball shape structure, and this long ball shape has main cross section diameter and a given arc length, and this arc length is to be measured by air line distance between electrode the inner, and the ratio of full diameter and arc length is less than 1 and greater than 0.9.A kind of electric arc takes place and keeps medium to be positioned in the arc chamber, and it comprises the halide of sodium, scandium, lithium, thulium and thallium, and by the blanketing gas of selecting in argon, the xenon, and the mercury of specified rate is to obtain the modulating voltage of expectation.This lamp with one greater than 17W/cm ²Wall load carry out work.

As above the lamp that is produced can be realized these designing requirements, also has the consistency between better lamp and the lamp in addition, strengthen the harmony of color, life-span is long, the minimizing near ultraviolet is launched and is eliminated disagreeable end coating, and the dispersion of minimizing arc shield color and the dosage of filling by the chemistry of minimizing input for lamp reduce production costs.

Fig. 1 is the perspective view according to the lamp of one aspect of the invention;

Fig. 2 adopts the curve of the colour rendering index of the present invention and prior art lamp with respect to the life-span;

Fig. 3 is the curve that adopts the correlated colour temperature comparative lifetime of the present invention and prior art lamp;

Fig. 4 adopts the lumen of the present invention and prior art lamp to keep curve;

Fig. 5 is the cross-sectional view according to an electric arc tube embodiment of one aspect of the invention;

Fig. 6 is under the chemical substance of various prior aries and chemical substance of the present invention, the core body temperature curve when peak current;

In order to understand the present invention better, and other purpose, advantage and other ability are in conjunction with above-mentioned accompanying drawing, to describing below and claims describe.

With reference now to accompanying drawing,, particularly in Fig. 1, a kind of metal halide arc discharge lamp 10 comprises bulb 12 and electric arc tube 14, and electric arc tube 14 is installed in the bulb by installing rack 16, and electric arc tube can be placed in the guard shield 20, and this guard shield is also supported by installing rack 16.Give electric arc tube 14 by 22, one lampwicks 24 of base and electrical lead 26 and 28 with electrical energy transfer.Electric arc tube includes the material of a chemical fill or doses to send light when electric arc is lighted, and will introduce as the back.Guard shield 20 comprises that can transmit a light, heat proof material, for example cylindrical tube of quartzy system.

Just as noted, in this specific examples, installing rack 16 had both supported electric arc tube, also support shield in bulb 12 inside.Installing rack 16 comprises a metallic support rod 30, and it is fixed on the lampwick 24 by a hoop 31.Support stick is connected with inside protrusion 32 in bulb 12 upper ends.Support stick 30 heart part therein parallels with the central shaft of electric arc tube 14 and guard shield 20.Erecting device 16 comprises that further going up 40 and one on folder for one presss from both sides 42 down, and they are fixed to electric arc tube 14 and guard shield 20 on the support stick 30.Clip 40 and 42 preferably is fixed by welding on the support stick 30.

Also find to comprise that when chemical composition a kind of metal halide of being made up of the iodide of thulium, scandium, sodium and lithium joins in the arc pipe 14, and electric arc tube has beyond thought advantage generation being to work under the excessive power loading for prior art.For example finding ought a kind of like this chemical substance, wherein the molefraction of the iodide of thulium, scandium, sodium and lithium is respectively 0.316,0.020,0.474 and 0.190, this chemical substance is put into the cylindrical electric arc tube of low-power (being 75W), then this electric arc tube can be worked under 100W, so actual wall load is 100/75 * 15.5=20.67W/cm ², its performance improves unexpectedly, and the unfavorable effect that may occur under the situation of the chemical substance that adopts prior art owing to rising load here can not occur simultaneously.The colour rendering index characteristic of this lamp as shown in Figure 2, wherein: A is a curve of the lamp of the above-mentioned aspect according to the present invention, when being illustrated in initial value 87, remains on 84 under 10,000 hours.Curve B, C, D and E are the curves of describing the lamp of prior art.Equally, correlated colour temperature (CCT) also is very stable shown in the curve A of Fig. 3, is surpassing 10,000 hours, keeps initial value at 4600K ± 100K.And curve B, C, D and E are the curves of describing the lamp of prior art.Equally, it also is very stable after initial decline that lumen keeps (Fig. 4), and this initial decline is that tungsten evaporates caused from electrode when being worked under its rated power by lamp.In Fig. 4, A represents the curve according to the lamp of one aspect of the invention, and B, C, D, E represent the curve of the lamp of prior art.Curve C and D indication lamp are 15.5W/cm in the low-power average load of routine ²Situation, and E represents to be filled with the situation of lamp greater than design power load 33% time of the prior art of conventional filler.Although the light fixture that E represents has 10,000 hours life-span, it is good that its retention performance does not resemble with those lamps of the chemical substance after improving, and therefore, it is not all right not having the chemical fill after the improvement of the present invention.

Although with recited above different, it is found that with an optimum chemical dosage obtain higher performance gain and do not adopt prior art cylindrical electric arc tube and make the shape of electric arc tube consistent with the configuration of arc discharge more, it is higher that power loading is increased to.The known electric arc discharge adopts the variation of oval and this shape to mention in the electric arc tube in front more or less.For example, the U.S. patent No. 4,020,377, it discloses a kind of oval-shaped isothermal electric arc tube.Yet, a kind of electric arc tube 14 of special construction, as shown in Figure 5, it makes and goes a step further before the present technique and it is more desirable.Its shape is around main shaft " a " rotation formation Long Circle by an ellipse (its semiaxis " a "＞semiaxis " b ").If " a " and " b " is inside dimension, then interior surface area is $A=2\mathrm{\π}(b^2+\mathrm{ab}\frac{\mathrm{ARCSINe}}{e})$

Wherein $e=\frac{{(a^2-b^2)}^{1/2}}{a}$

Thereby average power load is P/A, and wherein P is an internal power.

Electric arc tube 14 is to be made or made and had a chamber 44 by other suitable translucent, high-temperature material by quartz, wherein is sealed with tungsten electrode 46, and sealing realizes by molybdenum foil 48 being placed a press seal 50.Arc tube chamber 44 has main cross section diameter Z and an arc length Y, and arc length is measured by the air line distance between the inside terminals of electric arc 46, and the ratio of Z/Y is less than 1 but greater than 0.9.In best form of implementation of the present invention, Z equals 0.440 " (1.1176cm); Y equals 0.472 " (1.1988cm); Z/Y equals 0.932.Electrode stretches into 3mm and eletrode tip not on the focus of Long Circle electric arc tube 14.The volume of this electric arc tube is 1.167cm ³With an interior surface area be 5.55cm ²

The allowed average power load of this shape is higher than the situation of the sodium-scandium-lithiumation of conventional prior art, and this is to cause owing to heat load more uniformly is applied on this suitable simple shape.In addition, it is higher to learn the admissible wall load of ingredients for thulium-scandium-sodium-lithium-iodide-thallium/mercuration.For example, for the conventional cylinder form of low-power (being 75W), wherein contain sodium-scandium-lithium iodide, under the situation of working long hours, load limit is to 15.5W/cm ², and contain this chemical composition ellipse, then reach 17.8W/cm ², the ellipse that further contains thulium-scandium-sodium-lithium-iodide and thallium/mercury is 26.7W/cm in wall load ²Good optical effect shown in having down, this result's appearance are because for the chemical substance that adopts the latter, make due to the reduction of fuse temperature.As shown in Figure 6, by it as can be seen, comprise that the fuse temperature of thallium/thulium Chemical composition that is lower than independent use thulium for about 850K.And neither use thallium also not use thulium, the fuse temperature is that 900K is lower than previous standard.

In Table I, with K, the lamp that the lamp of L representative represents to have the prior art of specifying filler, M, N represent to adopt the lamp of filler of the present invention.From table, can find out obviously that only increasing the wall of prior art lamp load will can not obtain benefit of the present invention.When replacing 100 torr argons with 100 torr xenons, the LPW of lamp M and N increases.The dosage of mercury is preferably an amount of the lamp voltage that expectation can be provided.For example, in order in electric arc tube, to obtain the modulating voltage of above-mentioned 95V, need the thallium of 15mg mercury and 0.3mg.Throwing in thallium the best way is to realize as the amalgam that contains the mercury of 0.5-2wgt; Yet, drop into and also can realize by thallium iodide.

Scandium is preferably with the form adding of iodide and the excessive iodide that the 0.13mg sheet metal is added in the absorption remaining oxygen impurity and removing is discharged by the metal iodized salt.

Table 1

Wall load-17.8W/cm ²Wall load-26.7W/cm ²

T _h≈925℃ T _h≈990℃

T _c≈790℃ T _c≈880℃

Chemical substance LPW CRI CCT LPW CRI CCT

K	Na/Sc/Li/Tm(no dyestuff) 24: 1: 10: 16MR Hg﹠100 torr Ar	83	83	4350	79	92	3800
								L	24: 1: 10: 16 MR 2%T1/Hg﹠100 torr Ar	91	81	4210	88	91	3610
M	48: 1: 10: 16 MR 2%Tl/Hg﹠100 torr Ar	92	78	3900	94	88	3560
								N	48: 1: 10: 16MR 2%Tl/Hg﹠100 torr Xe	98	75	4040	102	85	3670

Chemical dose as described herein has higher power loading tolerance (and this power loading is harmful to for the lamp of long-time use), and makes the lamp can life-saving, and LPW is greater than 90, and CCT is 3500-4040K.

Although show and what describe is the most preferred embodiment of thinking at present of the present invention, clearly for those skilled in the art, the invention scope not breaking away from claims of the present invention and being limited can carry out various variations or change.

Claims (11)

1. a high brightness metal halide lamp has the colour rendering index greater than 75, and the lumen per watt rated value is greater than 90, correlated colour temperature in 3500～4040K and wall load greater than 17W/cm ², comprising:

Glass shell and pass a pair of electric conductor of glass shell inside;

A quartz discharge tube, be arranged in the shell and comprise a pair of spaced electrode, this electrode is connected with electric conductor, be used for producing discharge at the lamp duration of work, discharge tube has an arc chamber, this arc chamber has the Long Circle structure of a main cross section diameter and a given arc length, this given arc length by in the electrode between the end points air line distance measure, the ratio of main cross section diameter and arc length is less than 1 and greater than 0.9; And

A kind ofly place arc chamber electric arc to produce and keep medium, it comprises the halide of sodium, scandium, lithium, thulium and thallium, the blanketing gas of selecting from argon and xenon, and the mercury that is used to the specified rate of the modulating voltage that obtains to expect.

2. according to the described lamp of claim 1, it is characterized in that: halide is iodide.

3. lamp according to claim 2 is characterized in that: the ratio of sodium, scandium, lithium, thulium is 48: 1: 10: 16.

4. lamp according to claim 3 is characterized in that: thallium adds as amalgam.

5. lamp according to claim 4 is characterized in that: the volume 1.167cm of arc chamber ³, arc length is 1.1988cm, described filler contains 15mg mercury and 0.3mg thallium.

6. lamp according to claim 5 is characterized in that: blanketing gas is to be xenon under 100 torrs at cold stuffing pressure.

7. lamp according to claim 6, it is characterized in that: lumen per watt is about 98, and described correlated colour temperature is about 4040K, and described colour rendering index is 75, and the about 17.8W/cm of described wall load ²

8. lamp according to claim 5, it is characterized in that: lumen per watt is about 102, and described correlated colour temperature is about 3670K, and described colour rendering index is about 85, and described wall load is about 26.7W/cm ²

9. lamp according to claim 5 is characterized in that: blanketing gas is to be about argon under 100 torrs at cold stuffing pressure.

10. lamp according to claim 9, it is characterized in that: lumen per watt is about 92, and described correlated colour temperature is about 3900K, and described colour rendering index is about 78, and described wall load is about 17.8W/cm ²

11. lamp according to claim 9 is characterized in that: lumen per watt is about 94, described correlated colour temperature is about 3560K, and described colour rendering index is about 88, and described wall load is about 26.7W/cm ²

Images