JP2007213976A - High pressure discharge lamp and image projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize good color temperature properties of a high pressure lamp for image projection while taking the environment into account. <P>SOLUTION: Electrodes 151, 152 are placed at a facing distance L of 3.0 mm or shorter in a discharge space 14 of a transparent valve 11. Xe at 3 atm or higher at the room temperature, at least one of metal halides of Sc, Dy, Nd and In, and zinc halide ZnX<SB>2</SB>(X shows halogen element) are enclosed in the discharge space 14. The high pressure lamp does not contain mercury basically, and has a lamp power of 80 W at Vl/L>10(V/mm) where Vl(V) is a lamp voltage. The high pressure lamp satisfies two inequalities: 0.4 (W/mm<SP>3</SP>)≤WL/V≤1.0 (W/mm<SP>3</SP>) (1) and 1.8×10<SP>-8</SP>(mol/mm<SP>3</SP>)≤Y/V≤4.0×10<SP>-8</SP>(mol/mm<SP>3</SP>) (2) where WL(W) is a lamp power, V(mm<SP>3</SP>) is a capacity inside the discharge space 14, and Y(mol) is a mol number of the enclosed ZnX<SB>2</SB>. This realizes improvement in lamp efficiency and color temperature, and can provide a light source excellent in color reproducibility for a projector. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention takes into account an environment in which mercury is essentially not enclosed, which is used as a light source of an image projection apparatus such as a liquid crystal projector, which requires a high efficiency, high output, high light collection efficiency and a compact design. The present invention relates to a high-pressure discharge lamp and an image projection apparatus using the same.

Conventionally, a high pressure discharge lamp mounted as a light source for a projector has an opposing electrode in a discharge space formed inside a translucent airtight container, and this electrode is joined to one end of a metal foil, An electrical lead-in wire is joined to the other end of the foil, and it has a pair of opposed sealing parts sealed with a reduced-pressure seal so as to maintain hermeticity at the metal foil part. It was an ultra-high pressure mercury lamp in which a discharge medium containing mercury, halogen, rare gas, or the like was enclosed and the mercury vapor pressure in the discharge space became high pressure of 10 MPa or more during lighting (for example, Patent Document 1).
Special table -2003-526182

  The technology of Patent Document 1 described above is that the ultra-high pressure mercury lamp encloses a large amount of mercury so that the mercury vapor pressure exceeds 10 MPa at the time of lighting. There wasn't.

  An object of the present invention is to solve a decrease in lamp efficiency and a reduction in color temperature, and to use a high-pressure discharge lamp excellent in color reproducibility and essentially free of mercury as a light source for a projector, and the high-pressure discharge lamp. An object is to provide an image projection apparatus.

In order to solve the above-described problems, a high-pressure discharge lamp according to the present invention includes a transparent quartz glass bulb, an electrode disposed at a facing distance of 3.0 mm or less in the discharge space of the bulb, and the discharge space. Inside, Xe of 3 atm or more at room temperature and at least one of Sc, Dy, Nd and In metal halides and zinc halide ZnX ₂ (X represents a halogen element) are enclosed, and essentially contains mercury. In a high pressure discharge lamp in which Vl / L> 10 (V / mm) and the lamp power is 80 (W) or more when the lamp voltage is Vl (V), the lamp power is set to WL (W), When the arc tube inner volume is V (mm ³ ) and the number of moles of the enclosed ZnX ₂ is Y (mol), the following expressions (1) and (2) are satisfied.

0.4 (W / mm ³ ) ≦ WL / V ≦ 1.0 (W / mm ³ ) (1)
1.8 × 10 ⁻⁸ (mol / mm ³ ) ≦ Y / V ≦ 4.0 × 10 ⁻⁸ (mol / mm ³ )
(2)

According to the present invention, by satisfying the above formulas (1) and (2), the lamp efficiency can be improved,
By increasing the color temperature, a light source having excellent color reproducibility can be obtained as a light source for a projector.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a configuration diagram for explaining an embodiment of a high-pressure discharge lamp according to the present invention. In FIG. 1, reference numeral 11 denotes a transparent quartz glass bulb, and an arcuate arc tube portion 12 and the bulb 11 formed of the same material as the arc tube portion 12 at both longitudinal ends thereof are hermetically sealed. It consists of stop portions 131 and 132. The arc tube portion 12 is formed with a discharge space 14 of a substantially elliptical rotating body in the longitudinal direction, and the discharge space 14 is extended from the inside of the sealing portions 131 and 132, for example, a dope material Electrodes 151 and 152 formed of pure tungsten material to which no is added are arranged so that their tips are opposed to each other with a gap. The shaft diameters of the electrodes 151 and 152 are φ0.5 mm, and coils 161 and 162 of φ0.2 mm are wound around one end of the electrodes 151 and 152. The tip portions of the electrodes 151 and 152 are melted by a plasma heat source, solidified into a substantially hemispherical shape and integrated, and projections 171 and 172 are formed so that the arc concentrates.

  The discharge space 14 includes a first halogen metal such as dysprosium (Dy), neodymium (Nd), scandium (Sc), and indium (In) mainly caused by light emission, and zinc mainly caused by lamp voltage. A discharge medium containing a second halogen metal such as (Zn) and a rare gas is enclosed.

  The sealing parts 131 and 132 are formed by being crushed, and metal foils 181 and 182 made of molybdenum (Mo) are sealed therein. One end of each of the metal foils 181 and 182 is welded to the electrodes 151 and 152, and nickel wires 191 and 192 are connected to the other ends, respectively. The wires 191 and 192 are lighting devices outside the lamp. 20 is an introduction lead for receiving power supply from 20.

  Here, mercury is essentially not enclosed in the discharge medium in the mercury-free high-pressure discharge lamp. “Essentially no mercury is enclosed” means not only that mercury is not enclosed at all, but also that less than 2 mg, preferably 1 mg or less of mercury is present per 1 cc of the internal volume of the airtight container. It means to do. However, it is environmentally desirable not to enclose mercury at all. When maintaining the electrical characteristics of the discharge lamp with mercury vapor as in the past, in a small high-pressure metal vapor discharge lamp with a relatively small distance between the electrodes, 200 to 400 mg per cc of the internal volume of the hermetic container, and in some cases Judging from the fact that 500 mg or more was enclosed, it can be said that the amount of mercury was substantially small.

  The rare gas is sealed at a pressure of 3 to 15 atmospheres. The rare gas is preferably Xe. The reason why the rare gas sealing pressure is set to 5 to 10 atm is that within this range, the desired luminous intensity can be obtained in a short time by speeding up the rising of the luminous flux up to several seconds immediately after lighting. If there is not much inconvenience in the time until the desired light intensity is obtained immediately after lighting, it is possible to lower the sealing pressure.

  Next, a specific specification example of the high-pressure discharge lamp that is turned on by the high-pressure discharge lamp of the present invention will be described with reference to FIG.

(1) Arc tube portion 12: Center outer diameter L1 ... 10.0 mm, wall thickness L2 ... 2.2 mm, inner diameter L3 ... 5.6 mm, sphere length L4 ... 8.0 mm, inner volume ... 130 mm ³
(2) Electrodes 151, 152: Electrode axis L5: φ0.5 mm, coils 161, 162 diameter L6: φ0.15 mm, protrusions 171, 172 maximum diameter L7: 1.0 mm, distance between electrodes L8: 2.0 mm
(3) Metal foils 181 and 182: Film thickness: 0.028 mm, width: 2.0 mm, length: 17 mm
(4) the discharge space 14: the light emitting metal _{halide, DyI 3 -NdBr 3 -ScI 3 -InBr} -CsI ... 0.6mg, ZnI 2 ... 3.0mg, MnI 2 ... 0.5mg, noble gases Xe10 atm ceramic heater (5) a discharge _{medium: ZnI 2, Dy-Nd-} in-Cs -based metal halide (luminescent metal), ZnI ₂ and ^{1.0mg (2.4 × 10 -8 (mol} / mm 3)), and other metal 0.6mg sealed, Xe gas sealed at about 9atm at room temperature (6) Rated lamp power: 100W
(7) Lamp voltage: 35V
(8) Lamp efficiency: 55lm / W
(9) Color temperature: 5,500K
(10) Average color rendering index Ra: 90
FIG. 3 shows the specifications of the prototype, including the above-described embodiment. FIGS. 4 and 5 are for explaining the relationship between the lamp voltage and Y / V and the relationship between the color temperature and Y / V. It is explanatory drawing of.

4 and 5, the value of Y / V satisfies the relationship of 1.8 × 10 ⁻⁸ (mol / mm ³ ) ≦ Y / V ≦ 4.0 × 10 ⁻⁸ (mol / mm ³ ). Thus, it can be seen that good characteristics can be obtained for both the lamp voltage and the color temperature.

  FIG. 6 shows WL / V test results when the samples B, E, and H of FIG. 3 were used and the lamp power was swung at 80 W, 100 W, and 120 W. Based on this result, FIG. FIG. 8 is an explanatory diagram for explaining the relationship between efficiency and WL / V, and FIG. 8 for explaining the relationship between color temperature and WL / V.

From FIG. 7 and FIG. 8, when the value of WL / V satisfies the relationship of 0.4 (W / mm ³ ) ≦ WL / V ≦ 1.0 (W / mm ³ ), either lamp efficiency or color temperature can be obtained. It can be seen that good characteristics can be obtained.

Thus, with the relationship between the lamp voltage and Y / V and the color temperature and Y / V, the value of Y / V is 1.8 × 10 ⁻⁸ (mol / mm ³ ) ≦ Y / V ≦ 4.0 × 10. By satisfying the relationship of ⁻⁸ (mol / mm ³ ), good characteristics are obtained for both the lamp voltage and the color temperature, and the value of WL / V is the lamp efficiency and the WL / V and the color temperature and the WL / V. However, by satisfying the relationship of 0.4 (W / mm ³ ) ≦ WL / V ≦ 1.0 (W / mm ³ ), good characteristics can be obtained in both lamp efficiency and color temperature.

  According to this embodiment, it is possible to improve the color temperature, the lamp voltage, and the lamp efficiency while being a high-pressure discharge lamp that is essentially not sealed with mercury.

  FIG. 9 is a system configuration diagram for explaining the image projection apparatus of the present invention when the high pressure discharge lamp having the configuration shown in FIG. 1 is mounted on a liquid crystal projector.

  In FIG. 9, reference numeral 91 denotes a liquid crystal projector. The liquid crystal projector 91 has a main body 92, and a projection opening 93 is formed on the front side of the main body 92. In addition, a light source 94 is disposed in the main body 92, and the light source 94 is formed by a reflector 96 as a reflecting means that is optically opposed to the high-pressure discharge lamp 95 and the high-pressure discharge lamp 95. A liquid crystal panel 97 serving as display means is disposed in front of the irradiation direction of the light source 94, and a projection lens 98 serving as projection means is disposed corresponding to the projection opening 93 in front of the liquid crystal panel 97. Yes. A screen 99 is disposed in front of the projection opening 93.

  Further, a lighting circuit 100 is connected to the high-pressure discharge lamp 95, a liquid crystal driving circuit 101 is connected to the liquid crystal panel 97, and a commercial AC power source 102 is connected to the lighting circuit 100 and the liquid crystal driving circuit 101. The lighting circuit 100 may be one that lights the high-pressure discharge lamp 95 with direct current or one that lights with alternating current.

  The image projection apparatus having the above-described configuration first lights the high-pressure discharge lamp 95 of the light source 94 with the power supplied from the lighting circuit 100. The light from the high pressure discharge lamp 95 is irradiated directly or reflected by the reflector 96 toward the liquid crystal panel 97. The liquid crystal panel 97 changes the display by the liquid crystal driving circuit 101, transmits the light from the light source 94, projects it by the projection lens 98, and displays an image on the screen 99.

  In addition, although the radial direction of the reflector 96 is open, a transparent front glass may be disposed, and the high-pressure discharge lamp 95 disposed in the reflector 96 may be sealed from the outside.

  In this liquid crystal projector, while using a high-pressure discharge lamp that does not contain mercury, in addition to good color temperature characteristics as a liquid crystal projector, good lamp efficiency and lamp voltage can be obtained, thus improving the color reproducibility of the image In addition, it is easy to obtain matching of optical design.

The block diagram for demonstrating one Embodiment of the high pressure discharge lamp of this invention. BRIEF DESCRIPTION OF THE DRAWINGS The block diagram for demonstrating Example 1 of the high pressure discharge lamp of this invention. Explanatory drawing for demonstrating the specification of the sample made as a prototype. Illustration for explaining a relationship of the relationship between the lamp voltage and Y (number of moles of ZnX ₂₎ / V (arc tube volume). Explanatory drawing for demonstrating the relationship between color temperature and Y / V. Explanatory drawing for demonstrating the test which used the samples B, E, and H of FIG. Explanatory drawing for demonstrating the relationship between lamp efficiency and WL (lamp electric power) / V. Explanatory drawing for demonstrating the relationship between color temperature and WL / V. 1 is a system configuration diagram for explaining an embodiment of an image projection apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Bulb 12 Light-emitting tube part 131,132 Sealing part 14 Discharge space 151,152 Electrode 161,162 Coil 171,172 Projection part 181,182 Metal foil 191,192 Wire 20 Lighting device 91 Liquid crystal projector 92 Main body 95 High pressure discharge lamp 99 screen

Claims (2)

A transparent quartz glass bulb, electrodes arranged at a facing distance of 3.0 mm or less in the discharge space of the bulb, and Xe and Sc, Dy, Nd, In of 3 atm or more at room temperature in the discharge space When at least one of the above metal halides and zinc halide ZnX ₂ (X represents a halogen element) is enclosed, essentially does not contain mercury, and the lamp voltage is Vl (V), Vl / L> In a high-pressure discharge lamp with a lamp power of 80 (W) or more at 10 (V / mm),
When the lamp power is WL (W), the arc tube inner volume is V (mm ³ ), and the number of moles of ZnX _{2 to be} sealed is Y (mol), the following expressions (1) and (2) are satisfied. A high-pressure discharge lamp characterized by comprising

0.4 (W / mm ³ ) ≦ WL / V ≦ 1.0 (W / mm ³ ) (1)

1.8 × 10 ⁻⁸ (mol / mm ³ ) ≦ Y / V ≦ 4.0 × 10 ⁻⁸ (mol / mm ³ )
(2) A high-pressure discharge lamp according to claim 1;
An image projection apparatus comprising: an image projection apparatus main body that projects an image based on light emitted from the high-pressure discharge lamp as a light source.

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