JP2000030666A - High-pressure mercury lamp and high-pressure mercury lamp luminescence device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-pressure mercury lamp vertically lighted in particular at the internal pressure of a hundred and tens atm. or above in consideration of a thermal load and gas convection. SOLUTION: An electrode 4 located on the upper side of a discharge container 2 made of quartz glass and an electrode 5 located on the loser side are arranged face to face, and mercury of 0.155 mg/mm3 or more and rare gas are sealed in the discharge container 2. The protruded length L1 (mm) of the upper electrode 4 into the discharge container 2 is larger than the protruded length L2 (mm) of the lower electrode 5 into the discharge container 2, and the lamp power W (w) and the maximum value D (mm) of the inner diameter of the discharge container 2 in the direction perpendicular to the axis connecting both electrodes 4, 5 are: 0.356×(W)1/2<=L1<=0.686×(W)1/2, L2<=0.755×(W)1/2.64, and (3.86)e0.0022W<=D<=(3.91)e0.0034W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-pressure mercury lamp. Particularly, an ultra-high pressure mercury lamp in which 0.155 mg / mm ³ or more of mercury is sealed in a discharge vessel and the mercury vapor pressure at the time of lighting is more than one hundred and several atmospheres, and which is used for a back-light of a projection type liquid crystal display device or the like. Regarding what is used as a light.

[0002]

2. Description of the Related Art In a projection type liquid crystal display device, a light source is horizontally arranged and turned on in order to keep the height low, and an image is illuminated uniformly on a rectangular screen with sufficient color rendering properties. Therefore, a horizontally lit metal halide lamp in which mercury or a metal halide is sealed is used as a light source. In recent years, with respect to metal halide lamps, further downsizing and point light sources have been promoted, and lamps with extremely small distance between electrodes have been put to practical use.

[0003] Against this background, in recent years, instead of metal halide lamps, lamps having an extremely high mercury vapor pressure, for example, 200 bar (about 197 atm) or more have been proposed. This is because by increasing the mercury vapor pressure, the spread of the arc is suppressed (narrowed down),
It is intended to further improve the light output. For example, JP-A-2-148561 and JP-A-6-52830.
Issue.

Japanese Patent Application Laid-Open No. 2-148561 (US Pat. No. 5,109,181) discloses that a discharge vessel having a pair of electrodes made of tungsten is mixed with a rare gas and 0.2 mg / mm.
³ or more mercury and 1 × 10 ^-6 to 1 × 10 ^-4 μmol / m
A high-pressure mercury lamp is disclosed which encloses a halogen in the range of m ³ and operates at a tube wall load of 1 W / mm ² or more.

The reason why the amount of mercury is 0.2 mg / mm ³ or more is to increase the pressure of mercury to increase the continuous spectrum in the visible light region, particularly in the red region, and to improve the color rendering. The reason for making the wall load 1 W / mm ² or more is
This is because it is necessary to increase the temperature of the coldest part in order to increase the pressure of mercury. Furthermore, it can be seen that the reason for enclosing the halogen is to prevent blackening of the tube wall.

On the other hand, JP-A-6-52830 (US Pat. No. 5,497,049) specifies the shape of a discharge vessel and the distance between electrodes in addition to the mercury amount, tube wall load value and halogen amount. Further, it is disclosed that bromine is used as a kind of halogen.

[0007] The reason for enclosing bromine are tube wall blackening prevention, electrode when together with the enclosed amount can exhibit a sufficient effect at 10 ^-6 μmol / mm ³ or more, more than 10 ^-4 μmol / mm ³ Is corroded.

On the other hand, such an ultra-high pressure mercury lamp performs horizontal lighting, that is, lighting in which a virtual line connecting the electrodes is arranged in parallel with the horizon. In this case, the thermal load is extremely high in the upper part of the discharge vessel due to the floating of the arc generated between the electrodes, while the thermal load is low in the lower part of the discharge vessel, and a high operating pressure of mercury is obtained. For this purpose, it is necessary to make the discharge vessel small, that is, to reduce the inner diameter of the light emitting space. However, if it is made too small, the quartz glass constituting the discharge vessel causes crystallization, so that the range in which the discharge vessel can be made small is limited.

On the other hand, recently, a so-called rear projection television, which is a liquid crystal projector television, in which a discharge lamp, which is a light source, is arranged in the television main body to illuminate the television screen from behind, has attracted attention. I have. In this television, the discharge lamp is not forced to be horizontally lit due to optical design, but can be arranged vertically. When the ultra-high pressure mercury lamp is vertically lit as described above, the effect of the thermal load in the discharge vessel is completely different from the case where the discharge lamp is horizontally lit. Specifically, the portions where the thermal load is high and the portions where the thermal load is low occur not at the tube wall near the arc but at the root of the electrode. In addition, the influence of gas convection in the discharge vessel changes greatly. The above-mentioned prior art document does not disclose that the discharge lamp is horizontally lit or vertically lit, and completely considers the thermal load in the discharge vessel and the influence of gas convection from this viewpoint. Not something.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-pressure mercury lamp which is operated at an internal pressure of more than one hundred and several atmospheres, taking into account thermal load and gas convection. It is to be. In particular, it is an object of the present invention to provide a vertically lit high-pressure mercury lamp in which the above problem is considered.

[0011]

In order to solve the above-mentioned problems, a high-pressure mercury lamp according to the present invention is characterized in that, in claim 1, a vertically arranged lamp is lit and a pair of electrodes is provided in a discharge vessel made of quartz glass. The discharge vessel is filled with mercury of 0.155 mg / mm ³ or more and a rare gas, and has a length L1 (mm) in which the upper electrode projects into the discharge vessel. Is longer than the length L2 (mm) of the lower electrode protruding into the discharge vessel, the lamp power W (W), and the maximum value of the inner diameter in the direction perpendicular to the axis connecting the pair of electrodes in the discharge vessel. D (mm) is 0.356 × (W) ^1/2 ≦ L1 ≦ 0.686 ×
(W) ^1/2 , L2 ≦ 0.755 × (W) ^{1 / 2.64} , and (3.86) e ^{0.0022 W} ≦ D ≦
(3.91) e characterized by ^0.0034W .

Further, the present invention is characterized in that the lower electrode is an anode and the upper electrode is a cathode for direct current lighting. Further, the discharge vessel is characterized in that a halogen selected from chlorine, bromine and iodine and a luminescent metal other than mercury are sealed. Further, in the high-pressure mercury lamp light-emitting device including the high-pressure mercury lamp and a power supply device for supplying a predetermined power to the high-pressure mercury lamp, a length L1 (mm) of the electrode located on the upper side protruding into the discharge vessel. Is longer than the length L2 (mm) of the lower electrode protruding into the discharge vessel, the lamp power W (W) of the high-pressure mercury lamp, and the direction perpendicular to the axis connecting the pair of electrodes in the discharge vessel. Of the inner diameter D in mm (mm)
Is 0.356 × (W) ^1/2 ≦ L1 ≦ 0.6
86 × (W) ^1/2 , L2 ≦ 0.755 × (W)
^{1 / 2.64} and (3.86) e ^0.0022W ≤
D ≦ (3.91) e ^0.0034W .

[0013]

FIG. 1 shows a high-pressure mercury lamp according to the present invention. The discharge lamp 1 is made of quartz glass and includes a central discharge vessel 2 and elongated sealing portions 3 connected to both ends thereof. In the discharge vessel 2 (hereinafter also referred to as “light-emitting space”), a cathode 4 and an anode 5 include 1.0 to 2.
They are arranged with a gap of about 0 mm. The cathode 4 is above and the rear end is embedded in the sealing portion 3 and joined to the metal foil 6, and the anode 5 is below and the rear end is likewise connected to the metal foil 6 in the sealing portion 3. Joined. External leads 7 are joined to the other ends of the respective metal foils 6.

In the light emitting space, mercury is sealed as a light emitting substance, and a rare gas such as argon or xenon is sealed as a lighting starting gas. The rare gas is, for example, 5.3 × 10
⁴ Pa is enclosed. Here, the amount of enclosed mercury is 0.155.
mg / mm ³ or more, which means that the vapor pressure during stable lighting becomes one hundred and several tens atmospheres or more.

An example of such a high-pressure mercury lamp is as follows. The maximum outer diameter of the discharge vessel is 12.2 mm and the maximum inner diameter is 6.
8 mm, light emitting space length (length in the axial direction of the lamp) 12.7
mm, amount of enclosed mercury 43.9 mg, internal volume of light emitting space 25
1 mm ^3, internal surface area 200 mm ² of the light-emitting space, the bulb wall loading 1.00 W / mm ^2, the rated power 200 W.

Here, the length L1 of the upper electrode 4 projecting into the discharge vessel 2 is longer than the length L2 of the lower electrode 5 projecting into the discharge vessel 2. As an example, the length L1 of the upper electrode 4 projecting into the discharge vessel 2 is 6.8 mm, and the length L2 of the lower electrode 5 projecting into the discharge vessel 2 is L2. 4.2mm
It is. Below the lower thermal load, the anode and the lower end of the discharge vessel are located close to each other, and this part can be heated by radiant heat from the anode in addition to the thermal effect from arc discharge. Can be completely evaporated, and a high internal pressure of one hundred and several tens atmospheres or more can be achieved. In such vertical lighting, the upper part of the discharge space is extremely thermally affected by violent gas convection. However, as in the present invention, the cathode 4 projects long into the discharge vessel 2. In this case, devitrification of the discharge vessel due to thermal influence can be prevented well.

Further, according to the present invention, the distance between the lighting power (W) of the lamp and the protruding length L1 of the upper electrode 4 and the protruding length L2 of the lower electrode 5 is 0.356.
× (W) ^1/2 ≦ L1 ≦ 0.686 × (W)
^1/2 and L2 ≤ 0.755 x (W) ^{1 / 2.64}
With this relationship, a sufficiently high operating pressure was selected, and a high-pressure mercury lamp that did not cause devitrification or the like could be obtained. This predicts that the lamp power will have a significant effect on the heat generated within the discharge vessel, and that the overhang of the upper electrode will affect gas convection and perfect devitrification at the top of the discharge vessel. As a result, the present inventors have conducted intensive studies and found a numerical range that can be said to be the optimum condition. Here, the protrusion length L1 of the electrode located on the upper side is equal to the lower limit value, that is, 0.356 × (W)
When it is less than ^1/2 , it means that the upper space in the discharge vessel is small, and the vitreous gas convection in the discharge vessel and thermal influence cause devitrification of the quartz glass. On the other hand, when the protruding length L1 of the electrode located on the upper side exceeds the upper limit value, that is, 0.686 × (W) ^1/2 , it means that the upper space in the discharge vessel becomes too large. However, mercury cannot be sufficiently vaporized, and as a result, a high operating pressure cannot be obtained.
Similarly, the protruding length L2 of the lower electrode is 0.75
If it exceeds 5 × (W) ^{1 / 2.64} , the space below the discharge vessel becomes too large, so that the temperature drops and mercury cannot be sufficiently vaporized, resulting in a high operating pressure. You will not be able to do it.

Further, in the present invention, between the operating power (W) of the lamp and the maximum value (D) of the inner diameter in the direction perpendicular to the axis connecting both electrodes in the discharge vessel, (3.86) e
^{By giving} the relationship of ^{0.0022 W} ≦ D ≦ (3.91) e ^{0.0034 W} , a sufficiently high operating pressure was similarly selected, and a high-pressure mercury lamp that did not cause devitrification or the like could be obtained. As before, the lamp power has a large effect on the heat generated in the discharge vessel, and the inner diameter in the discharge vessel affects gas convection and perfect devitrification on the side of the discharge vessel. The present inventors have made intensive studies from the prediction that they will try to find a numerical range that can be said to be the optimum condition. Here, the case where the inner diameter D of the discharge vessel is ^smaller than the lower limit value, that is, (3.86) e ^{0.0022 W} , means that the position of the arc is close to the tube wall on the side of the discharge vessel, and light emission is performed. This will cause devitrification in the tube. When the inner diameter D of the discharge vessel exceeds the upper limit value, that is, (3.91) e ^{0.0034 W} , the discharge vessel becomes too large to obtain a sufficient operating pressure.

Here, as a supplementary explanation, the applicant of the present application has previously disclosed in Japanese Patent Application No. 10-153943 that, when a high-pressure mercury lamp is vertically arranged, the protruding length L1 of an electrode located on the upper side in a discharge vessel is considered. By defining the maximum value D of the inner diameter in the direction perpendicular to the axis connecting the pair of electrodes in the discharge vessel and the high pressure mercury lamp and the high pressure mercury lamp light emitting device that are practically no problem for about 2000 hours, ing. However, as a result of further studies by the present inventors, the protrusion length L2 of the lower electrode, which is not defined in the above-mentioned application, is newly defined, and further, L1, D
Is newly defined in correspondence with the above-mentioned value, thereby enabling an effect that is more than the effect of the invention according to the above-mentioned application, specifically, lighting for about 5000 hours without practical problems.

This is because, by slightly increasing the maximum inner diameter D in the discharge vessel, the occurrence of devitrification is satisfactorily suppressed, and the optimum diameter for obtaining a good operating pressure without increasing the volume of the discharge vessel. This defines the electrode projection lengths L1 and L2.

FIG. 2 shows a spectrum of the high-pressure mercury lamp of the present invention. As is clear from the figure, the wavelength 380-380
It is shown that the light is effectively emitted in the visible region around 760 nm. In particular, continuous radiation in the red region having a wavelength of 600 to 7600 nm is large, which is caused by the amount of mercury enclosed of 0.155 m.
It is shown to be greatly increased compared to a normal high pressure mercury lamp of less than g / mm ³ .

The high-pressure mercury lamp of the present invention is preferably used in a lamp power range of 70 W to 250 W. FIG. 3 shows the protruding length L 1 of the electrode 4 located on the upper side in this range and the discharge vessel. In the example, the value of the maximum value (D) of the inner diameter in the direction perpendicular to the axis connecting both electrodes is shown.

FIG. 4 shows a high-pressure mercury lamp light emitting device according to the present invention. The high-pressure discharge lamp 41 is built in a reflection mirror 42, and a power supply device 43 is electrically connected to the lamp 41. Light emitted from the lamp 41 is incident on the reflection mirror 42 or directly on the integrator lens 44, and irradiates the liquid crystal panel 47 via the plurality of dichroic mirrors 45 and the reflection mirror 46. Then, an image is projected on the screen 49 through the projection lens 48. And
A predetermined power (W) is supplied from the power supply device 43 to the lamp 41.

In the high-pressure mercury lamp of the present invention, in a vertically lit lamp, the length of the protruding length of the electrode located on the upper side and the electrode located on the lower side, and the direction perpendicular to the axis connecting the two electrodes in the discharge vessel. By specifying the maximum value of the inner diameter of the discharge vessel, a sufficiently high operating pressure can be obtained, and strong gas convection inside the discharge vessel can be satisfactorily dealt with, providing a long-life high-pressure mercury lamp without enclosing halogen. It became possible to do. Specifically, it has been confirmed that lighting without practical problems is maintained for 5000 hours without enclosing halogen.

The high-pressure mercury lamp of the present invention has a DC lighting type,
The present invention is not limited to the AC lighting type and can be applied to any lighting method. In the case of a DC lighting type lamp, the electrode located on the upper side is a cathode and the electrode located on the lower side is an anode.

Further, the high-pressure mercury lamp of the present invention can obtain a sufficiently long life without enclosing the halogen as described above. However, this does not exclude the encapsulation of halogen, and does not exclude chlorine and chlorine. By enclosing a halogen selected from bromine and iodine, it is possible to extend the life using a halogen cycle.

Further, the high-pressure mercury lamp of the present invention can use the luminescent color of the metal by enclosing the luminescent metal in addition to mercury, whereby the color rendering properties can be further improved. It is. As such a luminescent metal, for example, indium, zinc, cadmium, a rare earth metal, or the like can be sealed.

[0028]

As described above, in the high-pressure mercury lamp of the present invention, 0.155 mg / mm ³ or more of mercury or the like is sealed in the discharge vessel, and the protruding length of the upper electrode and the lower electrode By defining the protruding length of the located electrode, the maximum inner diameter of the discharge vessel, the lamp power, etc., it is possible to obtain a high internal pressure of over one hundred and several atmospheres, thereby increasing the continuous spectrum in the visible light region, especially in the red region. be able to. And, even under such ultrahigh pressure conditions, it is possible to provide a lamp in which the problems of thermal load, gas convection and arc are well considered. And a very long lighting life of 5000 hours or more could be achieved.

[Brief description of the drawings]

FIG. 1 shows a high-pressure mercury lamp according to the present invention.

FIG. 2 shows a spectral distribution by a high-pressure mercury lamp according to the present invention.

FIG. 3 shows a numerical example of the present invention.

FIG. 4 shows a high pressure mercury lamp light emitting device according to the present invention.

[Explanation of symbols]

 1: Discharge lamp 2: Discharge vessel 3: Sealing part 4: Electrode 5: Metal foil 6: External lead

Claims (5)

[Claims] A discharge vessel made of quartz glass has a pair of electrodes opposed to each other.
/ Mm ³ and a high-pressure mercury lamp filled with a rare gas. The high-pressure mercury lamp is vertically lit and lit, and a length L1 of an electrode located above the electrode protruding into the discharge vessel. (Mm) is longer than the length L2 (mm) of the lower electrode projecting into the discharge vessel, the lamp power W (W), the inner diameter in the direction perpendicular to the axis connecting the pair of electrodes in the discharge vessel. Maximum value D (mm)
Is 0.356 × (W) ^1/2 ≦ L1 ≦ 0.686 ×
(W) ^1/2 , L2 ≦ 0.755 × (W) ^{1 / 2.64} , and (3.86) e ^{0.0022 W} ≦ D ≦
(3.91) e A high-pressure mercury lamp characterized by ^0.0034W . 2. The high-pressure mercury lamp according to claim 1, wherein the high-pressure mercury lamp is for direct current lighting in which an anode is arranged below and a cathode is arranged above. 3. The high-pressure mercury lamp according to claim 1, wherein a halogen selected from chlorine, bromine and iodine is sealed in the discharge vessel. 4. The high-pressure mercury lamp according to claim 1, wherein a luminescent metal other than mercury is sealed in the discharge vessel. 5. A discharge vessel made of quartz glass has a pair of electrodes opposed to each other.
And / mm ³ of mercury, a rare gas is lit arranged vertically is sealed, an electrode length electrode positioned in the upper side projects into the discharge vessel L1 (mm) is located below the discharge In a high pressure mercury lamp light emitting device comprising a high pressure mercury lamp protruding into a container and having a length longer than L2 (mm) and a power supply device for supplying a predetermined power to the high pressure mercury lamp, the lamp power W (W), the maximum value D (mm) of the inner diameter in the direction perpendicular to the axis connecting the pair of electrodes in the discharge vessel is 0.356 × (W) ^1/2 ≦ L1 ≦ 0.686 ×
(W) ^1/2 , L2 ≦ 0.755 × (W) ^{1 / 2.64} , and (3.86) e ^{0.0022 W} ≦ D ≦
(3.91) e A high pressure mercury lamp light emitting device characterized by ^0.0034W .