JP2005005183A - High-pressure mercury lamp, light source device, and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-pressure mercury lamp preventing deformation or explosion of a luminous tube due to use for a long time, and capable of radiating a light flux with excellent color rendering properties, a light source device, and a projector. <P>SOLUTION: The high-pressure mercury lamp 11 is provided with a luminous tube 111 having a discharge space 111A1, a pair of electrodes 112 arranged in the discharge space 111A1 of the luminous tube 111, and an enclosed substance of mercury as well as rare gas sealed in the discharge space 111A1 of the luminous tube 111. It is so constituted that discharge light emission is made between the electrodes 112, and a part of the light flux irradiated from the luminous tube 111 is sent back into the luminous tube 111 by an auxiliary reflecting mirror 13. Mercury as a sealed substance is sealed in the discharge space 111A1 by a sealing amount of 0.15 mg/mm<SP>3</SP>to 0.32 mg/mm<SP>3</SP>at a vapor pressure of 150 bar to 190 bar. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００３７】
ここで、光束の演色性の評価としては、実施例１〜５の光源装置１０から射出される光束の演色評価数Ｒａを測定し、この演色評価数Ｒａが所望の値よりも大きいものを良（○）、小さいものを悪（×）とする。
また、発光部１１１Ａの変形の有無の評価としては、実施例１〜５の光源装置１０を長時間点灯させ、所定時間毎に発光部１１１Ａの直径を測定し、この直径寸法の変化から発光部１１１Ａの変形の有無を測定する。
【００３８】
演色性の評価結果としては、表１に示すように、実施例１〜４は演色評価数Ｒａが所望の値よりも大きくなり演色性を改善できたが、実施例５は演色性を改善できなかった。これは、実施例５において、水銀封入量および水銀蒸気圧が低い値で放電空間１１１Ａ１内に封入したため、可視光領域の連続スペクトルが減少し、副反射鏡１３における戻り光による演色性の改善を相殺してしまったと考えられる。
また、発光部１１１Ａの変形の有無の評価結果としては、図４に示すように、実施例３は光源装置１０を長時間点灯させても発光部１１１Ａの直径に変化はなく、発光部１１１Ａの変形は見られなかった。一方、実施例１は光源装置１０を所定時間点灯させた後、徐々に発光部１１１Ａの直径が大きくなり、２０００時間後には発光部１１１Ａが破裂してしまった。なお、実施例２，４，５に関しても、表１に示すように、実施例３と同様に、発光部１１１Ａの変形は見られなかった。これは、実施例１において、水銀封入量および水銀蒸気圧が高い値で放電空間１１１Ａ１内に封入したため、発光管１１１内の内部気圧を抑えることができず、高圧水銀ランプ１１の点灯および副反射鏡１３による戻り光により発光管１１１内の温度が高くなるにしたがって、発光管１１１が変形し、最後には破裂したと考えられる。
したがって、本発明の水銀封入量が０．１５ｍｇ／ｍｍ^３〜０．３２ｍｇ／ｍｍ^３の範囲内、および水銀蒸気圧が１５０ｂａｒ〜１９０ｂａｒの範囲内に適合する条件において、発光管１１１から射出される光束の演色性の改善、および発光管１１１の変形の回避が実施できることが分かった。
【図面の簡単な説明】
【図１】本実施形態に係るプロジェクタの光学系を示す模式図。
【図２】前記実施形態における光源装置の構造を示す断面図。
【図３】前記実施形態における高圧水銀ランプの分光スペクトルを示す図。
【図４】発光部の変形の有無の評価結果を示す図。
【符号の説明】
１・・・プロジェクタ、１０・・・光源装置、１１・・・高圧水銀ランプ、１２・・・楕円リフレクタ、１３・・・副反射鏡、４２Ｒ，４２Ｇ，４２Ｂ・・・液晶パネル（光変調装置）、５０・・・投写光学装置、１１１・・・発光管、１１１Ａ１・・・放電空間、１１１２・・・電極。[0001]
BACKGROUND OF THE INVENTION
The present invention includes an arc tube having a discharge space, a pair of electrodes disposed opposite to the discharge space of the arc tube, and an enclosure of mercury and a rare gas sealed in the discharge space of the arc tube, The present invention relates to a high-pressure mercury lamp, a light source device, and a projector having discharge light emitted between electrodes and returning light in which part of a light beam emitted from the arc tube returns into the arc tube.
[0002]
[Background]
Conventionally, a projector that modulates a light beam emitted from a light source according to image information and enlarges and projects an optical image is used. Such a projector is used for a presentation at a conference or the like together with a personal computer. In recent years, such projectors are used for home theater applications in response to the need to watch movies on a large screen at home.
As light sources used in projectors, discharge arc tubes such as metal halide lamps and high-pressure mercury lamps are used.
As such a discharge-type arc tube, there has been proposed a lamp that emits a light beam having a good color rendering property as described below.
For example, a high-pressure mercury lamp having an extremely high mercury vapor pressure (for example, 200 bar or higher) in which an arc tube having a pair of electrodes made of tungsten is filled with an enclosure of rare gas, mercury, and a halogenated compound. It is known (see, for example, Patent Document 1).
Here, the enclosed amount of mercury is 0.2 mg / mm ³ As described above, the mercury vapor pressure is increased to increase the continuous spectrum in the visible light region, particularly the red region, thereby improving the color rendering. Moreover, the tube wall load of the arc tube is 1 W / mm ² This is because it is necessary to increase the temperature of the coldest part in order to increase the pressure of mercury. Further, the reason for encapsulating the halogenated compound is to prevent blackening of the tube wall of the arc tube.
[0003]
[Patent Document 1]
JP-A-2-148561
[0004]
[Problems to be solved by the invention]
Since the high-pressure mercury lamp described in Patent Document 1 has a mercury vapor pressure of 200 bar or more, the internal pressure of the arc tube is high. In addition, when the high pressure mercury lamp is turned on, the temperature of the arc tube becomes a high temperature exceeding 1000 ° C. For this reason, the high-pressure mercury lamp described in Patent Document 1 has a problem that the arc tube is deformed or ruptured during long-time lighting.
[0005]
An object of the present invention is to provide a high-pressure mercury lamp, a light source device, and a projector that can prevent deformation or rupture of an arc tube due to long-term use and can emit a luminous flux with good color rendering properties.
[0006]
[Means for Solving the Problems]
The high-pressure mercury lamp of the present invention includes an arc tube having a discharge space, a pair of electrodes disposed opposite to the discharge space of the arc tube, and an inclusion of mercury and a rare gas sealed in the discharge space of the arc tube. A high-pressure mercury lamp that discharges and emits light between the electrodes, and is configured so that a part of a light beam emitted from the arc tube returns into the arc tube, and the mercury is 0.15 mg / mm. ³ ~ 0.32mg / mm ³ And is sealed in the discharge space with a vapor pressure of 150 bar to 190 bar.
Here, the configuration in which a part of the light beam emitted from the arc tube returns to the inside of the arc tube is, for example, a part of the light beam emitted from the arc tube to an optical device in which a high-pressure mercury lamp is used. A configuration may be adopted in which a sub-reflecting mirror that reflects the light is provided. In addition to the configuration in which the sub-reflector is provided in the optical device, a configuration in which the optical device using the high-pressure mercury lamp is mounted may be employed, or a configuration in which the optical device is attached to the arc tube itself may be employed. .
[0007]
The high-pressure mercury lamp of the present invention is configured such that a part of the light beam emitted from the arc tube returns into the arc tube. In such a configuration, the inclusions (mercury and rare gas) in the arc tube absorb the energy of the return light, the luminous efficiency is improved, and the color rendering is improved. However, in such a high-pressure mercury lamp, the temperature in the arc tube tends to increase due to energy absorption, and the arc tube is likely to be deformed or ruptured during long-time lighting as in the case of a conventional high-pressure mercury lamp.
In the present invention, the amount of enclosed mercury is 0.15 mg / mm. ³ ~ 0.32mg / mm ³ Since it is sealed in the discharge space of the arc tube with a vapor pressure of 150 bar to 190 bar, the internal pressure in the arc tube can be suppressed, and even if the temperature in the arc tube becomes high, light emission due to long-term use The tube can be prevented from being deformed or ruptured, and the life of the high-pressure mercury lamp can be extended.
Therefore, it is possible to extend the life while improving the color rendering properties, so that the object of the present invention can be achieved.
Here, the enclosed amount of mercury as the inclusion is 0.15 mg / mm ³ If the mercury vapor pressure is lower than 150 bar, the continuous spectrum in the visible light region decreases, so that the improvement in color rendering due to the return light is offset and the color rendering can not be improved satisfactorily. On the other hand, the enclosed amount of mercury as the inclusion is 0.32 mg / mm ³ If the mercury vapor pressure is higher than 190 bar, the internal pressure in the arc tube cannot be suppressed, and if the temperature in the arc tube becomes high due to lighting and return light of the high-pressure mercury lamp, the arc tube Cannot avoid deformation or rupture.
[0008]
The high-pressure mercury lamp of the present invention includes a sub-reflecting mirror that returns a part of the light beam emitted from the arc tube to the arc tube, and the sub-reflecting mirror is substantially half the front side in the light beam emission direction of the discharge space of the arc tube. Hereinafter, it is preferable to be attached so as to cover 1/3 or more.
According to the present invention, since the sub-reflecting mirror is attached to the high-pressure mercury lamp itself, the sub-reflecting mirror is compared with a configuration in which the sub-reflecting mirror is provided in a light source device in which the high-pressure mercury lamp is used or an optical device in which the light source device is mounted. Thus, the area for capturing the luminous flux can be reduced, and the return light can be efficiently returned into the arc tube with a simple configuration.
In addition, since the sub-reflector is mounted so as to cover approximately one-third or less of the light emission direction front side of the discharge space of the arc tube, it is returned by the sub-reflector out of the light beam emitted from the arc tube. Effective return light can be generated without increasing the amount of light more than necessary and minimizing the return light from the sub-reflector.
Here, when the sub-reflecting mirror is attached so as to cover the arc tube beyond approximately half of the light emission direction front side of the discharge space of the arc tube, the return light by the sub-reflecting mirror is more than necessary, It becomes difficult to emit an appropriate luminous flux from the high-pressure mercury lamp.
In addition, when the sub-reflecting mirror is mounted so as to cover the arc tube less than 1/3 of the discharge space of the arc tube in the light emission direction, there is little return light from the sub-reflecting mirror, and the inclusion in the arc tube As a result, the energy absorption of the return light due to the light becomes small, and the color rendering property cannot be improved appropriately.
[0009]
In the light source device of the present invention, it is preferable that a halogenated compound of any one of chlorine, bromine and iodine is sealed in the discharge space in addition to mercury and a rare gas.
According to the present invention, since a halogenated compound is enclosed in the discharge space in addition to mercury and a rare gas, the constituent material of the electrode adheres to the inner surface of the discharge space of the arc tube using the halogen cycle. Can be prevented. Therefore, the energy of the luminous flux is not absorbed by the constituent material adhering to the inner surface of the discharge space, the temperature rise of the arc tube can be avoided, and the life of the high-pressure mercury lamp can be further extended.
Here, the amount of the halogenated compound to be enclosed is not particularly limited, and the halogenated compound may be enclosed within a range in which blackening of the tube wall of the arc tube can be satisfactorily prevented.
[0010]
The light source device of the present invention includes the high-pressure mercury lamp described above and a reflector that emits the light beam emitted from the high-pressure mercury lamp in a certain direction.
Here, as the reflector, a parabolic reflector, an elliptical reflector, or the like can be adopted, and the reflecting surface of the reflector is preferably a so-called cold mirror that reflects visible light and transmits infrared light.
According to the present invention, since the light source device includes the high-pressure mercury lamp and the reflector described above, it can enjoy the same operations and effects as the high-pressure mercury lamp described above.
In addition, since the light source device includes a high-pressure mercury lamp that can extend the life, it is not necessary to devise and design an explosion-proof structure for avoiding the scattering of the lamp due to the explosion of the high-pressure mercury lamp.
[0011]
The projector of the present invention includes the light source device described above, a light modulation device that modulates the light beam emitted from the light source device according to image information, and a projection optical device that magnifies and projects the modulated light beam. It is characterized by.
According to the present invention, since the projector includes the light source device described above, the projector can enjoy the same operations and effects as the light source device described above.
In addition, since the projector is provided with a light source device that can extend the life and improve the color rendering, it is always stable and can project a clear image for a long period of time.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing an optical system of a projector according to the present embodiment.
The projector 1 is an optical device that modulates a light beam emitted from a light source according to image information, forms an optical image, and magnifies and projects the image on a screen. The light source device 10, the uniform illumination optical system 20, and color separation optics. The optical element which comprises the system 30, the relay optical system 35, the optical device 40, and the projection optical device 50, and constitutes the optical systems 20 to 35, is in the light guide 2 in which a predetermined illumination optical axis A is set. The positioning is adjusted and stored.
[0013]
The light source device 10 emits a light beam emitted from the high-pressure mercury lamp 11 in a fixed direction and illuminates the optical device 40. As will be described in detail later, the high-pressure mercury lamp 11, the elliptical reflector 12, and the sub-reflection are described later. A mirror 13 and a collimating concave lens 14 are provided.
The luminous flux emitted from the high-pressure mercury lamp 11 is emitted as convergent light by aligning the emission direction to the front side of the apparatus by the elliptic reflector 12, collimated by the collimating concave lens 14, and emitted to the uniform illumination optical system 20. .
[0014]
The uniform illumination optical system 20 is an optical system that divides the light beam emitted from the light source device 10 into a plurality of partial light beams and uniformizes the in-plane illuminance of the illumination area. The first lens array 21 and the second lens array 22 are used. , A polarization conversion element 23, a superimposing lens 24, and a reflection mirror 25.
The first lens array 21 functions as a light beam splitting optical element that splits the light beam emitted from the high-pressure mercury lamp 11 into a plurality of partial light beams, and is arranged in a matrix in a plane orthogonal to the illumination optical axis A. A plurality of small lenses.
The second lens array 22 is an optical element that collects a plurality of partial light beams divided by the first lens array 21 described above, and in the same manner as the first lens array 21, a matrix is formed in a plane orthogonal to the illumination optical axis A. It is the structure provided with the several small lens arranged in a shape.
[0015]
The polarization conversion element 23 is a polarization conversion element that aligns the polarization direction of each partial light beam divided by the first lens array 21 with linear polarization in one direction.
Although not shown, the polarization conversion element 23 has a configuration in which polarization separation films and reflection mirrors that are inclined with respect to the illumination optical axis A are alternately arranged. The polarization separation film transmits one polarized light beam among the P-polarized light beam and S-polarized light beam included in each partial light beam, and reflects the other polarized light beam. The other polarized light beam reflected is bent by the reflecting mirror and emitted in the emission direction of the one polarized light beam, that is, the direction along the illumination optical axis A. One of the emitted polarized light beams is polarized and converted by a phase difference plate provided on the light beam exit surface of the polarization conversion element 23, and the polarization directions of all the polarized light beams are aligned. By using such a polarization conversion element 23, the light beam emitted from the high-pressure mercury lamp 11 can be aligned with the polarized light beam in one direction, so that the utilization factor of the light source light used in the optical device 40 is improved. Can do.
[0016]
The superimposing lens 24 condenses a plurality of partial light beams that have passed through the first lens array 21, the second lens array 22, and the polarization conversion element 23 and superimposes them on the image forming regions of the liquid crystal panels 42R, 42G, and 42B. It is. In this example, the superimposing lens 24 is a spherical lens having a flat end surface on the incident side and a spherical end surface on the exit side of the light beam transmission region, but an aspherical lens can also be used.
The light beam emitted from the superimposing lens 24 is bent by the reflection mirror 25 and emitted to the color separation optical system 30.
[0017]
The color separation optical system 30 includes two dichroic mirrors 31 and 32, and a reflection mirror 33. A plurality of partial light beams emitted from the uniform illumination optical system 20 from the dichroic mirrors 31 and 32 are converted into red (R), It has a function of separating light of three colors, green (G) and blue (B).
The dichroic mirrors 31 and 32 are optical elements in which a wavelength selection film that reflects a light beam in a predetermined wavelength region and transmits a light beam of another wavelength is formed on the substrate. The dichroic mirror 31 disposed in the front stage of the optical path is A mirror that transmits red light and reflects other color light. The dichroic mirror 32 disposed in the latter stage of the optical path is a mirror that reflects green light and transmits blue light.
[0018]
The relay optical system 35 includes an incident side lens 36, a relay lens 38, and reflection mirrors 37 and 39, and has a function of guiding the blue light transmitted through the dichroic mirror 32 constituting the color separation optical system 30 to the optical device 40. Have. The reason why such a relay optical system 35 is provided in the optical path of the blue light is that the optical path length of the blue light is longer than the optical path lengths of the other color lights, so that the light use efficiency is reduced due to light divergence or the like. It is for preventing. In this example, since the optical path length of blue light is long, such a configuration is used. However, a configuration in which the optical path length of red light is increased is also conceivable.
[0019]
The red light separated by the dichroic mirror 31 described above is bent by the reflection mirror 33 and then supplied to the optical device 40 via the field lens 41. Further, the green light separated by the dichroic mirror 32 is supplied to the optical device 40 through the field lens 41 as it is. Further, the blue light is condensed and bent by the lenses 36 and 38 and the reflection mirrors 37 and 39 constituting the relay optical system 35 and supplied to the optical device 40 via the field lens 41. The field lens 41 provided in the front stage of the optical path of each color light of the optical device 40 is provided to convert each partial light beam emitted from the second lens array 22 into a light beam parallel to the illumination optical axis. Yes.
[0020]
The optical device 40 modulates an incident light beam according to image information to form a color image, and includes liquid crystal panels 42R, 42G, and 42B as light modulation devices to be illuminated, and a color combining optical system. And a cross dichroic prism 43. Incidentally, an incident side polarizing plate 44 is interposed between the field lens 41 and each of the liquid crystal panels 42R, 42G, and 42B. Although not shown, between the liquid crystal panels 42R, 42G, and 42B and the cross dichroic prism 43 is omitted. In this case, an exit side polarizing plate is interposed, and light modulation of incident color light is performed by the entrance side polarizing plate 44, the liquid crystal panels 42R, 42G, and 42B, and the exit side polarizing plate.
[0021]
The liquid crystal panels 42R, 42G, and 42B are a pair of transparent glass substrates in which liquid crystal, which is an electro-optical material, is hermetically sealed. For example, incident side polarization is performed according to a given image signal using a polysilicon TFT as a switching element. The polarization direction of the polarized light beam emitted from the plate 44 is modulated. The image forming area for modulating the liquid crystal panels 42R, 42G, and 42B is rectangular, and the diagonal dimension is 0.7 inches, for example.
[0022]
The cross dichroic prism 43 is an optical element that synthesizes an optical image modulated for each color light emitted from the exit side polarizing plate to form a color image. The cross dichroic prism 43 has a substantially square shape in plan view in which four right angle prisms are bonded together, and a dielectric multilayer film is formed on the interface where the right angle prisms are bonded together. One of the substantially X-shaped dielectric multilayer films reflects red light, and the other dielectric multilayer film reflects blue light. These dielectric multilayer films cause red light and blue light to be reflected. The light is bent and aligned with the traveling direction of the green light, so that the three color lights are synthesized.
The color image emitted from the cross dichroic prism 43 is enlarged and projected by the projection optical device 50 to form a large screen image on a screen (not shown).
[0023]
FIG. 2 is a cross-sectional view showing the structure of the light source device 10.
The light source device 10 described above is housed in a lamp housing (not shown) and is detachable from the light guide 2 so that the light source device 10 can be replaced when the high-pressure mercury lamp 11 is ruptured or the luminance is lowered due to the life. It has become.
As shown in FIG. 2, the high-pressure mercury lamp 11 includes an arc tube 111 made of a quartz glass tube, a pair of electrodes 112 disposed in the arc tube 111, and an enclosure (not shown).
[0024]
The arc tube 111 has a light emitting portion 111A at a central portion that bulges in a spherical shape, and a sealing portion 111B at portions extending on both sides of the light emitting portion 111A.
A substantially spherical discharge space 111A1 is formed in the light emitting portion 111A, and a pair of electrodes 112 and an enclosure (not shown) are enclosed in the discharge space 111A1.
Inside the sealing portion 111B, a metal foil 111B1 made of molybdenum that is electrically connected to the pair of electrodes 112 is inserted and sealed with a glass material or the like. Further, a lead wire 113 as an electrode lead wire is connected to the metal foil 111B1, and the lead wire 113 extends to the outside of the high-pressure mercury lamp 11.
[0025]
The pair of electrodes 112 are tungsten electrodes, and are disposed at a predetermined distance in the discharge space 111A1.
The enclosure is composed of mercury, a noble gas, and a halogenated compound.
Here, mercury is 0.15 mg / mm ³ ~ 0.32mg / mm ³ It is preferable to be sealed at a vapor pressure of 150 bar to 190 bar.
Further, the rare gas is used for assisting light emission in the light emitting portion 111A and is not particularly limited, but commonly used argon, xenon, or the like can be used.
Further, the halogenated compound can use any halogen of chlorine, bromine and iodine, and it is particularly preferable to use bromine. The amount of the halogenated compound enclosed is not particularly limited. ^-6 -10 ^-4 μmol / mm ³ It is preferable to be enclosed with.
In the high pressure mercury lamp 11 described above, when a voltage is applied to the lead wire 113 extending outward from the sealing portion 111B, a discharge occurs between the electrodes 112, and the light emitting portion 111A emits light.
[0026]
The elliptical reflector 12 is an integrally molded product made of glass provided with a neck part 121 through which the sealing part 111B of the high-pressure mercury lamp 11 is inserted and an elliptical curved reflection part 122 extending from the neck part 121.
An insertion hole 123 is formed at the center of the neck portion 121, and the sealing portion 111 </ b> B is disposed at the center of the insertion hole 123.
The reflection part 122 is formed by vapor-depositing a metal thin film on the inner surface of an elliptical curved glass. The reflection surface of the reflection part 122 is a cold mirror that reflects visible light and transmits infrared rays.
The high-pressure mercury lamp 11 is disposed inside the reflecting portion 122 and is disposed such that the light emission center between the electrodes in the light emitting portion 111A is the first focal position L1 of the elliptical curved surface of the reflecting portion 122.
When the high-pressure mercury lamp 11 is turned on, as shown in FIG. 2, the light beam emitted from the light emitting unit 111A is reflected by the reflecting surface of the reflecting unit 122 and converges to the second focal position L2 of the elliptical curved surface. It becomes convergent light.
[0027]
When fixing the high-pressure mercury lamp 11 to such an elliptical reflector 12, the sealing portion 111B of the high-pressure mercury lamp 11 is inserted into the insertion hole 123 of the elliptical reflector 12, and the emission center between the electrodes 112 in the light-emitting portion 111A. Is arranged so as to be the first focal position L1 of the elliptical curved surface of the reflecting portion 122, and the inside of the insertion hole 123 is filled with an inorganic adhesive mainly composed of silica / alumina. In this example, the lead wire 113 coming out of the front sealing portion 111B is also exposed to the outside through the insertion hole 123.
The dimension of the reflecting portion 122 in the optical axis direction is shorter than the length of the high-pressure mercury lamp 11. When the high-pressure mercury lamp 11 is fixed to the elliptical reflector 12 in this manner, the front-side dimension of the high-pressure mercury lamp 11 is reduced. The sealing portion 111 </ b> B protrudes from the light beam exit side opening of the elliptical reflector 12.
[0028]
The sub-reflecting mirror 13 is a reflecting member that covers the front side of the light emission direction of the discharge space 111A1 of the light emitting unit 111A. Like the cold mirror.
Here, it is preferable that the sub-reflecting mirror 13 covers a range of approximately half or more and 1/3 or less of the front side of the light emission direction of the discharge space 111A1 of the light emitting unit 111A.
A part of the light beam emitted forward from the light emitting part 111A of the high-pressure mercury lamp 11 is reflected by the reflecting surface of the sub-reflecting mirror 13 and returns to the light emitting part 111A again. Part of the return light is absorbed in the encapsulated material enclosed in the discharge space 111A1 of the light emitting unit 111A, and the other return light travels toward the elliptical reflector 12 side, and the reflective part of the elliptical reflector 12 Injected from 122.
[0029]
FIG. 3 is a diagram showing a spectral spectrum of the high-pressure mercury lamp 11. Specifically, FIG. 3 is a diagram comparing spectral spectra of a high-pressure mercury lamp to which the sub-reflecting mirror 13 is attached and a high-pressure mercury lamp to which the sub-reflecting mirror 13 is not attached.
In FIG. 3, a spectral spectrum S1 indicated by a broken line is a spectral spectrum of the high-pressure mercury lamp 11 of the present embodiment to which the sub-reflecting mirror 13 is attached, and a spectral spectrum S2 indicated by a solid line is the spectroscopic spectrum S2 to which the sub-reflecting mirror 13 is attached. It is the spectrum of the high-pressure mercury lamp that is not.
As shown in FIG. 3, the spectral spectrum S <b> 1 has a greater continuous emission in the red region with a wavelength of 600 nm to 780 nm, especially with respect to the spectral spectrum S <b> 2, thereby improving the color rendering of the light beam emitted from the arc tube 111. I understand.
[0030]
According to the above-described embodiment, there are the following effects.
(1) Since the high-pressure mercury lamp 11 includes the sub-reflecting mirror 13 and is configured to return a part of the light beam emitted from the arc tube 111 to the arc tube 111 again, the energy of the return light is absorbed by the enclosure, Compared with a configuration in which the sub-reflecting mirror 13 is not provided, the color rendering properties of the light beam emitted from the arc tube 111 can be improved. In addition, the enclosed amount of mercury as the inclusion is 0.15 mg / mm ³ ~ 0.32mg / mm ³ The internal pressure in the arc tube 111 can be suppressed by enclosing it in the discharge space 111A1 of the arc tube 111 within the range of 150 bar to 190 bar of the vapor pressure. Therefore, even if the temperature in the arc tube 111 increases due to the energy absorption of the return light by the sub-reflecting mirror 13, the arc tube 111 can be prevented from being deformed or ruptured due to prolonged use, and the life of the high-pressure mercury lamp 11 can be extended. Can be planned.
[0031]
(2) Since the sub-reflecting mirror 13 is attached to the arc tube 111 so as to cover approximately half or more and 1/3 or less of the front side of the discharge space 111A1 in the luminous flux emission direction, a portion other than the arc tube 111, for example, the elliptical reflector 12 is provided. Compared with the configuration in which the sub-reflecting mirror is provided, the area for capturing the light beam can be reduced, and the return light can be efficiently returned to the arc tube with a simple configuration. Further, since the sub-reflecting mirror 13 is attached so as to cover approximately half or less of the discharge space 111A1 of the discharge space 111A on the front side in the light beam emission direction and 1/3 or more, It is possible to generate effective return light without increasing the return light by the reflecting mirror 13 more than necessary and minimizing the return light by the sub-reflecting mirror 13.
(3) Since a halogenated compound is enclosed as an enclosure in the discharge space 111A1 of the arc tube 111, tungsten, which is a constituent material of the electrode 112, adheres to the inner surface of the discharge space 111A1 using the halogen cycle. Can be prevented. Therefore, the energy of the luminous flux is not absorbed by tungsten attached to the inner surface of the discharge space 111A1, the temperature rise of the arc tube 111 can be avoided, and the life of the high-pressure mercury lamp 11 can be further extended.
[0032]
(4) Since the light source device 10 includes the high-pressure mercury lamp 11 described above, the explosion-proof structure for avoiding scattering of the arc tube 111 due to rupture of the high-pressure mercury lamp 11 when used for a long period of time is designed. You don't have to.
(5) Since the sub-reflecting mirror 13 is attached to the arc tube 111 so as to cover approximately half of the front side of the discharge space 111A1 in the luminous flux emission direction, the luminous flux emitted to the front side of the light emitting portion 111A is reflected to the rear side. Therefore, even if the elliptical curved surface of the reflecting portion 122 is small, all the light beams emitted from the light emitting portion 111A can be emitted in a constant direction, and the size of the elliptical reflector 12 in the optical axis direction can be reduced. Therefore, the light source device 10 can be reduced in size.
(6) Since the projector 1 includes the light source device 10 capable of extending the life and improving the color rendering, it is always stable and can project a clear image for a long period of time.
[0033]
Note that the present invention is not limited to the above-described embodiments, and includes modifications as described below.
In the above embodiment, mercury, a rare gas, and a halogenated compound are used as the enclosed material in the high-pressure mercury lamp 11, but the present invention is not limited to this. It can be used as a high-pressure mercury lamp 11. In addition to mercury, rare gas, and halogenated compounds, other substances may be enclosed in the high-pressure mercury lamp 11 as inclusions.
In the embodiment, a cooling device for cooling the light source device 10 may be provided. For example, a configuration in which a heat radiating member is provided in the light source device 10 or a configuration in which cooling air is blown to the heat radiating member by a cooling fan or the like to improve heat radiating characteristics may be employed. Further, a cooling device including a thermoelectric conversion element using the Peltier effect may be provided to cool the light source device 10. In such a configuration, the cooling efficiency of the light source device 10 can be improved, the temperature of the high-pressure mercury lamp 11 can be reduced, and deformation or rupture of the high-pressure mercury lamp 11 can be further avoided.
[0034]
In the above-described embodiment, the configuration in which the sub-reflecting mirror 13 is attached to the arc tube 111 is described as a configuration for returning the return light to the arc tube 111, but the configuration is not limited thereto. For example, a sub-reflector that returns the return light to the arc tube 111 may be attached to the elliptical reflector 12 of the light source device 10, and a configuration that is attached to the rear stage of the light source device 10, that is, the light guide 2 of the projector 1 is adopted. Also good.
In the embodiment, the light source device 10 is configured to use the elliptical reflector 12 as a reflector. However, the present invention is not limited to this, and a parabolic reflector may be employed.
In the above-described embodiment, the light source device 10 serving as the light source device of the present invention is employed in the projector 1 including the liquid crystal panels 42R, 42G, and 42B. However, the present invention is not limited thereto, and a light modulation device using a micromirror is provided. The light source device of the present invention may be adopted for the projector.
In addition, the specific structure, shape, and the like when implementing the present invention may be other structures as long as the object of the present invention can be achieved.
[0035]
【Example】
In order to confirm the effect of the present invention, the following experiment was conducted.
Using the light source device 10 in the above embodiment, the length of the arc tube 111 is 11 mm, and the volume in the light emitting portion 111A of the arc tube 111 is 68 mm. ³ The tube wall load (lamp power / light emitting portion inner surface area) of the arc tube 111 is 2.3 W / mm. ² The lamp power is fixed at 200 W, the amount of enclosed mercury and the vapor pressure are changed, the color rendering properties of the light beam emitted from the light source device 10 in the five embodiments 1 to 5, and the light emitting unit 111A The presence or absence of deformation was evaluated. In addition, the rare gas and halogenated compound which are enclosure are enclosed with the same thing and the same quantity in Examples 1-5.
The results are shown in Table 1 and FIG. FIG. 4 shows the evaluation results of the presence or absence of deformation of the light emitting unit 111A in Example 1 and Example 3 to simplify the description.
[0036]
[Table 1]

[0037]
Here, as the evaluation of the color rendering properties of the light beam, the color rendering index Ra of the light beam emitted from the light source device 10 of Examples 1 to 5 is measured, and the color rendering index Ra is larger than a desired value. (○), a small thing is regarded as evil (×).
In addition, as an evaluation of the presence or absence of deformation of the light emitting unit 111A, the light source device 10 of Examples 1 to 5 is turned on for a long time, the diameter of the light emitting unit 111A is measured every predetermined time, and the light emitting unit The presence or absence of deformation of 111A is measured.
[0038]
As the evaluation results of color rendering properties, as shown in Table 1, in Examples 1 to 4, the color rendering index Ra was larger than a desired value and the color rendering properties were improved, but Example 5 was able to improve the color rendering properties. There wasn't. This is because in Example 5, the mercury encapsulated amount and the mercury vapor pressure were enclosed in the discharge space 111A1, so that the continuous spectrum in the visible light region was reduced, and the color rendering property by the return light in the sub-reflector 13 was improved. It is thought that it has offset.
As shown in FIG. 4, the evaluation result of the presence or absence of deformation of the light emitting unit 111A is that, in Example 3, the diameter of the light emitting unit 111A does not change even when the light source device 10 is turned on for a long time. No deformation was seen. On the other hand, in Example 1, after the light source device 10 was turned on for a predetermined time, the diameter of the light emitting unit 111A gradually increased, and after 2000 hours, the light emitting unit 111A burst. Regarding Examples 2, 4, and 5, as shown in Table 1, as in Example 3, no deformation of the light emitting unit 111A was observed. This is because in Example 1, since the mercury enclosed amount and the mercury vapor pressure were enclosed in the discharge space 111A1, the internal pressure in the arc tube 111 could not be suppressed, and the high-pressure mercury lamp 11 was turned on and sub-reflected. It is considered that the arc tube 111 is deformed and finally ruptured as the temperature in the arc tube 111 increases due to the return light from the mirror 13.
Therefore, the mercury encapsulation amount of the present invention is 0.15 mg / mm. ³ ~ 0.32mg / mm ³ It was found that the color rendering properties of the light beam emitted from the arc tube 111 can be improved and the deformation of the arc tube 111 can be avoided under the conditions in which the mercury vapor pressure is within the range of 150 bar to 190 bar.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an optical system of a projector according to an embodiment.
FIG. 2 is a cross-sectional view showing a structure of a light source device in the embodiment.
FIG. 3 is a diagram showing a spectral spectrum of a high-pressure mercury lamp in the embodiment.
FIG. 4 is a view showing an evaluation result of presence / absence of deformation of a light emitting unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Projector, 10 ... Light source device, 11 ... High pressure mercury lamp, 12 ... Ellipse reflector, 13 ... Subreflective mirror, 42R, 42G, 42B ... Liquid crystal panel (light modulation device) ), 50... Projection optical device, 111... Arc tube, 111 A 1.

Claims (5)

An arc tube having a discharge space, a pair of electrodes disposed in the discharge space of the arc tube, and an inclusion of mercury and a rare gas sealed in the discharge space of the arc tube, and discharge light emission between the electrodes A high-pressure mercury lamp having return light in which a part of the light beam emitted from the arc tube returns to the arc tube,
The mercury ^is enclosed amount of ^{0.15mg / mm 3 ~0.32mg / mm 3} , a high-pressure mercury lamp, characterized by being sealed in the discharge space in the vapor pressure of 150Bar～190bar. The high-pressure mercury lamp according to claim 1,
A sub-reflecting mirror that returns a part of the luminous flux emitted from the arc tube into the arc tube;
The high-pressure mercury lamp is characterized in that the sub-reflecting mirror is attached so as to cover approximately half or less and one-third or more of the discharge space of the arc tube in the light emission direction front side. The high-pressure mercury lamp according to claim 1 or 2,
A high-pressure mercury lamp, wherein a halogenated compound of chlorine, bromine, or iodine is sealed in the discharge space in addition to mercury and a rare gas. A light source device comprising: the high-pressure mercury lamp according to any one of claims 1 to 3; and a reflector that emits a light beam emitted from the high-pressure mercury discharge lamp in a predetermined direction. 5. A light source device according to claim 4, a light modulation device for modulating a light beam emitted from the light source device according to image information, and a projection optical device for enlarging and projecting the modulated light beam. Projector.

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