JP2010061844A - Light source device and projector - Google Patents

Abstract

A light source device and the like capable of reducing an applied voltage required at the start of discharge light emission more effectively.
A light source device includes a light emitting tube having a visible light emitting portion that emits visible light by discharge light emission, a lamp having a reflector that reflects the visible light, and a tip of the visible light emitting portion. A microwave radiating unit 40 that radiates microwaves to the arc tube 20 is provided so as to cover the side, and the visible light emitting unit 21 starts the discharge light emission in a state where the microwaves are emitted.
[Selection] Figure 2

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 problems, a light source device according to the present invention covers a lamp having an arc tube that emits visible light by discharge light emission, a reflector that reflects the visible light, and a tip side of the arc tube. And at least one microwave radiating section that radiates microwaves to the arc tube, wherein the arc tube starts the discharge emission in a state where the microwaves are radiated.

  The light source device according to the present invention includes a lamp having a light emitting tube that emits visible light by discharge light emission, a reflector that reflects the visible light, and a tip near the reflector, and a microwave is provided in the light emitting tube. A plurality of microwave radiating portions that radiate the light, and the arc tube starts the discharge light emission in a state where the microwave is radiated.

  In addition, a projector according to the present invention includes any one of the light source devices 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 microwave radiation portion may be provided in the vicinity of the arc tube, and at least a portion in the vicinity of the arc tube may be formed of a material that reflects the visible light and the microwave.

  According to this, the light source device or the like can concentrate the microwaves by the visible light emitting unit, and can also improve the utilization efficiency of the visible light by reflecting the visible light.

  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 an arc tube, a reflector, the image input unit 150 is an image signal input terminal, an image signal conversion circuit, etc. The processing 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 includes an arc tube 20 that emits visible light by discharge light emission, a reflector 10 that reflects visible light, and a microwave radiation unit 40 that emits microwaves. Note that a microwave having an arbitrary wavelength can be applied as the microwave, but 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. The microwave radiating unit 40 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 reflects a visible light and a microwave (for example, aluminum The arc tube 20 is made of lead wires 26 and 27 to which an alternating current is supplied from the lighting control unit 130, and metal foils 24 and 25 connected to the lead wires 26 and 27. And the electrodes 22 and 23 connected to the metal foils 24 and 25, and the spherical visible light emitting section 21 in which the tips of the electrodes 22 and 23 are arranged and 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 radiating unit 40 to radiate microwaves. The microwave radiating unit 40 radiates a microwave that is a kind of high frequency toward the center of the arc tube 20 (step S12). The microwave concentrates 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 by the microwave radiating unit 40 ( 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.

  In addition, since the microwave radiating unit 40 is provided in the vicinity of the visible light emitting unit 21 and the portion in the vicinity of the visible light emitting unit 21 is formed of a material that reflects visible light and microwaves, the light source device In 140, the microwave can be concentrated by the visible light emitting unit 21, and the visible light can also be reflected, whereby the utilization efficiency of visible light can be increased.

(Second embodiment)
Next, a light source device having a configuration in which a plurality of microwave radiating portions are provided near the tip of the reflector 10 and the microwaves are concentrated on the visible light emitting portion 21 will be described.

  FIG. 5 is a cross-sectional view of the light source device 141 according to the second embodiment. FIG. 6 is a front view of the light source device 141 in the second embodiment. The light source device 141 has eight microwave radiating portions 41 at the tip of the reflector 10. The configuration other than the microwave radiation unit 41 is the same as that of the light source device 140 of the first embodiment.

  The microwave radiating unit 41 is cylindrical and radiates microwaves linearly toward the center of the visible light emitting unit 21. Thereby, since the microwaves concentrate on the visible light emitting unit 21, the light source device 141 can perform discharge light emission at a low voltage.

  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.

(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 number of the microwave radiation portions 40 of the first embodiment may be two or more. Further, the number of the microwave radiating portions 41 of the second embodiment is not limited to 8, and may be 7 or less, or 9 or more.

  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. It is a front view 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, 100 Projector, 110 Operation part , 120 power supply, 130 lighting control unit, 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 radiating portion provided to cover the tip side of the arc tube, and radiating microwaves to the arc tube;
Including
The arc tube starts the discharge emission in a state where the microwave is radiated,
Light source device. The light source device according to claim 1,
The microwave radiation part is
Provided close to the arc tube,
At least a portion close to the arc tube is formed of a material that reflects the visible light and the microwave,
Light source device. A lamp having an arc tube that emits visible light by discharge light emission, and a reflector that reflects the visible light;
A plurality of microwave radiation portions provided near the tip of the reflector and radiating microwaves to the arc tube;
Including
The arc tube starts the discharge emission in a state where the microwave is radiated,
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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