JPH10241632A - High-pressure discharge lamp lighting method, high-pressure discharge lamp lighting device, and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance projection surface luminous intensity, when a high-pressure discharge lamp is used for projection by suppressing thickening of a discharge arc. SOLUTION: A high-pressure discharge lamp 11, wherein a halide of a light-emitting metal is sealed in a short-arc discharge container 1, is lighted by alternate letting flow of a pulse current and a stand-by current. Preferably, discharge electric field intensity is 7 to 55V/mm, a cycle period of the pulse current of 0.5 to 20ms, a duty ratio relative to the stand-by current is 50% or less, and a peak value ratio of the pulse current is 1/5 or less. Preferable lamp power is 250W or less in the case, where a medium for buffering is a rare gas, and 350W or less in the case of mercury. When the pulse current flows in a state that a discharge arc is narrowed down by the stand-by current, the discharge arc does not get thicker because the light-emitting metal whose excitation level is lower than that of the medium for buffering emits light only in a center part of the discharge arc. As a result, light-gathering efficiency by means of an optical system is improved and projection surface luminous intensity is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high pressure discharge lamp lighting method, a high pressure discharge lamp lighting device, and a lighting device using the same.

[0002]

2. Description of the Related Art In order to obtain a high light-collecting efficiency for projection by combining a short-arc high-pressure discharge lamp with a reflecting mirror having a reflecting surface that forms a spheroid, a paraboloid of revolution or a spherical surface, there are several applications. Has been implemented. For example, a semiconductor wafer exposure apparatus, a projector, a liquid crystal projector, an overhead projector, and the like.

[0003] Different light sources are used for the above-mentioned applications. Ultra-high pressure mercury lamps are used in exposure apparatuses, xenon lamps are used in projectors, and metal halide lamps are used in liquid crystal projectors and overhead projectors.

[0004] The method of lighting these discharge lamps is as follows.

[0005] In an exposure apparatus, for example,
As disclosed in Japanese Patent No. 5395, pulse lighting is performed for the purpose of reducing discharge current during a period in which a shutter is closed. Similar attempts have been made in projectors.

In liquid crystal projectors and overhead projectors, continuous AC or DC lighting is performed.

[0007] Pulse lighting different from the pulse lighting described above is described in "The high-pressure Sodium" by JJ Groot.
Chapter 7 of "Lamp" discloses an attempt to change the luminous characteristics by pulse-lighting a high-pressure sodium lamp in which Na is sealed as a luminescent substance. In other words, it is described that by lighting with a pulse current, the emission of Na atoms from higher levels increases, and the light color shifts from orange to white.

By the way, as described above, a short arc type metal halide lamp used for a liquid crystal projector or an overhead projector has excellent color rendering properties as compared with a mercury lamp or a high-pressure sodium lamp, and has much higher luminous efficiency than a xenon lamp. As a result, applications are becoming more and more widespread.

[0009]

However, the metal halide lamp is filled with a rare earth metal such as Sc or Dy or an alkali metal such as Na or Li, which has a lower excitation level than mercury or a rare gas, in the form of a halide. ing. These low-excitation metals also emit light in relatively low temperature regions around the discharge arc. For this reason, there has been a problem that the light-emitting portion becomes thicker and the light-collecting property becomes worse as the size of the optical system is reduced to reduce the size of a device such as a liquid crystal projector.

On the other hand, as a method for suppressing the thickness of the discharge arc, a method of increasing the mercury up to about 100 atm and emitting light without enclosing a rare earth metal or an alkali metal is described in "THE high pressure marcury vapor lamour" by Ellen Barth.
ps and their applications ".

However, in the above method, since the operating pressure is very high, the influence at the time of rupture of the arc tube is large, and the 620 n
Since there is little red component of m or more, there is also a problem of color on the projection surface.

Conventionally, in a metal halide lamp,
When pulse lighting was performed, the luminous efficiency was reduced, and the emission line spectrum of mercury was strengthened to lower the color rendering properties. Therefore, pulse lighting was not performed.

The present invention suppresses the thickness of the discharge arc,
It is an object of the present invention to provide a high-pressure discharge lamp lighting method, a high-pressure discharge lamp lighting device, and a lighting device using the same, in which the irradiation surface illuminance is improved when the high-pressure discharge lamp is used for projection, and therefore suitable for projection. .

[0014]

According to a first aspect of the present invention, there is provided a method for lighting a high pressure discharge lamp, comprising: a short arc type discharge vessel in which a pair of electrodes are sealed at both ends of a translucent airtight vessel; A high-pressure discharge lamp including a discharge medium containing a halide, a starting gas and a buffer medium and sealed in an airtight container is lit by alternately passing a pulse current and a standby current.

In the present invention and each of the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified.

First, the discharge vessel will be described.

The hermetic container may be made of any material as long as it is a material which can sufficiently withstand the normal operating temperature of the discharge lamp and can emit radiation generated by the discharge to the outside. For example, quartz glass, translucent alumina, and ceramics such as YAG are allowed.

The pair of electrodes have the same structure when operated by an alternating current. However, when operated by a direct current, the anode generally has a larger heat dissipation area than the cathode, because the temperature of the anode rises sharply. The short arc type is to reduce the distance between the electrodes so as to be as close to a point light source as possible and to efficiently collect light by an optical system such as a reflecting mirror or a lens. The distance is 7 mm or less. That is, when the distance between the electrodes exceeds 7 mm, the upward curvature of the arc due to the convection of the discharge medium becomes too large. Therefore, in the present invention, the short arc type refers to one having a distance between the electrodes of 7 mm or less, preferably 4 mm.
Hereinafter, it is optimally 1.5 to 3 mm or less. The distance between the electrodes is measured at the tip of the electrode.

In the discharge medium, the starting gas is at least one of xenon, krypton, and argon. The luminescent metal can be any halide, such as iodide and / or bromide, of the luminescent metal. The present invention is effective when the discharge medium contains a luminescent metal having a lower excitation level than a rare gas or mercury, such as a rare earth metal and an alkali metal. In addition, luminescent metals of a high-pressure discharge lamp suitable for projection such as a liquid crystal projector and an overhead head projector include In, Tl, Sc, Dy, and Nd, and Sn and Pb can be further added as necessary. .

When Sn is added in the form of iodide in an amount of 0.05 to 0.5 mg per 1 cc of the discharge space, the discharge vessel is devitrified due to the reaction between another luminescent metal such as Dy and quartz glass to reduce the luminous flux. It is known that there is an inhibitory action. However, in the conventional DC or AC lighting, there is a disadvantage that the luminous efficiency of Sn is low and the arc spreads. Therefore, it has been recognized that enclosing Sn is not suitable for a high-pressure discharge lamp for projection. . That is, when SnI ₃ is added, Sn generates continuous light in the periphery of the arc having a relatively low temperature, so that the color rendering properties are improved, but the luminous efficiency is reduced and the arc is spread. is there.

It should be noted, however, that when a metal halide lamp is turned on with a pulse current, these disadvantages become negligible. In the present invention, Sn emits light at the center of the arc similarly to other light-emitting metals, so that the above-described inconvenience does not occur. In addition, the effect of suppressing the reaction between the other luminescent metal and the quartz glass remains as it is.

As the buffering medium, at least one of xenon, krypton and argon can be used. In this case, it can also serve as a starting gas.
In this case, since the buffer medium does not contain mercury, it is safe in terms of environmental measures and does not contain ultraviolet rays due to mercury discharge, so that the liquid crystal and the like used in the projection device can be protected from deterioration due to ultraviolet irradiation.

On the other hand, mercury can also be used as a buffering medium. When mercury is used as the buffering medium, the discharge electric field strength can be increased as compared with a rare gas. As a result, the ratio of electrode loss, which is power loss that does not contribute to light emission, is reduced, so that a high-pressure discharge lamp with high luminous efficiency can be obtained.

Next, lighting of the high pressure discharge lamp will be described.

The pulse current has an appropriate repetition period and a duty ratio with respect to the standby current, so that the arc cools to an appropriate level during the flow of the standby current in consideration of heat diffusion due to heat conduction of the plasma. Shall be set.

Since the standby current acts only to maintain the discharge, it is smaller than the pulse current, so that the discharge arc in the discharge vessel is thin while the standby current is flowing. , The arc temperature is low. When a pulse current flows in such a state, a large amount of electric charges are carried in the narrow discharge arc, so that the plasma arc temperature rises and increases the thermal ionization to cover the increased current. When the pulse current disappears, the standby current flows and the arc temperature drops again. In the meantime, even atoms with lower excitation levels than buffer media such as Dy,
Since light is emitted only at the center of the arc as in the case of atoms having a high excitation level, the discharge does not increase. As a result, it is considered that the illuminance of the projection surface is improved.

According to the present invention, the illuminance of the projection surface is clearly improved as compared with the case of lighting with a flat direct current, and can be improved by 20% or more if desired. However, even if the projection surface illuminance is improved by 20% or less, it is sufficiently useful.

According to a second aspect of the present invention, there is provided a method for lighting a high pressure discharge lamp, comprising: a short arc type discharge vessel in which a pair of electrodes are sealed at both ends of a translucent airtight vessel; a luminescent metal halide; And a high-pressure discharge lamp including a discharge medium containing a buffering medium and sealed in an airtight container.
At a discharge electric field strength of 55 V / mm, a pulse current and a standby current are alternately passed and lighted.

In the present invention, the voltage applied to the high-pressure discharge lamp is defined by a preferable range of the discharge electric field strength.

When the buffering medium is a rare gas, the discharge electric field strength is preferably selected within a relatively small range of 7 to 25 V / mm. Since the discharge electric field intensity is small, the lamp power is generally small, and 20
Suitable for high-pressure discharge lamps of up to 250 W. If it is less than 20 W, it cannot be practically used for projection. Even when the discharge electric field intensity is less than 7 V / mm, the projection surface illuminance is improved for projection, but the lamp current increases to consume a predetermined lamp power, so that the load on the electrodes increases. If the power is less than 20 W, it cannot be used for projection.

Next, when the buffering medium is mercury, the discharge electric field strength is preferably selected within a relatively large range of 15 to 55 V / mm. Discharge electric field strength is 55V /
If it exceeds mm, the pressure of the rare gas during lighting increases, so that protection against rupture of the discharge vessel is required. When mercury is used as the buffering medium, the discharge electric field strength can be increased as described above, and accordingly, the lamp power can be increased. This is suitable for a high-pressure discharge lamp of 20 to 350 W for projection.

According to a third aspect of the present invention, there is provided the high pressure discharge lamp lighting method according to the first or second aspect, wherein the pulse current has a repetition period of 0.5 to 20 m.
s, the duty ratio to the standby current is 50% or less, and the peak current ratio is 1/5 or less.

According to the present invention, a pulse current, which is a lamp current, is defined in relation to a standby current.

The repetition period, together with the duty ratio, affects thermal diffusion due to thermal conduction of plasma. That is, when the duration of the pulse current is long or the pause period is short, the discharge arc is not cooled to a required degree, and accordingly, the discharge arc does not become thin. This means
This means that the effect of improving the illuminance of the projection surface by the pulse lighting decreases.

On the other hand, if the repetition period exceeds 20 ms, the light emission interval becomes too wide and the contribution to the brightness perceived by human eyes decreases. Also, the repetition cycle is 0.5 ms
If it is less than the predetermined value, the discharge arc will not be reduced to a required degree, and the sufficient effect of the present invention cannot be obtained. Preferably it is 2 ms or more.

If the duty ratio exceeds 50%, the ratio of the pulse current conduction time becomes large, and it becomes difficult to obtain the desired effect.

When the peak current ratio of the standby current to the pulse current is 1/5 or less, the illuminance of the projection surface can be improved by 20% or more as compared with the case of lighting by flat DC.
The higher the peak current of the pulse current, the higher the luminance of the central portion of the discharge arc. However, the standby current should be reduced as the peak current is increased. However, if the standby current is reduced too much, care must be taken because the discharge arc will extinguish during standby discharge.

According to a fourth aspect of the present invention, there is provided a lighting device for a high pressure discharge lamp, comprising: a short arc type discharge vessel in which a pair of electrodes are sealed at both ends of a translucent airtight vessel; a luminescent metal halide; And a pulse lighting means for lighting a high-pressure discharge lamp including a discharge medium containing a buffer medium and sealed in an airtight container by alternately passing a pulse current and a standby current.

The present invention specifies an apparatus for pulse lighting a so-called metal halide lamp in which a halide of a luminescent metal is sealed. That is, a pulse lighting means for alternately passing a pulse current and a standby current is provided.

The pulse lighting means may have the following configuration, for example. That is, in order to apply a pulse current, a voltage is applied to the high-pressure discharge lamp from a DC power supply or an AC power supply, and the high-pressure discharge lamp is short-circuited at a predetermined cycle and a duty ratio by a switching means while the lamp current is flowing. And In order to supply the standby current, for example, if the current from the power supply is periodically short-circuited as described above and an auxiliary power supply is provided in parallel with the power supply, the standby current can be supplied while the pulse current is interrupted. A current can be supplied. of course,
An isolator such as a diode is inserted into each of the power supplies as necessary to prevent interference between the power supplies.

As another configuration, a potential source having an appropriate value is connected in series with the switching means. Then, when the switching means is turned on, a voltage equal to the potential of the potential source is applied to the high-pressure discharge lamp, and this voltage causes a standby current to flow from the power supply to the high-pressure discharge lamp.

The peak value of the pulse current can be varied. For this purpose, the output voltage of the pulse lighting means is made adjustable or the power supply voltage to the pulse lighting means is made variable.

The repetition period and / or duty ratio of the pulse current and the standby current can be changed. For this purpose, the switching cycle and / or duty ratio of the switching means may be adjusted. It is common practice to connect an oscillator with a variable oscillation frequency and / or phase to the control pole of the switching means as described above.

The waveform of the pulse current is not limited to a square wave. For example, the shape may be a sine wave, a triangle wave, or the like.

When a flat DC voltage is applied to a high-pressure discharge lamp, a step-down chopper can be used. The step-down chopper is also responsible for the current limiting function.

The ballast element can be inserted on the power supply side of the pulse circuit or lighting means.

A high pressure discharge lamp lighting device according to a fifth aspect of the present invention is the high pressure discharge lamp lighting device according to the fourth aspect,
The pulse lighting means forms a discharge electric field intensity of 7 to 25 V / mm in the high-pressure discharge lamp in which the buffer medium of the discharge medium is xenon and / or argon, and lights the high-pressure discharge lamp at a lamp power of 250 W or less. Features.

The present invention specifies the desired discharge field strength and lamp power when the buffering medium is at least one of xenon, krypton and argon. These ranges are described in claim 2.

According to a sixth aspect of the present invention, there is provided the high pressure discharge lamp lighting device according to the fourth aspect.
The lighting means forms a discharge electric field intensity of 15 to 55 V / mm in a high-pressure discharge lamp in which the buffer medium of the discharge medium is mercury, and switches the high-pressure discharge lamp to a lamp power of 350 V / mm.
It is characterized in that it is turned on at W or less.

The present invention specifies the desired discharge field strength and lamp power when the buffering medium is mercury. These ranges are the same as those described in claim 2.

According to a seventh aspect of the present invention, there is provided the high pressure discharge lamp lighting device according to any one of the fourth to sixth aspects, wherein the pulse lighting means has a repetition period of 0.5 to 20 ms, a standby current of 0.5 to 20 ms. A pulse current having a duty ratio of 50% or less and a peak current ratio of 1/5 or less is supplied to the high-pressure discharge lamp.

The present invention specifies a pulse current, which is a lamp current, as a high-pressure discharge lamp lighting device in relation to a standby current. These are the same as those described in claim 3.

The discharge lamp lighting device according to the invention of claim 8 is:
The high pressure discharge lamp lighting device according to any one of claims 4 to 7, wherein a short arc-shaped discharge vessel in which a pair of electrodes are sealed at both ends of a translucent airtight vessel, a luminescent metal halide, and starting. A high-pressure discharge lamp including a discharge medium containing a gas for use and a buffer medium and sealed in an airtight container.

The present invention is a high-pressure discharge lamp lighting device including a high-pressure discharge lamp as a part of its structure. The high-pressure discharge lamp may be integrally provided with a reflecting mirror.

According to a ninth aspect of the present invention, in the high pressure discharge lamp lighting device according to any one of the fourth to eighth aspects, the high pressure discharge lamp includes at least a halide of a luminescent metal in the discharge medium. In, Tl, S
It is characterized by containing iodide or bromide of c, Dy, Nd.

The present invention specifies a high-pressure discharge lamp in which a luminous metal exhibiting a luminous color suitable for projection is specified. In addition to the above metals, iodide and / or bromide of Sn or Pb may be encapsulated.

According to a tenth aspect of the present invention, there is provided a lighting device, comprising: a lighting device main body; and the high pressure discharge lamp lighting device according to the eighth or ninth aspect supported by the lighting device main body.

The present invention is applicable to any lighting apparatus used in combination with an optical system such as a reflecting mirror or a lens, as well as for projection such as a liquid crystal projector and an overhead projector.

[0059]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially cutaway front view showing an example of a high-pressure discharge lamp used in the present invention.

In the figure, 1 is a discharge vessel, 2 is an anode, 3
Is a cathode, 4a and 4b are sealing metal foils, 5 is an anode lead wire,
Reference numeral 6 denotes a cathode lead wire, 7 denotes a base, and 8 denotes a power supply line.

The discharge vessel 1 is made of quartz glass and has a spindle-shaped discharge space 1a at the center and a pair of sealing portions 1b1 and 1b2 at both ends. Sealing metal foils 4a and 4b are embedded in the sealing portions 1b1 and 1b2.

The anode 2 includes a tungsten electrode shaft 2a having a base connected to one end of a sealing metal foil 4a, and a tungsten anode main portion 2b fixed to the tip.

The cathode 3 has a base end connected to one end of the sealing metal foil 4b, and has a tip made of a tungsten rod thinner than the anode axis which acts as a cathode main part.

The anode lead wire 6 is connected to the other end of the sealing metal foil 4a and is led out of the sealing portion 1b1.

The cathode lead wire 7 is connected to the other end of the sealing metal foil 4b and is led out from the sealing portion 1b2.

FIG. 2 is a partially cutaway front view showing another example of the high-pressure discharge lamp used in the present invention.

In the figure, the same parts as those in FIG.

This embodiment differs from FIG. 1 in that the discharge vessel 1 is made of a translucent ceramic such as translucent alumina. That is, the discharge space portion 1a and the small diameter portions 1c at both ends thereof.
And into the small diameter portion 1c of the ceramic container integrally molded with
A sleeve 9 in which the base ends of the anode shaft 2a and the cathode 3 are inserted and connected to the anode lead wire 6 and the cathode lead wire 7, respectively, is inserted and hermetically sealed with a glass sealing material 10 called frit glass. ing.

FIG. 3 is a lamp current waveform diagram showing a first embodiment of the high pressure discharge lamp lighting method according to the present invention.

In the figure, P is a pulse current, S is a standby current, T ₁ is a time width of the pulse current, and T ₀ is a repetition period. The duty ratio D of the pulse current P is obtained by the following equation.

D = T ₁ / T _{0 The} pulse current P and the standby current S are alternately passed through the high-pressure discharge lamp shown in FIG. 1 or FIG. When the standby current S flows therein, the discharge is merely continued and almost no light is emitted. At this time, since the flowing current is small, the discharge arc is narrowed and narrowed. Next, when the pulse current P flows, a large amount of charge is carried through the narrowed and narrowed discharge arc, so that the plasma arc temperature rises to increase the thermal ionization, and the current flowing therethrough is reduced. It is considered to cover. At this time, since the luminescent metal having a relatively low excitation level such as Dy enclosed in the high-pressure discharge lamp emits light only at the center of the narrowed discharge arc, the optical system works efficiently, and as a result, the projection surface Illuminance is improved.

FIG. 4 is a partial sectional front view showing a first embodiment of the high pressure discharge lamp lighting device of the present invention.

In the figure, the same parts as those in FIG.

In this embodiment, the high-pressure discharge lamp 11 has the discharge vessel 1 made of ceramics and the reflector 12 in one piece.

The reflecting mirror 12 is formed by glass molding. The reflecting mirror 12 is provided with a neck portion 12a at the top, and a multilayer interference reflecting film 12c that reflects visible light and infrared light is covered on the inner surface of the reflecting mirror main portion 12b. I have. Also, the reflecting mirror main part 12a
Is formed with a through hole 12d. The base 7 of the high-pressure discharge lamp 11 is fixed to the neck portion 12a via the base cement 13. Further, the power supply line 8
Is passed through the through hole 12d of the reflecting mirror 12 and led out to the rear side of the reflecting mirror 12.

Numeral 14 denotes a pulse lighting means for causing a pulse current and a standby current to flow through the high-pressure discharge lamp 11 alternately as shown in FIG.

FIG. 5 is a circuit diagram showing a second embodiment of the high pressure discharge lamp lighting device according to the present invention.

In the figure, the same parts as those in FIG.

This embodiment shows a specific configuration example of the pulse lighting means. That is, the pulse lighting means 14 includes the rectifying means and the step-down chopper 14a and the switching circuit 1
4b. Reference numeral 15 denotes a commercial frequency AC power supply.

The switching circuit 14b is composed of a series circuit of a switching means 14b1 and a potential source 14b2, and is connected to the high-pressure discharge lamp 11 in parallel. The switching unit 14b1 is repeatedly turned on and off at a predetermined cycle and duty ratio by a control unit (not shown).

Then, the rectifying means and the step-down chopper 1
4a rectifies the commercial frequency alternating current, inputs the non-smoothed direct current output to the step-down chopper, and outputs a flat DC voltage of a required value. This DC voltage is applied to the high-pressure discharge lamp 11, and a lamp current flows. When the switching means 14b1 is turned on at a predetermined timing, the high pressure discharge lamp 1
Since 1 is short-circuited, the lamp current which has been flowing until now is cut off. As a result, a pulse current flows through the high-pressure discharge lamp 11. However, when the switching means 14b1 is turned on, the potential source 14b2 is connected to both ends of the high-pressure discharge lamp 11, so that a voltage equal to the potential of the potential source 14b2 is applied to the high-pressure discharge lamp 11, thereby generating a pulse current. Since the standby current flows after the current is cut off, the high-pressure discharge lamp 11 continues to discharge even when the pulse current is cut off.

FIG. 6 is a circuit diagram showing a high-pressure discharge lamp lighting device according to a third embodiment of the present invention.

In the figure, the same portions as those in FIGS. 4 and 5 are denoted by the same reference numerals, and description thereof will be omitted.

This embodiment shows another specific example of the structure of the pulse lighting means. That is, the pulse lighting means 14 includes a main lighting means 14A and a sub-lighting means 14B.

The main lighting means 14A comprises a first rectifying and step-down chopper 14a, a switching circuit 14b ', and a first isolator 14c, for example, a diode. The first isolator 14c is connected in series between the main lighting means 14A and the high-pressure discharge lamp 11.

The auxiliary lighting means 14B comprises a second rectifying / step-down chopper 14d and a second isolator 14e, for example, a diode, and is connected in parallel with the main lighting means 14A. The second isolator 14e is connected in series between the high-pressure discharge lamp 11 and the auxiliary lighting means 14B. The sub-lighting means 14B obtains power from the low-frequency AC power supply 15.

Thus, in this embodiment, the pulse lighting means 14 is composed of the main lighting means 14A and the sub-lighting means 14A.
B, the main lighting means 14A is responsible for passing the pulse current, and the sub-lighting means 14B is responsible for passing the standby current. That is, the main lighting means 14A passes a pulse current to the high-pressure discharge lamp 11 at a repetition cycle determined by the switching frequency of the switching means 14b1. On the other hand, since the sub-lighting means 14B continuously applies a low voltage to the high-pressure discharge lamp 11, the standby current is supplied to the high-pressure discharge lamp when the switching means 14b1 is off. The first and second isolators 14c and 14e prevent the current from flowing.

FIG. 7 is a conceptual diagram showing an image projection device which is an embodiment of the illumination device of the present invention.

In the figure, the same parts as those in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted. 16 is a liquid crystal display means, 17 is an image control means, 18 is an optical system, 19 is a main body case, 20
Is the screen.

The liquid crystal display means 16 displays an image to be projected by liquid crystal, and irradiates illumination light emitted from the high-pressure discharge lamp 11 and condensed by the reflecting mirror 12 from the back thereof.

The image control means 17 drives and controls the liquid crystal display means 16, and can have a television receiving function if necessary.

The optical system 18 collects the light transmitted through the liquid crystal display means 16 and projects it on the screen 20.

The main body case 19 houses each of the above-mentioned components.

[0095]

[Embodiment 1] The high pressure discharge lamp of this embodiment and the lighting conditions are as follows.

Discharge vessel: The total length is 50 mm, the maximum outer diameter of the discharge space is 8 mm, and the distance between the electrodes is 2.0 mm.

Discharge medium: the luminescent metal halide is Dy
_{I 3 0.04mg, DyBr 3 0.16mg,} NdBr 3
0.03 mg, InBr 0.08 mg and CsI.
02 mg, xenon 5 atm as starting gas and buffer gas.

The rated lamp power of the high-pressure discharge lamp is 100 W.

Lighting condition: The lamp voltage is 50 V and the lamp current is 5 A (all are effective values).

This high-pressure discharge lamp was incorporated in a reflector having a spheroid with an opening diameter of 80 mm, lit with various pulse currents and standby currents, and the illuminance at the center of the screen when projected was measured. Table 1 shows the results in terms of relative illuminance with the illuminance being 100% in the case of lighting by flat direct current.

[0101]

[Table 1] As is clear from Table 1, according to the present embodiment, an illuminance of 120% or more is obtained as compared with the lighting by the flat direct current.

[0102]

Embodiment 2 In this embodiment, in addition to the configuration of Embodiment 1, Sn
This is a high-pressure discharge lamp in which 0.1 mg of I ₂ is filled per 1 cc of discharge space. Table 2 shows the results of measuring the illuminance maintenance ratio for each of the high-pressure discharge lamps of Example 2 and pulse 3 in Table 1.

[0103]

[Table 2] As is clear from Table 2, according to the present embodiment, although the initial illuminance is slightly lowered, the illuminance maintenance ratio is significantly improved.
The fact that SnI ₂ suppresses the decrease in luminous flux due to the reaction between other luminescent metals and quartz glass, and the pulsed lighting ignores the disadvantages of reduced luminous efficiency and arc spread that were problems with conventional DC or AC lighting. It is easy to understand that it is possible.

[0104]

Embodiment 3 The high-pressure discharge lamp of this embodiment and the lighting conditions are as follows.

Discharge vessel: The total length is 60 mm, the maximum outer diameter of the discharge space is 10 mm, and the distance between the electrodes is 1.5 mm.

Discharge medium: the luminescent metal halide is Dy
_{I 3 0.07mg, DyBr 3 0.25mg,} NdBr 3
0.05 mg, InBr 0.12 mg and CsI.
03 mg, the starting gas is 500 torr of argon, and the buffer medium is mercury.

Lighting condition: The lamp voltage is 50 V and the lamp current is 3 A (all are effective values).

The rated lamp power of the high-pressure discharge lamp is 150 W.

This high-pressure discharge lamp was incorporated into a reflector having a spheroidal surface with an opening diameter of 90 mm, lit with various pulse currents and standby currents, and the illuminance at the center of the screen when projected was measured. Table 3 shows the results expressed in terms of relative illuminance with the illuminance being 100% in the case of lighting by flat direct current.

[0110]

[Table 3] As is clear from Table 3, according to the present embodiment, an illuminance of 120% or more is obtained as compared with the lighting by the flat direct current as in the first embodiment.

[0111]

Embodiment 4 In this embodiment, in addition to the configuration of Embodiment 3, Sn
This is a high-pressure discharge lamp in which 0.1 mg of I ₂ is filled per 1 cc of discharge space. Table 4 shows the results of measuring the illuminance maintenance ratio for each of the high-pressure discharge lamps of Example 3 and pulse 3 in Table 3.

[0112]

[Table 4] As is clear from Table 4, according to the present example, although the initial illuminance is slightly reduced, the illuminance maintenance ratio is significantly improved.
The fact that SnI ₂ suppresses the decrease in luminous flux due to the reaction between other luminescent metals and quartz glass, and the pulsed lighting ignores the disadvantages of reduced luminous efficiency and arc spread that were problems with conventional DC or AC lighting. It is easy to understand that it is possible.

[0113]

According to the first to third aspects of the present invention, a high-pressure discharge lamp enclosing a halide of a light-emitting metal is lit by alternately passing a pulse current and a standby current to light a buffer medium. A high-pressure discharge lamp lighting method that raises the illuminance of the projection surface when projected using an optical system, because the luminescent metal with a lower excitation level emits light only at the center of the discharge arc narrowed down by the standby current flow Can be provided.

According to the second aspect of the present invention, it is possible to provide a method of lighting a high-pressure discharge lamp for lighting at a required lamp power for projection by additionally defining a discharge electric field intensity.

According to the third aspect of the present invention, it is possible to provide a method for lighting a high-pressure discharge lamp in which the illuminance of the projection surface is increased by 20% or more by additionally defining the pulse current.

According to each of the fourth to eighth aspects of the present invention, the high pressure discharge lamp in which the halide of the luminescent metal is sealed is provided with the pulse lighting means for alternately passing the pulse current and the standby current, thereby providing a buffer. Light emitting metal whose excitation level is lower than that of the medium emits light only at the center of the discharge arc narrowed down by the standby current flow, so the high-pressure discharge lamp that raises the illuminance on the projection surface when projected using an optical system An apparatus can be provided.

According to the fifth aspect of the present invention, it is possible to provide a high pressure discharge lamp lighting device in which a preferable discharge electric field intensity is specified when the buffering medium is a rare gas high pressure discharge lamp.

According to the sixth aspect of the present invention, it is possible to provide a high pressure discharge lamp lighting device in which the discharge electric field intensity is preferably specified for a high pressure discharge lamp of mercury as a buffering medium.

According to the seventh aspect of the present invention, it is possible to provide a high-pressure discharge lamp lighting device in which the illuminance of the projection surface is increased by 20% or more by additionally defining the pulse current.

According to the eighth aspect of the present invention, it is possible to provide a high pressure discharge lamp lighting device including a high pressure discharge lamp.

According to the ninth aspect of the present invention, it is possible to provide a high-pressure discharge lamp lighting device including a high-pressure discharge lamp in which a luminescent metal suitable for projection is enclosed.

According to the tenth aspect, it is possible to provide a lighting device having the effects of the first to ninth aspects.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing an example of a high-pressure discharge lamp used in the present invention.

FIG. 2 is a partially cutaway front view showing another example of the high-pressure discharge lamp used in the present invention.

FIG. 3 is a lamp current waveform diagram showing a first embodiment of the high pressure discharge lamp lighting method of the present invention.

FIG. 4 is a partially sectional front view showing a first embodiment of the high-pressure discharge lamp lighting device of the present invention.

FIG. 5 is a circuit diagram showing a second embodiment of the high pressure discharge lamp lighting device of the present invention.

FIG. 6 is a circuit diagram showing a third embodiment of the high pressure discharge lamp lighting device of the present invention.

FIG. 7 is a conceptual diagram showing an image projection device as an embodiment of the illumination device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Discharge container 2 ... Anode 3 ... Cathode 7 ... Base 11 ... High pressure discharge lamp 12 ... Reflector 12a ... Neck part 12b ... Reflector main part 12c ... Visible light reflection / infrared transmission film 14 ... Pulse lighting means

Claims (10)

[Claims] 1. A short arc type discharge vessel in which a pair of electrodes are sealed at both ends of a translucent hermetic vessel, and a hermetically sealed vessel containing a luminescent metal halide, a starting gas and a buffering medium. A high-pressure discharge lamp lighting method, characterized in that a high-pressure discharge lamp having a discharge medium is lit by alternately passing a pulse current and a standby current. 2. A short arc type discharge vessel comprising a pair of electrodes sealed at both ends of a translucent airtight vessel, and a hermetically sealed vessel containing a luminescent metal halide, a starting gas and a buffering medium. A high-pressure discharge lamp lighting method characterized in that a pulse current and a standby current are alternately passed at a discharge electric field strength of 7 to 55 V / mm through a high-pressure discharge lamp provided with a discharge medium, and the lamp is lit. 3. A pulse current having a repetition period of 0.5 to 2
0 ms, duty ratio to standby current is 50%
3. The high pressure discharge lamp lighting method according to claim 1, wherein the peak current ratio is 1/5 or less. 4. A short arc type discharge vessel comprising a pair of electrodes sealed at both ends of a light-transmitting hermetic vessel, and a hermetically sealed vessel containing a luminescent metal halide, a starting gas and a buffering medium. A high-pressure discharge lamp lighting device comprising: a high-pressure discharge lamp provided with a discharge medium; and a pulse lighting means for lighting the high-pressure discharge lamp by alternately passing a pulse current and a standby current. 5. The pulse lighting means according to claim 1, wherein said high-pressure discharge lamp has a buffer medium of at least one of xenon, krypton and argon.
5. The high pressure discharge lamp lighting device according to claim 4, wherein the discharge electric field intensity is formed and the high pressure discharge lamp is lit at a lamp power of 250 W or less. 6. A pulse lighting means for a high pressure discharge lamp in which the buffer medium of the discharge medium is mercury is 15 to 55 V / m.
5. The high pressure discharge lamp lighting device according to claim 4, wherein a discharge electric field intensity of m is formed, and the high pressure discharge lamp is lit at a lamp power of 350 W or less. 7. A pulse lighting means having a repetition cycle of 0.5
20 ms, duty ratio to standby current is 5
The high-pressure discharge lamp lighting device according to any one of claims 4 to 6, wherein a pulse current having a peak current ratio of 0% or less and a peak current ratio of 1/5 or less is supplied to the high-pressure discharge lamp. 8. A short arc type discharge vessel in which a pair of electrodes are sealed at both ends of a translucent airtight vessel, and a light-emitting metal halide, a starting gas and a buffering medium, which are enclosed in the hermetic vessel. The high pressure discharge lamp lighting device according to any one of claims 4 to 7, further comprising a high pressure discharge lamp having a discharge medium. 9. A high-pressure discharge lamp according to claim 1, wherein said light-emitting metal halide is at least In, Tl, Sc, D
The high pressure discharge lamp lighting device according to any one of claims 4 to 8, further comprising an iodide or bromide of y or Nd. 10. A lighting device comprising: a lighting device main body; and the high pressure discharge lamp lighting device according to claim 8 supported by the lighting device main body.