JPH08273401A - Floodlight source, floodlight source lighting device and liquid crystal projector - Google Patents

Abstract

PURPOSE: To prevent the deposition of fluorescent material produced in a DC lighting type metal halide lamp of a heavy tube wall load by a simple construction. CONSTITUTION: An electrode 102a becomes a cathode and an electrode 102b becomes an anode. Respectively the cathode 102a is made of an electrode shaft 203 of 10mm in length and 0.7mm in thickness whose material is tungusten- thorium alloy containing thorium, and the anode is made of the electrode whose tip portion 222 is expanded up to 1.5mm diameter. The distance L of the electrodes between the cathode 102a and the anode 102b is set to be 6mm, and one side metal foil conductor 106 connected to the anode 102 is electrically connected so as to be same potential with a reflector 110.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light projecting light source, a light projecting light source lighting device, a light projecting device and a liquid crystal projector in which light emitted from a metal halide lamp is reflected and projected by a reflector.

[0002]

2. Description of the Related Art A direct-current type metal halide lamp disclosed in Japanese Patent Laid-Open No. 60-72154 has N as a light emitting substance.
When a substance such as a having a small atomic diameter is used, the atoms escape from the quartz constituting the arc tube.
The change in the light emission characteristics during the life is reduced. Also, 40
Metal halide lamps used with a high tube wall load of W / cm2 or more have a large amount of luminescent substance enclosed, so that the emission of luminescent substance becomes large. When such a state is reached, the amount of light traveling from the lamp to the reflecting surface of the reflector is significantly reduced, which reduces the amount of reflected light. When such a light source is used in a liquid crystal projector, there is a drawback that the illuminance on the screen, which is the light projecting surface, is extremely lowered.

[0003]

In the above lamp, when an element having an ion radius of Ne atom size or He atom size, such as Na or Li, is used, the ions are emitted from the outside of the arc tube. It occurs because a portion having a negative potential, for example, is pulled by a lead wire.

In order to eliminate such a phenomenon, it is necessary to cover the lead wire with a glass sleeve, which causes a problem that the structure becomes complicated.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent deposition of a luminescent substance which occurs in a DC lighting type metal halide lamp having a high tube wall load with a simple structure. An object of the present invention is to provide a light source, a light projecting device, and a liquid crystal projector.

[0006]

According to a first aspect of the present invention, an airtight container made of quartz glass, electrodes sealed at both ends inside the container, and a metal halide sealed in the airtight container,
A metal halide lamp with mercury and noble gas;
A reflector having a light-transmissive opening and accommodating the metal halide lamp so that the electrode that operates as a cathode thereof is located on the light-transmissive opening side, and has the same potential as that of the electrode that operates as an anode; A projection light source characterized by being provided.

According to a second aspect, an airtight container made of quartz glass, a cathode sealed at one end of the container, an anode sealed at the other end, and a metal halide lamp having a metal halide, mercury and a rare gas in the airtight container; Has a light projecting portion and a reflecting surface on the inner surface, and the lamp is arranged so that the cathode is located on the light projecting portion side, and the light emitted from the lamp is reflected by the reflecting surface and output from the light projecting portion. And a reflector having the same potential as that of the anode, and the projector light source.

According to a third aspect of the present invention, there is provided the light projecting light source according to the first or second aspect, wherein the reflector is arranged so that a front light projecting portion side of the reflector faces downward.

According to a fourth aspect, the metal halide lamp is
The floodlighting source according to any one of claims 1 to 3, wherein the light-emitting substance contains at least one of Na, Mg, Al, and Li.

According to a fifth aspect of the present invention, there is provided a light projecting light source according to any one of the first to fourth aspects, and a lighting means for stably forming a discharge between electrodes of the lamp of the light projecting light source. Is a lighting device for projecting a light source.

According to a sixth aspect of the present invention, there is provided a light projecting light source according to any one of the first to fourth aspects, a lighting means for stably forming a discharge between electrodes of the lamp of the light projecting light source, and the light projecting light source. And a housing for accommodating the lighting means.

According to a seventh aspect of the present invention, there is provided a light projecting light source according to any one of the first to fourth aspects; a lighting means for stably forming discharge between electrodes of the lamp of the light projecting light source device; A liquid crystal projector comprising: a liquid crystal panel that allows light from the projector to pass therethrough to project an image; and a housing that houses the light projecting light source, the lighting means, and the liquid crystal panel.

In the present invention, the airtight container is a container constituting an arc tube.

Further, the term "DC lighting" or "DC of the DC power source" includes rectified AC, pulse lighting, and the like.

[0015]

According to the present invention, since the potential of the reflector is set to be the same as the potential of the electrode that operates as an anode, the ions in the discharge medium inside the airtight container repel the positive potential of the reflector outside the airtight container. Therefore, the discharge medium is less likely to deposit outside the airtight container.

According to the second aspect, since the potential of the reflector is set to the same potential as the potential of the anode, the ions in the discharge medium inside the airtight container repel the positive potential of the reflector outside the airtight container, so that the discharge medium is discharged. Less precipitation outside the airtight container.

According to the third aspect, it has the action of any of the second to third aspects.

According to the fourth aspect, the operation according to any one of the first to third aspects is provided.

According to the fifth aspect, the operation according to any one of the first to third aspects is provided.

According to the sixth aspect, the operation according to any one of the first to third aspects is provided.

[0021] According to claim 7, the operation according to any one of claims 1 to 3 is achieved.

According to the eighth aspect, the operation according to any one of the first to third aspects is provided.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in FIGS. FIG. 1 is a partial cross-sectional side view showing a horizontally lit state of a light projection light source lighting device.

In FIG. 1, 109 is a lamp,
Reference numeral 101 denotes an airtight container made of quartz glass, and the light emitting portion of the airtight container 101 is a substantially elliptical rotator made of quartz glass having a thickness of 1.4 mm. The light emitting portion has a major axis of about 15 mm and a minor axis. Of about 10 mm, resulting in an internal surface area of about 4.7 cm2 and an internal volume of about 0.9.
It is cc.

Electrodes 102a and 102b are sealed on both ends of the airtight container 101, respectively. These electrodes 102a, 102b
Are lit by direct current, so that one electrode 102a serves as a cathode and the other electrode 102b serves as an anode. However, in the case of the present embodiment, each of the cathodes 102a is composed of an electrode shaft 203 made of a tungsten-thorium alloy containing thorium and having a length of 10 mm and a thickness of 0.7 mm, and the anode has a diameter of 1 mm. Tip 2 bulged to 0.5 mm
It is composed of 22. Incidentally, these cathode 102a and anode
The electrode-to-electrode distance L of 102b is 6 mm, and the cathode protrusion length Y is in the range of 3 to 7 mm, here 5 mm.

The pair of electrodes 102a and 102b are sealed by the sealing portion 105.
, 105 connected to the metal foil conductors 106, 106 sealed. The metal foil conductors 106, 106 are Mo foils and have a width of 3 m.
m and the thickness is 30 μm. One of the metal foil conductors 106 connected to the anode 102 is electrically connected via an external lead wire to a base 107 attached to the end portion so that it has the same potential as a reflector 110 described later. It is electrically connected. The other metal foil conductor 106 connected to the cathode 102a is connected to the external lead wire 108. The outer lead wire 108 is made of Mo metal having a diameter of 0.8 mm.

In such an airtight container 101, for example, 22 mg of mercury is enclosed, and a rare earth metal such as Dy, Nd, Tl, In, Sn, Cs, etc., iodide and bromide of 2.0 mg is used as a light emitting metal. It is enclosed,
Further, 40 KPa of argon gas is enclosed as a rare gas, which constitutes a short arc metal halide lamp 109.

The lamp 109 is attached to the reflector 110. The reflector 110 is made of metal, and has a reflecting surface 111 made of a vapor-deposited film of TiO2 --SiO2 or the like having excellent reflection characteristics on the inner surface of the rotating curved surface. The front projection part 112 of the reflector 110, for example, has an opening diameter of 90 m.
It is formed to about m, and the support cylinder 113 is provided on the top of the back.
Are formed. The lamp 109 is attached to the support cylinder 113.
The base 107 of the lamp is fixed by an adhesive 114 such as insulating cement.
1 One O1 is the central axis of the reflector 110, that is, the optical axis O2
The lamp 109 and the reflector 109
It is attached to the 110.

In this case, in the lamp 109, the cathode 102a is located on the light-projecting portion 112 side of the reflector 110, and the anode 102b is located on the support tube portion 113 and is supported by the reflector 110.

An introduction hole 115 is formed in the reflector 110, and the external lead wire 108 of the lamp 109 penetrates through the introduction hole 115 and is guided to the back side.

The light source 116 is constituted by the reflector 110 and the short arc metal halide lamp 109 fixed to the reflector 110 as described above, and the base 107 and the external lead wire 108 are connected to the DC power source 117 to project light. A light source lighting device is configured. The DC power supply 117 is connected to the lamp 109
On the other hand, for example, a voltage such that the no-load voltage is about 280V is applied. By applying such a voltage, the lamp is lit by direct current, the lamp current becomes 2.7 A, the lamp voltage is 92 V, and the lamp power is 247 W.

The operation of the light projecting light source 116 will be described.

As shown in FIG. 1, the light projecting light source 116 is used in a posture in which the reflector 110 has its optical axis O2 -O2 oriented substantially horizontally, and the short arc metal halide lamp 109 is lit horizontally.

Since the short arc metal halide lamp 109 is connected to the DC power supply 117 and is turned on by direct current, the metal ions in the airtight container 101 are strongly affected by the electric field in the airtight container created by both electrodes, and thus the cathode It is attracted to the 102a side. Further, since the reflector has a positive potential, metal ions are not deposited from the airtight container 101. Therefore, it is possible to prevent a decrease in the amount of light directly emitted from the lamp 109 and a decrease in the amount of light projected from the light projecting light source 116. Therefore, when the light from the light projecting light source 116 is projected onto, for example, the screen, it is possible to prevent the illuminance of the screen from decreasing.

In FIG. 1, a light suppressing portion is provided on the outer surface of the anode side, except for the central portion of the airtight container 101 and the anode 102b side.
118 For example, if a diffusion surface such as frost processing is formed,
This light suppressor 118 is used in the cathode 10 from the beginning of the lamp life.
The amount of light emitted from the side 2a is suppressed, and even if devitrification occurs on the side of the cathode 102a during the life, it is possible to prevent the amount of light in this region from changing.

FIG. 2 is a conceptual diagram of a color liquid crystal projector as an embodiment of the present invention. The color liquid crystal projector includes a lamp 109 and a reflector 110 that reflects the light emitted from the lamp 109 inside the projector body 60.
And a condensing lens 63 for condensing the reflected light reflected by the reflector 110.

The light radiated forward from the condenser lens 119 illuminates the color liquid crystal panel (LCD) 122, and the image of the three primary colors RGB of the liquid crystal panel 122 is projected on the screen 66 via the projection lens 63. Let

Reference numeral 64 denotes a liquid crystal driving device, which is supplied with power from a power source 65 and controls an image on the liquid crystal panel 122 so that images of three colors are superimposed and projected on a screen 66 to display a color image. Become.

In another embodiment of the present invention, the lamp shaft O
The 1 O 1 and the optical axes O 2 O 2 may be used in a vertical posture.

That is, the reflector 110 has an optical axis O2 0.
2 is installed in a vertical position, so the lamp axis O1
-O1 is also vertical. In this case, the lamp 109 connected to the DC power supply 117 is an electrode that becomes a cathode during DC lighting.
It suffices that the 102a is arranged on the lower side in the vertical direction, and the cathode 102a is arranged on the light projecting section 112 side of the reflector 110. In the case of such a configuration, when the lamp is turned on,
Not only the metal ions in 101 do not deposit from the airtight container due to the electric field, but the rare earth metal as the light emitting metal receives gravity and gathers in the vicinity of the cathode 102a located on the lower side, further lowering the temperature of the cathode. , And the temperature of the cathode located on the lower side due to convection becomes low, and thus excess light-emitting metal easily collects on the cathode side, and the combined action of these increases the concentration of the light-emitting metal in the vicinity of the cathode 102a.

As a result, the luminescent metal collects on the side of the cathode 102a, and devitrification does not occur at the center of the airtight container 101 or on the side of the upper anode 102b. Therefore, a decrease in the amount of light traveling toward the reflecting surface 111 is small, and a large amount of reflected light can be secured. Therefore, the downward light amount does not decrease as the lighting time elapses.

[0042]

According to the first aspect of the present invention, the potential of the reflector is set to be the same as the potential of the electrode that operates as an anode. Therefore, the ions in the discharge medium inside the airtight container are equal to the positive potential of the reflector outside the airtight container. Due to the repulsion, the discharge medium is less likely to deposit outside the airtight container. Therefore, a long-life metal halide lamp can be provided.

According to the second aspect, since the potential of the reflector is set to be the same as the potential of the anode, the ions in the discharge medium inside the airtight container repel the positive potential of the reflector outside the airtight container. Less precipitation outside the airtight container. Therefore, a long-life metal halide lamp can be provided.

According to claim 3, the effect according to any one of claims 2 and 3 can be obtained.

According to claim 4, the effect of any one of claims 1 to 3 can be obtained.

According to claim 5, the effect of any one of claims 1 to 3 can be obtained.

According to claim 6, the effect of any one of claims 1 to 3 can be obtained.

According to claim 7, the effect of any one of claims 1 to 3 can be obtained.

According to claim 8, the effect of any one of claims 1 to 3 can be obtained.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional side view showing an embodiment of a projection light source lighting device of the present invention.

FIG. 2 is a side view of a main part of the embodiment of the present invention.

FIG. 3 is a conceptual diagram of an embodiment of a liquid crystal projector of the present invention.

[Explanation of symbols]

 101 ... Airtight container, 102a ... Cathode, 102b ... Anode, 109 ... Metal halide lamp, 110 ... Reflector, 111 ... Reflective surface, 112 ... Projector, 117 ... DC power supply, 122, 128 ... Liquid crystal panel.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H01J 61/073 H01J 61/073 B 61/20 61/20 D 61/88 61/88 C H04N 5 / 74 H04N 5/74 K

Claims (7)

[Claims] 1. An airtight container made of quartz glass, electrodes sealed at both ends inside the container, and a metal halide lamp provided with a metal halide, mercury, and a rare gas sealed in the airtight container; A metal halide lamp is housed so that the electrode that operates as a cathode thereof is located on the light transmission opening side, and a reflector that has the same potential as that of the electrode that operates as an anode is provided. A characteristic light source. 2. An airtight container made of quartz glass, a cathode sealed at one end of the container, an anode sealed at the other end, and a metal halide lamp containing a metal halide, mercury and a rare gas in the airtight container; The lamp is disposed so that the cathode and the inner surface have a reflecting surface, and the cathode is located on the light projecting portion side, and the light emitted from the lamp is reflected by the reflecting surface to be output from the light projecting portion and the anode And a reflector having the same electric potential as the electric potential; 3. The reflector is arranged so that a front light projecting portion side of the reflector faces downward.
Alternatively, the projection light source described in 2. 4. The floodlighting source according to claim 1, wherein the metal halide lamp contains at least one of Na, Mg, Al and Li as a light emitting substance. 5. A light projecting light source according to any one of claims 1 to 4, and a lighting means for stably forming a discharge between electrodes of the lamp of the light projecting light source. A characteristic light source lighting device. 6. A light projecting light source according to any one of claims 1 to 4, a lighting means for stably forming a discharge between electrodes of the lamp of the light projecting light source, and the light projecting light source and the lighting means. And a housing for accommodating the. 7. A light projecting light source according to any one of claims 1 to 4, a lighting means for stably forming a discharge between electrodes of the lamp of the light projecting light source device, and a light from the light projecting light source. A liquid crystal panel that projects an image by passing through the light source;
A liquid crystal projector comprising: a housing for housing a lighting means and a liquid crystal panel;