JPH11283576A - Vertical lighting dc high pressure discharge lamp, vertical lighting dc high pressure discharge lamp device, and image projecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vertical lighting DC high pressure discharge lamp with less effects from the shadow of an electrode and high screen quality, and provide a vertical lighting DC high pressure discharge lamp device using this, and an image projecting device. SOLUTION: An airtight container 1 is made of a quartz glass and has a spindle-shaped bulb part 1a having an outer diameter of about 15.5 mm in the center, a pair of sealing parts 1b1, 1b2 faced in the major axis direction of the bulb part 1a, and a chip part 1c in part on the side surface of the bulb part 1a. Then when a straight line connecting the centers of the sealing parts 1b1, 1b2 is made as a lamp shaft, the center of an anode 2 agrees with the lamp shaft, and a cathode 2 is biased toward the chip side. The degree of biased is 1.5-3.0 mm, and (a-n)/L (mm) is 0.29-2.7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC high-pressure discharge lamp for vertical lighting, a DC high-pressure discharge lamp for vertical lighting using the same, and an image projection apparatus.

[0002]

2. Description of the Related Art As a light source for a liquid crystal projector, an overhead projector, or the like, a metal halide lamp of a short arc type, in which a metal halide containing at least one of dysprosium Dy and neodymium Nd is sealed as a discharge medium, has been known for its excellent light emitting performance. Became used. Initially, metal halide lamps used for these applications were of the type that were lit by alternating current. Recently, it has been found that DC lighting can respond to the demand for extending the life of metal halide lamps for such applications. Is infiltrating.

In a high-pressure discharge lamp of the AC lighting type, the pair of electrodes have the same structure because the pair of electrodes alternately operate as a cathode and an anode every positive and negative half cycles.

On the other hand, a DC lighting high pressure discharge lamp, that is, a DC lighting high pressure discharge lamp for vertical lighting, operates when one electrode is a cathode and the other electrode is an anode.
Its role is immutable throughout. The anode is formed larger than the cathode in order to prevent the lamp from shortening its life or deteriorating its characteristics due to a temperature rise caused by electron collision or the like.

Further, this type of high-pressure discharge lamp is arranged such that the lamp axis substantially coincides with the central axis of a reflecting mirror having a paraboloid of revolution, a spheroid, a spherical surface or an appropriate combination of these.

[0006]

However, the DC high-pressure discharge lamp for vertical lighting sometimes has a problem that required characteristics cannot be obtained when projected on a screen via an optical system. In other words, the unique characteristic of the DC lighting method is that the so-called cataphoresis phenomenon occurs in which the inclusions (positive and negative ions) separate according to the positive and negative polarities at the time of lighting. It leads to unevenness and uneven illuminance. Dysprosium Dy
And when at least one of neodymium Nd is included as a discharge medium, a particularly strong reddish emission is generated by cataphoresis near the tip of the cathode, and when this is projected on a screen, the peripheral portion becomes reddish, resulting in lowering the quality of the screen. It has become.

On the other hand, in the case of vertical lighting, there is no inclination due to the gravity of the arc as compared with the case of horizontal lighting, and it is not necessary to carry out an optical design taking this into consideration. However, since there is no inclination of the arc, there is a problem that the electrode itself tends to be shadowed.

The present invention provides a DC high-pressure discharge lamp for vertical lighting, which is less affected by the shadow of the electrodes when projecting the screen, and thus has a high screen quality, a DC high-pressure discharge lamp for vertical lighting using the same, and an image projection apparatus. The purpose is to do.

[0009]

According to a first aspect of the present invention, there is provided a direct-current high-pressure discharge lamp for vertical lighting, wherein a main light-emitting portion has a swelling shape, a fire-resistant and translucent airtight container; The length of the protruding portion in the tube axis direction is 2a, and the anode is shifted from the discharge center by 1.5 to 3.0 mm with respect to the anode and the anode which are sealed with a distance L therebetween in the hermetic container. A discharge medium containing a metal halide containing at least one of dysprosium Dy and neodymium Nd, a rare gas, and mercury sealed in an airtight container;
(An) / L (mm) is 0.29 or more and less than 2.7.

A vertical high-voltage direct-current discharge lamp according to a second aspect of the present invention includes an integrated reflecting mirror whose central axis is substantially aligned with the lamp axis. It is a DC high pressure discharge lamp for lighting.

The DC high pressure discharge lamp for vertical lighting according to the third aspect of the present invention is the high pressure discharge lamp according to the second aspect, wherein the anode is located on the top side of the reflecting mirror.

According to a fourth aspect of the present invention, there is provided a DC high-pressure discharge lamp device for vertical lighting according to any one of the first to third aspects, and the DC high-pressure discharge lamp for vertical lighting is energized. A lighting device.

According to a fifth aspect of the present invention, there is provided an image projection apparatus according to any one of the first to third aspects, a DC high-pressure discharge lamp for vertical lighting; a lighting device for lighting the DC high-pressure discharge lamp for vertical lighting; Means for irradiating from behind the light emitted from the DC high-pressure discharge lamp and condensed by the reflecting mirror; an optical system for condensing the light transmitted through the image means and projecting it on a screen; And a main body case for housing the main body.

According to a sixth aspect of the present invention, there is provided an image projection apparatus comprising: a DC high-pressure discharge lamp for vertical lighting according to any one of claims 1 to 3; a lighting device for lighting the DC high-pressure discharge lamp for vertical lighting; Image display means for irradiating light emitted from the direct-current high-pressure discharge lamp for use and condensed by a reflecting mirror from behind; image control means for controlling the image display means;
An optical system for condensing light transmitted through the image display means and projecting the light on a screen; and a main body case for accommodating each of the above-described components.

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

The fire resistance of the hermetic container means that it is made of a material which can sufficiently withstand the normal operating temperature of the discharge lamp. In addition, the light-transmitting property only needs to have a light transmittance that enables light generated by the discharge in the hermetic container to be effectively guided to the outside. It is allowed to be formed of a material such as quartz glass, translucent ceramics, and a single crystal such as alumina and YAG. In order to prevent a reaction between the discharge medium and the hermetic container as required, a thin film of a chemically stable substance can be formed on the inner surface of the hermetic container by a method such as deposition and replacement. However, for high pressure discharge lamps, quartz glass is the most practical material for the hermetic container and is suitable for providing the hermetic container on an industrial scale.

In the hermetic container, the bulb surrounding the light emitting portion is formed in a shape such as a sphere, a spheroid, or a spindle.
If necessary, sealing portions for hermetically and mechanically supporting the electrodes at both ends are formed so as to protrude.

The anode and cathode are not limited to special materials as long as they are refractory metals, but tungsten is most suitable. A short distance between the two electrodes means that an appropriate distance may be set so that a so-called short arc, that is, an electrode-stable type discharge occurs.

Since the anode is heated by collision of electrons,
In order to increase the heat capacity and the heat radiation area, it is formed large. Specifically, use a solid refractory metal thicker than the electrode shaft, forming heat dissipation grooves around it as necessary, or winding the coil at a position slightly receded from the tip of the electrode shaft. Can be. In any case, it is desirable that the tip of the anode be adjusted in advance to have a relatively small area for the stability of the arc.

The cathode can be made of a refractory metal, such as a tungsten rod, which is smaller than the anode. Further, the cathode passes through the center of the anode and is deviated toward the chip portion relative to a virtual anode center line parallel to the lamp axis. Although the reddishness of the periphery on the screen decreases as the ratio of the deviation increases, the ratio can be set to an appropriate ratio so that the loss as a whole of the optical system does not become too large.

The discharge medium is at least dysprosium D
It is essential to include y and one kind of neodymium Nd, but any other discharge medium is allowed. As a high-pressure discharge lamp for a liquid crystal projector, the following configuration provides a preferable result in terms of required luminous characteristics, that is, luminous efficiency, correlated color temperature, chromaticity, and color rendering. Dysprosium Dy and neodymium Nd are the main components, and thallium Tl and / or tin Sn are added as subcomponents as necessary, and an appropriate amount of iodine I is added to these components.
And / or bromine Br is sealed together with mercury and a rare gas.

According to the present invention, 1.5-1.5.
A cathode shifted by 3.0 mm, and (a−n) / L (m
When m) is 0.29 or more and less than 2.7, the influence of the shadow of the electrode is reduced.

According to the second aspect of the present invention, since the reflecting mirror is integrated, it is easy to exhibit optical performance. It is suitable for applications such as liquid crystal projectors and overhead projectors.

According to the third aspect of the present invention, in order to maintain the temperature of the cathode in a predetermined range, a heat insulating material may be provided on the outer surface of the airtight container near the cathode. Since it is located on the top side of the reflecting mirror, the heat retaining material does not block the light that is going to be incident near the top of the reflecting mirror, so that the effective light amount does not decrease. Therefore, the effective light amount can be increased.

In the invention of claim 4, the lighting device may have any configuration as long as it can stably light the DC high pressure discharge lamp for vertical lighting of claims 1 to 3. However, when used in devices such as liquid crystal projectors and overhead projectors, it is important that they are lightweight and compact, and those that are mainly composed of semiconductors are particularly preferable because of their ease of control such as dimming. It is. As a lighting device mainly composed of a semiconductor, for example, a circuit configuration mainly composed of a step-down chopper satisfies the above-mentioned request relatively well.

The invention of claim 5 includes, for example, a liquid crystal projector, an overhead projector and the like.

The invention according to claim 6 includes a liquid crystal projector and the like. And the image projection apparatus which has the effect of each invention of Claim 1 thru | or 3 can be provided.

[0028]

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

FIG. 1 is a partial sectional view showing a first embodiment of a DC high-pressure discharge lamp for vertical lighting according to the present invention.

In the figure, 1 is an airtight container, 2 is an anode, 3
Is a cathode, and 4 is a reflecting mirror. In the airtight container 1, dysprosium Dy, neodymium Nd, thallium T
A luminescent metal composed of 1 and tin Sn, iodine I and bromine Br as halogen, mercury, and argon as a rare gas are enclosed.

The hermetically sealed container 1 is made of quartz glass, and has a spindle-shaped valve portion 1a having an outer diameter of 15.5 mm at the center, and a pair of sealing portions 1b1 and 1b2 opposed to its longitudinal direction.
The tip part 1c is integrally provided on a part of the side surface of the valve part 1a.

The anode 2 has a shaft 2a made of tungsten.
And a coil portion 2c formed by winding a tank stainless wire around the shaft 2a so as to project the tip 2b of the shaft. And it is mechanically supported by the sealing part 1b1 by the shaft rod 2b, and is electrically connected to the metal foil 5 embedded in the sealing part 1b1.

The cathode 3 is made of tungsten, and the electrode main part 3a and the shaft part 3b are formed of one tungsten rod. The shaft portion 3b is mechanically supported by the sealing portion 1b2 and is electrically connected to the metal foil 5 embedded in the sealing portion 1b2.

The metal foil 5 is made of molybdenum and sealed in the sealing portions 1b1 and 1b2, respectively, and electrically connects the inside of the airtight container 1 and the outside while maintaining the airtightness. . The metal foil 5 has a thickness of 30 μm and a width of 3 μm.
mm.

When the lamp axis is a straight line connecting the centers of the sealing portions 1b1 and 1b2, the center of the anode 2 coincides with the lamp axis, and the cathode is displaced toward the chip. The degree is 1.8 mm, and (an) / L (m
m) is 1.29.

The distance between the anode 2 and the cathode 3, ie, the distance between the electrodes, is actually about 0.5 to 3 times the area of the tip of the anode, ie, the thickness of the shaft rod 2b in this embodiment. It is a target.

The reflecting mirror 4 is formed by glass molding, has a cylindrical neck portion 4a at the top, and has a reflecting film (not shown) that reflects visible light and infrared light on the inner surface of the reflecting mirror main portion 4b. ) Is applied. Also, the reflecting mirror main body 4
A through hole 4c is formed in b.

The DC high pressure discharge lamp for vertical lighting has its base 6 fixed to the neck 4a via a base cement 7. External conductor 8 and metal foil 5
The lead wire 9 is guided to the rear side of the reflecting mirror 4 through the through hole 4c of the reflecting mirror 4.

FIG. 2 is a front view of a main part of a second embodiment of the DC high pressure discharge lamp for vertical lighting according to the present invention.

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

This embodiment differs from the embodiment shown in FIG. 1 in the configuration of the anode 2 and the mode of deviation of the cathode 3.

The anode 2 'has a large-diameter anode main portion 2'd at the tip of the shaft portion 2'a. The area of the tip of the anode main portion 2'd is limited by the tapered portion 2'e. The anode 2 ′ is connected to the metal foil 5 by being inclined downward in the figure. That is, the lamp axis A-
An anode center line BB 'parallel to the lamp axis passing through the center of the tip of the anode 2 with respect to the line A' is deviated in a direction away from the tip portion 1c.

On the other hand, the cathode 3 has a lamp axis AA '
They are arranged on the line with their center lines aligned.

FIG. 3 is a circuit diagram showing an embodiment of a lighting device for a DC high-pressure discharge lamp for vertical lighting according to the present invention.

In the figure, 11 is a DC power supply, 12 is a step-down chopper, 13 is lamp current detecting means, 14 is lamp voltage detecting means, 15 is a starting circuit, 16 is a DC step-down discharge lamp of the present invention, 17 is feedback means, 18 is a control means.

Then, the DC voltage is chopped at a high frequency in the step-down chopper 12 and smoothed to light the DC high-pressure discharge lamp 16 for vertical lighting. Then, the feedback means 17 determines a required amount of feedback in accordance with the respective outputs of the lamp current detection means 13 and the lamp voltage detection means 14, and feeds it back to the control means 18. Since the control means 18 changes the chopping duty of the step-down chopper 12, the vertical lighting DC high-pressure discharge lamp 16 can be controlled with constant power. If necessary, return means 1
In 7, the life judgment conditions such as the initial lamp voltage or the condition that the lamp voltage during lighting is lower than the lamp voltage at the time of previous lighting are set in advance, and when these conditions are satisfied, the DC high voltage discharge for vertical lighting is set. It is also possible to determine that the lamp has reached the end of its life and to shut off the power.

FIG. 4 is a conceptual diagram showing an embodiment in which the image projection apparatus of the present invention is applied to a liquid crystal projector.

In the figure, 4 is a reflecting mirror, 19 is a DC high-pressure discharge lamp for vertical lighting of the present invention, and both are preliminarily integrated as shown in FIG. 21
Is a liquid crystal image display means, which is radiated from the DC lighting high-pressure discharge lamp 19 for vertical lighting from the back thereof, and the light condensed by the reflecting mirror 4 is reflected by the second reflecting mirror 4b at an angle of 45. 25. Reference numeral 22 denotes an image control unit for driving and controlling the liquid crystal image display unit 21. The image control unit 22 may include a television receiving unit if necessary. Reference numeral 23 denotes an AC power supply, which provides a required power supply to the lighting device 24 of the DC high-pressure discharge lamp for vertical lighting and the image control means 22. It is assumed that the lighting device 24 of the DC high-pressure discharge lamp for vertical lighting has a built-in rectifying means or is interposed between the lighting device 24 and the AC power supply 23. Reference numeral 25 denotes an optical system which condenses light transmitted through the liquid crystal image display means 21 to form a screen 26.
To project. Reference numeral 27 denotes a main body case which houses the above-described components.

[0049]

According to the first to sixth aspects of the present invention, it is possible to provide a direct-current high-pressure discharge lamp for vertical lighting that is not affected by the shadow of the electrode while being vertically lit.

According to the second aspect of the present invention, it is possible to provide a DC high pressure discharge lamp for vertical lighting in which a reflecting mirror is integrated.

According to the third aspect of the present invention, it is possible to provide a direct-current high-pressure discharge lamp for vertical lighting with a large amount of effective light, in which the anode is located on the top side of the reflecting mirror.

According to the invention of claim 4, it is possible to provide a DC high-pressure discharge lamp device for vertical lighting having the effects of claims 1 to 3.

According to the fifth aspect of the present invention, it is possible to provide an image projection apparatus having the effects of the first to third aspects.

According to the invention of claim 6, it is possible to provide an image projection apparatus having the effects of claims 1 to 3 and suitable for a liquid crystal projector.

[Brief description of the drawings]

FIG. 1 is a first DC high-pressure discharge lamp for vertical lighting according to the present invention.
Partial sectional front view showing an embodiment of the present invention.

FIG. 2 shows a second embodiment of a DC high-pressure discharge lamp for vertical lighting according to the present invention.
Main part front view showing the embodiment of the present invention

FIG. 3 is a circuit diagram showing an embodiment of a DC high-pressure discharge lamp device for vertical lighting according to the present invention.

FIG. 4 is a conceptual diagram showing an embodiment in which the image projection device of the present invention is applied to a liquid crystal projector.

[Explanation of symbols]

 1. Airtight container 2. Anode 3. Cathode 4. Reflector

Claims (6)

[Claims] A main light-emitting portion has a bulging shape and is a fire-resistant and light-transmitting airtight container; And a cathode deviated by 1.5 to 3.0 mm from the discharge center with respect to the anode sealed opposite to the anode and a metal containing at least one of dysprosium Dy and neodymium Nd sealed in an airtight container And a discharge medium containing a halide, a rare gas and mercury of (a-n) / L (mm).
Is higher than or equal to 0.29 and less than 2.7. 2. The apparatus according to claim 1, further comprising an integrated reflector whose central axis is substantially aligned with the lamp axis.
A high-pressure DC discharge lamp for vertical lighting as described in the above. 3. The high-pressure discharge lamp according to claim 22, wherein the anode is located on the top side of the reflecting mirror. 4. A vertical lighting DC high pressure discharge lamp according to claim 1, and a lighting device for energizing the vertical lighting DC high pressure discharge lamp. DC high pressure discharge lamp device for vertical lighting. 5. A DC high-pressure discharge lamp for vertical lighting according to any one of claims 1 to 3, a lighting device for lighting the DC high-pressure discharge lamp for vertical lighting, and reflection and radiation from the DC high-pressure discharge lamp for vertical lighting. Image means for irradiating the light condensed by the mirror from behind; optical system for condensing the light transmitted through the image means and projecting it on a screen; and a main body case for accommodating each of the above-mentioned components. An image projection device characterized in that: 6. A DC high-pressure discharge lamp for vertical lighting according to any one of claims 1 to 3, a lighting device for lighting the DC high-pressure discharge lamp for vertical lighting, and reflection and radiation from the DC high-pressure discharge lamp for vertical lighting. Image display means for irradiating the light condensed by the mirror from behind; image control means for controlling the image display means; an optical system for condensing light transmitted through the image display means and projecting the light on a screen; An image projecting device, comprising: a main body case for housing each of the above components.