JP4595951B2 - Light source device, projector - Google Patents

Description

  The present invention relates to a light source device that emits a light beam, a light irradiation method, and a projector including the light source device.

  According to the conventional light source device for light output illumination, electrode discharge lamps such as halogen lamps, metal halide lamps, and high-pressure mercury lamps have been used. Furthermore, the projector is used as a video projection device in various directions such as a presentation at a conference and a home theater at home. As a light source device used in such a projector, a discharge lamp having electrodes such as a halogen lamp, a metal halide lamp, and a high-pressure mercury lamp is used.

  For example, as disclosed in Patent Document 1, an electrodeless light source has a structure having a large cavity resonator. Moreover, as disclosed in Patent Document 2, a method using a plasma state of gas has been proposed for the electrodeless light source.

JP 2002-280191 A JP-A-10-162980

  However, in the structure of Patent Document 1, since the microwave wavelength is 12 cm and the limit of the usable wavelength is up to half of that, there is a limit to downsizing the size of the cavity resonator. That is, in this cavity resonator, the light source device used for the illumination device or the like, in particular, the light source used for the projector is too large, and it has been difficult to reduce its size. Moreover, although the efficiency is improved by confining the microwave well by using the cavity resonator, the light extraction may not be sufficiently performed, and the microwave cannot be fully utilized. In the method of Patent Document 2, before and after plasma generation, an insulator is formed before plasma discharge and a conductive body is formed after plasma discharge, so that the impedance changes drastically. In order to cope with this change in impedance, an impedance adjustment circuit, that is, both a matching adjustment circuit and a reflected wave are provided. In addition, by providing this matching adjustment circuit in the projector, it is possible to cope with impedance changes before and after plasma generation, but the projector system configuration becomes complicated, which is sufficient in terms of cost and stable operation. I couldn't say that.

  The objective of this invention is providing the projector provided with the light source device which can be reduced in price more inexpensively, and a light source device.

  The light source device of the present invention includes a microwave generation unit, a coaxial line extending from the microwave generation unit, a light emitting unit disposed at a tip of the coaxial line, a reflector having a light beam reflecting surface, and the front surface of the reflector And a control unit that controls the microwave generation unit, the light emitting unit, and the shielding plate. It is characterized by being.

  According to the present invention, by providing the light source device with the shielding plate as the reflecting portion, it is possible to configure the cavity resonator with the reflecting portion and the reflector using the reflector before plasma generation. On the other hand, after the plasma is generated, resonance characteristics can be obtained by the plasma itself. For this reason, the cavity resonator as in the prior art is unnecessary, and if the cavity resonator is not required, the matching circuit is also unnecessary. If the number of components constituting the light source device is reduced, it is possible to provide a light source device that can be realized at a lower price and at a reduced size.

  In the light source device of the present invention, it is desirable that the light emitting unit is an electrodeless light source.

  In the light source device according to the aspect of the invention, it is preferable that the support portion of the light emitting portion is a coaxial line extending from the microwave generation portion.

  In the light source device of the present invention, it is preferable that a diameter of the arc tube is larger than a diameter of the support portion.

  According to this invention, since the diameter of the arc tube is larger than the diameter of the support portion, the available microwave energy can be more concentrated, and thus the light source device capable of further improving the plasma utilization efficiency. Can be provided.

In the light source device of the present invention, the coaxial line includes a metal conductor part, an insulator that covers the metal conductor part, a metal shield layer that covers an outer periphery of the insulator and is grounded (to ground),
Preferably, the coaxial line has a metal shield part in a portion other than a range in contact with the arc tube.

  According to the present invention, since an inductance component can be generated equivalently, a series resonance circuit can be formed, so that microwave energy can be stored, and the microwave energy is efficiently converted into plasma. It is possible to provide a light source device that can

  In the light source device of the present invention, the insulator is preferably a heat-resistant insulator.

  According to this invention, since the insulator is a heat-resistant insulator, a light source device capable of improving durability against heat can be provided.

  In the light source device of the present invention, it is desirable that the distance between the light emission center of the arc tube and the light beam reflecting surface of the reflector is approximately ¼ of the wavelength λ of the microwave.

  According to the present invention, since the distance between the center of the arc tube and the light flux reflecting surface of the reflector is about 1/4 of the wavelength λ, the arc tube is placed at a position where the electromagnetic field strength of the standing wave in the light emitting portion is increased. By disposing the light source device, it is possible to provide a light source device that can suppress the reflected wave below a certain level and excite plasma efficiently.

  In the light source device of the present invention, the shortest distance between the light emission center of the arc tube and the shielding surface of the shielding plate is an extension of the coaxial line, and corresponds to approximately ¼ wavelength of the wavelength of the microwave. It is desirable that the distance be

  In the light source device of the present invention, it is desirable that the light flux reflecting surface of the reflector is made of a metal material.

  According to the present invention, since the light flux reflecting surface of the reflector is made of a metal material, the metal material has a high reflectivity, and therefore a light source device capable of improving the microwave reflection efficiency can be provided.

  In the light source device of the present invention, it is desirable that at least the reflection surface of the shielding plate is formed of a metal material.

  According to the present invention, since the reflecting surface of the shielding plate is formed of a metal material, the metal material has a high reflectance, and thus a light source device capable of improving the microwave reflection efficiency can be provided.

  The light source device of the present invention preferably has an opening / closing mechanism for the shielding plate.

  In the light source device of the present invention, the gap between the end surface of the opening on the front surface of the reflector and the reflecting surface of the shielding plate of the reflector having a light beam reflecting surface corresponds to approximately ¼ wavelength of the microwave wavelength. It is desirable to be less than the distance.

  According to the present invention, it is possible to provide a light source device capable of forming a good cavity resonator.

  In the light irradiation method of the light source device of the present invention, the light source device includes a microwave generation unit and a reflection unit, the step of radiating the microwave from the microwave generation unit, and the extension from the microwave generation unit A step of radiating a microwave from an end of the coaxial line, a step of emitting a light beam emitted by the microwave from a light emitting portion, and opening the shielding plate after the light emitting portion starts to emit light, And a step of opening and closing the reflecting portion that stops light emission of the light emitting portion after being closed.

  According to this invention, the light source device can open and close the shielding plate as the reflecting portion at an appropriate timing. When the shielding plate is opened, microwave irradiation can be performed, and after the shielding plate is closed, generation of microwaves can be stopped. By opening and closing the shielding plate as the reflecting portion, it is possible to take out the plasma when necessary and to stop taking it out.

  A projector according to the present invention is formed by the light source device described above, a light modulation unit that modulates the light beam emitted from the light source device according to image information, and forms an optical image, and the light modulation unit. And a projection unit for projecting the optical image.

  According to the present invention, as described above, since the light source device that can reduce power consumption and can be reduced in size at a lower price is mounted, labor saving and downsizing can be achieved. It is possible to provide a projector that can be realized.

  (Embodiment)

  Hereinafter, embodiments of the light source device and the projector according to the present invention will be described in detail with reference to the accompanying drawings.

  The configuration of the projector will be described.

  FIG. 1 is a block diagram showing a configuration of an optical system of a projector equipped with a light source device according to the present embodiment.

  As shown in FIG. 1, the optical system 5 of the projector 1 is roughly configured by a light source device 10, an illumination optical system 60, a light modulation unit 70, a color synthesis optical system 80, and a projection unit 90. . The light source device 10 includes a microwave generation unit 100 and a light emitting unit 500.

  The microwave generation unit 100 has a function of radiating microwaves. The light emitting unit 500 has a function of emitting light by the microwave radiated from the microwave generating unit 100. Further, the illumination optical system 60 has a function of making the illuminance of the light beam emitted from the light source device 10 uniform and separating it into each color light. The light modulator 70 has a function of modulating the light beams of the respective color lights separated by the illumination optical system 60 according to image information to form an optical image. The color synthesizing optical system 80 has a function of synthesizing optical images of the respective color lights separated by the illumination optical system 60 and modulated by the light modulator 70. The projection unit 90 has a function of projecting the optical image synthesized by the color synthesis optical system 80.

  Next, the configuration of the light source device will be described.

  FIG. 2 is a schematic diagram illustrating a configuration of the light source device according to the present embodiment.

  As shown in FIG. 2, the light source device 10 is schematically configured to include a microwave generation unit 100, a light emitting unit 500, and a light source case 15 that houses the microwave generation unit 100 and the light emitting unit 500. The light emitting unit 500 includes a light emitting tube 510, a shielding plate 520 as a reflecting unit, a reflector 530, and a support unit 540 as a coaxial line.

  The microwave generator 100 is disposed on the back side of the reflector 530. The arc tube 510 (glass sphere) is made of quartz glass. The arc tube 510 has a substantially spherical shape, and a light emitting region 511 having a spherical shape with an inner diameter of about 1 mm filled with a light emitting substance that emits light by microwaves is formed therein. In addition, it is suitable that the inner diameter of the light emitting region 511 is approximately 1 mm to 2 mm. The arc tube 510 has an electrodeless structure in which no electrode is provided inside the light emitting region 511.

  In addition, although quartz glass is used as a material for forming the arc tube 510, it is not limited thereto. For example, a material such as transparent sapphire or translucent ceramics may be used. Thereby, the light transmittance and heat resistance of the arc tube 510 can be improved. Further, mercury, a rare gas, and a small amount of halogen are enclosed as a light emitting substance enclosed in the light emitting region 511 of the arc tube 510, but the invention is not limited thereto. For example, a rare gas such as neon, argon, krypton, xenon, or halogen, or a metal or metal compound such as mercury or sodium may be enclosed together with these gases.

  The reflection unit 520 includes a drive unit 550 that can open and close the reflection unit 520, and the reflection unit 520 is connected to the drive unit 550 via a shaft 551. Therefore, when the drive unit 550 is driven, the reflection unit 520 opens and closes. For example, when the reflecting portion 520 is open, light emitted from the arc tube 510 can be transmitted. Conversely, when the reflecting portion 520 is closed, the light emitted from the arc tube 510 can be blocked. The reflection portion 520 is formed of a metal member that is a conductive material, and has a microwave reflection surface 521 that reflects microwaves. The microwave reflecting surface 521 reflects the microwave 100 a and is disposed so that the reflected microwave 100 a is focused on the central region 512 of the arc tube 510. In addition, although the shape of the microwave reflective surface 521 was made into the planar shape, it is not restricted to this. For example, it may have a parabolic shape or a spherical curved surface.

  The reflector 530 is made of quartz glass, and a light beam reflecting surface 531 having a parabolic curved surface is formed on the inner surface side of the reflector 530 so as to face the outer surface of the arc tube 510. The light beam reflecting surface 531 is formed of a dielectric multilayer film that transmits microwaves and reflects light beams. In addition, the parabolic shape of the light beam reflecting surface 531 is formed so that the central region 512 of the arc tube 510 installed on the inner surface side of the reflector 530 is substantially in focus. The shape of the light beam reflecting surface 531 may have a spherical curved surface.

  One end of the support portion 540 supports and fixes the arc tube 510, and the other end supports and fixes the reflector 530. Accordingly, the arc tube 510 is supported at a predetermined position on the inner surface side of the reflector 530 and is fixed to the reflector 530.

  The light source case 15 is formed using a metal member that is a conductive material capable of shielding microwaves. In addition, the metal member forming the light source case 15 may be formed so as to have a mesh knitted shape or a plurality of holes having a diameter equal to or less than ¼ wavelength of the wavelength of the microwave.

  Note that the light source case 15 that houses the microwave generation unit 100 and the light emitting unit 500 includes the microwave 100 a emitted from the microwave generation unit 100 by the reflection unit 520 and the microwave reflected by the reflection unit 520. The microwave 100b reflected by 100b and other components is blocked from the outside. The light source device 10 is mainly used as a light emitter, and is, for example, an electrodeless light source lamp having no electrode.

  Next, the light emitting unit mounted on the light source device will be described in more detail.

  FIG. 3 is a schematic diagram illustrating a configuration of a light emitting unit mounted on the light source device according to the present embodiment, (a) is a diagram illustrating a state where the reflecting unit is closed, and (b) is a diagram illustrating It is a figure which shows the state which the reflection part is open. FIG. 4 is a block diagram illustrating a configuration of the light source device.

  As shown to Fig.3 (a), the reflection part 520 is arrange | positioned so that it may cover on the reflector 530, and it is comprised so that opening and closing is possible. The support portion 540 is disposed so as to protrude from the inner surface of the reflector 530, and an arc tube 510 (glass sphere) is disposed at the tip of the support portion 540. When the wavelength of the microwave is λ and the oscillation frequency is 2.45 GHz, the reflection unit 520 is configured such that the central position A of the arc tube 510 and the microwave reflection surface 521 constitute a cavity resonator with the reflection unit 520. Has been placed. Considering the material and conductor portion of the coaxial cable being used, the overall size is set to approximately ¼ of the wavelength (λg) in the dielectric material of the coaxial cable. The closed space closed by the shutter is configured to be a cavity resonator at 2.45 GHz. The reflection part 520 is made of a metal material. Metal materials are highly conductive and can form equipotential surfaces, so they reflect microwaves. As a result, standing waves can be generated in a closed space where the shutter is closed, and as a result, a resonance state is maintained. Can do. In addition, since there is a conductor with a shield portion exposed at the center, the electric field strength near the conductor portion inevitably increases. With this large electric field strength, the gas in the quartz glass can be efficiently converted into plasma. The reflecting portion 520 is fixed to the shaft 551 and is configured to be able to rotate in the rotation direction about the shaft 551 by driving the motor 550. In addition, in the same figure, the reflection part 520 has shown the closed state. The reflector 530 has a bowl shape, and its inner surface is covered with a metal having high optical reflectivity such as aluminum. By closing the reflecting portion 520, it also serves as a cavity resonator. The support part 540 has a shield part 541 on its outer periphery, and the shield part 541 is formed using a metal member that is a conductive material capable of shielding microwaves. In addition, an insulating material resistant to heat is used in the support portion 540. When the arc tube 510 emits light and the gas in the arc tube 510 is in a plasma state, the temperature of the arc tube 510 is assumed to exceed 100 ° C. Therefore, ceramic materials such as alumina and quartz that are resistant to heat are used as insulators. It is used as Further, as shown in the figure, the center position A of the arc tube 510 and the microwave reflecting surface 521 are arranged so as to constitute a reflecting portion 520 and a cavity resonator. The arc tube 510 is disposed at a position where the electromagnetic field intensity increases. In the air, the interval H is about 30 mm. And since a reflected wave can be restrained below fixed, a plasma can be excited efficiently. In addition, when the size of the arc tube 510 (glass sphere) is set to the diameter D1, and the size of the support portion 540 is set to the diameter D2, the configuration is such that D1> D2 (or D1 = D2). The microwave energy that can be used can be more concentrated, and the plasma utilization efficiency can be further improved.

  As shown in FIG. 3 (b), the reflecting portion 520 is disposed at a position off the reflector 530. The support portion 540 has an unshielded portion 542 that does not have a shielding function at its tip, and the unshielded portion 542 is in contact with the arc tube 510. The structure of the support portion 540 is a coaxial cable. Here, the unshielded portion 542 is an inductance component L, the capacitance component C1 until the tip of the support portion 540 (coaxial cable) and plasma formation, the plasma formation portion is the resistance component R, and the plasma formation portion and the support portion 540 (coaxial cable). ) To the unshielded portion 542 can be represented by a capacitance component C2. Considering this state with an equivalent circuit, it is a state of series resonance, and the resonance frequency f in this series resonance can be obtained by a well-known equation (the equation is omitted). In addition, by providing the unshielded portion 542 in the support portion 540 (coaxial cable), an inductance component can be generated equivalently and a series resonance circuit is formed, so that microwave energy can be stored. . And microwave energy can be efficiently converted into plasma. In addition, by providing the light source device 10 (see FIG. 2) with the reflective portion 520 that can be opened and closed, the reflector 520 and the reflector 530 can form a cavity resonator using the reflector 530 before plasma generation. On the other hand, after the plasma is generated, the support part 540 (coaxial cable) has the unshielded part 542, so that a series resonance circuit can be configured using the inductance component (L) and the capacitance component (C). Therefore, it is not necessary to obtain the resonance characteristics with the reflecting portion 520 and the reflector 530. That is, after the plasma is generated, resonance characteristics can be obtained with the plasma itself. Therefore, according to the present embodiment, a cavity resonator as in the prior art is not necessary. Once the plasma is generated, the LC resonance state can be adjusted to the frequency of the input microwave, and impedance matching is not required, so that a matching circuit can be eliminated. . If the matching circuit is not required, the number of parts is reduced, and thus downsizing can be realized. In the figure, the arc tube 510 is lit and in a state where plasma light can be irradiated.

  As shown in FIG. 4, the light source device 10 controls the amplifier 120 by obtaining a reflectance from the reflected wave intensity, an oscillator 100 as a microwave generation unit that oscillates a microwave, an amplifier 120 that amplifies the microwave, and the reflected wave intensity. The control unit 800, a circulator 570 that restricts the signal flow direction, a power monitor 560 as a detection unit, a light emitting unit 500 that emits plasma light, and a drive unit 550 that opens and closes the reflection unit 520 are schematically configured. Has been.

  The oscillator 100 is a diamond SAW oscillator that applies a surface acoustic wave (SAW), which is a solid-state high-frequency oscillator.

  The amplifier 120 can amplify the signal output from the oscillator 100 and output a 2.45 GHz band high-frequency signal. The amplifier 120 and the oscillator 100 are electrically connected.

  The light emitting unit 500 has a light emitting tube 510 (see FIG. 2), and can emit plasma light by electric power supplied from the circulator 570. The light emitting unit 500 and the circulator 570 are electrically connected.

  The reflection unit 520 as the reflection unit operates by driving the drive unit 550. And this reflection part 520 and the drive part 550 are electrically connected.

  The drive unit 550 is a motor, and can open and close the reflection unit 520 according to instructions from the control unit 800. And this drive part 550 and the control part 800 are electrically connected.

  The power monitor 560 can monitor the power intensity of the circulator 570. The power monitor 560 and the control unit 800 are electrically connected. Therefore, the result monitored by the power monitor 560 can be fed back to the control unit 800. By controlling the amplifier 120 based on the fed back data, the intensity of the high frequency signal oscillated from the oscillator 100 is controlled to approach an appropriate value. The monitoring method in the power monitor 560 can be performed by measuring and detecting the magnitude of the microwave current by using, for example, a Schottky diode (SBD) (not shown).

  The circulator 570 can introduce the high-frequency signal amplified by the amplifier 120 into the light emitting unit 500. And this circulator 570 and the light emission part 500 are electrically connected. The high-frequency signal amplified to the high-frequency output level can excite the light-emitting substance enclosed in the light-emitting tube 510 included in the light-emitting unit 500 to cause the light-emitting tube 510 to emit light.

  The control unit 800 is provided in the projector 1 (see FIG. 6), and can control the projector 1 and the light source device 10. Furthermore, the drive part 550 which opens and closes the reflection part 520 can be controlled.

  Next, the operation of the light source device will be described.

  FIG. 5 is a flowchart showing an operation procedure of the light source device according to the present embodiment. In addition, it demonstrates for every step including the advancing direction of a microwave and light (light beam).

  In step S1 of FIG. 5, microwave emission is started. The microwave generation unit 100 (see FIG. 2) generates a high-frequency signal and directs it to the reflection unit 520 constituting the light emitting unit 500 shown in FIG. 2 as a microwave 100a (indicated by the broken arrow in FIG. 2). Radiate.

  In step S2 of FIG. 5, the microwave is amplified. The microwave 100a (see FIG. 2) is amplified by an amplifier 120 (see FIG. 4) as an amplifier.

  In step S3 of FIG. 5, light is irradiated. The emitted microwave 100a (see FIG. 2) is a substantially plane wave, passes through the light beam reflecting surface 531 of the reflector 530 shown in FIG. The microwave 100a that has reached the reflecting portion 520 has energy converging in the central region 512 of the arc tube 510 because the microwave reflecting surface 521 includes the reflecting portion 520 and the cavity resonator. By the microwave 100b focused on the central region 512, the luminescent substance enclosed in the light emitting region 511 is excited (and ionized) in the central region 512, which is the substantially central region of the light emitting region 511, and emits plasma. As a result, the entire light emitting region 511 emits light. The light emitting region 511 of the arc tube 510 shown in FIG. 2 emits light, whereby a light beam 500a (indicated by the solid line arrow in FIG. 1) is emitted to the outside of the arc tube 510. The emitted light beam 500 a reaches the light beam reflection surface 531 of the reflector 530 and is reflected. In the present embodiment, the light beam 500b reflected by the light beam reflecting surface 531 is a parallel light beam that is substantially parallel to the illumination optical axis L (illustrated by a one-dot chain line in FIG. 2).

  In step S4 of FIG. 5, it is confirmed by the power monitor of the detection unit 560 (see FIG. 4) that the reflected wave is below a certain value. If the reflected wave is below a certain value, the process proceeds to the next step S5.

  In step S5 of FIG. 5, the drive unit 550 shown in FIG. 3B is driven to open the reflection unit 520. At this time, after the plasma is generated, the support part 540 (coaxial cable) has the unshielded part 542, so that a series resonance circuit can be configured using the inductance component (L) and the capacitance component (C). Therefore, it is not necessary to obtain the resonance characteristics between the reflecting portion 520 and the reflector 530. That is, after the plasma is generated, resonance characteristics can be obtained with the plasma itself, and plasma emission continues even without the reflection portion 520.

  In step S6 of FIG. 5, the drive unit 550 shown in FIG. 3B is stopped and light is irradiated for a predetermined time. Then, the light beam 500b (see FIG. 2) emitted from the light source device 10 enters the first lens array 611 (see FIG. 2) of the illumination optical system 60 constituting the optical system 5.

  In step S7 of FIG. 5, when a predetermined time has passed and the desired role is finished, the driving unit 550 shown in FIG. 3A is stopped and the reflecting unit 520 is closed.

  In step S8 of FIG. 5, the microwave emission is stopped. The oscillation of the high frequency signal oscillated from the microwave generator 100 (see FIG. 1) is stopped.

  Next, the circuit configuration and operation of the projector will be described.

  FIG. 6 is a block diagram of the circuit system of the projector.

  As shown in FIG. 6, the projector 1 includes a control unit 800, a signal conversion unit 810, an image processing unit 820, a liquid crystal panel driving unit 830, an operation receiving unit 840, a power supply unit 850, a storage unit 860, and It has a fan drive unit 870 and the like. Each unit is connected to each other by a bus B. The optical system 5 includes a light source device 10 (microwave generator 100, light emitter 500), a light modulator 70, a projection unit 90, and the like.

  The signal conversion unit 810 is connected to an image input terminal 815 installed on the outer surface of the projector 1 main body. Then, for example, an analog image signal supplied from an external image signal supply device (not shown) connected to the image input terminal 815 is received. As analog image signals, image signals such as RGB signals representing computer images output from a personal computer and composite image signals representing moving images output from a video recorder or a television receiver are input to the image input terminal 815, for example. Supplied. Then, the signal conversion unit 810 performs AD conversion on the analog image signal input from the image input terminal 815 and outputs the analog image signal to the image processing unit 820 as a digital image signal.

  The image processing unit 820 converts image data into an image memory (not shown) in order to make the input digital image signal a signal suitable for display on a liquid crystal panel 71 (see FIG. 7) constituting the light modulation unit 70 described later. ) And reading out under predetermined conditions, and the like, and then converted again into an analog image signal and output to the liquid crystal panel drive unit 830 as an image signal. The image processing is suitable for scaling processing that matches the resolution of the liquid crystal panel 71 by enlarging and reducing the image represented by the image signal, and for displaying the gradation value of the image signal on the liquid crystal panel 71. Γ correction processing for converting to a gradation value is included. Note that image processing such as scaling processing and γ correction processing by the image processing unit 820 is performed by executing firmware that defines the image processing procedure stored in the storage unit 860.

  The liquid crystal panel driving unit 830 supplies the image signal output from the image processing unit 820 and a driving voltage based on the image signal to the liquid crystal panel 71 (see FIG. 7) to drive it. The control unit 800 is a CPU (Central Processing Unit), and can send and receive signals to and from each unit via the bus B, thereby performing overall control of the operation of the projector 1.

  The storage unit 860 stores, for example, various control programs for instructing and controlling the operation of the projector 1, such as an activation program for instructing the procedure and contents of processing when the projector 1 is activated, firmware, and accompanying data. It is remembered.

  When the user performs an operation on the operation unit 841 or the remote control 842 installed on the outer surface of the main body of the projector 1, the operation reception unit 840 receives the operation input and sends operation signals serving as triggers for various operations to the control unit 800. Output to.

  The fan drive unit 870 drives (rotates) the fan 875 by a drive circuit (not shown) in accordance with a fan drive command from the control unit 800. Also, a plurality of fans 875 are installed inside the projector 1 and rotate to inhale outside air from the outside of the projector 1 to cause an air flow, and the light emitting unit 500, the light modulation unit 70, and the power supply unit 850. The portions that generate heat can be cooled by dissipating the heat generated by the air and exhausting the heated air to the outside of the projector 1.

  The power supply unit 850 guides AC power from the external power supply 880 from the plug, performs processing such as transformation, rectification, and smoothing by a built-in AC / DC conversion unit (all not shown), and outputs a stabilized DC voltage to the projector. 1 can be supplied to each part.

  The microwave generation unit 100 of the light source device 10 can emit light (turn on) and emit no light (extinguish) the light emitting unit 500 in accordance with a control command from the control unit 800. Further, the projector 1 is equipped with the light source device 10 in the present embodiment.

  Next, the configuration and operation of the optical system of the projector will be described.

  FIG. 7 is a schematic diagram showing the configuration of the optical system of the projector.

  As shown in FIG. 7, the optical system 5 includes a light source device 10, an illumination optical system 60, a light modulation unit 70, a color synthesis optical system 80, and a projection unit 90. Then, the light beam emitted from the light source device 10 is modulated in accordance with image information by the light modulation unit 70 to form an optical image, and the formed optical image is displayed on the screen S (see FIG. 6) via the projection unit 90. Is projected onto the screen.

  As shown in FIG. 2, in the light source device 10, when the microwave generation unit 100 is driven, the microwave 100 a excites the luminescent material enclosed in the arc tube 510 of the light emitting unit 500 to emit light. The light beam 500 a radiated from 510 is reflected as a parallel light beam 500 b approximately parallel to the illumination optical axis L by the light beam reflecting surface 531 of the reflector 530, and the light beam 500 b is emitted from the light source device 10. The light emitting unit 500 includes a reflecting unit 520.

  Next, in addition to the light source device 10, the optical system 5 includes an illumination optical system 60, a light modulation unit 70, a color synthesis optical system 80, and a projection lens 91 that constitutes a projection unit 90. The illumination optical system 60 includes an integrator illumination optical system 61, a color separation optical system 62, and a relay optical system 63.

  In addition, the optical component housing 65 accommodates the components constituting the light source device 10, the illumination optical system 60, the light modulation unit 70, and the color synthesis optical system 80, and is integrated into a unit. ing. The illumination optical system 60 can be changed or omitted as appropriate depending on the optical system used.

  The integrator illumination optical system 61 constituting the illumination optical system 60 is an optical system for making the luminous flux emitted from the light source device 10 uniform in the plane perpendicular to the illumination optical axis L (illustrated by a one-dot chain line). . The integrator illumination optical system 61 includes a light source device 10, a first lens array 611, a second lens array 612, a polarization conversion element 613, and a superimposing lens 614.

  The first lens array 611 has a configuration in which small lenses having a substantially rectangular outline when viewed from the illumination optical axis L direction are arranged in a matrix. Each small lens divides the light beam emitted from the light source device 10 into partial light beams and emits them in the direction along the illumination optical axis L. The second lens array 612 has substantially the same configuration as the first lens array 611, and has a configuration in which small lenses are arranged in a matrix. The second lens array 612 has a function of forming an image of each small lens of the first lens array 611 together with the superimposing lens 614 on a liquid crystal panel 71 described later.

  The polarization conversion element 613 is an optical element that converts (aligns) the polarization directions of the partial light beams divided by the first lens array 611 and the second lens array 612 into polarized light beams in substantially one direction. The polarization conversion element 613 has a configuration in which polarization separation films (not shown) and reflection films (not shown) that are inclined with respect to the illumination optical axis L 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 film and emitted in the emission direction of one polarized light beam, that is, the direction along the illumination optical axis L. The emitted polarized light beam is polarized and converted by a phase difference plate (not shown) disposed on a light beam exit surface (not shown) of the polarization conversion element 613, and the polarization direction of the polarized light beam is aligned as a polarized light beam in one direction. .

  In the projector 1 using the liquid crystal panel 71 of the type that modulates a polarized light beam, only a polarized light beam in one direction can be used, and therefore approximately half of the light beam from the arc tube 510 that emits a polarized light beam in a random direction is not used. For this reason, by using the polarization conversion element 613, the light emitted from the light emitting tube 510 and emitted from the light source device 10 is converted into a polarized light beam in a substantially unidirectional direction, thereby increasing the light use efficiency in the light modulator 70. ing.

  The superimposing lens 614 collects a plurality of partial light beams that have been converted into polarized light beams in substantially one direction by the polarization conversion element 613, and superimposes them on image forming regions of three liquid crystal panels 71 (to be described later) of the light modulator 70. It is an element. The light beam emitted from the superimposing lens 614 is emitted to the color separation optical system 62.

  The color separation optical system 62 includes two dichroic mirrors 621 and 622 and a reflection mirror 623. A plurality of partial light beams emitted from the integrator illumination optical system 61 are separated into three color lights of red (R), green (G), and blue (B) by two dichroic mirrors 621 and 622.

  The relay optical system 63 includes an incident side lens 631, a pair of relay lenses 633, and reflection mirrors 632 and 635. In this embodiment, the relay optical system 63 has a function of guiding the blue light, which is the color light separated by the color separation optical system 62, to a blue light liquid crystal panel 71B described later of the light modulator 70.

  At this time, the dichroic mirror 621 of the color separation optical system 62 transmits the green light component and the blue light component and reflects the red light component among the light beams emitted from the integrator illumination optical system 61. The red light reflected by the dichroic mirror 621 is reflected by the reflection mirror 623, passes through the field lens 619, and reaches the liquid crystal panel 71R for red light. The field lens 619 converts each partial light beam emitted from the second lens array 612 into a light beam parallel to the central axis (principal ray). The same applies to the field lens 619 provided on the light incident side of the liquid crystal panels 71B and 71G for blue light and green light.

  Of the blue light and green light transmitted through the dichroic mirror 621, the green light is reflected by the dichroic mirror 622, passes through the field lens 619, and reaches the liquid crystal panel 71G for green light. On the other hand, the blue light passes through the dichroic mirror 622, passes through the relay optical system 63, passes through the field lens 619, and reaches the liquid crystal panel 71B for blue light. Note that the relay optical system 63 is used for blue light because the optical path length of the blue light is longer than the optical path lengths of the other color lights, thereby preventing a decrease in light use efficiency due to light divergence or the like. It is to do. That is, this is to transmit the partial light beam incident on the incident side lens 631 to the field lens 619 as it is. The relay optical system 63 is configured to pass blue light of the three color lights, but is not limited thereto. For example, it is good also as a structure which lets red light pass.

  The light modulator 70 modulates the incident light beam according to image information to form a color image. The light modulator 70 includes three incident polarizing plates 72 (red light incident polarizing plate 72R for red light and green light incident polarizing plate 72G for green light) on which each color light separated by the color separation optical system 62 is incident. And blue light incident polarizing plate 72B). Also, three liquid crystal panels 71 (red light liquid crystal panel 71R for red light, green light liquid crystal panel 71G for green light, and blue light for blue light) as light modulation devices installed at the subsequent stage of each incident polarizing plate 72 A liquid crystal panel 71B). In addition, three emission polarizing plates 73 (red light emission polarizing plate 73R for red light, green light emission polarizing plate 73G for green light, and blue light emission polarizing plate for blue light are installed at the rear stage of each liquid crystal panel 71. 73B).

  The liquid crystal panel 71 (71R, 71G, 71B) uses, for example, a polysilicon TFT (Thin / Film / Transistor) as a switching element, and the liquid crystal is hermetically sealed in a pair of opposed transparent substrates. . The liquid crystal panel 71 modulates and emits the light beam incident through the incident polarizing plate 72 according to the image information.

  The incident polarizing plate 72 transmits only polarized light beams in one direction among the color lights separated by the color separation optical system 62 and absorbs other light beams. A polarizing film is attached to a substrate such as sapphire glass. It is a thing. The exit polarizing plate 73 is configured in substantially the same manner as the entrance polarizing plate 72, and transmits only the polarized light beam in a predetermined direction among the light beams emitted from the liquid crystal panel 71 and absorbs the other light beams. The polarization axis of the polarized light beam to be transmitted is set to be orthogonal to the polarization axis of the polarized light beam transmitted through the incident polarizing plate 72.

  The color synthesis optical system 80 includes one cross dichroic prism 81. The cross dichroic prism 81 is an optical element that synthesizes an optical image modulated for each color light emitted from the exit polarizing plate 73 to form a color image. The cross dichroic prism 81 has a substantially square shape in plan view in which four right-angle prisms are bonded. A dielectric multilayer film is formed along the interface at the substantially X-shaped interface where the right-angle prisms are bonded together. One of the substantially X-shaped dielectric multilayer films reflects red light, the other dielectric multilayer film reflects blue light, and red light and blue light correspond to the corresponding dielectric multilayer films. Reflected and bent by the film. Green light is transmitted through both dielectric multilayer films.

  Thereby, the traveling direction of red light and blue light can be aligned with the traveling direction of green light, and three color lights are synthesized. The color light synthesized by the cross dichroic prism 81 is emitted in the direction of the projection lens 91 constituting the projection unit 90. The image light emitted from the cross dichroic prism 81 is projected on the screen S by the projection lens 91.

  The liquid crystal panel 71 (71R, 71G, 71B), the exit polarizing plate 73 (73R, 73G, 73B), and the cross dichroic prism 81 are unitized so as to be integrated.

According to the configuration of the light source device and the projector in the embodiment as described above, the following effects can be obtained.
(1) By providing the light source device 10 with the reflecting portion 520, a cavity resonator can be configured with the reflecting portion 520 + the reflector 530 using the reflector 530 before plasma generation. After the plasma is generated, resonance characteristics can be obtained with the plasma itself. For this reason, the cavity resonator as in the prior art is unnecessary, and if the cavity resonator is not required, the matching circuit is also unnecessary. If the number of components constituting the light source device 10 is reduced, it is possible to provide the light source device 10 that can be realized at a lower price and at a reduced size.
(2) When the diameter of the arc tube 510 is the diameter D1 and the size of the support portion 540 is the diameter D2, if the diameter D1 of the arc tube 510 is larger than the diameter D2 of the support portion, the usable micro Since the energy of the wave can be more concentrated, it is possible to provide the light source device 10 that can further improve the plasma utilization efficiency.
(3) Since an inductance component can be generated equivalently, a series resonance circuit can be formed, so that microwave energy can be stored, and this microwave energy can be efficiently converted into plasma. A light source device 10 can be provided.
(4) Since the distance H between the center O of the arc tube 510 and the reflecting portion 520 is approximately ½ of the wavelength λ, the arc tube 510 is located at a position where the electromagnetic field intensity of the standing wave in the light emitting portion 500 increases. By providing the light source device 10, it is possible to provide the light source device 10 that can suppress the reflected wave to a certain level or less and can excite plasma efficiently.
(5) Since the reflection part 520 and the reflector 530 are formed of a metal material, the metal material has a high reflectance, and thus the light source device 10 capable of improving the microwave reflection efficiency can be provided.
(6) Since the plasma can be taken out when necessary by opening and closing the reflecting portion 520, the light source device 10 capable of reducing power consumption can be provided.
(7) The light source device 10 can open and close the reflection unit 520 at an appropriate timing. When the reflecting portion 520 is opened, microwave irradiation can be performed, and when the reflecting portion 520 is closed, generation of microwaves can be stopped. In this manner, by opening and closing the reflecting portion 520, it is possible to take out plasma when necessary and to stop taking it out. For example, when the light emitting unit 500 is damaged, it is determined that the light emitting unit 500 has failed, and the light source device 10 can also close the reflecting unit 520.
(8) Since the light source device 10 that can reduce power consumption and can be reduced in size at lower cost is mounted, the projector 1 that can achieve labor saving and downsizing. Can be provided.

  The present invention has been described above with reference to preferred embodiments. However, the present invention is not limited to the above-described embodiments, and includes modifications as described below, as long as the object of the present invention can be achieved. Any other specific structure and shape can be set.

(Modification 1)
In the above-described embodiment, the arc tube 510 having a spherical lens is adopted in the present invention. However, the present invention is not limited to this. For example, a cylindrical lens or hemispherical lens having a kamaboko shape may be used for the arc tube 510. Even if it does in this way, if the space | interval H is set so that it may become the distance of about 1/2 of wavelength (lambda), the effect similar to this embodiment can be acquired.

(Modification 2)
In the above-described embodiment, the light source device 10 is used as the light source of the projector 1, but the present invention is not limited to this. For example, you may employ | adopt the light source device 10 as light emission sources of light sources, such as a headlamp, an illuminating device, and an exposure apparatus. If it does in this way, the use (application range) of the light source device 10 can be expanded.

FIG. 3 is a block diagram showing a configuration of an optical system of a projector equipped with the light source device according to the embodiment. The schematic diagram which shows the structure of a light source device. It is a schematic diagram which shows the structure of a light emission part, (a) is a figure which shows the state in which the reflection part is closed, (b) is a figure which shows the state in which the reflection part is open. The block diagram which shows the structure of a light source device. The flowchart which shows the operation | movement procedure of a light source device. The block diagram of the circuit system of a projector. FIG. 2 is a schematic diagram illustrating a configuration of an optical system of a projector.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Projector, 10 ... Light source device, 70 ... Light modulation part, 90 ... Projection part, 100 ... Oscillator as microwave generation part, 120 ... Amplifier, 500 ... Light emission part, 510 ... Light emission tube, 520 ... Reflection part Shield plate, 530 ... reflector, 540 ... support portion as coaxial line, 541 ... shield portion, 542 ... unshielded portion, 550 ... drive portion, 560 ... power monitor as detection portion, 570 ... circulator, 800 ... control portion, D1 ... diameter, D2 ... diameter, H ... interval.

Claims (14)

A microwave generator,
A coaxial line extending from the microwave generator;
An arc tube disposed at the tip of the coaxial line;
A reflector having a light beam reflecting surface;
A shielding plate that is disposed so as to be openable and closable on the opening side of the front surface of the reflector, and whose surface facing the reflector is a microwave reflecting surface that reflects the microwave generated from the microwave generating unit ;
A support for the arc tube ;
Light source device characterized in that it comprises a control unit for controlling the the previous SL microwave generating unit and the arc tube the shielding plate. The light source device according to claim 1, wherein the arc tube is an electrodeless light source. The light source device according to claim 1 or 2, wherein the support portion of the arc tube is a coaxial line extending from the microwave generation portion.   The light source device according to claim 1, wherein a diameter of the arc tube is larger than a diameter of the support portion. The coaxial line is made and the metal conductor portion, an insulator covering the metal wire part, from a metal shield layer outer periphery was coated further grounded to the ground of the insulator,
5. The light source device according to claim 1, wherein the coaxial line has a metal shield part in a portion other than a range in contact with the arc tube. The light source device according to claim 5 , wherein the insulator is a heat-resistant insulator. Distance between the light beam reflection surface of the light-emitting center of the light emitting tube reflector, as claimed in any one of claims 1 to 6, characterized in that substantially one quarter of the wave length of the microwave Light source device.   The shortest distance between the light emission center of the arc tube and the shielding surface of the shielding plate on the extension line of the coaxial line is a distance corresponding to approximately ¼ wavelength of the microwave wavelength. The light source device according to any one of claims 1 to 7.   The light source device according to any one of claims 1 to 8, wherein a light beam reflecting surface of the reflector is made of a metal material. The light source device according to claim 1, wherein at least the microwave reflecting surface of the shielding plate is formed of a metal material.   The light source device according to claim 1, further comprising an opening / closing mechanism for the shielding plate. The gap between the end surface of the opening on the front surface of the reflector and the microwave reflection surface of the shielding plate of the reflector having a light beam reflection surface is not more than a distance corresponding to approximately ¼ wavelength of the microwave wavelength. The light source device according to claim 1, wherein: A light irradiation method for irradiating light from a light source device,
The light source device includes a microwave generation unit, a coaxial line extending from the microwave generation unit, an arc tube disposed at a tip of the coaxial line, a reflector having a light beam reflecting surface, and an opening in the front of the reflector A shielding plate that is arranged to be openable and closable on the part side, and whose surface facing the reflector is a microwave reflection surface that reflects the microwave generated from the microwave generation unit, the microwave generation unit and the light emission A control unit for controlling the tube and the shielding plate ,
Radiating microwaves from the microwave generator;
Radiating microwaves from an end of a coaxial line extending from the microwave generating part in a state where the opening is closed by the shielding plate ;
A step of injecting a light beam emitted by the microwave from the light emitting tube,
And closing step of after said arc tube and initiate the luminescence opening the shielding plate, said shielding plate to stop the light emission of the light emitting tube after closing the shield plate,
The light irradiation method of the light source device characterized by comprising. The light source device according to any one of claims 1 to 12,
A light modulation unit that modulates the light beam emitted from the light source device according to image information and forms an optical image;
A projection unit that projects the optical image formed by the light modulation unit;
A projector comprising:

Images