JPH11317198A - Discharge lamp, lamp device and liquid crystal projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp capable of maintaining high mechanical strength, even if its sealed part is formed thin. SOLUTION: This discharge lamp 1 consists of an airtight container 2 made of quartz glass having a swelled part 3 and a sealed part 23, a discharge medium having mercury sealed in the swelled part 3 of the airtight container 2, an anode 5 and a cathode 6 facing each other in a discharge space 4 in the swelled part 3, metal foils 11, 13, 18 connecting with them, and external leadwires 14, 19 welded to the metal foils 11, 13, 18. It is also equipped with a pair of electrode structural bodies 7, 8 provided at both ends of the airtight container 2 by welding the metal foils 11, 13, 18 to the external lead wires 14, 19, and the sealing surfaces of the sealed part 23 are twisted each other at an angle within 10 deg.-90 deg. with a longitudinal center line of the airtight container 2 as a center.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp, a lamp device, and a liquid crystal projector, and more particularly, to a short arc mercury lamp, a lamp device including the short arc mercury lamp and a reflector, and the lamp device as a light source. The present invention relates to a liquid crystal projector used.

[0002]

2. Description of the Related Art Conventionally, floodlights, image display devices, and the like have been widely used, and high-pressure discharge lamps are often used as light sources. Among these high-pressure discharge lamps, short-arc type high-pressure discharge lamps which are close to a point light source and whose light distribution control is easy, such as xenon lamps and meta-halide lamps, have recently become remarkably popular. It is being widely used as a light source for projectors. A liquid crystal projector is a device that projects an image, and is a device that can project not only a still image but also a moving image. Since various images can be projected by inputting a video signal or an image signal of a personal computer, it is used as a presentation tool, for a simple theater, or as a large screen TV. And are used in various fields.

[0003] Since this liquid crystal projector is still very expensive as compared with a TV or the like, cost reduction is being promoted by miniaturizing each part as an improvement, and brightness is still not enough in the market. Since the level has not reached an acceptable level, improvements using special optics are under way. In this type of apparatus, a high-pressure discharge lamp is currently used to meet these demands, and further demands for short gaps, high efficiency, and long life are being made. Further, in order to reduce the product cost, the cost requirement for the lamp becomes severe, and it is necessary that the lamp be simple and highly reliable.

In order to meet these demands, a sealing step performed to form an arc tube is an important point, and the method of this step determines the cost and reliability of a product. In order to solve this problem, pinching is currently used as a method for shortening the processing time and efficiently manufacturing. In the case of this pinch method, sealing portions pressed flat on both sides of the bulging portion of the hermetic container made of quartz glass are formed.

[0005]

The direction of the sealing surfaces of the sealing portions formed on both sides of the bulging portion is the same in all the sealing portions, and the thickness of the sealing portion is the same. Has a problem that the mechanical strength in one direction is low as a whole because it is thinner than other parts. That is, since the sealing surfaces of the thinly formed sealing portions are in the same direction, when a bending stress is applied over the entire length, the sealing portion is weak against a force in a direction of a small thickness.

[0006]

According to the first aspect of the present invention,
An airtight container made of quartz glass having a bulging portion and a sealing portion;
A discharge medium containing mercury sealed in the hermetic container; an anode and a cathode facing each other in the discharge space in the bulging portion, a metal foil connected thereto, and an external lead wire welded to the metal foil; A metal foil and a pair of electrode assemblies provided at both ends of the hermetic container by welding the external lead wires, wherein a sealing surface of the sealing portion is centered on a longitudinal center line of the hermetic container. The discharge lamps are twisted at an angle of 10 to 90 ° with each other.

According to a second aspect of the present invention, there is provided a discharge lamp according to the first aspect, wherein the light emitting portion of the discharge lamp is positioned at a focal point and the base of one end of the discharge lamp is fixedly held. And a reflecting mirror for reflecting light from the light source in a predetermined direction.

According to a third aspect of the present invention, there is provided the lamp device according to the second aspect connected to lighting means; a liquid crystal display panel driven by a liquid crystal driving means; An optical system for projecting the transmitted light to the screen; and an opening for containing the lighting means, the lamp device, the liquid crystal driving means, the liquid crystal display panel, and the optical system, and projecting the light transmitted through the liquid crystal display panel to the screen. And a liquid crystal projector comprising:

[0009]

FIG. 1 shows a first embodiment of the present invention.
A description will be given based on FIG. This embodiment relates to a discharge lamp 1. The discharge lamp 1 includes an airtight container 2 made of quartz glass and this airtight container 2.
And a discharge medium containing mercury sealed in the bulging portion 3, and an anode 5 and a cathode 6 facing each other in a discharge space 4 in the bulging portion 3. And a pair of electrode structures 7 and 8. In this case, the size of the bulging portion 3 is such that the short axis (inner diameter) is 8 mm, the long axis is 12 mm, and the tube wall load is 55 W / cm ^2.
Designed for The thickness of the bulging portion 3 is 2 mm.

One electrode assembly 7 includes an electrode main body 9 serving as an anode 5 disposed in the discharge space 4 of the bulging portion 3 and an electrode shaft 1.
0, a metal foil 11 for hermetic sealing, a lead wire 12, a metal foil 13 for hermetic sealing, and an external lead wire 14 are integrally connected and sealed in the hermetic container 2. The portion protruding from the airtight container 2 is the terminal portion 15.
And the external connection line 16 is connected. The above-described anode 5 is made of tungsten having a diameter of 2.0 mm, and is formed of metal foils 11 and 13 having a width of 2 mm and a length of 15 mm.
The lead wire 12 is made of molybdenum. Further, the other electrode structure 8 is connected to the discharge space 4 of the bulging portion 3.
An electrode body 17 serving as the cathode 6 disposed therein, a metal foil 18 for hermetic sealing, and an external lead wire 19 are integrally connected and sealed in the hermetic container 2. This cathode 6 has 0.7
It is formed of tungsten having a diameter of mm. A coil 20 is wound around the outer periphery of the cathode 6 to prevent a temperature rise and prevent evaporation of a cathode material such as tungsten. The electrode assembly 8 is connected to a base 22 having terminal screws 21 formed at an end of the airtight container 2.

The airtight container 2 has sealing portions 2 on both sides of the bulging portion 3.
3, the anode-side sealing portion 25 is formed to be longer than the cathode-side sealing portion 24. Cathode side sealing part 24
Is provided with a pinch seal portion 26 sealing the metal foil 18 of the electrode assembly 8. Further, the anode side sealing portion 25 includes an electrode shaft sealing portion 27 and a pinch seal portion 2 for sealing the metal foil 11.
8 and a chip space 2 in which a chip for gas filling is formed
9 and a pinch seal portion 30 for enclosing a part of the metal foil 13 and the external lead wire 14.

Thus, the pinch seal portions 26, 28, 30 of the cathode side sealing portion 24 and the anode side sealing portion 25, respectively.
Are flattened by pressing, and their sealing surfaces are twisted within a range of 10 to 90 ° about the center line in the longitudinal direction of the airtight container 2. Therefore, in each of the pinch seal portions 26, 28, and 30, no sealing surface faces in the same direction. For example, as shown in A, B, and C of FIG.
₁ and C are inclined by θ ₂ .

In such a configuration, when a voltage is applied to the discharge lamp 1, an arc is generated between the anode 5 and the cathode 6, and the discharge lamp 1 is turned on. As a result, the temperature rises, but the rise in temperature increases not only in the bulging portion 3 serving as the light emitting portion, but also in the sealing portion 23 in which the electrode assemblies 7 and 8 are sealed. When a mechanical load acts on the discharge lamp 1,
That is, when bending stress is applied to the whole, the plurality of sealing portions 23 having a flat cross section, specifically, the sealing surfaces of the pinch seal portions 26, 28, and 30 face different directions. Therefore, any one of the pinch seal portions 26, 28, and 30 is only weak against bending, and the whole is in a strong state. Therefore, regardless of whether the discharge lamp 1 is used in horizontal lighting or vertical lighting, a mechanically stable state is obtained and the degree of deformation is small.

Next, a second embodiment of the present invention will be described with reference to FIG. In the present embodiment, a lamp device 31 is formed using the above-described discharge lamp 1. That is, a reflecting mirror 33 having an upward opening is installed in the box 32, and a light emitting unit (anode 5)
The discharge lamp 1 is mounted vertically with the portion facing the cathode 6). At this time, the anode-side sealing portion 25 of the discharge lamp 1 protrudes from the upper edge portion 34 of the reflecting mirror 33, but a cylindrical spacer made of an insulator having a sufficient length to cover the anode-side sealing portion 25. 35 is attached to the reflecting mirror 33, and a flat front glass 36 is attached to the upper edge of the spacer 35.

In such a configuration, by arranging the discharge lamp 1 in a sealed or nearly closed state by the spacer 35 and the front glass 36, it is possible to prevent ultraviolet radiation from the discharge lamp 1. Thus, when used in a liquid crystal projector or the like to be described later, it is possible to prevent deterioration of optical components and the like due to ultraviolet rays.

Further, since the lamp is used in the vertical lighting mode, when the discharge lamp 1 ruptures, the front glass 36 prevents the fragments and the like from being scattered, and is collected inside the reflecting mirror 33. In addition, since the front glass 36 is provided, a silencing effect at the time of rupture can be obtained.

In the embodiment, the discharge lamp 1 may be disposed horizontally to light horizontally.

A third embodiment of the present invention will be described with reference to FIG. In the present embodiment, a liquid crystal projector 37 is formed using the above-described lamp device 31. That is, the liquid crystal projector 37 includes the above-described lamp device 31 connected to the lighting device 38 and the liquid crystal driving device 39.
Liquid crystal display panel 40 driven by the
An optical system 42 for projecting the light radiated from 1 through the liquid crystal display panel 40 to a screen 41, that is, a mirror 4
3, a lens 44, a lighting means 38, a lamp device 31, a liquid crystal driving means 39, an opening 45 for accommodating the liquid crystal display panel 40 and the optical system 42 and projecting light transmitted through the liquid crystal display panel 40 to the screen 41. Case 4
6 Also in this case, the discharge lamp 1 of the lamp device 31 is vertically lit in the vertical state. Therefore, the liquid crystal display panel 40 is provided horizontally, and the optical axis is 9
An image is projected on the screen 41 on the vertical plane after being bent by 0 °.

Also in this case, a lamp device 31 in which the discharge lamp 1 is horizontal may be used.

[0020]

According to the first aspect of the present invention, an airtight container made of quartz glass having a swelling portion and a sealing portion; a discharge medium sealed in the airtight container and having mercury; It comprises an anode and a cathode facing each other in the discharge space, a metal foil connected to the anode and a cathode, and an external lead wire welded to the metal foil. The metal foil and the external lead wire are welded and arranged at both ends of the hermetic container. A pair of electrode structures provided;
Since the sealing surface of the sealing portion is a discharge lamp in which the sealing surface is twisted at an angle of 10 to 90 ° with respect to the longitudinal center line of the hermetic container, when an external force is applied, sealing at a plurality of locations is performed. Since the sealing surfaces of the portions are oriented in different directions, the mechanical strength can be increased as a whole even if those sealing portions are formed thin, and the degree of deformation can be reduced. Things.

According to a second aspect of the present invention, there is provided a discharge lamp according to the first aspect, wherein the light emitting portion of the discharge lamp is positioned at a focal point and a base at one end of the discharge lamp is fixedly held. Since the lamp device is formed by a reflecting mirror that reflects light from the lamp in a predetermined direction, the lamp characteristics and the life can be improved.

According to a third aspect of the present invention, there is provided a lamp device according to the second aspect connected to lighting means; a liquid crystal display panel driven by a liquid crystal driving means; An optical system for projecting the transmitted light to the screen; and an opening for containing the lighting means, the lamp device, the liquid crystal driving means, the liquid crystal display panel, and the optical system, and projecting the light transmitted through the liquid crystal display panel to the screen. Since the liquid crystal projector is formed by the housing thus formed, it is possible to manufacture a liquid crystal projector including a discharge lamp with high luminance and a long life.

[Brief description of the drawings]

FIG. 1 shows the first embodiment of the present invention, and is a front view of a discharge lamp.

FIG. 2 is a side view of the discharge lamp.

FIG. 3 shows a second embodiment of the present invention and is a longitudinal sectional front view of a lamp device.

FIG. 4 is a vertical sectional side view showing a third embodiment of the present invention and schematically showing an internal structure of a liquid crystal projector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Discharge lamp 2 Airtight container 3 Swelling part 4 Discharge space 5 Anode 6 Cathode 7 Electrode structure 8 Electrode structure 13 Metal foil 14 External lead wire 18 Metal foil 19 External lead wire 31 Lamp device 33 Reflecting mirror 38 Lighting means 39 Liquid crystal driving means Reference Signs List 40 liquid crystal display panel 41 screen 42 optical system 45 opening 46 housing

Claims (3)

[Claims] 1. An airtight container made of quartz glass having a swelling portion and a sealing portion; a discharge medium filled with mercury sealed in the airtight container; and anodes facing each other in a discharge space in the swelling portion. A cathode and a metal foil connected to them and an external lead wire welded to the metal foil, and a pair of electrode assemblies disposed at both ends of the hermetic container by welding the metal foil and the external lead wire; Wherein the sealing surfaces of the sealing portions are 10 to 10 around the longitudinal center line of the hermetic container.
A discharge lamp characterized by being twisted at an angle of 90 ° or less. 2. The discharge lamp according to claim 1, wherein a light-emitting portion of the discharge lamp is located at a focal point and a base at one end of the discharge lamp is fixedly held, so that light from the discharge lamp is directed in a predetermined direction. And a reflecting mirror for reflecting light to the lamp. 3. A lamp device according to claim 2, wherein said lamp device is connected to lighting means; a liquid crystal display panel driven by liquid crystal driving means; and light emitted from said lamp device and passed through said liquid crystal display panel is projected onto a screen. An optical system that emits light; a housing that houses a lighting unit, a lamp device, a liquid crystal driving unit, a liquid crystal display panel, and an optical system, and that has an opening formed to project light transmitted through the liquid crystal display panel onto a screen; A liquid crystal projector comprising: