JP2009043451A - Arc tube, light source device, and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an arc tube with improved heat conduction efficiency inside a coil portion, and to provide a light source device and a projector which are equipped with the arc tube. <P>SOLUTION: The arc tube 51A has a pair of electrodes 8A disposed inside thereof and includes a light emitting portion which emits light by discharging between the pair of electrodes 8A. At least one of the pair of electrodes 8A includes a shank portion 81 and a coil portion 821 provided at the tip end side of the shank portion 81 which is close to the other electrode 8A. The coil portion 821 consists of one turn of a wire around the shank portion 81, and includes a plurality of winding portions 8221 arranged in the axis direction of the coil portion 821. Each winding portion 8221 has abutment surfaces 822A and 822B in surface contact with adjacent winding portions 8221. Due to this structure, a contact area of each winding portion 8221 can be increased, so that the heat conduction efficiency inside the coil portion 821 increases. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light-emitting tube having a light-emitting portion in which a pair of electrodes is arranged and discharges light between the pair of electrodes, a light source device including the light-emitting tube, and a projector.

  Conventionally, a light emitting part in which a pair of electrodes are arranged and a discharge space in which a light emitting substance such as mercury and a rare gas is enclosed is formed, and extends in a direction away from each other across the light emitting part, and An arc tube having a pair of sealing portions each provided with an electrode lead wire connected to each electrode is known. In such an arc tube, when a voltage is applied to the electrodes via the electrode lead wire, a discharge is started between the electrodes, and a luminescent substance in the discharge space reacts to emit light.

  Here, in particular, in the electrode provided in the arc tube of AC lighting system, the anode and the cathode are alternately handled by the polarity inversion at the time of voltage application. For this reason, in order to reduce the thermal load at the time of an anode, it is necessary to enlarge the heat capacity of the electrode tip. Specifically, when the arc tube is turned on, the tip of the electrode becomes very hot. Therefore, in order to avoid thermal melting of the tip of the electrode, it is necessary to increase the diameter of the tip of the electrode according to the wattage. is there. To meet this need, it is formed by melting the shaft (electrode bar), the coil provided on the tip side of the shaft close to the other electrode, and the tip side of the coil. An electrode having a dome-shaped electrode tip is known (for example, see Patent Document 1).

  In the electrode described in Patent Document 1, a two-layer coil formed of a wire having a substantially circular cross section is attached to a shaft portion, and then the tip end side of the coil is melted to form an electrode tip portion (main body portion). To do. By providing such a coil in the electrode, the heat capacity of the electrode tip can be increased, and the heat of the electrode tip can be flowed out to the coil, thereby suppressing deterioration of the electrode tip. it can. In addition, by appropriately adjusting the number of layers of the coil, it is possible to easily adjust the diameter of the electrode according to the wattage of the discharge lamp.

JP 2004-288394 A

However, in the electrode described in Patent Document 1, since the coil is formed of a wire having a substantially circular shape in cross section, contact between adjacent winding portions (a portion corresponding to one turn of the wire) in the first layer coil. Since the area and the contact area between the winding part and the shaft part are small, there is a problem that the heat conduction efficiency is low.
Specifically, the heat generated at the tip of the electrode is conducted to the coil and the shaft, and among these, the heat conducted to the coil is transmitted through the wound wire and between the wound parts that come into contact with each other. Is transmitted from the electrode tip to the coil rear end. At this time, since the wire constituting the coil has a substantially circular cross section, a gap is generated between each winding portion and the shaft portion, and when the contact portion between adjacent winding portions is viewed in cross section, Each winding part will be in point contact with each other. For this reason, there is a problem that heat conduction efficiency from the winding portion on the electrode front end side to the winding portion on the rear end side is low, and heat generated at the electrode front end portion cannot be efficiently conducted inside the coil.

  An object of the present invention is to provide an arc tube, a light source device, and a projector that can improve the heat conduction efficiency inside the coil section.

  In order to achieve the above-described object, the arc tube of the present invention is an arc tube having a light emitting portion in which a pair of electrodes are arranged and discharges light between the pair of electrodes, , At least one of which includes a shaft portion and a coil portion provided on the tip side which is a side close to the other electrode in the shaft portion, and the coil portion corresponds to one turn of the wire with respect to the shaft portion. And a plurality of winding portions arranged along the axial direction of the coil portion, and each winding portion has a contact surface that is in surface contact with the adjacent winding portions. Features.

  According to the present invention, each winding portion in the coil portion provided on the distal end side of the shaft portion has a contact surface that comes into surface contact with the adjacent winding portions, so that the contact area between the winding portions is The heat transmitted to the winding part located on the electrode tip side can be quickly transmitted to the winding part adjacent to the winding part via the respective contact surfaces. . Accordingly, the heat generated at the tip of the electrode can be quickly conducted inside the coil from the tip to the rear of the coil, thereby improving the heat conduction efficiency inside the coil. be able to. Moreover, since it can suppress that an electrode front-end | tip part becomes an abnormally high temperature state by this, degradation of the said electrode can be suppressed and, by extension, lifetime improvement of an arc tube can be achieved.

In this invention, it is preferable that the said winding part has another contact surface which surface-contacts with the said axial part.
Here, the heat generated at the tip of the electrode is directly conducted to the coil part and is also conducted to the coil part via the shaft part. For this reason, when the wire forming the coil has a substantially circular cross section, as in the electrode described in Patent Document 1, the contact portion between each winding portion and the shaft portion of the coil is cross-sectioned. When viewed, since each winding part and the shaft part are in point contact, the contact area between the shaft part and the winding part is small, and the heat conduction efficiency between the shaft part and the winding part is too high. Absent.
On the other hand, according to the present invention, since the winding portion has another contact surface that comes into surface contact with the shaft portion, the contact area between the shaft portion and the winding portion can be increased. Compared with the electrode described in Patent Document 1, the heat conduction efficiency from the shaft portion to the winding portion can be improved. Therefore, heat conduction from the shaft portion to the winding portion can be performed quickly, and the electrode tip portion can be further suppressed from becoming an abnormally high temperature state.

In this invention, it is preferable that the layer most spaced apart from the said shaft part in the said coil part has a corner | angular part in the site | part used as the outer surface of the said coil part. Furthermore, it is more preferable that the corner portion is located in a range from the approximate center of the coil portion in the direction along the axial direction of the coil portion to the tip of the coil portion.
Here, at the time of starting the lighting of the arc tube, the electric field (electric field) is concentrated on a corner portion such as a step on the outer surface of the electrode, and the corner portion tends to be a discharge starting point. By forming such a corner on the outer surface of the electrode, the discharge starting point can be positioned at the corner.

In addition, the light emitting portion of the arc tube often has a substantially spherical shape centered around the center between the electrodes, and when an electrode is provided in such a light emitting portion, a discharge occurs on the rear end side of the coil portion. When the starting point is located, the probability of collision of the arc with the inner wall of the light emitting part is high. When the arc collides with the inner wall, not only is the inner wall damaged, but the constituent material of the inner wall is liberated, resulting in an environmental change in the discharge space. This environmental change induces deterioration of the electrodes and blackening of the light emitting portion, and shortens the life of the arc tube.
On the other hand, when the above-mentioned corner is formed in the range from approximately the center of the coil portion to the tip, the distance from the corner to the inner wall of the arc tube is set to the distance from the rear end of the coil portion to the inner wall. Since the distance can be longer than the distance, the probability of an arc collision with the inner wall can be reduced. Therefore, the occurrence of the environmental change described above can be suppressed, and the life of the arc tube can be extended.

In the present invention, it is preferable that the contact surface on the front end side of the winding portion and the contact surface on the rear end side that is a side away from the other electrode are formed substantially in parallel. .
According to the present invention, when each winding part is arranged along the axial direction of the coil part, the contact surface on the front end side and the contact surface on the rear end side are parallel to each other in each winding part. According to this, of two adjacent winding parts, the contact surface on the rear end side of the winding part located on the front end side, and the contact surface on the front end side of the winding part located on the rear end side Can be reliably brought into contact with each other without a gap. Therefore, the adhesion degree of each winding part can be raised, and, thereby, the heat conduction efficiency between the winding parts can be further improved.

In the present invention, the wire that forms the winding portion has a substantially parallelogram in cross section, and the contact surface on the front end side and the contact surface on the rear end side are opposite to each other on the wire material. It is preferable that they are a pair of surfaces.
According to the present invention, the wire rod has a substantially parallelogram shape in cross section, so that the contact surface on the tip side of the winding part and the rear end of the winding part located on the tip side of the winding part The contact area with the contact surface on the side can be reliably increased. Therefore, the heat conduction efficiency between the winding parts can be reliably improved. In addition, in such a case, the surface facing the shaft portion of the pair of surfaces connecting the contact surfaces can be formed as another contact portion. The contact area between the shaft portion and the shaft portion can be reliably increased.
Accordingly, it is possible to improve the heat conduction efficiency between the shaft portion and the coil portion, and thus it is possible to reliably suppress the deterioration of the electrode.

In this invention, it is preferable that the corner | angular part by the side of the said rear end of the cross-sectional shape of the said wire is the acute angle part.
According to the present invention, since the corner portion on the rear end side and the shaft portion side of the cross-sectional shape of the wire rod is an acute angle portion, the end portion on the electrode rear end side of the winding portion formed by the wire rod and the shaft The crossing angle with the part is an obtuse angle. According to this, since the end portion on the electrode rear end side of the layer formed by the winding portion can be gently inclined, the electric field (electric field) is concentrated on the end portion when starting the lighting of the arc tube. Can be suppressed. Therefore, it can suppress that the said edge part becomes a discharge starting point, and, thereby, the collision probability to the light emission part of an arc can be reduced. Such an effect is particularly effective when the light emitting part has a substantially spherical shape as described above.

Alternatively, in the present invention, the wire that forms the winding portion has a substantially oval cross section, and the contact surface on the front end side and the contact surface on the rear end side are respectively in the wire material. A pair of surfaces that are opposite to each other and are substantially parallel to each other are preferable.
According to the present invention, since the wire has a substantially oval shape in cross-section, the coil portion is formed in comparison with the case where the wire portion having the substantially parallelogram shape in cross-section is wound around the shaft portion to form the coil portion. Formation can be performed easily. In addition, since a pair of surfaces connecting each contact portion is connected and the surface facing the shaft portion is a curved surface, the coil portion is formed first, and then formed along the axial direction of the coil portion. Even when the shaft portion is inserted into the opening portion to constitute the electrode, the shaft portion comes into contact with the curved surface of each winding portion, so that the shaft portion can be easily inserted. Therefore, the coil can be easily formed.

In this invention, it is preferable that the said axial part has a groove | channel according to the shape of the surface of the said winding part facing the said axial part.
According to the present invention, since the contact area between the winding part and the shaft part can be increased by arranging the winding part along the groove, the heat conduction efficiency between the coil part and the shaft part can be increased. Can be further improved.
Further, since the winding portion is fitted into the groove, the coil portion can be prevented from sliding along the shaft portion. Accordingly, the coil portion can be fixed to the shaft portion.
Furthermore, when the groove is a spiral groove formed along the outer surface of the shaft portion from the tip of the shaft portion, the shaft portion can be twisted into the opening formed inside the coil portion. Therefore, the manufacturing process of the electrode can be simplified as compared with the case where the coil portion is formed by winding the wire along the outer surface of the shaft portion.

In addition, a light source device of the present invention includes the above-described arc tube, and a reflecting mirror that aligns light emitted from the arc tube in one direction and emits it as a light beam.
According to the present invention, the same effects as those of the arc tube described above can be achieved.

The projector of the present invention includes the above-described light source device, a light modulation device that modulates the light beam emitted from the light source device according to image information, and a projection optical device that projects the modulated light beam. It is characterized by.
According to the present invention, the same effects as those of the light source device described above can be obtained. Further, since the life of the arc tube can be extended, maintenance work such as replacement of the light source device can be saved.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
[Configuration of Projector 1]
FIG. 1 is a schematic diagram showing a schematic configuration of a projector 1 according to the present embodiment.
The projector 1 modulates a light beam emitted from a light source device 411 provided therein according to image information to form image light, and an image related to the image light is projected on a projection surface such as a screen (not shown). Enlarged projection. As shown in FIG. 1, the projector 1 includes an exterior housing 2, a projection lens 3, an optical unit 4, and the like.
In addition to these, the projector 1 includes a cooling unit 91 configured by a cooling fan or the like that cools the interior of the projector 1, a power supply unit 92 that supplies power to each component in the projector 1, and the entire projector 1. The control unit 93 and the like for controlling are provided, and these are arranged in the exterior housing 2.
Among these, the power supply unit 92 applies an AC rectangular wave voltage to the electrode lead lines 514 and 515 of the arc tube 51A that constitutes the light source device 411 described later.

[Configuration of exterior casing 2 and projection lens 3]
The exterior housing 2 is formed in a substantially rectangular parallelepiped shape in which the projection lens 3, the optical unit 4, and the like are housed and arranged inside. Although this exterior housing | casing 2 was formed with the synthetic resin in this embodiment, you may form not only this but other materials, such as a metal, for example.
The projection lens 3 is a projection optical device that forms an image of the image light formed by the optical unit 4 on a projection surface such as a screen (not shown) and enlarges and projects an image related to the image light. The projection lens 3 is configured as a combined lens in which a plurality of lenses are housed in a cylindrical lens barrel.

[Configuration of Optical Unit 4]
The optical unit 4 is a unit that optically processes a light beam emitted from a light source to form image light corresponding to image information under the control of the control unit 93 described above. As shown in FIG. 1, the optical unit 4 extends along the back surface of the exterior housing 2 and has a substantially L shape in plan view that extends along the side surface of the exterior housing 2. .
The optical unit 4 houses and arranges an illumination optical device 41, a color separation optical device 42, a relay optical device 43, an electro-optical device 44, and these optical components 41 to 44, and a projection lens 3 in a predetermined manner. And an optical component casing 45 which is supported and fixed at the position.

  The illumination optical device 41 illuminates an image forming area of a later-described liquid crystal panel 442 constituting the electro-optical device 44 substantially uniformly. The illumination optical device 41 includes a light source device 411, a first lens array 412, a second lens array 413, a polarization conversion element 414, and a superimposing lens 415.

  The light source device 411 is reflected by the discharge lamp 5 that emits a radial light beam, the main reflecting mirror 6 that reflects the emitted light emitted from the discharge lamp 5 and converges it at a predetermined position, and the main reflecting mirror 6. The collimating concave lens 7 that collimates the converged light beam with respect to the illumination optical axis A and a housing (not shown) that accommodates the collimating concave lens 7 are provided. The configurations of the discharge lamp 5 and the main reflecting mirror 6 will be described in detail later.

The first lens array 412 has a configuration in which a plurality of small lenses are arranged in a matrix in a plane substantially orthogonal to the illumination optical axis A. These small lenses have a substantially rectangular outline when viewed from the direction of the illumination optical axis A. Each of these small lenses divides the light beam emitted from the light source device 411 into a plurality of partial light beams.
The second lens array 413 has a configuration similar to that of the first lens array 412, and has a configuration in which small lenses corresponding to the small lenses of the first lens array 412 are arranged in a matrix. The second lens array 413 has a function of forming an image of each small lens of the first lens array 412 together with the superimposing lens 415 on an image forming area of a liquid crystal panel 442 described later of the electro-optical device 44. .

The polarization conversion element 414 is disposed between the second lens array 413 and the superimposing lens 415, and converts light from the second lens array 413 into substantially one type of linearly polarized light.
Specifically, each partial light converted into approximately one type of linearly polarized light by the polarization conversion element 414 is finally superimposed on an image forming area of a liquid crystal panel 442, which will be described later, by a superimposing lens 415. In a projector using a liquid crystal panel of a type that modulates polarized light, only one type of polarized light can be used, and therefore approximately half of the light from the light source device 411 that emits randomly polarized light cannot be used. For this reason, by using the polarization conversion element 414, the light emitted from the light source device 411 is converted into substantially one type of linearly polarized light, and the light use efficiency in the electro-optical device 44 is increased.

The color separation optical device 42 includes two dichroic mirrors 421 and 422 and a reflection mirror 423, and a plurality of partial light beams emitted from the illumination optical device 41 by the dichroic mirrors 421 and 422 are converted into red (R) and green ( G) and blue (B) are separated into three color lights.
The relay optical device 43 includes an incident side lens 431, a relay lens 433, and reflection mirrors 432 and 434, and has a function of guiding the red light separated by the color separation optical device 42 to the liquid crystal panel 442R for red light. .

  At this time, the dichroic mirror 421 of the color separation optical device 42 transmits the red light component and the green light component of the light beam emitted from the illumination optical device 41 and reflects the blue light component. The blue light reflected by the dichroic mirror 421 is reflected by the reflection mirror 423, passes through the field lens 441, and reaches the blue light liquid crystal panel 442B. The field lens 441 converts each partial light beam emitted from the second lens array 413 into a light beam parallel to the central axis (principal ray). The same applies to the field lens 441 provided on the light incident side of the other liquid crystal panels 442G and 442R for green light and red light.

  Of the red light and green light transmitted through the dichroic mirror 421, the green light is reflected by the dichroic mirror 422, passes through the field lens 441, and reaches the liquid crystal panel 442G for green light. On the other hand, the red light passes through the dichroic mirror 422, passes through the relay optical device 43, and further passes through the field lens 441 to reach the liquid crystal panel 442R for red light. Note that the relay optical device 43 is used for red light because the optical path length of the red light is longer than the optical path lengths of the other color lights, thereby preventing a decrease in light use efficiency due to light diffusion or the like. It is to do. That is, this is to transmit the partial light beam incident on the incident side lens 431 to the field lens 441 as it is. The relay optical device 43 is configured to pass red light out of the three color lights, but is not limited thereto, and may be configured to pass blue light, for example.

The electro-optical device 44 modulates the three color lights emitted from the color separation optical device 42 according to image information, and combines the modulated color lights to form an optical image (color image).
As shown in FIG. 1, the electro-optical device 44 includes the above-described field lens 441, a liquid crystal panel 442 as a light modulation device (442R for a red light liquid crystal panel, 442G for a green light liquid crystal panel, and 442G; A liquid crystal panel for blue light is referred to as 442B), three incident-side polarizing plates 443 respectively disposed on the light incident side of each liquid crystal panel 442, and 3 disposed on the light emission side of each liquid crystal panel 442. And two crossing dichroic prisms 446 as a color synthesizing optical device, and three crossing dichroic prisms 446 disposed on the light beam emission side of the three viewing angle compensation plates 444, respectively. ing.

The incident-side polarizing plate 443 receives light of each color whose polarization direction is aligned in approximately one direction by the polarization conversion element 414. The incident-side polarizing plate 443 is aligned by the polarization conversion element 414 in the incident light flux. Only polarized light having substantially the same direction as that of the polarized light beam is transmitted, and other light beams are absorbed. Such an incident-side polarizing plate 443 has a configuration in which a polarizing layer is attached to a light-transmitting substrate such as sapphire glass or crystal.
A liquid crystal panel 442 as a light modulation device has a configuration in which liquid crystal, which is an electro-optical material, is hermetically sealed between a pair of transparent glass substrates, although detailed illustration is omitted. In the liquid crystal panel 442, the alignment state of the liquid crystal is controlled according to the drive signal that is the image information input from the control unit, and the polarization direction of the polarized light beam emitted from the incident-side polarizing plate 443 is modulated. As a result, image light is formed.

The viewing angle compensation plate 444 is formed in a film shape, and birefringence generated in the liquid crystal panel 442 when the light beam is obliquely incident on the liquid crystal panel 442 (when the light is incident on the liquid crystal panel in a direction inclined with respect to the normal direction) The phase difference generated between ordinary light and extraordinary light due to is compensated. The viewing angle compensation plate 444 is an optical anisotropic body having negative uniaxiality, and the optical axis is oriented in a predetermined direction within the film surface and oriented so as to be inclined at a predetermined angle from the film surface in the out-of-plane direction. is doing.
The viewing angle compensator 444 can be composed of, for example, a disc support having a discotic compound layer formed on a transparent support such as triacetyl cellulose (TAC) via an alignment layer. Can be used.

  The exit-side polarizing plate 445 transmits only the light beam having a polarization direction perpendicular to the transmission axis of the light beam in the incident-side polarizing plate 443 out of the light beam emitted from the liquid crystal panel 442 and passing through the viewing angle compensation plate 444, and other light beams. It absorbs. Such an exit-side polarizing plate 445 can have the same configuration as the above-described incident-side polarizing plate 443.

  The cross dichroic prism 446 forms an optical image (color image) by combining the modulated light modulated for each color light emitted from the emission side polarizing plate 445. The cross dichroic prism 446 has a square shape in plan view in which four right angle prisms are bonded together, and two dielectric multilayer layers are formed at the interface where the right angle prisms are bonded together. These dielectric multilayer layers transmit the color light through the exit side polarizing plate 445 disposed on the side facing the projection lens 3 (G color light side), and the remaining two exit side polarizing plates 445 (R color light side and B color side). Reflects colored light via the colored light side). In this manner, the color lights modulated by the incident-side polarizing plates 443, the liquid crystal panels 442, the viewing angle compensation plates 444, and the emission-side polarizing plates 445 are combined to form a color image.

[Configuration of Discharge Lamp 5]
FIG. 2 is a longitudinal sectional view showing the discharge lamp 5 and the main reflecting mirror 6 of the light source device 411.
As shown in FIG. 2, the discharge lamp 5 is a light source that emits light, and includes an arc tube 51A formed of quartz glass, a sub-reflecting mirror 52 and a trigger line 53 attached to the arc tube 51A. ing. In addition, as such a discharge lamp 5, various discharge light source lamps that emit light with high luminance can be employed, and for example, a metal halide lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, and the like can be employed.

[Configuration of arc tube 51A]
The arc tube 51A is an AC lighting type arc tube. The arc tube 51A is formed in the central portion of the arc tube 51A and has a light emitting part 511 that swells in a substantially spherical shape, sandwiching the light emitting part 511, and in a direction away from both ends of the light emitting part 511. A pair of extending sealing portions 512 and 513 (the left sealing portion in FIG. 2 is 512 and the right sealing portion is 513).
Among these, inside the light emitting part 511, a pair of electrodes 8A (the electrode on the sealing part 512 side is 8AL and the electrode on the sealing part 513 side is 8AR) are arranged, and between the pair of electrodes 8A, A discharge space S is formed in which a luminescent material containing mercury, a rare gas, and a small amount of halogen is enclosed.

  Molybdenum metal foils 5121 and 5131 electrically connected to the electrodes 8AL and 8AR, respectively, are inserted inside the pair of sealing portions 512 and 513, and the light emitting portion 511 in the pair of sealing portions 512 and 513 is inserted. The end on the opposite side is sealed with a glass material or the like. These metal foils 5121 and 5131 are further connected to electrode lead lines 514 and 515, respectively, and the electrode lead lines 514 and 515 extend to the outside of the arc tube 51A. When a voltage is applied to the electrode lead lines 514 and 515 by the power supply unit 92 described above, a potential difference is generated between the electrodes 8AL and 8AR through the metal foils 5121 and 5131, and a discharge is generated. The image D is formed and the light emitting unit 511 emits light.

[Configuration of main reflector 6]
Here, the main reflecting mirror 6 will be described.
The main reflecting mirror 6 corresponds to the reflecting mirror of the present invention, and is an integrally molded product made of glass that reflects incident light and converges it to the second focal point on the illumination optical axis A. The main reflecting mirror 6 is fixed with an adhesive B to one sealing portion 512 of the discharge lamp 5 (sealing portion 512 located on the proximal end side in the light emission direction of the light source device 411). Such a main reflecting mirror 6 is formed with a substantially cylindrical neck 61 through which the sealing portion 512 is inserted, and a concave curved reflector 62 extending from the neck 61.
Among these, a reflection surface 621 on which a metal thin film is deposited is formed on the surface of the rotation curve shape on the side facing the light emitting portion 511 in the reflection portion 62. The reflecting surface 621 is formed as a cold mirror that reflects visible light and transmits infrared rays and ultraviolet rays.

The neck portion 61 is formed with an opening 611 having a substantially circular shape in plan view through which the sealing portion 512 is inserted, and the adhesive B is injected into the opening 611 in a state where the sealing portion 512 is inserted. Thereby, the sealing portion 512 and the main reflecting mirror 6 are bonded and fixed. At this time, the positions of the discharge lamp 5 and the main reflecting mirror 6 are the center positions of the arc image D (the arc image D generated by the discharge between the body portions 824 described later of the electrode 8A) in the light emitting portion 511 of the discharge lamp 5. C is set to be near the first focal point of the reflecting surface 621 of the main reflecting mirror 6.
In the present embodiment, the main reflecting mirror 6 is composed of an ellipsoidal reflector having a rotational ellipsoid, but may be composed of a parabolic reflector having a rotational paraboloid. In this case, the collimating concave lens 7 is omitted. Further, the main reflecting mirror 6 may be constituted by a free-form curved reflector.

[Configuration of Sub-Reflecting Mirror 52]
The sub-reflecting mirror 52 is a glass molded product attached to the sealing portion 513 (sealing portion 513 opposite to the side where the main reflecting mirror 6 is attached) of the arc tube 51A. It is formed of the same material. The sub-reflecting mirror 52 includes a substantially cylindrical neck portion 521 having an opening 5211 through which the sealing portion 513 is inserted, and a reflecting portion 522 extending from the neck portion 521.

  Among these, the reflection part 522 is arrange | positioned so that the sealing part 513 side (tip side of the light emission direction of the light source device 411) in the light emission part 511 may be covered when the sub-reflection mirror 52 is attached to the sealing part 513. The light emitting portion 511 is formed in a substantially bowl shape so as to follow the outer shape. A reflection surface 5221 is formed on a surface of the reflection portion 522 that faces the light emitting portion 511. The reflection surface 5221 is formed as a cold mirror that reflects visible light and transmits infrared rays and ultraviolet rays. Yes.

  By attaching such a sub-reflecting mirror 52 to the arc tube 51A, light emitted from the light emitting unit 511 to the side opposite to the main reflecting mirror 6 side is reflected by the reflecting surface 5221. Then, the light enters the reflecting surface 621 of the main reflecting mirror 6. For this reason, the light is reflected by the reflection surface 621 and focused on the second focal point, similarly to the light directly incident on the reflection surface 621 from the light emitting unit 511. Thereby, it is possible to suppress the generation of light that is directly emitted from the light emitting unit 511 to the front end side in the light beam emission direction of the light source device 411 and that does not enter the first lens array 412 that is positioned downstream of the light source device 411. .

[Configuration of trigger wire 53]
The trigger wire 53 is a starting auxiliary line for improving the lighting performance of the arc tube 51A, one end is wound around the sealing portion 512 in a coil shape, and the center is the light emitting portion 511, the sub-reflecting mirror 52, and the sealing portion. The other end is arranged along the line 513, and the other end is connected to the electrode lead line 515 through the connection portion 516. One end of a lead wire 517 extending to the outside of the main reflecting mirror 6 is connected to the connecting portion 516 through an insertion hole 622 formed in the vicinity of the edge of the reflecting portion 62 of the main reflecting mirror 6. The other end of the lead wire 517 is connected to a terminal 54 for applying a voltage to the electrode lead wire 515 and the trigger wire 53.
By providing such a trigger line 53 and applying a high voltage pulse voltage to the trigger line 53, the lighting performance of the discharge lamp 5 can be improved.

[Configuration of electrode 8A]
3 and 4 are a side view and a sectional view showing the electrode 8A (electrode 8A on the sealing portion 512 side). In FIG. 4, only one side in the direction orthogonal to the axial direction of the electrode 8A is shown.
As described above, the pair of electrodes 8A includes the electrode 8AL disposed on the sealing portion 512 side and the electrode 8AR disposed on the sealing portion 513 side, and the electrodes 8AL and 8AR have the same configuration. have.
Among these, as shown in FIGS. 3 and 4, the electrode 8AL has a shaft portion 81 which is a tungsten core rod whose rear end side (side away from the electrode 8AR) is connected to the metal foils 5121 and 5131 described above. And a large-diameter portion 82A that is provided on the distal end side (side adjacent to the electrode 8AR) of the shaft portion 81 and has a larger diameter than the shaft portion 81.

  The large-diameter portion 82A includes a coil portion 821 formed by winding a tungsten wire L around the shaft portion 81 on the distal end side of the shaft portion 81, and the distal ends of the coil portion 821 and the shaft portion 81. And a main body portion 824 having a dome shape formed by melting by arc discharge or the like. That is, the large diameter portion 82A includes a main body portion 824 formed on the front end side and a coil portion 821 provided on the rear end side of the main body portion 824 and formed by winding a plurality of layers of the wire L. I have. The diameter of the main body 824 is substantially the same as the diameter of the coil portion 821.

The coil portion 821 is formed as a two-layer coil having an inner layer 822 and an outer layer 823.
Specifically, as shown in FIG. 4, the inner layer 822 is formed by winding the wire L around the shaft portion 81 a predetermined number of times from the front end side to the rear end side of the shaft portion 81. After the main body 824 is formed, the inner layer 822 becomes a 5-turn coil. That is, the inner layer 822 has five winding portions 8221 corresponding to one winding of the wire along the outer periphery of the shaft portion 81 after the main body portion 824 is formed.

As shown in FIG. 4, the wire L forming such an inner layer 822 is formed in a substantially parallelogram shape in sectional view, and the inner layer 822 is formed densely without a gap.
Specifically, the inner layer 822 has one surface out of a pair of surfaces of which the one acute angle portion faces the electrode rear end side and the pair of surfaces sandwiching the acute angle portion among the pair of acute angle portions of the substantially parallelogram in cross section. The wire L is wound around the shaft portion 81 so that 822C is disposed along the shaft portion 81.
In such an inner layer 822, an end surface 822A on the electrode tip side of each winding part 8221 and an end surface 822B on the electrode rear end side of the winding part 8221 adjacent to the winding part 8221 on the electrode tip side are respectively There is no gap, and the respective end surfaces 822A and 822B are in contact with each other in almost all the regions. Similarly, the end surface 822B on the electrode rear end side in each winding portion 8221 and the end surface 822A on the electrode front end side of the winding portion 8221 adjacent to the winding portion 8221 on the electrode rear end side, respectively, have no gap, In addition, the end surfaces 822B and 822A are in contact with each other in almost all the regions. These end surfaces 822A and 822B correspond to the contact surfaces of the present invention, and the end surface 822C corresponds to another contact surface of the present invention.

  With such a configuration, no gap is formed between each of the winding parts 8221 and between each of the winding parts 8221 and the shaft part 81, and the inner layer 822 is formed of the coil part 821 of each winding part 8221. The end surfaces 822A and 822B along the axial direction are densely formed so as to be in contact with the end surfaces 822B and 822A of the adjacent winding portions 8221, respectively. Of the outer surface of the inner layer 822, the surfaces facing the outer layer 823 are flush with each other.

  The outer layer 823 is formed by winding the wire L formed with the inner layer 822 back from the rear end side of the shaft portion 81 toward the front end side and covering the inner layer 822. This outer layer 823 has three winding parts 8231 after the formation of the main body part 824, and each winding part 8231 located at the approximate center of the coil part 821 has an outer surface of an adjacent winding part 8231. , And are formed so as not to contact each other in the direction along the axial direction of the shaft portion 81. Thereby, the outer layer 823 is formed sparsely as a whole. Therefore, an acute angle portion having a substantially parallelogram shape in cross-sectional view of the wire L is located on the electrode tip side of each winding portion 8231, thereby forming a corner portion 823A.

[Discharge starting point at the start of lighting of electrode 8A]
When a high voltage pulse voltage is applied to each electrode 8A, ions such as rare gas collide with the outer surface of the large diameter portion 82A, and the large diameter portion 82A is heated. Here, since the electric field (electric field) is concentrated on the acute angle portion on the outer surface of the coil portion 821, the acute angle portion is likely to be the starting point of discharge, but the winding portion 8221 and the shaft portion 81 on the rear end side of the electrode in the inner layer 822. Since the inclination angle becomes an obtuse angle, the electric field (electric field) is unlikely to concentrate at the end on the rear end side. On the other hand, since the corner portion 823A, which is an acute angle portion of the wire L, is positioned at the end portion of each winding portion 8231 of the outer layer 823 on the electrode tip side, an electric field (electric field) tends to concentrate on the corner portion 823A. .
For this reason, the site | part which opposes the trigger line 53 in either of these corner | angular parts 823A becomes a discharge starting point, and discharge is started at the time of the lighting start of the arc_tube | light_emitting_tube 51A at the said discharge starting point. Then, heat generated by the discharge is conducted to the main body 824 on the electrode tip side by the wire L forming the outer layer 823. Thus, when the main body 824 is heated until it reaches a predetermined temperature range, a discharge occurs between the main bodies 824 of the pair of electrodes 8A, and the lighting of the arc tube 51A is stabilized and becomes a steady state.

[Heat conduction when the electrode 8A is turned on]
In the steady state of the arc tube 51A, as described above, discharge occurs between the main body portions 824 of the respective electrodes 8A, so that the main body portion 824 becomes very high temperature. Here, since the main body portion 824 is formed by melting the tip side of the coil portion 821 and the shaft portion 81, the main body portion 824 is connected to the inner layer 822 and the outer layer 823 of the coil portion 821. Among these, the inner layer 822 is formed by densely winding the wire L having a substantially parallelogram in cross-sectional view as described above, and each winding portion 8221 has an end surface 822A on the electrode tip side and a back side of the electrode. The end surfaces 822B on the end side are in surface contact with each other, and no gap is formed between the winding portions 8221.

  For this reason, the heat conducted to the winding part 8221 connected to the main body part 824 is efficiently conducted to each winding part 8221 in surface contact with each other. Further, each of the winding portions 8221 is also in surface contact with the shaft portion 81, and no gap is formed between the winding portion 8221 and the shaft portion 81, so that heat conduction between the shaft portion 81 and the inner layer 822 is performed. Efficiency can be improved.

According to the projector 1 of the present embodiment described above, the following effects can be obtained.
Each winding part 8221 forming the inner layer 822 of the coil part 821 has end faces 822A and 822B that are in surface contact with adjacent winding parts 8221 without any gaps. Since these end surfaces 822A and 822B are substantially parallel to each other, even when the wire L is wound around the shaft portion 81 to form a plurality of winding portions 8221, the adjacent winding portions 8221 are appropriately in surface contact with each other. Can be made. According to this, since the heat conduction efficiency in the inner layer 822 can be increased, it is possible to suppress the main body portion 824 from being in an abnormally high temperature state. Accordingly, it is possible to suppress the deterioration of the electrode 8A, and thereby to extend the life of the arc tube 51A.

  End portions 822 </ b> C that are in surface contact with the shaft portion 81 without any gap are formed on the winding portions 8221 that form the inner layer 822. According to this, the heat conduction efficiency between the inner layer 822 and the shaft portion 81 can be increased. Therefore, the heat of the main body portion 824 can be efficiently conducted to the inner layer 822 via the shaft portion 81, so that the main body portion 824 can be further suppressed from being in an abnormally high temperature state.

The winding portions 8231 constituting the outer layer 823 are formed so as not to contact each other, thereby forming a corner portion 823A. According to this, not only can an acute angle part where an electric field (electric field) is easily concentrated be formed on the outer surface of the coil part 821, but the acute angle part can be directed to the electrode tip side, and the discharge starting point can be more distal. Can be located on the side. Furthermore, since the inner layer 822 is formed by winding the wire L so that the acute angle portion faces the electrode rear end side, the electrode rear end side in the inner layer 822 becomes an obtuse angle with respect to the shaft portion 81. Concentration of the electric field on the rear end side of the electrode can be suppressed. Accordingly, the discharge starting point at the start of lighting of the arc tube 51A can be positioned at the corner portion 823A.
Further, since the corner portion 823A is positioned at the approximate center of the coil portion 821, the discharge starting point is not positioned on the electrode rear end side in the outer layer 823. For this reason, since it is possible to suppress the arc caused by the discharge at the discharge starting point from colliding with the inner wall of the light emitting portion 511, it is possible to suppress the occurrence of white turbidity and blackening of the arc tube 51A, and consequently the arc tube 51A. It is possible to extend the service life.

  Since the wire L forming the inner layer 822 has a substantially parallelogram shape in cross section, the winding surface 8221 adjacent to the end surfaces 822A and 822B and the shaft portion 81 on the end surface 822C and the surface without a gap. Can be contacted. According to this, since the inner layers 822 and the shaft portion 81 can be brought into close contact with each other, the heat conduction efficiency between the winding portions and between the winding portion and the shaft portion can be reliably improved. it can. In addition, since no gap is generated between the winding portions and between the winding portion and the shaft portion, the heat capacity of the coil portion 821 can be increased, and the main body portion 824 and thus the electrode 8A can be surely deteriorated. Can be suppressed.

[2. Second Embodiment]
Next, a projector according to a second embodiment of the invention will be described.
The projector according to the present embodiment has the same configuration as that of the projector 1 described above. However, in the electrode included in the arc tube of the projector according to the present embodiment, the inner layer of the coil portion is formed by a wire having a substantially rectangular shape in cross section. The projector of this embodiment is different from the projector 1. In the following description, parts that are the same as or substantially the same as those already described are assigned the same reference numerals and description thereof is omitted.

  The projector according to the present embodiment has the same configuration as that of the above-described projector 1 except that the arc tube 51B is provided instead of the arc tube 51A, and the arc tube 51B includes an electrode 8B instead of the electrode 8A. Others have the same configuration as the arc tube 51A.

FIG. 5 is a cross-sectional view showing the electrode 8BL of the arc tube 51B according to the present embodiment. In FIG. 5, only one side in the direction orthogonal to the axial direction of the electrode 8B is shown.
The pair of electrodes 8B includes an electrode 8BL disposed on the sealing portion 512 side and an electrode (not shown) disposed on the sealing portion 513 side, and has the same configuration.
Among these, as shown in FIG. 5, the electrode 8BL is formed on the shaft portion 81 and the tip side of the shaft portion 81 (the side close to the other electrode (not shown)) and has a diameter larger than that of the shaft portion 81. And a large-diameter portion 82B having a large size. The large-diameter portion 82B includes a coil portion 825 and a main body portion 824 formed by dissolving the coil portion 825 and the distal end side of the shaft portion 81.

The coil portion 825 has an inner layer 826 formed by winding one wire L1 around the shaft portion 81, and an outer layer 827 formed by winding a wire L2 different from the wire L1 around the inner layer 826. is doing.
Among these, the inner layer 826 is formed by winding a wire L1 having a substantially rectangular shape in cross section around the shaft portion 81. After the main body portion 824 is formed, the inner layer 826 is a winding portion 8261 that is one turn around the shaft portion 81. There are six. Among these, the winding part 8261 on the electrode tip side is buried in the main body part 824.

  Each winding portion 8261 forming the inner layer 826 is in surface contact with the adjacent winding portion 8261 without any gap at the end surface 826A on the electrode front end side and the end surface 826B on the electrode rear end side. Furthermore, each winding portion 8261 is in surface contact with the shaft portion 81 without a gap at an end surface 826 </ b> C facing the shaft portion 81. By forming each winding part 8261 in this way, heat conducted from the main body part 824 is efficiently conducted to the entire inner layer 826 of the coil part 825 through the winding part 8261.

  The outer layer 827 is formed of a wire L2 that is different from the wire L1 that forms the inner layer 826, and the wire L2 has a cross-sectional shape that combines a substantially triangular shape and a substantially rectangular shape that abuts on one side of the triangular shape. is doing. The outer layer 827 has six winding portions 8271 corresponding to one turn along the outer periphery of the inner layer 826 after the main body portion 824 is formed. It is buried in the part 824.

These winding portions 8271 are in surface contact with the adjacent winding portions 8271 without any gaps at the end surface 827A on the electrode front end side and the end surface 827B on the electrode rear end side that are substantially parallel to each other. Further, the end surface of the winding portion 8271 facing the inner layer 826 is in surface contact with the corresponding winding portion 8261 in the inner layer 822.
Furthermore, the corner | angular part 827C derived from the wire L2 is formed in the end surface according to the outer surface of the coil part 825 in each winding part 8271. FIG. Here, the wire L1 is made of tungsten, but the wire L2 is made of a material obtained by adding a starting auxiliary substance such as thorium to tungsten. For this reason, in these corner portions 827C, not only the electric field (electric field) is likely to be concentrated at the start of lighting of the arc tube 51B, but also discharge is likely to occur due to the starting auxiliary substance. Becomes the discharge starting point.

According to the projector of the present embodiment described above, the same effects as those of the projector 1 described above can be obtained, and the following effects can be obtained.
That is, the inner layer 826 and the outer layer 827 of the coil part 825 are formed of different wire materials L1 and L2, and the wire material L2 forming the outer layer 827 contains a starting auxiliary substance. According to this, not the electrode rear end side of the inner layer 826 but the corner portion 827C of the outer layer 827 can be set as the discharge starting point. Accordingly, the discharge starting point is located on the rear end side of the electrode, and the arc generated at the discharge starting point can be prevented from traveling toward the other electrode 8B so that the arc is generated on the inner wall of the light emitting portion 511. The probability of collision can be reduced.

[3. Third Embodiment]
Next, a projector according to a third embodiment of the invention will be described.
The projector according to the present embodiment has the same configuration as that of the projector 1 described above. However, in the electrode included in the arc tube of the projector according to the present embodiment, the inner layer of the coil portion is formed by a wire having a substantially oval shape in cross section. In addition, the projector of this embodiment is different from the projector 1 in that a groove corresponding to the end surface of the inner layer is formed in the shaft. In the following description, parts that are the same as or substantially the same as those already described are assigned the same reference numerals and description thereof is omitted.

FIG. 6 is a cross-sectional view showing the electrode 8CL of the arc tube 51C according to the present embodiment. In FIG. 5, only one side in the direction orthogonal to the axial direction of the electrode 8CL is shown.
The projector of this embodiment has the same configuration as the projector 1 except that the arc tube 51C is provided instead of the arc tube 51A, and the arc tube 51C includes an electrode 8C instead of the electrode 8A. The configuration is the same as that of the arc tube 51A.
The pair of electrodes 8C includes an electrode 8CL disposed on the sealing portion 512 side and an electrode (not shown) disposed on the sealing portion 513 side, and each has the same configuration.
Among these, as shown in FIG. 6, the electrode 8CL includes a shaft portion 81C and a large-diameter portion 82C having a coil portion 828 and a main body portion 824. In addition, the coil part 828 of this embodiment is not formed by winding a wire around the shaft part 81C, but a coil that is a source of the coil part 828 is manufactured in advance and is formed at the center of the coil. After the shaft portion 81C is inserted into the formed opening, the main body portion 824 is formed.

  In the shaft portion 81C, a spiral groove 81C1 is formed in a range from the front end side of the shaft portion 81C to a position corresponding to the electrode rear end side of the coil portion 828. The shape of the spiral groove 81C1 is set in accordance with the shape of the end face 829C of each winding portion 8291 constituting the inner layer 829 of the coil portion 828 described later, and increases the degree of adhesion between the inner layer 829 and the shaft portion 81C. The coil portion 828 is easily twisted into the shaft portion 81C.

The coil portion 828 includes an inner layer 829 formed of a tungsten wire L3 having a substantially oval shape in cross section and an outer layer 830 formed of a wire L4 having a corner portion 830C on one side of the substantially oval shape in cross section. It is configured as a two-layer coil.
Among these, the outer layer 830 has six winding portions 8301 after the formation of the main body portion 824, and the winding portions 8301 have both ends of the end surface on the inner layer 829 side (in the direction along the axial direction of the coil portion 828). It is the same as the winding part 8271 except that it has a shape with rounded corners at both ends. That is, each winding portion 8301 has end faces 830A and 830B that are substantially parallel to each other as contact portions of the present invention on the electrode front end side and the electrode rear end side, and adjacent windings on the end faces 830A and 830B. The portion 8301 is in surface contact with no gap. Further, each winding portion 8301 has a corner portion 830C serving as a discharge starting point on the outer surface side of the coil portion 828.

  The inner layer 829 has six winding portions 8291 corresponding to one winding of the wire L3 with respect to the shaft portion 81C after the formation of the main body portion 824, and the winding portion 8291 on the electrode tip side is buried in the main body portion 824. ing. Each winding portion 8291 has a pair of end faces 829A and 829B that are substantially parallel to each other, that is, end faces 829A and 829B on the electrode front end side and electrode rear end side, and are adjacent to each other on the end faces 829A and 829B. It is in surface contact with the winding portion 8291 without a gap. That is, these end surfaces 829A and 829B correspond to the contact surfaces of the present invention.

Further, the end face 829C facing the shaft portion 81C in each winding portion 8291 is formed in an arc shape, and the end surface 829C reduces resistance when the coil is inserted into the shaft portion 81, and The degree of adhesion with the formed spiral groove 81C1 is increased. In other words, the end surface 829C corresponds to another contact surface of the present invention.
In addition, the rear end side of the winding portion 8291 on the electrode rear end side is exposed to the electrode rear end side from the outer layer 830, and the rear end side of the winding portion 8291 has a curved surface shape with a corner. ing. For this reason, it is possible to suppress the electric field concentration at the time of starting the lighting of the arc tube 51C in the part, and thereby it is possible to suppress the part from becoming a discharge starting point.

According to the projector of the present embodiment described above, the same effects as those of the projector 1 described above can be obtained, and the following effects can be obtained.
As for winding part 8291 which constitutes inner layer 829, end face 829C on the side facing shaft part 81C is formed in an arc shape. Further, a spiral groove 81C1 corresponding to the end face 829C is formed in the shaft portion 81C. According to this, since the resistance when the shaft portion 81C is screwed into the coil that is the basis of the coil portion 827 can be reduced, the process for attaching the already manufactured coil to the shaft portion 81C can be easily performed. it can.
Further, since the spiral groove 81C1 is formed, the spiral groove 81C1 and the winding portion 8291 are in surface contact with each other with a curved surface, so that the contact area between the shaft portion 81C and the inner layer 829 can be increased. The heat conduction efficiency can be improved.

[4. Modification of Embodiment]
The best configuration for implementing the present invention has been disclosed in the above description, but the present invention is not limited to this. That is, the description limited to the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such is included in this invention.

  In each of the above embodiments, each of the winding portions 8221, 8261, and 8291 forming the inner layers 822, 826, and 829 has end surfaces 822C, 826C, and 829C that are in surface contact with the shaft portions 81 and 81C without any gaps. The invention is not limited to this. That is, not all of the winding portions forming the inner layer may be in surface contact with the shaft portion without a gap.

  In the first to third embodiments, the wire rods L, L1, and L3 forming the inner layers 822, 826, and 829 are substantially parallelogram shape in cross section, substantially rectangular shape in cross section, and substantially oval shape in cross section, respectively. However, the present invention is not limited to these. That is, when the winding portion is formed, if the wire rod has a shape that is orthogonal to the direction along the axial direction of the coil portion and the opposite end surfaces are substantially parallel to each other, other shapes are used. You may form a coil part with the wire which has.

  In the first embodiment, the winding portions 8231 forming the outer layer 823 are formed so as not to contact each other in the axial direction of the coil portion 821, thereby forming the corner portions 823A. However, the present invention is not limited to this. Absent. For example, only two adjacent winding parts 8231 of the coil part 821 may be configured not to contact each other, or each adjacent winding part 8231 may be formed to contact each other.

  In the said 3rd Embodiment, although the spiral groove according to the end surface 829C of the winding part 8291 was formed in the axial part 81C, this invention is not limited to this. For example, it is good also as a structure in which the groove | channel contact | abutted to the end surface 829C of the winding part 8291 is formed in a part of shaft part. In addition, the electrode 8C is formed by twisting the shaft portion 81C into the coil portion 828. However, the present invention is not limited to this, and by winding the wire L3 along the spiral groove 81C1, The inner layer 829 may be formed.

In each of the above embodiments, the arc tubes 51A and 51B have the pair of electrodes 8A and 8B having the same configuration, but the present invention is not limited to this. In other words, at least one of the pair of electrodes may have the above-described configuration.
In each of the above embodiments, the coil portions 821, 825, and 828 each have two layers of inner layers 822, 826, and 829 and outer layers 823, 827, and 830. However, the present invention is not limited to this, and the coil portion is not limited thereto. The number of layers and the number of winding portions of each layer may be appropriately set according to the wattage of the arc tube.

In each of the above embodiments, the projector 1 includes the three liquid crystal panels 442R, 442G, and 442B, but the present invention is not limited to this. That is, the present invention can also be applied to a projector using two or less or four or more liquid crystal panels.
In each of the above embodiments, the configuration in which the optical unit 4 has a substantially L shape in plan view has been described. However, the configuration is not limited thereto, and for example, a configuration having a substantially U shape in plan view may be employed. .
Further, in each of the above embodiments, the transmissive liquid crystal panel 442 having a different light beam incident surface and light beam emission surface is used, but a reflective liquid crystal panel having the same light incident surface and light emission surface is used. Also good.

  In each of the above embodiments, the projector 1 including the liquid crystal panel 442 is illustrated as the light modulation device. However, any other configuration may be used as long as the light modulation device forms an optical image by modulating the incident light beam according to image information. You may employ | adopt a light modulation apparatus. For example, the present invention can be applied to a projector using a light modulation device other than liquid crystal, such as a device using a micromirror. When such a light modulation device is used, the polarizing plates 443 and 445 on the light incident side and the light emitting side can be omitted.

  In each of the above embodiments, the light source device 411 including the discharge lamp 5 having the arc tubes 51A and 51B is employed in the projector 1, but the present invention is not limited to this. That is, such a light source device 411 can also be used for other illumination devices. Further, the discharge lamp 5 can be used alone.

  INDUSTRIAL APPLICABILITY The present invention can be used as an arc tube, and particularly as an arc tube used in a light source device and a projector.

1 is a schematic diagram illustrating a configuration of a projector according to a first embodiment of the invention. The longitudinal cross-sectional view which shows the discharge lamp and main reflector in the said embodiment. The side view which shows the electrode in the said embodiment. Sectional drawing which shows the electrode in the said embodiment. Sectional drawing which shows the electrode of the arc tube with which the projector which concerns on 2nd Embodiment of this invention is provided. Sectional drawing which shows the electrode of the arc tube with which the projector which concerns on 3rd Embodiment of this invention is provided.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Projector, 3 ... Projection lens (projection optical apparatus), 6 ... Main reflection mirror (reflection mirror), 8A (8AL, 8AR), 8B (8BL), 8C (8CL) ... Electrode, 81, 81C ... Shaft part, 411: light source device, 442 (442R, 442G, 442B) ... liquid crystal panel (light modulation device), 51A, 51B, 51C ... arc tube, 511: light emitting unit, 821, 825, 828 ... coil unit, 8221, 8261, 8291 ... winding part, 822A, 822B, 826A, 826B, 829A, 829B ... end face (contact face), 822C, 826C, 829C ... end face (other contact face), 823A, 827C, 830C ... corner, 81C1 ... Spiral groove (groove).

Claims (10)

A light-emitting tube having a light-emitting portion in which a pair of electrodes are arranged and discharges and emits light between the pair of electrodes,
At least one of the pair of electrodes is
A shaft portion, and a coil portion provided on the tip side which is the side close to the other electrode in the shaft portion,
The coil part is one turn of the wire with respect to the shaft part, and has a plurality of winding parts arranged along the axial direction of the coil part,
Each said winding part has the contact surface which mutually contacts the said winding part, respectively, The arc tube characterized by the above-mentioned. The arc tube of claim 1, wherein
The arc tube according to claim 1, wherein the winding portion has another contact surface in surface contact with the shaft portion. The arc tube according to claim 1 or 2,
The arc tube according to claim 1, wherein the layer of the coil portion that is farthest from the shaft portion has a corner portion at a portion that is an outer surface of the coil portion. The arc tube according to any one of claims 1 to 3,
The arc tube characterized in that the abutment surface on the front end side of the winding part and the abutment surface on the rear end side, which is the side away from the other electrode, are formed substantially parallel to each other. . The arc tube according to claim 4, wherein
The wire forming the winding part has a substantially parallelogram shape in cross section,
The arc tube according to claim 1, wherein the abutting surface on the front end side and the abutting surface on the rear end side are a pair of surfaces that are opposite to each other in the wire. The arc tube of claim 5, wherein
An arc tube characterized in that a corner on the rear end side of the cross-sectional shape of the wire and on the shaft side is an acute angle portion. The arc tube according to claim 1 or 2,
The wire forming the winding part has a substantially oval cross section,
The arc tube according to claim 1, wherein the contact surface on the front end side and the contact surface on the rear end side are a pair of surfaces that are opposite to each other and substantially parallel to each other in the wire. The arc tube of claim 7,
The shaft portion has a groove corresponding to the shape of the surface of the winding portion facing the shaft portion.   A light source device comprising: the arc tube according to any one of claims 1 to 8; and a reflecting mirror that aligns light emitted from the arc tube in one direction and emits it as a light beam.   A light source device according to claim 9, a light modulation device that modulates a light beam emitted from the light source device according to image information, and a projection optical device that projects the modulated light beam. projector.

Images