JP2010061845A - Light source device and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source device or the like that further effectively reduces an applied voltage required when discharge light emission is started. <P>SOLUTION: The light source device 140 includes: a lamp having an arc tube 20, which includes a visible-light emitting part 21 for emitting visible light by discharge light emission, and a reflector 10 that reflects the visible light; at least one microwave radiation source 50 that radiates a microwave; and at least one microwave reflection part 40 that is provided on the rear-face side of a reflecting surface of the reflector 10 so as to radiate the microwave. The microwave reflection part 40 reflects the microwave radiated from the microwave radiation source 50 so as to focus it at the visible-light emitting part 21 via the reflector 10. The visible-light emitting part 21 starts the discharge light emission while the microwave is focused thereat. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light source device and a projector.

  A light source device such as a projector includes a lamp, an igniter that starts the lamp, and a ballast that performs a transition from glow discharge to arc discharge. The igniter applies a high voltage of about several kV to several tens of kV to cause dielectric breakdown between the electrodes of the lamp, and then the ballast supplies the current to the lamp to discharge the lamp from glow discharge to arc discharge. To migrate.

  Thus, since the voltage applied by the igniter is a high voltage, the electrode of the lamp is easily consumed, and the usable period of the light source device is shortened. In addition, noise is generated at the moment when a voltage is applied by the igniter, and the noise may affect the operation of a circuit such as a light source device. Furthermore, the higher the voltage applied by the igniter, the larger the Tesla coil required for the igniter, and the larger the light source device.

In order to provide a high-pressure discharge lamp that suppresses power supply noise at the time of starting by starting at a lower starting voltage, Japanese Patent Application Laid-Open No. 2007-317529 discloses a high-voltage pulse between a pair of electrodes of an arc tube. There is described a high-pressure discharge lamp having a power supply circuit for applying and starting an arc tube and a light emitting diode for irradiating ultraviolet rays from the outside of the arc tube.
JP 2007-317529 A

  However, in the case of a method of simply irradiating ultraviolet rays as in the method of Japanese Patent Application Laid-Open No. 2007-317529, the ultraviolet rays are diffused, energy utilization efficiency is poor, and the effect of reducing the starting voltage is low.

  An object of the present invention is to provide a light source device and a projector capable of reducing the applied voltage required at the start of discharge light emission more effectively.

  In order to solve the above-described problems, a light source device according to the present invention includes a lamp having an arc tube that emits visible light by discharge light emission, a reflector that reflects the visible light, and at least one microwave that emits microwaves. A radiation source, and at least one microwave reflection unit that is provided on a back surface side of the reflection surface of the reflector and reflects the microwave, wherein the microwave reflection unit includes the microwave from the microwave radiation source. A wave is reflected and concentrated on the arc tube via the reflector, and the arc tube starts the discharge emission in a state where the microwave is concentrated.

  A projector according to the present invention includes the light source device described above and a projection unit that projects an image using the visible light as a light source.

  According to the present invention, the light source device or the like is more effectively applied at the start of discharge light emission because the number of electrons in the visible light emitting part is further increased by concentrating the microwave on the visible light emitting part. The voltage can be reduced.

  The light source device may include a first microwave sub-reflecting unit that reflects the microwave from the microwave radiation source to the microwave reflecting unit.

  According to this, even when the microwave radiation source emits a linear microwave, the microwave can be uniformly dispersed by the microwave sub-reflecting portion, and the utilization efficiency of the microwave can be improved. it can.

  The light source device may include a second microwave sub-reflecting unit that is provided so as to cover a distal end side of the arc tube and reflects the microwave to the arc tube.

  According to this, by providing the microwave reflecting part on the optical path side of the visible light emitting part, the microwave reflected by the microwave reflecting part is also concentrated on the visible light emitting part, so that the microwave is more efficiently transmitted to the visible light. It can be concentrated on the light emitting part.

  Embodiments in which the present invention is applied to a light source device in a projector will be described below with reference to the drawings. In addition, the Example shown below does not limit the content of the invention described in the claim at all. In addition, all the configurations shown in the following embodiments are not necessarily essential as means for solving the invention described in the claims.

(First embodiment)
FIG. 1 is a functional block diagram of the projector 100 in the first embodiment. The projector 100 includes an operation unit 110 that gives a lamp lighting instruction in accordance with a user operation, a power source 120, a lighting control unit 130, a light source device 140, an image input unit 150 that inputs an image signal, and image processing. The unit 160 and the optical system 170 are included.

  Note that the functions of these units may be implemented in the projector 100 using, for example, the following hardware. For example, the operation unit 110 is a button, a remote controller, the lighting control unit 130 is a ballast, an igniter, the light source device 140 is a light emitting tube, a reflector, etc., the image input unit 150 is an image signal input terminal, an image signal conversion circuit, etc. The unit 160 can employ an image processing circuit or the like, and the optical system 170 can employ a lens, a mirror, a liquid crystal panel, a liquid crystal driving circuit, or the like.

  Here, the light source device 140 will be described in more detail. FIG. 2 is a cross-sectional view of the light source device 140 in the first embodiment. The light source device 140 is provided on the back side of the reflecting surface of the reflector 10, the arc tube 20 that emits visible light by discharge light emission, the reflector 10 that reflects visible light, the microwave radiation source 50 that emits microwaves, and the reflector 10. , Including a microwave reflection unit 40 that reflects microwaves, and a microwave sub-reflection unit (first microwave sub-reflection unit) 80 that reflects microwaves from the microwave radiation source 50 to the microwave reflection unit 40. It is configured.

As the microwave, a microwave having an arbitrary wavelength can be applied. For example, a generally used 2.45 GHz microwave may be applied. The reflector 10 is made of a material such as quartz glass or crystallized glass. As the shape of the reflector 10, an elliptical curved surface or other shapes can be adopted. Further, the microwave reflection unit 40 and the microwave sub-reflection unit 80 are formed of a material that reflects microwaves (for example, aluminum, silver, copper, iron, etc.). Lead wires 26 and 27 to which current is supplied, metal foils 24 and 25 connected to the lead wires 26 and 27, electrodes 22 and 23 connected to the metal foils 24 and 25, and tips of the electrodes 22 and 23 are It is configured to include a spherical visible light emitting unit 21 that is disposed and in which a rare gas or the like is enclosed. In addition, the reflector 10 and the arc tube 20 are bonded by the bonding portion 30.

  Next, a lighting procedure using these units will be described. First, a conventional lighting procedure will be described. FIG. 3 is a flowchart showing a conventional lighting procedure.

  The conventional lighting procedure is as follows. First, the lighting control unit receives a lamp lighting instruction (step S1), supplies an igniter pulse to the light source device (step S2), and determines whether the lamp is lit (step S3). When the lamp is lit, the lighting control unit supplies a discharge maintaining current to the lamp (step S4), and determines whether the lamp is continuously lit (step S5). When the lamp is lit, the lighting control unit supplies a stable current to the lamp (step S6), and the lamp is stably lit (step S7).

  In the conventional procedure, the applied voltage at the time of igniter pulse generation (step S2) is high, the lamp electrode is consumed quickly, noise due to electromagnetic waves is easily generated, and the Tesla coil of the igniter circuit is also enlarged.

  Next, the lighting procedure in the present embodiment will be described. FIG. 4 is a flowchart showing a lighting procedure in the first embodiment.

  The operation unit 110 instructs the power source 120 to drive the power source 120 in response to an operation instruction to turn on the user's power source, and instructs the lighting control unit 130 to turn on the lamp (step S11).

  The lighting control unit 130 instructs the microwave radiation source 50 to radiate microwaves. The microwave radiation source 50 radiates a microwave that is a kind of high frequency toward the microwave sub-reflecting unit 80 (step S12). The microwave is reflected by the microwave sub-reflecting unit 80, further reflected by the microwave reflecting unit 40, transmitted through the reflector 10, and concentrated on the visible light emitting unit 21.

  Thereby, an electric field concentrates on the visible light emission part 21, and the number of electrons increases. As the number of electrons increases, electrons easily flow between the electrodes 22 and 23, and dielectric breakdown between the electrodes at the start of lamp lighting tends to occur.

  The igniter circuit in the lighting control unit 130 generates an igniter pulse having a voltage lower than that of the conventional one (step S13). For example, when the conventional igniter pulse is about 7 kV, the igniter pulse of this embodiment may be less than 7 kV.

  The lighting control unit 130 determines whether the lamp is lit (step S14), and when the lamp is lit, supplies a discharge sustaining current to the arc tube 20 (step S15). Further, the lighting control unit 130 determines whether or not the lamp (the arc tube 20) is lit (step S16), and when the lamp is lit, stops the microwave emission from the microwave radiation source 50 ( Step S17).

  The lighting control unit 130 supplies a stable current to the arc tube 20 (step S18). Thereby, the lamp (the arc tube 20) is stably lit (step S19).

  As described above, according to the present embodiment, the light source device 140 concentrates the microwave on the visible light emitting unit 21, thereby increasing the number of electrons in the visible light emitting unit 21. The applied voltage required at the start of light emission can be reduced. Further, according to the present embodiment, the inrush current at the start of lamp lighting can be reduced. Further, these effects can reduce noise at the time of igniter pulse generation, reduce lamp electrode consumption, and extend the life of the lamp.

  Further, according to this embodiment, a smaller tesla coil for the igniter circuit can be adopted.

  Further, according to this embodiment, even when the microwave radiation source 50 emits a linear microwave, the microwave sub-reflecting unit 80 can uniformly disperse the microwave, Use efficiency can be increased.

(Second embodiment)
Next, a second microwave that is provided so as to cover the plurality of microwave radiation sources, the plurality of microwave radiation units, and the distal end side of the visible light emitting unit 21, and reflects the microwaves to the visible light emitting unit 21. A light source device including a sub-reflecting unit will be described.

  FIG. 5 is a cross-sectional view of the light source device 141 according to the second embodiment. The light source device 141 has two microwave radiation sources 51-1 and 51-2 at the tip of the reflector 10. The light source device 141 includes a microwave radiation unit 41-1 that reflects the microwave from the microwave radiation source 51-1 to the visible light emitting unit 21, and a microwave radiation source on the rear surface side of the reflection surface of the reflector 10. The microwave radiation unit 41-2 that reflects the microwave from 51-2 to the visible light emitting unit 21 is provided. Furthermore, the light source device 141 is provided so as to cover the distal end side of the visible light emitting unit 21, and includes a microwave sub-reflecting unit 81 (second microwave sub-reflecting unit) that reflects microwaves to the visible light emitting unit 21. Have.

  A part of the microwave sub-reflecting portion 81 is bonded to the visible light emitting portion 21 by the bonding portion 31. Other configurations are the same as those of the light source device 140 of the first embodiment.

Further, the microwave sub-reflecting unit 81 is formed so that a portion close to the visible light emitting unit 21 covers the tip side of the visible light emitting unit 21, and a material that reflects visible light and microwaves (for example, For example, the microwave radiated from the microwave radiation source 51-1 is reflected by the microwave radiation part 41-1, and is visible light emitted through the reflector 10. Incident on the part 21. Further, the microwave transmitted through the visible light emitting unit 21 is reflected by the microwave sub-reflecting unit 81 and enters the visible light emitting unit 21. The same applies to the microwaves emitted from the microwave radiation source 51-2.

  As described above, also according to the present embodiment, the light source device 141 can achieve the same operational effects as those of the first embodiment.

  In addition, by using a plurality of microwave radiation sources 51 and a plurality of microwave radiation units 41, a larger amount of micro-waves is generated by the visible light emitting unit 21 than in the case of using one microwave radiation source and one microwave radiation unit. The waves can be concentrated.

  Further, the microwave sub-reflecting part 81 is provided in the vicinity of the visible light emitting part 21, and at least a part close to the visible light emitting part 21 is formed of a material that reflects visible light and microwaves. The light source device 141 can concentrate the microwaves by the visible light emitting unit 21 and can also improve the utilization efficiency of visible light by reflecting visible light.

(Other examples)
In addition, application of this invention is not limited to the Example mentioned above, A various deformation | transformation is possible. For example, the configuration of the first embodiment and the configuration of the second embodiment may be combined. For example, the microwave sub-reflection portion 81 is added to the configuration of the first embodiment, or the microwave radiating portion 41 and the microwave radiation source 51 are added to the configuration of the first embodiment in which the microwave sub-reflection portion 81 is further added. Or may be added.

  Further, the projector 100 may radiate microwaves not only at the start of lamp lighting but also during lamp lighting. According to this, since the visible light emitting unit 21 can be in an electric field concentration state even while the lamp is lit, it is possible to promote the emission of electrons from the electrodes 22, 23, etc., and to stabilize the arc discharge.

  The application target of the light source device 140 is not limited to the projector 100, and may be various devices (for example, lighting devices) that emit visible light by discharge light emission.

  The projector 100 is not limited to a liquid crystal projector (transmission type, reflection type such as LCOS), and may be a projector using a DMD (Digital Micromirror Device), for example. DMD is a trademark of Texas Instruments Incorporated. Further, the function of the projector 100 may be distributed and implemented in a plurality of devices (for example, a PC and a projector).

It is a functional block diagram of the projector in a 1st Example. It is sectional drawing of the light source device in a 1st Example. It is a flowchart which shows the conventional lighting procedure. It is a flowchart which shows the lighting procedure in a 1st Example. It is sectional drawing of the light source device in a 2nd Example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Reflector, 20 Light emission tube, 21 Visible light emission part, 22, 23 Electrode, 24, 25 Metal foil, 26, 27 Lead wire, 30, 31 Bonding part, 40, 41 Microwave radiation part, 50, 51 Microwave radiation Source, 80 microwave sub-reflecting section (first microwave sub-reflecting section), 81 microwave sub-reflecting section (second microwave sub-reflecting section), 100 projector, 110 operation section, 120 power source, 130 lighting control section 140 light source device, 150 image input unit, 160 image processing unit, 170 optical system

Claims (4)

A lamp having an arc tube that emits visible light by discharge light emission, and a reflector that reflects the visible light;
At least one microwave radiation source emitting microwaves;
At least one microwave reflecting portion provided on the back side of the reflecting surface of the reflector and reflecting the microwave;
Including
The microwave reflection unit reflects the microwave from the microwave radiation source and concentrates on the arc tube through the reflector,
The arc tube starts the discharge emission in a state where the microwave is concentrated,
Light source device. The light source device according to claim 1,
Including a first microwave sub-reflecting unit that reflects the microwave from the microwave radiation source to the microwave reflecting unit;
Light source device. The light source device according to claim 1,
A second microwave sub-reflecting portion provided to cover the distal end side of the arc tube and reflecting the microwave to the arc tube;
Light source device. The light source device according to any one of claims 1 to 3,
A projection unit that projects an image using the visible light as a light source;
including,
projector.

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