CN1838373A - Ultra-high voltage mercury lamp - Google Patents
Ultra-high voltage mercury lamp Download PDFInfo
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- CN1838373A CN1838373A CN 200610009349 CN200610009349A CN1838373A CN 1838373 A CN1838373 A CN 1838373A CN 200610009349 CN200610009349 CN 200610009349 CN 200610009349 A CN200610009349 A CN 200610009349A CN 1838373 A CN1838373 A CN 1838373A
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Abstract
The present invention provides an ultra-high pressure mercury lamp in which blackening and deformation of an electrode generated in a light emitting tube is suppressed, having long life of use, with suppressed flicker. This is the ultra-high pressure mercury lamp in which a pair of electrodes are opposed and arranged in the light emitting tube, in which 0.15 mg/mm<SP>3</SP>or more of mercury is sealed in as a light emitting material, and in which a coil part is formed by winding a conductive wire of a prescribed length around the tip part of an electrode shaft part of the pair of the electrodes which carries out a negative electrode action, and in the coil part, a proportion of a contact area of the conductive wire and the shaft part per a unit length in the shaft direction is the maximum in the rear end part of the coil part, and a part in which the proportion of the contact area is small is formed at least in one part in front of the rear end part.
Description
Technical field
The present invention relates to LCD device or in the DLP projection arrangements such as (digital optical processor) that has used DMD (Digital Micromirror Device), use, in luminous tube, encapsulated 0.15mg/mm
3Above mercury and when illumination mercury steam pressure reach extra-high-pressure mercury vapour lamp more than 150 atmospheric pressure.
Background technology
Liquid crystal projection apparatus or used DMD with projection-type projection arrangements such as DLP as representative in, because for the screen of rectangle, require it to have even and sufficient colour rendering and energy illumination image, therefore, in light source, use the metal halid lamp that has encapsulated mercury or metal halide.Recently, this metal halid lamp develops towards further miniaturization, point-source of light direction, and the minimum Halogen lamp LED of electrode spacing is also used.
Under such background, recently, replace metal halid lamp, proposed when illumination, mercury steam pressure is up to for example lamp of having no precedent more than 150 atmospheric pressure.By raising mercury steam pressure like this, can suppress the diffusion of (dwindling) arc light, simultaneously, further improve light output.For example, in patent documentation 1, patent documentation 2, disclosed this extra-high-pressure mercury vapour lamp.
According to the mercury vapor lamp that discloses in the above-mentioned document, in having the luminous tube of spherical illuminating part, central portion is provided with pair of electrodes relatively, encapsulated 0.15mg/mm in the inner space of luminous tube
3The above mercury as luminescent substance simultaneously, in order to carry out halogen cycle, also is packaged with the halogen gas of ormal weight.
In this extra-high-pressure mercury vapour lamp, for example, shown in patent documentation 3,, be easy to transfer to arc discharge from glow discharge for when illumination is started, make near the coil portion that the electrode front end, forms be exposed to discharge space mostly with the lead system of twining.
[patent documentation 1] spy opens flat 2-148561 communique
[patent documentation 2] spy opens flat 6-52830 communique
[patent documentation 3] spy opens the 2001-319617 communique
Summary of the invention
In the last few years, because very strong to the requirement of miniaturization and the output of enhancing light, therefore, the tube wall of the extra-high-pressure mercury vapour lamp that uses in projection arrangement load tended to more and more higher, and the distance between electrode and the luminous tube inwall is tended to shorter and shorter.Unfavorable condition can appear in this extra-high-pressure mercury vapour lamp, that is: when starting utilizes direct current during the initial stage and throws light on by the lamp lighting device, the discharge of coil portion during by starting, will be attached near the coil portion luminous tube inwall as the tungsten of electrode constitute, thereby produce the bad phenomenon of luminous tube blackening.
In addition, the warpage of electrode, thus can't obtain desired briliancy and length of illumination, and reduction of service life, also can cause scintillation.
As mentioned above, when the warpage of electrode,, therefore, can produce the problem of shortening in useful life owing to flicker or luminous tube blackening reduce light transmittance and the length of illumination too short light beam that reduces that becomes.
In view of above problem, the object of the present invention is to provide a kind of extra-high-pressure mercury vapour lamp, it can suppress the generation of luminous tube blackening and electrode deformation, and useful life is longer, can suppress flicker.
In order to solve above-mentioned problem, extra-high-pressure mercury vapour lamp of the present invention is oppositely arranged pair of electrodes in luminous tube, simultaneously as luminescent substance, is packaged with 0.15mg/mm
3Above mercury, in above-mentioned pair of electrodes, play the leading section of the electrode axial region of cathodic process, lead by the coiling specific length forms coil portion, it is characterized in that: in above-mentioned coil portion, the contact area of above-mentioned lead and above-mentioned axial region is with respect to the ratio of the unit length of the axial length direction rearward end maximum at this coil portion, and, the less part of ratio of formation contact area at least a portion before the above-mentioned rearward end.
Herein, above-mentioned coil portion is portion's lead of closely reeling in its back-end preferably, and forms the part of the loose described lead of reeling at least a portion before this rearward end.
In addition, the gap between the adjacent wires is preferably 0.05～0.3mm in the lead of above-mentioned coil portion leading section.
Preferably, increase contact area thus by establish and form the different metal parts of lead of above-mentioned coil portion at folder between axial region and the lead.
In addition, above-mentioned metal parts is preferably formed by the 2nd lead.
In addition, the diameter of above-mentioned the 2nd lead is preferably less than the diameter of above-mentioned lead.
In addition, above-mentioned metal parts preferably is made of sintered body.
In addition, preferably form groove by the surface that in above-mentioned axial region, is equivalent to the coil portion rearward end, and, make lead embed this groove, increase the ratio of lead and the contact area of axial region thus.
When the inventor produces the reason of blackening at the research luminous tube, notice after mercury vapor lamp starting just when glow discharge is transferred to arc discharge, when producing rearward end (abbreviating " rearward end " as) with coil portion when be the discharge of starting point, electric current can be concentrated to the coil portion rearward end.
Find in addition:, thereby produce the phenomenon of blackening just because of the rearward end of current concentration in coil portion.
And find that length of illumination that can't obtain to wish and the problems such as flicker that light occurs also are because the deposition of above-mentioned tungsten and growth and electrode deformation causes.
For above-mentioned phenomenon, utilize Fig. 5 that an example of in the past extra-high-pressure mercury vapour lamp is elaborated herein.
Fig. 5 is for amplifying near the view the electrode root in the extra-high-pressure mercury vapour lamp in the past.Though Fig. 8 (a) and (b) are represented identical structure, Fig. 8 (a) acceptance of the bid is useful on the symbol of description architecture, indicates the symbol that the reaction in the luminous tube is described among Fig. 8 (b).Fig. 8 (c) is near the view the coil portion 22 in the further enlarged drawing 8 (a).In the figure, 1 is luminous tube, and 2 is electrode, and 21 is the axial region of electrode, and 22 is around the coil portion that forms by wire coils such as tungsten.
The inventor is to being accompanied by bright lamp, and the reason that distance L shortens has been carried out following supposition.
At the starting initial stage, direct current is flow through, thereby when extra-high-pressure mercury vapour lamp is thrown light on, the discharge type of starting several seconds at initial stage is observed by oscilloscope and video camera, find following phenomenon.
At first, behind the insulation breakdown, realize starting by tens volts the mercury arc discharge that produces from electrode surface, afterwards, after the mercury of cathode surface evaporates fully, carry out the glow discharge of several hectovolts as negative electrode in DC area.By glow discharge, fully heated as the electrode of negative electrode work (below, abbreviate " negative electrode " as) 2, then be easy to emit hot electron, and transfer to tens volts hot arc discharge from negative electrode 2.When carrying out glow discharge, to discharge with the form that covers whole negative electrode 2, the sharp-pointed wedge gap K place current density between coil portion 22 and axial region 21 increases, and enters arc discharge since then.
Afterwards, when carrying out this hot arc discharge, in the K of gap, the tungsten that then is locally heated can be from the surface with the radial evaporation of dispersing as if current concentration.Because the ionization voltage of the tungsten of evaporation is lower than mercury and inert gas, therefore, easily by electric arc e ionization, electric arc e is directed to the inner surface of nearest luminous tube 1 from the rearward end of coil portion 22.
As a result, as shown in the figure, the inner surface of luminous tube 1 will contact with high-temperature electric arc e or with its collision, owing to this reason, thereby get local formation pit at the inner surface of luminous tube 1, simultaneously, as the quartz glass (SiO of the constituent material of luminous tube 1
2) evaporation.The SiO of evaporation
2Be decomposed into Si and O by discharge plasma, thereby make the tungsten oxidation that constitutes negative electrode, the result, the oxide that causes tungsten is from negative electrode 2 evaporations.When the oxide with tungsten is transported to the coil rearward end, forms the W shown in the dotted line by deoxygenation and pile up, thereby more shortened distance D.
Should be taken into account: will occur this phenomenon with certain probability during owing to the mercury vapor lamp starting, therefore, can cause the accumulation of tungsten,, can cause constantly growth and deposition until the inner surface that contacts luminous tube 1 by repeating of these reactions.
In addition, the inventor finds that also following phenomenon can form unfavorable condition.
A kind of situation is: the evaporant of above-mentioned tungsten oxide also is transported to the part outside the negative electrode coil portion rearward end, cathode for example, and crystallization and generate thrust again.When this thrust is grown between electrode, the length of illumination that is suitable for optical system that can't obtain to wish.In addition, because interelectrode arc loss diminishes, the voltage step-down of lamp, therefore, general use for discharge lamp stabilizer can be controlled at predetermined electric current with the magnitude of current according to the voltage of lamp, if it is low during the voltage ratio steady illumination of lamp, then input is lower than desirable electrical power and throws light on, in this case, because the electrical power step-down of lamp, therefore, can further reduce luminous efficiency.
Worse: also have the situation that a plurality of thrusts occur, at this moment, the bright spot of arc light will move between the front end of thrust, thereby make light output produce scintillation.
The inventor finds: if can suppress from the electrical discharge arc of coil portion rearward end generation, so also can suppress at this place and the produced simultaneously current concentration of discharge, thereby can avoid constituting the evaporation of the quartz glass of luminous tube, the result can avoid the generation of above-mentioned phenomenon.
The invention effect
According to extra-high-pressure mercury vapour lamp of the present invention, in coil portion, comprise that the rearward end of its rear end compares with its place ahead, because the contact area of axial region and lead is bigger, good from lead to the heat conduction of axial region, therefore, can avoid heat in coil portion, to produce high temperature.And in the place ahead of rearward end, in the less part of the contact area of lead and axial region, owing to suppressed from the heat conduction of axial region to coil portion, therefore, temperature rises, thereby is easy to form hot arc discharge at this place.As a result, hot arc discharge is to take place in the less part of the contact area of lead and axial region, takes place from the rearward end of coil portion is then difficult.
Like this, by reducing the arc discharge that produces from the coil portion rearward end, can avoid being attached near the coil portion the luminous tube inwall to cause the phenomenon of luminous tube blackening as the tungsten that electrode forms material, simultaneously, can make the hot arc discharge that at once forms after light on away from the luminous tube inwall, thereby suppress the evaporation of quartz glass, and avoid the cathode oxidation phenomenon that causes thus.
Its result, can effectively prevent because of the luminous tube blackening reduce the problem of light transmittance, because of length of illumination become too short light beam is reduced the cause problem that shortens useful life and the generation of scintillation.
In addition, in above-mentioned extra-high-pressure mercury vapour lamp, the gap xmin. by making above-mentioned coil portion follows the effect that is produced by hollow effect between 0.05～0.3mm, can control the occurrence positions of hot arc discharge well.The gap that forms above-mentioned scope more than one place is set at least in the place outside the coil portion rearward end, and thus, that can avoid forming the problems referred to above more reliably produces arc discharge from the coil rear end.The gap of above-mentioned scope can be arranged at except that the coil rearward end Anywhere, but even more ideal at the front end place of coil.
In addition, can pass through at coil front end place, the contact area of electrode axial region and coil is reduced in gap between spread loop and the electrode axial region, perhaps opposite, by in the coil rear end side, gap between landfill coil and the electrode axial region is to increase these two kinds of methods of contact area or any method wherein of electrode axial region and coil, and retarder front end place makes it be easy to reach the temperature that is transferred to arc discharge from glow discharge to the thermal diffusion of electrode axial region.Its result, the starting point that the thermotropism arc discharge is shifted can concentrate on the front of coil portion, thereby can prevent reliably that the coil rear end from becoming the starting point of discharge when hot arc discharge.
Description of drawings
Fig. 1 is the profile that is used to illustrate the extra-high-pressure mercury vapour lamp of first embodiment of the invention.
Fig. 2 is the enlarged drawing of negative electrode, wherein, (a) is front view, (b) for comprising the profile of central shaft.
Fig. 3 is for amplifying near the axial section of coil portion that has shown negative electrode, and it has illustrated the 2nd embodiment of negative electrode of the present invention.
Fig. 4 is used to illustrate the 3rd embodiment of negative electrode of the present invention, wherein, (a) is front view, (b) for comprising the profile of central shaft.
Fig. 5 is used to illustrate the 4th embodiment of negative electrode of the present invention, wherein, (a) is front view, (b) for comprising the profile of central shaft.
Fig. 6 is the profile that contains the cathode center axle that is used to illustrate other embodiments of the invention.
Fig. 7 is the profile that contains the cathode center axle that is used to illustrate other embodiments of the invention.
Fig. 8 is for amplifying the view that shows electrode root of the prior art.
Embodiment
Fig. 1 is the profile that is used to illustrate the extra-high-pressure mercury vapour lamp of first embodiment.
Extra-high-pressure mercury vapour lamp 100 has the luminous tube of for example being made by quartz glass 1.Luminous tube 1 has roughly spherical illuminating part 11 and the bar-shaped closure 12,12 that links to each other with illuminating part 11 two ends.In the internal space S of luminous tube 1, be provided with negative electrode 2 and anode 3 relatively.Negative electrode 2 comprises axial region 21 and the coil portion 22 by lead W is formed on the axial region 21, and anode 3 comprises axial region 31 and is arranged on the body 32 of axial region 31 front ends.
Being embedded with the power supply of for example being made by molybdenum in the closure 12,12 in luminous tube 1 respectively seals with metal forming 4,4 and with them.One end of these metal formings 4,4 and the base end part 211,311 of axial region 21,31 welded together realizing is electrically connected, the other end is electrically connected with welding together with realization with outer lead 5,5 from closure 12,12 outwardly directed power supplies.
In luminous tube 1, be packaged with mercury, halogen gas and inert gas.
Mercury is used to obtain necessary visible wavelength, the radiating light of 360～780nm for example, and the mercury steam pressure when making illumination reaches more than 150 atmospheric pressure, should encapsulate 0.15mg/mm
3Above mercury.Amount of mercury is different and different with temperature conditions, can be according to the mercury steam pressure appropriate change amount of mercury of hope.
For inert gas,, can encapsulate the argon gas of 5～50kPa, for example 13kPa in order to improve the illumination startability.
Halogen is to enclose with iodine, bromine, chlorine etc. and the form of the compound of mercury or other metal, and the scope of encapsulation amount is 10
-6～10
-1μ mol/mm
3, for example 3.0 * 10
-4μ mol/mm
3Increase the service life though its function also has the halogen cycle of utilization,, the minimal type as discharge lamp of the present invention and have high in the discharge lamp of pressure, its main purpose is to prevent the luminous tube devitrification.
Fig. 2 represents the negative electrode enlarged drawing of extra-high-pressure mercury vapour lamp shown in Figure 1.Fig. 2 (a) has shown front view, and Fig. 2 (b) is the major part enlarged drawing in the section that comprises central axis L.In Fig. 2, the part identical with Fig. 1 adopted identical label.
Herein, " the rear end 22a " of coil portion is meant the rearmost end of the lead W of the formation coil portion 22 that is positioned on the electrode axial region 21, " rearward end 222 " is meant the zone of the specific length that comprises above-mentioned coil portion rear end 22a, and it suitably is set at 20～60% of coil portion 22 total lengths.Coil portion " leading section 221 " is meant the zone of the specific length that comprises lead W front end, and it is the zone outside the rearward end 222.
Like this, the coiling of lead W is different along the length direction of axial region at interval, ratio in the per unit length of the contact area of lead W and axial region 21 reaches maximum in rearward end 222, therefore, compare with other parts, in rearward end 222, the heat that produces during glow discharge is easy to be transmitted to axial region 21, thereby can promote heat radiation.And at the leading section 221 of coil portion 22, because less with the contact area of electrode axial region 21, therefore, hot less to axial region 21 conduction, the temperature in the coil portion 22 is higher.
Like this, because in coil portion 22, rearward end 222 temperature are lower and have the higher part of temperature in the position in its place ahead, therefore, the leading section 221 of position transfer that hot arc discharge the takes place coil portion outside the rearward end 222 can be made, thereby the probability of the hot arc discharge of rearward end 222 generations can be reduced.
Its result, by reducing the hot arc discharge that produces from coil portion rearward end 222, can avoid tungsten as the electrode constitute to be attached near the coil portion 22 illuminating part inwall 11A goes up and causes illuminating part 11 blackening, simultaneously, because hot arc discharge and illuminating part inwall 11A are isolated, therefore, can also suppress to constitute the evaporation of the quartz glass of luminous tube 1, and the oxidative phenomena of avoiding the negative electrode 2 that causes thus.
On above basis, in the leading section 221 of coil portion 22, be preferably with adjacent lead W gap xmin. each other more than 0.05mm, for example in the part of 0.05～0.5mm.Like this, owing to by making gap xmin. within the scope of 0.05～0.3mm, can obtain heats, thereby the leading section 221 of coil portion 22 is heated up by the hollow effect of what is called (seeing below explanation) generation, therefore, be easier to become the starting point of hot arc discharge.
At this moment, in the rearward end 222 of coil portion 22, the gap of lead W is preferably less than 0.05mm.Like this, just can not produce the heating effect that produces by hollow effect.Therefore, situation about raising with leading section 221 temperature combines, and can avoid rearward end 222 to produce hot arc discharge effectively.
Below, hollow effect is carried out simple declaration.
In general, if reduce the interval of lead in the negative electrode coil portion, 2 negative glows of coil surface are overlapped, and reduce the distance in cathode fall district and the distance of negative glow respectively.In common discharge, if interelectrode discharge voltage value is remained identical value, then above-mentioned discharge voltage nearly all is loaded into the cathode fall district, therefore, causes the electric field in cathode fall district to increase.In addition, the further increase meeting of ion concentration further increases the ion current density between negative electrode.In addition, by shortening the distance of negative electrode falling portion, for the energy that the electronics that flies out from negative electrode quickens to be obtained,, therefore, can reduce the ratio of its loss on the way in the dark portion of negative electrode district because the number of times that collides reduces.Its result, electronics will fly into negative glow with high-energy, thereby promote the ionization in the negative glow and excite.Because the negative glow luminous intensity also can increase, therefore, ultraviolet ray contained in light can be collided negative electrode, thereby promotes that negative electrode sends photoelectron.Therefore, glow current density also increases, and coil temperature on every side raises, thereby can transfer to hot arc discharge quickly than other negative electrode position.
On the other hand, owing to do not exist under the situation in gap at the coil of negative electrode, therefore its function and planar cathode, can not reduce the distance in the cathode fall district of coil surface much at one, therefore, can not obtain to promote the effect of above-mentioned photoelectron emissions.So glow current density is lower, thereby coil temperature is risen.
In order to make this electrode that can obtain hollow effect, for example, can adopt following method to make electrode in electrode length direction part.
For example, the lead of being made by tungsten etc. can be reeled a few by certain interval, further reel so that lead closely links to each other each other at its rear, thereby make the coil forming body.It is set to the axial region that is produced by tungsten system, and fixes by modes such as riveted joints.Perhaps, also lead directly can be wound up into the electrode axial region, pass through riveted and fixed equally.
Part enlarges or changes coil span if desired, then can carry out program control to the conveying capacity of the winding wire of electrode axial region or coiling by lathe, can carry out thus freely changing, thus the pitch of the coil portion that acquisition is wished.In addition,, can apply tensile stress, thereby stretch and the enlarged pitch in an end or the part of coil by after the pitch coiling coil uniformly-spaced.If this stress is used for the stress that cuts off end winding, then can reduces work hours.In addition, in the coil of uniformly-spaced reeling, by selecting in the part and apply the riveted joint equal pressure, also can local selectively troclia distance.
The data relevant have below been provided with negative electrode.
The diameter of axial region 21 for example is φ 0.8mm in the scope of φ 0.3mm～φ 3mm, and its volume is at 4mm
3～40mm
3Scope within, for example be 23mm
3In addition, surface area is at 10mm
2～45mm
2, for example be 20mm
2, total length for example is 10mm at 7mm～20mm.In the axial region 21, will be equivalent to half part of total length and be embedded in the closure 12, remaining half is exposed in the internal space S.The diameter that constitutes the wire tungsten of lead W is 0.2mm～0.6mm, for example be 0.25mm, is about 2～10 circles with respect to the coiling number of turns of axial region 21, for example is 5 to enclose.The pitch of leading section 221 is 0.2mm～2mm, for example is 0.3mm.
In addition, axial region and lead preferably use purity at the tungsten more than 99.99%.
Extra-high-pressure mercury vapour lamp according to the present invention as described hereinbefore, in the rearward end that comprises the coil portion rear end, since with ratio in the per unit length of the contact area of electrode axial region greater than other parts, therefore, the heat that produces in glow discharge is easy to be transmitted to axial region in rearward end, thereby can promote heat radiation, and rearward end is maintained lower temperature.At the leading section of the higher relatively coil portion of temperature, can hot arc discharge take place with high probability.
Its result, can reduce the arc discharge that produces from the coil portion rearward end, thereby can avoid tungsten as the electrode constitute to be attached near the coil portion the luminous tube inwall and cause the phenomenon of luminous tube blackening, simultaneously, isolate by make the hot arc discharge and the luminous tube inwall that form after light at once, can suppress the evaporation of quartz glass, and avoid the cathode oxidation phenomenon that causes thus.
In addition, if also formed the part that the conductor spacing reaches 0.05～0.3mm scope at the leading section of coil portion, then owing to the heats that can obtain to produce by hollow effect, therefore, can make the leading section that concentrates on coil portion of hot arc discharge, thereby can avoid producing arc discharge, and prevent that current concentration is in this position in rearward end.
Below, the 2nd embodiment of the present invention is described.Fig. 3 has shown the negative electrode that relates to the present invention the 2nd embodiment separately, wherein, (a) is front view, (b) profile.Other structure outside the negative electrode is identical with above-mentioned the 1st embodiment, the Therefore, omited to their explanation.
Lead W forms the gap between adjacent lead, simultaneously, all reel by a constant pitch in whole winding portion 22.That is, in the present embodiment, the area in the per unit length of lead W and electrode axial region 21 contacts is more identical than in whole winding portion 22 almost being.
At the outer peripheral face of this electrode axial region 21, from the rear end 22a of coil portion 22 forwards, reeling with predetermined distance is provided with the 2nd lead 23.The 2nd lead 23 is by refractory metal, and for example tungsten filament constitutes, and the scope that part is set accounts for 20～60% of coil portion 22 total lengths.In addition, it is thin that the 2nd lead preferably constitutes the lead of coil portion like that such as present embodiment, so just can too not increase coil dimension, and its advantage is: coil can be suppressed at Min. to the obstruction from the utilization of the outgoing beam that sends between electrode.Specifically, when the diameter of wire of coil portion 22 sides was 0.25mm, its diameter was about 0.1mm.
The set-up mode of this 2nd lead 23 is: when the lead W with formation coil portion 22 contacts, can insert in its gap, in this way, lead W contacts with electrode axial region 21 by lead 23, thereby has in fact enlarged contact area.
Like this, because by the 2nd lead of on electrode axial region 21, reeling, enlarged contact area between electrode axial region 21 and the coil portion 22 by the 2nd lead 23, therefore, can make the heat in coil portion 22 rearward end 222 be transferred to axial region 21 rapidly, so that promote the heat radiation at this place.Therefore, coil portion 22 rearward end 222 are compared with the part that does not possess the 2nd lead 23 that is positioned at its place ahead, and temperature is difficult to rise, thereby can avoid the generation of hot arc discharge.
Its result can obtain the same effect with above-mentioned the 1st embodiment.
Below, the 3rd embodiment of the present invention is described.Fig. 4 has shown the negative electrode that relates to the present invention the 3rd embodiment separately, wherein, (a) is front view, (b) is profile.Herein, other structure outside the negative electrode is identical with above-mentioned the 1st embodiment, the Therefore, omited to their explanation.
Lead W is formed with the gap between the lead that is adjacent, simultaneously, all reel by certain pitch in whole winding portion 22.Like this, the area of the per unit length that contacts with electrode axial region 21 of lead W is more certain than in whole winding portion 22 almost being.
On the outer peripheral face of electrode axial region 21, from rearward end 222 position after a while of coil portion 22, axially the place ahead is provided with the tungsten sintered body 24 of specific length.This sintered body 24 is that the tungsten powder and the mixture of an amount of binding agent are coated after the regulation zone, in vacuum environment (for example 6 * 10
-5Pa) form in, by high temperature (for example, 2000 ℃) calcination.By tungsten sintered body 24 is set, in fact increased the area that lead W contacts with electrode axial region 21 by tungsten sintered body 24, thereby promote the heat in the aura arc light to shift to electrode axial region 21, therefore, in the aura arc light, compare the more difficult rising of the temperature of this part with the other parts that tungsten sintered body 24 is not set.
Fig. 5 has shown the negative electrode that relates to the present invention the 4th embodiment separately, wherein, (a) is front view, (b) is profile.Herein, other structure outside the negative electrode is identical with above-mentioned the 1st embodiment, the Therefore, omited to their explanation.
In this embodiment, on axial region 21,, formed less and the end difference 21A that the rear end diameter is bigger of front diameter, on the outer surface of the large-diameter portion of end difference 21A, formed spiral groove 25 in the assigned position source.
The section semicircle that this groove 25 adapts for the diameter with lead W, its total length is 20～60% of coil portion 22 total lengths.
So that terminal part and the almost consistent mode of the rear end 22a of lead W embed lead W in the described groove 25, thereby formed in rearward end 222 zones of coil portion 22, in fact increased the contact area ratio of lead W and axial region 21.
Like this, because on electrode axial region 21, be formed with the groove 25 that lead W cooperates in the part suitable with coil portion 22 rearward end 222, and enlarged contact area, therefore, can make the heat in the rearward end 222 of coil portion 22 be transferred to axial region 21 rapidly, thereby promote the heat radiation at this place.Therefore, coil portion 22 rearward end 222 are compared with its place ahead, the more difficult rising of temperature, thus can avoid the generation of hot arc discharge.
Above, though be illustrated according to embodiment,, the present invention should not be limited to this, and can carry out appropriate change.
Promptly, according to the present invention, as long as make the contact area between the lead and electrode axial region in the coil portion reach maximum at the rearward end place of containing this coil rear end with respect to the ratio of axial region unit length, and the formation of at least a portion place except that rearward end contact area gets final product less than the part of rearward end in coil portion.Its reason is: by the part outside the coil portion rearward end is local at least the place higher than this rearward end temperature is set, the occurrence positions of hot arc discharge is moved to the front side of coil portion.Like this, distortion as above-mentioned the 1st embodiment, for example, as shown in Figure 6, under the situation of the pitch that changes lead W, if reel closely at rearward end 222 places of coil portion, at least a portion in its place ahead, have than loose winding around distant curling part 223, reel that part is also harmless closely even exist at the front end place so.In this case, owing to formed high-temperature portion at distant curling part 223, therefore, be easy to produce from here hot arc discharge, the result can suppress to produce hot arc discharge by rearward end 222 equally.
In addition, between lead W and electrode axial region 21, can press from both sides and establish other parts, as long as in the total length setting of coil portion 22 and can uniform heat conduction from lead to electrode axial region.For example, as shown in Figure 7, other coil component 26 of forming with the pitch certain way etc. can be set between lead W and electrode axial region 21.
In addition, though the foregoing description relates to dc lighting formula extra-high-pressure mercury vapour lamp,, the present invention is not limited thereto, and it also is applicable to and exchanges illuminated extra-high-pressure mercury vapour lamp.
Below, confirm that to being used to the experimental example of action effect of the present invention describes.
At first, make many experiment lamps according to the structure of Fig. 1.In addition, the pitch of appropriate change coiler part and made many lamps that relate to comparative example.
The basic specification of lamp is as follows.
The material of luminous tube is a quartz glass, and total length is 74mm, and the maximum diameter portion of illuminating part is Φ 10mm, and illuminating part total length 10mm, internal volume are 66mm
3, the diameter of closure is Φ 6.5mm, long is 32mm.
The axial region material of cathode side electrode is a tungsten, and its diameter is 0.8mm, total length 11mm.
At the front end large-diameter portion of anode, maximum outside diameter is 1.8mm, and total length is 3mm.The axial region material is a tungsten, and external diameter is 0.8mm, and total length is 13mm.
The metal forming used thickness is 25 μ m, and wide is 2mm, and length is that the molybdenum foil of 14mm, outside guide rod use the molybdenum system bar of diameter as Φ 0.8mm.
In addition, in illuminating part, encapsulated the mercury of 18mg.
The coil portion that is formed at cathode side is to be that the tungsten filament of 1.0mm is reeled and formed by line footpath Φ 0.25mm, length.From the front end of coil portion, with the part of the line is busy circle total length 40% as the leading section of coil portion, on the other hand, will be from the rear end of coil portion, the length of circle total length 40% that the line is busy partly is decided to be the rearward end of coil portion.
In this experimental example, by following table 1 conductor spacing is changed between 0 (zero, promptly less than 0.05)～3.0mm, all take n=3 to put the test of going out to the lamp of all size.In point goes out test, lamp be input as 200W (initial voltage is 80V, and electric current is 2.5A), lighted 5 minutes, extinguished 5 minutes, carry out repeatedly 500 times.
Following form has been summarized result of the test.After the blackening situation that the negative electrode root produced after the evaluation of blackening was to use microscope viewpoint to go out, the classification of carrying out according to outward appearance, ◎ symbol (dual circle) expression does not have blackening, zero symbol (substance circle) expression has some blackening but influences light transmission hardly, △ symbol (triangle) expression is compared light transmission and has been reduced half approximately but still have light transmission with the starting stage, * symbolic representation is because of blackening, and light transmission almost disappears.
[table 1]
| Specification | Lamp 1 | | | Lamp 4 | Lamp 5 | Lamp 6 | |
| The interval of coil leading section lead | 0(＜0.05) | 0(＜0.05) | 0.3 | 0.05 | 0.1 | 0.3 | |
| The interval of coil rearward end lead | 0.3 | 0(＜0.05) | 0.3 | 0(＜0.05) | 0(＜0.05) | 0(＜0.05) | |
| Estimate | Point goes out after 100 times | △ | ○ | ○ | ○ | ◎ | ◎ |
| Point goes out after 300 times | × | △ | △ | ○ | ◎ | ◎ | |
| Point goes out after 500 times | × | × | × | △ | ○ | ○ |
As shown in table 1, in lamp 1, produced tangible blackening, after going out, 300 points almost lose light transmission.Resemble the identical lamp (that is, lamp in the past) in whole winding portion gap lamp 2, the lamp 3 the stage of going out through 300 points because of the influence that blackening produces has significantly reduced light transmission, after 500 points go out, almost lose light transmission.On the other hand, as lamp 4, be almost 0 (zero) at the interval of coil rear end side lead, form in the lamp in 0.05mm gap in front, can see: still have enough light transmissions after 300 points go out, the influence of blackening significantly reduces.And, after 500 points go out, engendered the influence of blackening, but still had light transmission, and had enough durabilities.
In addition, when 0.1mm, 0.3mm are further expanded as in the gap of coil front, obviously draw, after 300 points go out, also and blackening phenomena occurs, after 500 points go out, still have enough light transmissions from the result of lamp 5, lamp 6.
Above result shows, is set at 0.05mm～0.3mm by the gap with the lead of coil front, and the gap of coil rear end side lead is set at less than 0.05mm, can significantly reduce blackening phenomena, thereby make the light transmission of luminous tube maintain high level.
In addition, check that the illumination condition of lamp in the above-mentioned experimental example is found afterwards, for lamp 4～lamp 6, leading section deposit and length of illumination shorten the bad phenomenon of the oxide of tungsten do not occur at electrode.In addition, oxidate and scintillation that tungsten also do not occur.Therefore, according to the present invention, can effectively prevent to form the phenomenon that a plurality of oxide projections cause the arc light bright spot to move in the lamp in the past.
In above experimental example, though used the lamp of dc lighting formula,, for the AC system discharge lamp,, therefore, also be applicable to the AC system discharge lamp because the electrode of folk prescription plays the cathodic process of the glow discharge that hockets.
Claims (8)
1. an extra-high-pressure mercury vapour lamp is oppositely arranged pair of electrodes in luminous tube, simultaneously as luminescent substance, is packaged with 0.15mg/mm
3Above mercury,
Play the leading section of the electrode axial region of cathodic process in described pair of electrodes, the lead formation coil portion by the coiling specific length is characterized in that,
In described coil portion, the contact area of described lead and described axial region is with respect to the ratio of the unit length of the axial length direction rearward end maximum at this coil portion,
On at least a portion before the described rearward end, form the less part of ratio of contact area.
2. extra-high-pressure mercury vapour lamp according to claim 1 is characterized in that, described coil portion is portion's lead of closely reeling in its back-end, and forms the part of the loose described lead of reeling at least a portion before this rearward end.
3. extra-high-pressure mercury vapour lamp according to claim 2 is characterized in that, the gap in the lead of described coil portion leading section between the adjacent wires is 0.05～0.3mm.
4. according to any described extra-high-pressure mercury vapour lamp in the claim 1～3, it is characterized in that,, increase contact area thus by establish and form the different metal parts of lead of described coil portion at folder between axial region and the lead.
5. extra-high-pressure mercury vapour lamp according to claim 4 is characterized in that described metal parts is made of the 2nd lead.
6. extra-high-pressure mercury vapour lamp according to claim 5 is characterized in that the diameter of described the 2nd lead is less than the diameter of described lead.
7. extra-high-pressure mercury vapour lamp according to claim 4 is characterized in that described metal parts is made of sintered body.
8. extra-high-pressure mercury vapour lamp according to claim 1 is characterized in that, forms groove by the surface that is equivalent to the coil portion rearward end in described axial region, and, make lead embed this groove, increase the ratio of the contact area of lead and axial region thus.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005083434A JP2006269165A (en) | 2005-03-23 | 2005-03-23 | Ultra-high pressure mercury lamp |
| JP2005083434 | 2005-03-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1838373A true CN1838373A (en) | 2006-09-27 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200610009349 Pending CN1838373A (en) | 2005-03-23 | 2006-02-28 | Ultra-high voltage mercury lamp |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2006269165A (en) |
| CN (1) | CN1838373A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5034755B2 (en) * | 2007-08-06 | 2012-09-26 | セイコーエプソン株式会社 | Arc tube, light source device and projector |
| US8174194B2 (en) | 2007-08-06 | 2012-05-08 | Seiko Epson Corporation | Discharge lamp, light source device and projector |
| US8188663B2 (en) * | 2009-01-05 | 2012-05-29 | General Electric Company | High intensity discharge lamp |
| JP5369360B2 (en) * | 2009-09-11 | 2013-12-18 | 岩崎電気株式会社 | Light source electrode |
| JP5056916B2 (en) * | 2010-07-12 | 2012-10-24 | ウシオ電機株式会社 | High pressure discharge lamp |
| JP2013254636A (en) * | 2012-06-06 | 2013-12-19 | Iwasaki Electric Co Ltd | High pressure discharge lamp |
-
2005
- 2005-03-23 JP JP2005083434A patent/JP2006269165A/en not_active Withdrawn
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2006
- 2006-02-28 CN CN 200610009349 patent/CN1838373A/en active Pending
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|---|---|
| JP2006269165A (en) | 2006-10-05 |
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