JP2011082043A - Light source device and projection-type display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide light source device capable of adjusting impedance. <P>SOLUTION: The light source device includes a microwave generation section 10 for generating microwaves; a center conductor 30 for radiating microwaves while being connected to the microwave generation section 10; a discharge lamp 35 connected to the central conductor 30 for discharge lighting by microwaves; a reflector 40 that surrounds the periphery of the discharge lamp 35 and is formed from a conductive material with one end is open; and a coaxial pipe 50, disposed between the microwave generating section 10 and the reflector 40. A high-frequency transmission mode transmitted from the microwave generation section 10 is set as a TEM mode; in the coaxial pipe 50, the center conductor 30 is an internal conductor and an outer pipe 56 is an external conductor. An adjustment rod 55 is disposed which is formed by metal or a dielectric of which the position is adjustable from the outer pipe 56 toward the center conductor 30. By adjusting the distance between the adjustment rod 55 and the center conductor 30, impedance is adjusted. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light source device having a discharge lamp that emits light when irradiated with microwaves, and a projection display device including the light source device.

In recent years, a demand for a discharge lamp has been increased in place of a halogen lamp as a high-intensity light source. In particular, in a discharge lamp using microwaves for discharge lighting of the lamp, a discharge lamp having an electrode is less likely to be worn out than the conventional direct current and alternating current discharge lamps and can have a long life. In addition, an electrodeless lamp having no electrode can be realized by using a microwave, and a lamp having a longer life can be expected.
In the case of a light source device using a microwave, impedance matching is necessary to efficiently transmit electromagnetic wave energy to a lamp. Usually, a discharge lamp using microwaves confines a microwave in a reflector chamber as shown in, for example, Patent Document 1 in order to satisfy both a reflector that reflects light and a shielding of the microwave. The light is extracted by generating a plasma by placing.

JP 2008-262833 A

  However, in the configuration of the light source device as in Patent Document 1, since there is no mechanism for impedance matching, the lamp may not be turned on or the light may be darkened. For this reason, it is necessary to separately adjust the shape of the matching unit and the chamber, and there is a problem that the light source device is increased in size and cost.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A light source device according to this application example includes a microwave generation unit that generates a microwave, a central conductor that is connected to the microwave generation unit and radiates the microwave, and is connected to the central conductor and is A discharge lamp that is lit by microwaves, a reflector that is formed of a conductive material that surrounds the discharge lamp and is open at one end, and a coaxial that is disposed between the microwave generator and the reflector A high-frequency transmission mode transmitted from the microwave generation unit is a TEM mode, and the coaxial tube forms a coaxial tube having the central conductor as an inner conductor and an outer portion as an outer conductor, A metal or a dielectric whose position is adjustable from the outer shape toward the central conductor is disposed, and an impedance is adjusted by adjusting a distance between the metal or dielectric and the central conductor. Characterized in that the dancing is adjusted.

According to the light source device having this configuration, the metal or the dielectric whose position can be adjusted from the outer portion of the coaxial tube toward the central conductor is disposed. The impedance of the coaxial line can be adjusted by moving this metal or dielectric close to or away from the central conductor.
Thus, by adjusting the impedance of the coaxial line with respect to the fact that the conventional lamp does not light up or the light becomes dark, these problems can be solved and a highly efficient light source device can be obtained.
Further, it is not necessary to provide a matching unit separately, and the increase in size and cost of the light source device can be suppressed.

  Application Example 2 In the light source device according to the application example described above, it is preferable to have an adjustment rod whose position can be adjusted from the outer shape portion toward the center conductor.

  According to this configuration, the impedance of the light source device can be adjusted with an easy configuration.

  Application Example 3 In the light source device according to the application example described above, it is preferable that a plurality of the adjustment rods are arranged.

  According to this configuration, impedance adjustment is possible from a plurality of locations, and adjustment is easy. Further, there is an advantage that the adjustment range of the impedance is widened.

  Application Example 4 In the light source device according to the application example described above, it is preferable that the light source device includes an iris whose opening diameter can be adjusted from the outer shape portion toward the central conductor.

  According to this configuration, the iris (aperture) that can move concentrically with respect to the outer diameter of the center conductor is provided, and stable impedance adjustment is possible.

  Application Example 5 In the light source device according to the application example, it is preferable that the reflector includes an optical member that efficiently collects or polarizes light on an optical axis of a light beam emitted from the discharge lamp.

  Thus, by providing an optical member such as an optical lens in the reflector, the light guide distance from the light source to the optical member can be shortened, and the light utilization efficiency can be improved. Since a condensing lens, a collimating lens, or the like can be used as the optical member, the light beam can be condensed or collimated at the light beam exit of the light source device, and the degree of freedom in optical design is increased.

  Application Example 6 A projection display device according to this application example includes a microwave generation unit that generates a microwave, a central conductor that is connected to the microwave generation unit and radiates the microwave, and is connected to the central conductor. A discharge lamp that is lit by microwaves, a reflector that is formed of a conductive material that surrounds the discharge lamp and is open at one end, and is disposed between the microwave generation unit and the reflector. A high-frequency transmission mode transmitted from the microwave generator is a TEM mode, and the coaxial tube forms a coaxial tube having the central conductor as an inner conductor and an outer portion as an outer conductor. A metal or dielectric that can be adjusted in position from the outer shape toward the central conductor, and a distance between the metal or dielectric and the central conductor is adjusted. A light source device in which impedance is adjusted, a light modulation unit that modulates a light beam emitted from the light source device according to input image information to form an optical image, and an optical image formed by the light modulation unit. And a projection unit for projecting.

  According to the projection display device having this configuration, it is possible to provide a projection display device having a highly efficient light source device that can adjust the impedance of the coaxial line and has high light utilization efficiency. Further, it is not necessary to provide a matching unit separately from the light source device, which can contribute to downsizing of the projection display device.

1 is a schematic cross-sectional view illustrating a configuration of a light source device according to a first embodiment. The block diagram which shows schematic structure of the microwave generation part of 1st Embodiment. FIG. 7 is a schematic cross-sectional view showing a configuration of a light source device according to Modification 1. FIG. 10 is a schematic cross-sectional view illustrating a configuration of a light source device according to Modification 2. FIG. 10 is a schematic cross-sectional view illustrating a configuration of a light source device according to Modification 3. FIG. 10 is a schematic cross-sectional view illustrating a configuration of a light source device according to Modification Example 4. FIG. 6 is a block diagram illustrating a schematic configuration of a projector according to a second embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. In the drawings used for the following description, the ratio of dimensions of each member is appropriately changed in order to make each member easily recognizable.
(First embodiment)

FIG. 1 is a cross-sectional view illustrating a schematic configuration of the light source device of the present embodiment.
The light source device 1 includes a microwave generation unit 10 that generates a microwave and a light-emitting unit 20 that uses the microwave to emit light.
The light emitting unit 20 includes a coaxial tube 50, an adjustment rod 55, a central conductor 30, a discharge lamp 35, and a reflector 40.

The coaxial tube 50 includes a connector part 52, a matching part 54, and a central conductor 30, and is connected to the microwave generation part 10 at the connector part 52.
The center conductor 30 is formed in a cylindrical shape, extends in the direction of the optical axis P from the inside of the microwave generation unit 10, and radiates the microwave generated by the microwave generation unit 10. An outer tube 56 is provided so as to surround the central conductor 30 at an equal distance. The central conductor 30 and the outer tube 56 are made of a conductor formed of a metal such as copper or a dielectric formed of quartz glass. In the connector portion 52, an insulating member 53 such as ceramics or fluorine resin is provided between the central conductor 30 and the outer tube 56 so as not to short-circuit.

  The matching portion 54 is provided with an adjustment rod 55 that passes through the outer tube 56 and can be adjusted in the radial direction of the central conductor 30. Specifically, the outer tube 56 is provided with a female screw, and the adjustment rod 55 is provided with a male screw. By rotating the adjustment rod 55, the position of the adjustment rod 55 is brought closer to or away from the central conductor 30. Adjustment is possible. By making such adjustment, the impedance of the coaxial tube 50 is changed, and the resonant frequency of the propagating microwave can be adjusted. The adjusting rod 55 is made of a conductor or dielectric made of metal.

As described above, the coaxial tube 50 having the central conductor 30 as the inner conductor and the outer tube 56 as the outer conductor is formed, and microwaves can be transmitted in the direction of the optical axis P.
As a high-frequency transmission mode transmitted from the microwave generator 10, a TEM (Transverse Electro Magnetic) mode in which the electric field component and the magnetic field component are zero in the wave propagation direction is used. For this reason, there is little loss of transmission of microwaves, and efficient microwave propagation is possible.
In general, a conventional frequency as a microwave band is 3 GHz to 30 GHz, but in this embodiment, a 300 MHz to 30 GHz band corresponding to a UHF band to an SHF band is defined as a microwave band.

The reflector 40 is formed in a shape in which light is optically parallel or focused, and has an optical free-form surface. The reflector 40 has one end opened and the other end connected to the coaxial tube 50.
The shape of the reflector 40 is such that a portion close to the coaxial tube 50 is formed in a hemispherical shape and extends from there to the opening 42 in a cylindrical shape.
The reflector 40 is made of a metal such as aluminum, which is a conductor material, and is grounded to the ground. In this way, the electromagnetic wave shielded by the reflector 40 is electrically conducted to the ground.

Moreover, the inner surface 41 of the reflector 40 is formed in the mirror surface from which the reflectance of light becomes 90% or more. The inner surface 41 reflects the microwave and guides the light emitted from the discharge lamp 35 to the outside through the opening 42 of the reflector 40.
Even if the entire reflector 40 is not formed of a metal material, the surface of the reflector 40 facing the discharge lamp 35 may be formed of a metal material and electrically connected to the ground.

The center conductor 30 extends from the coaxial tube 50 into the reflector 40, and a discharge lamp 35 is provided at the tip of the center conductor 30. A reflector 40 is formed so as to surround the discharge lamp 35, and the discharge lamp 35 is disposed at the optical focal position of the reflector 40.
Thus, since the discharge lamp 35 is arranged at the optical focal position of the reflector 40, the light beam emitted from the discharge lamp 35 is derived while being efficiently reflected by the reflector 40, and the optical loss at the time of reflection is reduced. be able to.

The discharge lamp 35 is formed by enclosing a light emitting substance that emits light by microwaves in a transparent container formed of quartz glass or transparent ceramics which is a non-conductive material. As the light-emitting substance to be enclosed, a rare gas such as neon, argon, krypton, or xenon, mercury, a metal halide compound, or the like is used.
The discharge lamp 35 may have an electrode structure having electrodes or an electrodeless structure.

Next, the configuration of the microwave generator will be described with reference to the drawings.
FIG. 2 is a block diagram illustrating a schematic configuration of the microwave generation unit. The microwave generation unit 10 includes a high-frequency oscillation unit 11 that outputs a high-frequency signal, and a waveguide unit 12 that radiates the high-frequency signal output from the high-frequency oscillation unit 11 as a microwave.

  The high-frequency oscillating unit 11 includes a power source 13, a surface acoustic wave (SAW) oscillator as a high-frequency oscillator, and an amplifier 14. In this embodiment, a diamond SAW oscillator 15 is employed as the surface acoustic wave oscillator. The waveguide unit 12 includes a center conductor 30 and an isolator 16 as a safety device.

The high frequency oscillator 11 will be described in detail. The power supply 13 supplies power to the diamond SAW oscillator 15 and the amplifier 14. The subsequent stage of the diamond SAW oscillator 15 is connected to the previous stage of the amplifier 14. The high frequency signal output from the diamond SAW oscillator 15 is output after being amplified by the amplifier 14. The high frequency signal output from the amplifier 14 becomes a high frequency signal output from the high frequency oscillating unit 11.
In the present embodiment, a high frequency signal (2.45 GHz in this embodiment, wavelength λ is about 12 cm) amplified from the high frequency oscillating section 11 to a high frequency output level that excites and emits light emitted from the light emitting material sealed in the discharge lamp 35. ) Is output.

  Next, the waveguide unit 12 will be described in detail. The waveguide unit 12 guides the high-frequency signal output from the high-frequency oscillation unit 11 and emits it as the microwave 10A, and includes a central conductor 30 that radiates the microwave 10A and an isolator 16 as a countermeasure against reflected waves. ing.

The center conductor 30 is a center conductor that radiates microwaves having unidirectionality. The central conductor 30 can radiate a substantially planar microwave 10A.
The isolator 16 is installed behind the amplifier 14 and between the central conductor 30. Therefore, the reflected wave is prevented from returning to the high-frequency oscillator 11 as a result of radiating the microwave 10 </ b> A from the center conductor 30.

In the light source device 1 having the above configuration, the microwave generation unit 10 generates a high-frequency signal and radiates it as a microwave toward the reflector 40. The emitted microwave is a substantially plane wave and is reflected by the inner surface 41 of the reflector 40, and the reflected microwave converges at the center of the discharge lamp 35. The sealed luminescent material is excited (and ionized) by the microwave focused on the discharge lamp 35 and emits plasma, whereby the discharge lamp 35 emits light.
When the discharge lamp 35 emits light, a light beam is emitted. A part of the emitted light beam reaches the reflector 40 and is reflected. These light beams are led out from the opening 42 while being reflected by the inner surface 41 of the reflector 40.

  Here, when the resonance frequency of the microwave propagating through the central conductor is not matched, the lamp may not be lit or the light may be darkened. At this time, the adjustment rod 55 is turned to adjust the position of the adjustment rod 55 closer to or away from the center conductor 30, thereby changing the impedance of the coaxial tube 50 and adjusting the resonant frequency of the propagating microwave ( Matching). By doing so, the conventional lamp is not turned on or the impedance is adjusted in response to the darkness of the light, whereby a normal light emission and a highly efficient light source device can be obtained.

Next, the principle of adjusting the impedance will be described.
The impedance Z of the coaxial line is expressed by the following formula (1).

ただし、ε：線路の誘電率、Ｄ：外導体径、ｄ：内導体径、である。

Where ε is the dielectric constant of the line, D is the outer conductor diameter, and d is the inner conductor diameter.

From this equation (1), when the adjustment rod 55 is a conductor such as a metal, the outer conductor diameter D is changed by the insertion and removal of the adjustment rod 55, and the impedance Z changes. When the adjusting rod 55 is a dielectric, the impedance Z changes because the dielectric constant ε of the line has changed.
In this way, the impedance can be adjusted by adjusting the position of the adjusting rod 55.
(Modification 1)

Next, as a first modification of the first embodiment, a modification regarding the attachment of the adjustment rod for adjusting the impedance will be described. The modification 1 has the same configuration as that of the first embodiment except for the configuration of the matching unit.
FIG. 3 is a schematic cross-sectional view showing the configuration of the light source device of Modification 1. FIG. 3A is a cross-sectional view along the optical axis P direction, and FIG. 3B is a cross-sectional view in a direction orthogonal to the optical axis P direction of the matching portion.
In the light source device 2, the matching rod 54 of the coaxial tube 50 is provided with adjustment rods 55 from four directions. The impedance can be changed by adjusting the position of the adjusting rod 55.
Thus, impedance adjustment is possible from a plurality of locations, and adjustment is easy. Note that the number of adjusting rods 55 is not limited to four, and a plurality of adjusting rods 55 are effective.
(Modification 2)

Next, as a second modification of the first embodiment, a modification regarding another configuration for adjusting the impedance will be described. In the second modification, the configuration is the same as that of the first embodiment except for the configuration of the matching unit.
FIG. 4 is a schematic cross-sectional view showing the configuration of the light source device of Modification 2.
In the light source device 3, an iris 58 is provided in the matching portion 54 of the coaxial tube 50. The iris 58 can move concentrically with respect to the outer diameter of the center conductor 30. Thus, stable impedance adjustment is possible.
(Modification 3)

Next, as a third modification of the first embodiment, a third modification in which the reflector of the light source device includes an optical member will be described. The third modification has the same configuration as that of the first embodiment except for the optical member.
FIG. 5 is a schematic cross-sectional view showing a configuration of a light source device according to a modification.

As shown in FIG. 5A, the light source device 4 includes optical lenses 61 and 62 in the vicinity of the opening of the reflector 40. The optical lenses 61 and 62 are fixed inside the reflector 40 with a heat-resistant adhesive or the like.
The optical lens 61 is a convex lens, and the optical lens 62 is a concave lens. By combining these lenses, the light beam is condensed or converted into parallel light. The combination of lenses is not limited to this modified example, and can be appropriately changed and combined according to the purpose of use.

  As described above, by providing the reflector 40 with the optical lenses 61 and 62, the light guide distance from the discharge lamp 35 as the light source to the optical lenses 61 and 62 can be shortened, so that the light use efficiency is improved. Further, the light beam can be condensed or collimated at the exit of the light beam, increasing the degree of freedom in optical design.

As another modification, a light source device 5 in which an optical lens unit 70 is attached to the tip of a reflector 40 as illustrated in FIG.
In the optical lens unit 70, optical lenses 71 and 72 are fixed to a cylindrical lens housing 73. The optical lenses 71 and 72 are fixed to the lens housing 73 with an adhesive having heat resistance. Further, a screw is formed at the engaging portion between the lens housing 73 and the reflector 40, and the optical lens unit 70 can move along the optical axis P.

As described above, since the optical lens unit 70 is mounted on the reflector 40, if a plurality of optical lens units corresponding to the purpose are prepared, a single light source device can support a plurality of uses.
(Modification 4)

Next, as a fourth modification of the first embodiment, a modification in which the center conductor 30 of the light source device is covered with quartz glass will be described. In the fourth modification, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.
FIG. 6 is a schematic cross-sectional view illustrating a configuration of a light source device according to a modification.

As shown in FIG. 6, the center conductor 30 of the light source device 6 extends in the direction of the optical axis P from the inside of the microwave generation unit 10 so that the quartz tube 32 formed of transparent quartz glass covers the outer periphery of the center conductor 30. Is provided.
A portion of the quartz tube 32 surrounded by the reflector 40 swells in a substantially spherical shape, and a space portion 31 is formed therein, in which a luminescent material is enclosed. In the space portion 31, a central conductor 30 extending from the inside of the microwave generation unit 10 and a conductor 34 extending from the tip of the quartz tube 32 are arranged with a predetermined distance. Thus, the central conductor 30, the quartz tube 32, and the discharge lamp 35 are integrated.

  The microwave generated by the microwave generator 10 is radiated to the space 31 through the coaxial tube 50, and the plasma is concentrated in the space 31 by the conductor 34 formed and formed at the tip of the quartz tube 32. Accordingly, the discharge lamp 35 emits light by exciting (and ionizing) the light emitting substance in the space 31 and emitting plasma.

Further, by adjusting the adjustment rod 55 from the matching portion 54 toward or away from the center conductor 30 toward the quartz tube 32 covering the outer periphery of the center conductor 30, the impedance of the coaxial tube 50 changes and propagates through the micro tube. The resonant frequency of the wave can be adjusted.
In such a structure of the modified example 4, the same effect as that of the first embodiment can be obtained.
Note that the reflector 40 of the light source device 6 of Modification 4 may include an optical member as in Modification 3.
(Second Embodiment)

Next, a projector as a projection display device that employs the light source device described above will be described with reference to the drawings.
FIG. 7 is a block diagram illustrating a schematic configuration of the projector according to the present embodiment.
The projector 100 includes the light source device 1 and the optical system 110 described above.
The optical system 110 includes an illumination optical system 120, a light modulation unit 130, a color synthesis optical system 140, and a projection unit 150. The light source device 1 includes a microwave generation unit 10 and a light emitting unit 20.

  Next, the operation of the projector 100 will be described. Microwaves are emitted from the microwave generation unit 10, and the light emitting unit 20 emits light by the microwaves emitted from the microwave generation unit 10. Moreover, the illumination optical system 120 equalizes the illuminance of the light beam emitted from the light source device 1 and separates it into each color light.

  The light modulation unit 130 modulates the luminous flux of each color light separated by the illumination optical system 120 according to image information to form an optical image. The color synthesis optical system 140 synthesizes the optical images of the respective color lights separated by the illumination optical system 120 and modulated by the light modulation unit 130, and the projection unit 150 projects the optical image.

  The discharge lamp mounted on the projector 100 is a lamp using a microwave, and realizes a longer life of the light source device 1 compared with a projector provided with a lighting device using a conventional discharge lamp, and allows the replacement of the light source device. The troublesomeness can be reduced and the economic effect can be improved.

  In addition, by adopting the light source device 1 described above, it is possible to provide the projector 100 in which the impedance in the light source device 1 can be adjusted and the utilization efficiency of the light emitted from the discharge lamp is improved.

  DESCRIPTION OF SYMBOLS 1, 2, 3, 4, 5, 6 ... Light source device, 10 ... Microwave generation part, 10A ... Microwave, 11 ... High frequency oscillation part, 12 ... Waveguide part, 13 ... Power supply, 14 ... Amplifier, 15 ... Diamond SAW oscillator, 16 ... isolator, 20 ... light emitting part, 30 ... central conductor, 31 ... space part, 32 ... quartz tube, 34 ... conductor, 35 ... discharge lamp, 40 ... reflector, 41 ... inner surface, 42 ... opening, 50 DESCRIPTION OF SYMBOLS ... Coaxial pipe | tube, 52 ... Connector part, 53 ... Insulating member, 54 ... Matching part, 55 ... Adjustment rod, 56 ... Outer pipe | tube as an external part, 58 ... Iris, 61, 62 ... Optical lens as an optical member, 70 ... Optical lens unit, 71, 72 ... Optical lens as optical member, 100 ... Projector as projection display device, 110 ... Optical system, 120 ... Illumination optical system, 130 ... Light modulation unit, 14 ... color synthesizing optical system, 150 ... projection section, P ... optical axis, lambda ... microwave wavelengths.

Claims (6)

A microwave generator for generating microwaves;
A central conductor connected to the microwave generator and emitting the microwave;
A discharge lamp connected to the central conductor and ignited by the microwave;
A reflector formed of a conductive material surrounding the discharge lamp and having one end opened;
A coaxial tube disposed between the microwave generator and the reflector,
The high-frequency transmission mode transmitted from the microwave generator is a TEM mode,
The coaxial tube forms a coaxial tube having the central conductor as an inner conductor and an outer portion as an outer conductor,
A metal or dielectric that can be adjusted from the outer shape toward the central conductor is disposed,
An impedance is adjusted by adjusting a distance between the metal or dielectric and the central conductor. The light source device according to claim 1,
A light source device comprising an adjustment rod whose position is adjustable from the outer shape toward the central conductor. The light source device according to claim 2,
A light source device comprising a plurality of the adjustment rods. The light source device according to claim 1,
A light source device comprising an iris whose opening diameter is adjustable from the outer shape toward the central conductor. The light source device according to any one of claims 1 to 4,
The light source device, wherein the reflector includes an optical member that efficiently collects or polarizes light on an optical axis of a light beam emitted from the discharge lamp. A microwave generator for generating microwaves;
A central conductor connected to the microwave generator and emitting the microwave;
A discharge lamp connected to the central conductor and ignited by the microwave;
A reflector formed of a conductive material surrounding the discharge lamp and having one end opened;
A coaxial tube disposed between the microwave generator and the reflector,
The high-frequency transmission mode transmitted from the microwave generator is a TEM mode,
The coaxial tube forms a coaxial tube having the central conductor as an inner conductor and an outer portion as an outer conductor,
A light source device in which a metal or dielectric whose position is adjustable from the outer shape toward the central conductor is disposed, and an impedance is adjusted by adjusting a distance between the metal or dielectric and the central conductor,
A light modulator that modulates a light beam emitted from the light source device according to input image information to form an optical image;
And a projection unit that projects an optical image formed by the light modulation unit.

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