JP2008305758A - Light source device, and projection-type display device equipped with the device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source device capable of providing high-luminance light, and a projection-type display device equipped with the device. <P>SOLUTION: This light source device 1 includes a light source 2, a reflecting mirror 3, a lens 4, and a reflecting part 5. The light source 2 has a light emitting part 6, and a light transmission part 7 surrounding the light emitting part 6 and transmitting light generated by the light emitting part 6. The reflecting mirror 3 has an inside space formed into a rotationally symmetrical shape, and having an opening area gradually increasing toward a light emitting direction, houses the light transmission part 7 in the inside space, and reflects light emitted from the light emitting part 6 in a direction parallel to the rotationally symmetric axis of the rotationally symmetrical shape. The lens 4 is arranged at the light emitting direction side relative to the light transmission part 7, and refracts the light emitted from the light emitting part 6 in a direction parallel to the rotationally symmetric axis of the reflecting mirror 3. The reflecting part 5 is formed at the opposite side in the light emitting direction relative to the light transmission part 7 as a part of a spherical surface generally centering the light emitting part 6, and reflects the light emitted from the light emitting part 6. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light source device and a projection display device including the same.

  Recent projection display devices are often used in bright environments such as conference rooms, and improving the brightness of projected images is an important issue. The most reliable method for improving the brightness of the projected image is to increase the amount of light emission by increasing the power supplied to the light source. However, when this method is used, the temperature of the arc tube is increased, so that the lifetime of the arc tube is reduced. If the cooling capacity is increased in order to suppress the temperature rise in the light transmission part of the arc tube, the noise increases due to the expansion of the cooling structure. In addition, in order to increase the power supply, there is a problem that the size of the ballast or power supply unit that supplies power for stably emitting light from the light source increases.

  In order to improve the brightness of the projected image without these problems, it is necessary to increase the light use efficiency. Patent Documents 1 to 3 disclose related techniques for a configuration that increases the light use efficiency.

  As shown in FIG. 7, the optical device 101 disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2001-92011) includes an arc tube 102, a reflecting mirror 103, and a condenser lens 104. The arc tube 102 is arranged so that the optical axis of the reflecting mirror 103 and the discharge direction from the arc bright spot A of the arc tube 102 are orthogonal to each other. The reflecting mirror 103 has a spherical reflecting portion 105 and a parabolic reflecting portion 106. The configuration of the spherical reflector 105 and the paraboloid reflector 106 reduces the size of the optical device 101 and improves the utilization efficiency of light emitted from the arc tube 102.

  As shown in FIG. 8, the illumination device 201 disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 11-64795) includes a light source 202, a spheroid mirror 203 as a first reflecting mirror, and a second reflecting mirror. And a spherical mirror 204 which is a mirror. Further, a plano-concave lens 205, a cholesteric liquid crystal layer 206, and a phase plate 207 are arranged in this order along the light emission direction between the spherical mirror 204 and the irradiation target. Due to the positional relationship among the first reflecting mirror 203, the cholesteric liquid crystal layer 206, and the phase plate 207, the polarization conversion efficiency of the illumination device 201 is improved. Furthermore, since the first reflecting mirror 203 and the second reflecting mirror 204 cover the light source 202 over a wide range, the light collection efficiency of the light emitted from the light source 202 is also improved.

As shown in FIG. 9, an illumination device 301 disclosed in Patent Document 3 (Japanese Patent Laid-Open No. 11-143378) includes an arc tube 302, a parabolic reflector 303, and an auxiliary mirror 304. . The auxiliary mirror 304 includes a semi-elliptical reflecting surface 306 that covers a part of the light emitting unit 305 of the arc tube 302. Due to the arrangement relationship between the semi-elliptical reflection surface 306 and the light emitting unit 305, the parallelism of the light emitted from the lighting device 1 is improved, so that the light utilization efficiency is improved.
JP 2001-92011 A JP-A-11-64795 Japanese Patent Laid-Open No. 11-143378

However, for example, in the case of the structure of the light source device using the ellipsoidal reflector as disclosed in Patent Document 2, the base of the ellipsoidal reflector (the vicinity of the portion where the arc tube is connected to the ellipsoidal reflector). reflected light, may be irradiated in the vicinity of the distal end portion of the arc tube (see D ₂ in FIG. 10). In this case, as the power supplied to the arc tube increases, the region near the tip of the arc tube becomes hot. This causes disconnection or breakage of the arc tube, so there is a limit to increasing the power supplied to the arc tube. There was a problem that light having high luminance could not be obtained due to the limit of power supplied to the arc tube.

Further, for example, in the case of the structure of the light source device using the paraboloidal reflector as disclosed in Patent Documents 1 and 3, the light reflected by the base of the paraboloidal reflector has a spherical shape of the arc tube. parts sometimes transmitted (see D ₄ in FIG. 11). In this case, since the arc tube is made of transparent glass, the light transmitting portion of the arc tube refracts light in the same manner as the lens. Therefore, the light transmitted through the light transmission part is refracted and emitted in a direction D ₄ other than the desired direction D ₅ . As a result, the light output of the light source device is lost, and the light use efficiency is lowered, so that there is a problem that light having high luminance cannot be obtained.

Regardless of the shape of the reflecting mirror, a part of the light emitted from the arc tube is not reflected by the reflecting mirror but is scattered away from the optical axis (D in FIG. 10). see D ₆ of ₃ and 11). As a result, the light output of the light source device is lost, and the light use efficiency is lowered, so that there is a problem that light having high luminance cannot be obtained.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a light source device capable of realizing light with high luminance and a projection display device including the same.

The light source device of one embodiment of the present invention includes a light emitting unit, a light transmitting unit that surrounds the light emitting unit, transmits light generated by the light emitting unit, extends linearly from the light transmitting unit in a direction opposite to the light emitting direction, and emits light A first extending portion sealing a portion other than the tip portion of one of the electrodes positioned in the portion, and extending linearly from the light transmitting portion to the opposite side of the first extending portion when viewed from the light emitting portion A light source provided with a second extending portion that seals a portion other than the tip of the other electrode facing the one electrode, and is formed in a rotationally symmetric shape and gradually toward the light emitting direction It has an inner space where the opening area increases, and the light transmission part is housed in the inner space, and the light emitted from the light emitting part converges in a direction parallel to the rotational symmetry axis of the rotational symmetry or toward the rotational symmetry axis. A direction in which the first extension portion extends and a direction in which the second extension portion extends. Reflecting mirror whose axis of rotation symmetry is on the same line, and provided on the light emission direction side of the light transmission part, and converges the light emitted from the light emitting part toward a direction parallel to the rotational symmetry axis or a rotational symmetry axis A light refracting means that refracts the light in the direction, and is formed as a part of a spherical surface on the opposite side of the light emitting direction from the light transmitting portion and having the light emitting portion substantially at the center, and reflects the light emitted from the light emitting portion A light reflecting means.

  According to the present invention, the light emitted from the light emitting unit is emitted by the reflecting mirror, the light refracting means, and the light reflecting means in a direction parallel to the rotational symmetry axis of the reflecting mirror or a direction converged toward the rotational symmetry axis. . Therefore, it is possible to provide a light source device that can realize light with high luminance and a projection display device including the light source device.

The best mode for carrying out the present invention will be described with reference to the drawings. In FIGS. 1 to 4 showing all the embodiments, the locus of light emitted from the light source to the upper region in the drawing is illustrated as a light flux having an interval of 15 ° from the center of the light transmission part of the light source.
(First embodiment)
FIG. 1 is a cross-sectional view showing a configuration of a light source device according to a first embodiment of the present invention.

  The light source device 1 includes a light source 2, a reflecting mirror 3, a lens 4, and a reflecting unit 5. In addition, the shape of the cross section of the reflecting mirror 3 of a present Example is a paraboloid.

  The light source 2 includes a light emitting unit 6, a light transmitting unit 7, a first extending unit 8, and a second extending unit 9. In the light emitting unit 6, the tip portions of the two electrodes 10 and 11 are close to the center of the spherical light transmitting unit 7 and face each other. Further, in the light emitting unit 6, light is generated by arc discharge between both electrodes 10 and 11 to which power is supplied. The light transmitting unit 7 surrounds the light emitting unit 6 and transmits light generated by the light emitting unit 6 to the outside of the light source 2. The light emitting unit 6 is located at the center of the light transmitting unit 7. The first extending portion 8 extends linearly from the light transmitting portion 7 in a direction opposite to the light emitting direction (right direction in FIG. 1), and seals a portion other than the tip portion of the electrode 10. A part of the outer peripheral surface of the first extension 8 is connected to the end surface of the base 12 of the reflecting mirror 3 via an adhesive 13, so that the light source 2 is fixed to the reflecting mirror 3.

  Further, the second extending portion 9 extends from the light transmitting portion 7 in a straight line on the opposite side of the first extending portion 8 when viewed from the center of the light transmitting portion 7. The second extending portion 9 seals a portion other than the tip portion of the electrode 11. The light transmission part 7, the first extension part 8, and the second extension part 9 are configured to be coaxial (on the same line). With the above configuration, the light source 2 has the optical axis of the reflecting mirror 3 in which the direction in which the light source 2 extends (the optical axis of the light source) has a parabolic cross-sectional shape (that is, the rotationally symmetric axis of the paraboloid). ) And the reflecting mirror 3 so as to be on the same line.

  Further, the center of the light transmitting portion 7 is approximately disposed at the focal point of the reflecting mirror 3. Thereby, when the light generated at this center is reflected by the reflecting mirror 3, the light becomes parallel to the optical axis of the reflecting mirror 3. Therefore, the brightness of the light emitted from the light source device 1 can be increased. The light source 2 is a light source with excellent luminous efficiency called an ultra-high pressure mercury lamp. This light source is frequently used in a projection display device.

  The reflecting mirror 3 has an inner space where the opening area gradually increases from the base portion 12 toward the light emitting direction, and has a parabolic cross-sectional shape that is rotationally symmetric. The light transmission part 7 of the light source 2 is accommodated in this inner space. The light emitted from the light emitting unit 6 of the light source 2 is reflected in a direction parallel to the optical axis of the reflecting mirror 3 by the reflecting surface of the reflecting mirror 3 having a rotationally symmetric shape (light beams D, E, and F in FIG. 1). . Further, the reflecting surface may be composed of a plurality of layers made of a dielectric. The plurality of layers can enhance the light reflecting performance of the reflecting surface.

  The lens 4 functions as a light refracting unit that refracts the light emitted from the light emitting unit 6 of the light source 2. The lens 4 has an incident surface 4a on which light is incident and an output surface 4b on which light incident on the incident surface 4a is refracted and emitted. The lens 4 has a convex shape due to the shape of the entrance surface 4 a and the exit surface 4 b, and refracts incident light in a direction parallel to the optical axis of the lens 4. At least one of the entrance surface and the exit surface may be an aspherical surface or may be a flat surface. By constituting at least one of the entrance surface 4a and the exit surface 4b with an aspherical surface, it is possible to improve the deterioration of imaging performance and light collection performance (that is, spherical aberration).

  Further, since the lens 4 is rotationally symmetric, it has an optical axis that is a rotationally symmetric axis. The optical axis of the lens 4 coincides with the optical axis that is the rotationally symmetric axis of the reflecting mirror 3. Thus, the direction in which the first extension 8 of the light source 2 extends, the direction in which the second extension 9 of the light source 2 extends, and the optical axis that is the rotationally symmetric axis of the reflecting mirror 3. And the optical axis of the lens 4 are on the same line. The lens 4 has a through-hole penetrating the lens optical axis at the center thereof. The shape of the through hole is the same as the shape of the outer peripheral surface of the second extending portion 9 of the light source 2.

  The lens 4 is provided in the second extending portion 9 disposed in the light emitting direction with respect to the light transmitting portion 7 of the light source 2. The inner peripheral surface forming the through hole of the lens 4 and the outer peripheral surface of the second extending portion 9 of the light source 2 have the same shape, and the first extending portion 8 and the second extending portion of the light source 2 are also formed. The direction in which the protruding portion 9 extends (the optical axis of the light source) coincides with the optical axis of the reflecting mirror 3. Therefore, the three of the optical axis of the light source 2, the optical axis of the reflecting mirror 3, and the optical axis of the lens 4 coincide. Thereby, the light emitted from the light source 2 and refracted by the lens 4 is emitted in a direction parallel to the optical axis of the reflecting mirror 3 which is a desired direction.

  The lens 4 is preferably molded integrally with the light source 2. If the optical axis of the lens 4 coincides with the extending direction of the light source 2 at the time of molding, the extending direction of the light source 2 and the reflection are reflected when the integrally molded light source 2 and lens 4 are assembled to the reflecting mirror 3. It is only necessary to match the optical axis of the mirror 3. That is, it is not necessary to make the optical axis of the reflecting mirror 3 coincide with the optical axis of the lens 4 during assembly. On the other hand, if the light source 2 and the lens 4 are separately assembled to the reflecting mirror 3, there is a risk that the optical axis of the reflecting mirror 3 does not match the optical axis of the lens 4. If the light source 2 and the lens 4 are integrally molded, such a problem at the time of assembly can be avoided, so that the light emission performance that the light source device 1 should have can be sufficiently exhibited.

  The reflecting unit 5 functions as a light reflecting unit that reflects light emitted from the light emitting unit 6 of the light source 2. Further, the reflecting portion 5 is formed as a part of a spherical surface having the light emitting portion 6 as a substantially center on the opposite side of the light emitting direction when viewed from the center of the light transmitting portion 7 of the light source 2. Specifically, the region opposite to the light emitting direction represents a region in the light source device 1 that is on the inner side of a plane that passes through the center of the light transmitting unit 7 that is the light emitting unit 6 and is orthogonal to the optical axis of the reflecting mirror 3. Yes. The reflecting portion 5 in this embodiment is a mirror provided on the outer peripheral surface of the light transmitting portion 7. The reflecting portion 5 is disposed at a position facing the inner surface of the base portion 12 that forms the inner space of the reflecting mirror 3.

In the configuration of the light source device 1 having the lens 4 described above, the light directly incident from the light source 2 (light beams A, B, and C) and the light source 2 are emitted from the light source 2 to the incident surface of the lens 4, and the reflecting portion. After being reflected at 5, the incident light (light beam I) enters. Both lights are emitted by the lens 4 in a desired direction that is parallel to the optical axis of the reflecting mirror 3. As a result, light that has conventionally been a dissipative component of the light output (light in the front oblique direction D ₆ in FIG. 11) is incident on the lens 4 and refracted in the optical axis direction in the present embodiment, so The light can be emitted in the direction. That is, the utilization efficiency of the light emitted from the light source is improved.

In the configuration of the light source device 1 having the reflection unit 5 described above, light (light beams G, H, I) emitted from the light emitting unit 6 of the light source 2 on the side opposite to the light emission direction is reflected on the reflection unit 5. Incident. Then, since the reflection part 5 is concentric with the light transmission part 7 and the light reflection surface of the reflection part 5 has a shape of a part of a spherical surface, both the reflection angle and the incident angle with respect to the tangential line of the spherical surface are 90. °. Therefore, the light reflected by the light reflecting surface follows the same path as the path of the incident light. The reflected light passes through the center of the light transmission part 7 and passes through the light transmission part 7. Thereafter, a part of the transmitted light enters the reflecting mirror 3. The light incident on the reflecting mirror 3 is reflected in a direction parallel to the optical axis of the reflecting mirror 3, which is a desired direction, and is emitted to the outside of the light source device 1 (light beams G and H in FIG. 1). In this way, a part of the transmitted light is incident on the lens 4. The light incident on the lens 4 is refracted in a direction parallel to the optical axis of the reflecting mirror 3 and the optical axis of the lens 4 and is emitted to the outside of the light source device 1 (light flux I). As a result, the light travels to the base 12 of the reflecting mirror 3, and the light (light in the forward oblique direction D ₄ in FIG. 11) that has conventionally been a dissipative component of the light output is reflected in the reflecting portion 5 in this embodiment (light flux I). Reflected by. The reflected light enters the lens 4 and is refracted in the optical axis direction, and can be emitted in a desired direction. Here, in the light source device that does not have the reflection part 5 as in the prior art, the light (light flux G, H, I) emitted from the light emitting part 6 of the light source 2 on the side opposite to the light emitting direction is transmitted by the light transmitting part 7. Since the spherical portion of the light transmitting portion 7 has the same effect as the lens, the light passing through the portion is refracted and travels in a direction that does not occur, resulting in a loss. Therefore, the light reflection efficiency has been improved because the light flux that has been conventionally lost can be used by the reflecting portion 5.

  Conventionally, the light beams G, H, and I are concentrated on the base portion of the reflecting mirror and the region in the vicinity thereof. However, the light incident on the base 12 of the reflecting mirror 3 is reflected by the reflecting portion 5 of the present embodiment toward a region where the opening area of the reflecting mirror 3 is wide. Thereby, damage, such as a crack and peeling of a reflective surface by the heat | fever of the light irradiated to the layer which comprises the reflective surface of the reflective mirror 3, can be reduced. Furthermore, since the heat generation of the reflecting mirror due to the light concentrated on the base portion of the reflecting mirror can be suppressed, the rapid temperature rise of the light source accompanying the heat generation of the reflecting mirror can be suppressed. Therefore, the burst of the light source can be avoided and the life of the light source can be extended. Of the light emitted from the light source 2, the light (light fluxes J and K) incident on the adhesive 13 is light that causes a loss of light output. However, the volume of the adhesive can be reduced by appropriately using an adhesive with improved adhesive performance. Thereby, the space | interval of the reflective mirror 3 and the light source 2 can be restrained small. Therefore, the reflecting mirror 3 and the light source 2 can be configured so that the light incident on the adhesive agent can be reliably captured and reflected by the inner surface of the base 12 of the reflecting mirror 3 in the past.

As is apparent from FIGS. 1 and 11, the outer shape of the light source device 1 of this embodiment is exactly the same as that of the conventional light source device. Therefore, the light source device of this embodiment can be replaced with the light source device of an existing projection display device. This is extremely effective as a technique for improving the luminance of a projection display device already used in the market. From a design point of view, it can be used as a common light source device for a new projection display device. It should be noted that the interchangeability of the light source device of this embodiment is also applied to the light source devices of other embodiments of the present invention.
(Second embodiment)
FIG. 2 is a cross-sectional view showing a configuration of a light source device according to a second embodiment of the present invention.

  The light source device 21 of this embodiment is different from the light source device 1 of the first embodiment only in the configuration of the light reflecting means, and the other components are the same as those of the first embodiment. Therefore, in this embodiment, the features, functions, and effects of the light reflecting means will be mainly described.

  The light reflecting means of the present embodiment is a spherical portion 25 provided as a part of the reflecting mirror. The spherical portion 25 is provided as a part of a spherical surface concentric with the light transmitting portion 27, similarly to the reflecting portion 5 provided in the light transmitting portion 7 of the first embodiment. The spherical portion 25 is also connected to the base portion 32. The spherical portion 25 is provided on the reflecting mirror 23 so that the center of the spherical portion 25 having a part of a spherical surface and the focal point of the reflecting mirror 23 substantially coincide with each other. Further, the center of the light transmitting portion 27 is the center of the spherical portion 25 and is disposed at a position that is the focal point of the reflecting mirror 23. Thereby, when the light generated at the center of the light transmitting portion 27 (that is, the focal point of the reflecting mirror 23) is reflected by the reflecting mirror 23, the light becomes parallel to the optical axis of the reflecting mirror 23.

In the configuration of the light source device 21 having the spherical portion 25 described above, light (light beams G, H, I) emitted from the light emitting portion 26 of the light source 22 is incident on the spherical portion 25 on the side opposite to the light emitting direction. To do. Then, since the spherical portion 25 is concentric with the light transmitting portion 27 and the light reflection surface of the spherical portion 25 has a shape of a part of a spherical surface, both the reflection angle and the incident angle with respect to the tangential line of the spherical surface are 90. °. Therefore, the light reflected by the light reflecting surface follows the same path as the path of the incident light. The reflected light passes through the center of the light transmission part 27 and passes through the light transmission part 27. Thereafter, a part of the transmitted light enters the reflecting mirror 23. The light incident on the reflecting mirror 23 is reflected in a direction parallel to the optical axis of the reflecting mirror 23, which is a desired direction, and is emitted to the outside of the light source device 21 (light beams G and H). In this way, a part of the transmitted light is incident on the lens 24. The light incident on the lens 24 is refracted in a direction parallel to the optical axis of the reflecting mirror 23 and the optical axis of the lens 24 and is emitted to the outside of the light source device 21 (light flux I). Thus, the process proceeds to the base 32 of the reflector 23, a conventional light, which has been a dissipative component of the optical output (light obliquely forward D ₄ in FIG. 11) is, in the present embodiment is reflected by the spherical portion 25, Thereafter, the light enters the lens 24 and is refracted in the direction of the optical axis, so that the light can be emitted in a desired direction (light flux I). Therefore, the light use efficiency is improved.

  In the light source device 1 defined in the first embodiment, the reflecting portion 5 is provided in contact with the light transmitting portion 7 of the light source 2. As a result, when the light source 2 generates heat, the heat is directly transmitted to the reflecting portion 5 and the reflecting portion 5 generates heat.

  On the other hand, in the light source device 21 defined in this embodiment, the spherical portion 25 is provided apart from the light transmitting portion 27. Therefore, the distance from the center of the light transmission part 27 to the reflection surface of the spherical part 25 is ensured. Further, the shape of the base 12 of the parabolic reflector shown in the broken line in FIG. 2 (first embodiment) changes to the shape of the base 32 of the spherical reflector shown in the two-dot chain line (this embodiment). It has changed. Therefore, the area of the reflective surface of the spherical portion 25 of the present embodiment is larger than that of the reflective portion 5 of the first embodiment. Furthermore, the distance between the center of the light transmission part 27, which is a light source, and the reflecting surface is larger than that in the first embodiment. Therefore, since the density of the light beam incident on the reflecting surface is reduced, the heat generated on the reflecting surface is hardly transmitted to the light source 22, and the temperature rise of the light source 22 can be suppressed. Further, due to the reduction of the light flux density, it is possible to avoid damage to the reflecting surface due to intensive light irradiation on a plurality of layers constituting the reflecting surface of the spherical portion 25. That is, since heat resistance becomes high, a higher output light source can be used, and as a result, the brightness | luminance of a light source device can be raised.

In addition, since the light (light beam J in FIG. 1) incident on the adhesive 13 in the first embodiment can be captured by the spherical portion 25 in the present embodiment, the light utilization efficiency can be further improved.
(Third embodiment)
FIG. 3 is a cross-sectional view showing a configuration of a light source device according to a third embodiment of the present invention. In this embodiment, the shape of the cross section of the reflecting mirror is the same as that of the first embodiment (the elliptical surface is rotationally symmetric like the paraboloid of the first embodiment and thus has a rotationally symmetric axis). Only one thing is different. Therefore, the arrangement relationship between the reflecting mirror and other components, and the actions and effects caused by the arrangement relationship will be mainly described.

  The reflecting mirror 43 has a first focal point F1 and a second focal point F2. Here, along the optical axis of the reflecting mirror 43, the focal point closer to the light source 42 is referred to as a first focal point F1, and the far focal point is referred to as a second focal point F2. On the other hand, the lens 44 has a first focal point F3 and a second focal point F4 on both sides thereof. Here, the focal point on the light incident side of the lens 44 is referred to as a first focal point F3, and the focal point on the light emitting side is referred to as a second focal point F4. The lens so that the first focal point F3 of the lens 44 coincides with the first focal point F1 of the reflecting mirror 43, and the second focal point F4 of the lens 44 coincides with the second focal point F2 of the reflecting mirror 43. 44 is provided in the second extension 49 of the light source 42. Further, the center of the light transmitting portion 47 is disposed at a position that is the first focal point F <b> 1 of the reflecting mirror 43 and the first focal point F <b> 3 of the lens 44.

In the light source device 41 having the reflection mirror 43 described above, the light reflected by the reflection mirror 43 (light beams C to I) and the light refracted by the lens 44 (light beams A and B) are rotationally symmetric. The light is emitted from the light source device 41 so as to converge to one point toward the optical axis as the axis and the optical axis of the lens 44. This convergence point is the second focal point F2 of the reflecting mirror 43 and also the second focal point F4 of the lens 44. That is, in the present embodiment, light that has been a dissipative component of light output in the past (light in the front oblique direction D ₆ in FIG. 11) enters the lens 44 and is refracted in the optical axis direction of the reflecting mirror 43 and the lens 44. By doing so, it can be emitted in a desired direction. Therefore, the utilization efficiency of the light emitted from the light source is improved.

Further, light (light fluxes H and I) traveling from the center of the light transmitting portion 47 of the light source 42 to the base 52 of the reflecting mirror 43 is reflected by the reflecting portion 45. The reflected light travels so that the reflection path coincides with the incident path, passes through the center of the light transmission part 47, and passes through the light transmission part 47. Thereafter, the transmitted light is reflected by the reflecting mirror 43 and emitted to the outside of the light source device 41 so as to converge toward the second focal point F2 of the reflecting mirror 43 (the second focal point F4 of the lens 44). Thereby, all of the light traveling to the base portion 52 is reflected by the reflecting portion 45, so that no light is incident on the base portion 52. Has been a problem in the prior art, (see D ₂ in FIG. 10) light such as intensively incident on the tip portion of the second extending portion of the light source is reflected by the base of the reflector that is eliminated, the light source The disconnection and breakage of 42 can be avoided. Therefore, the power supplied to the two electrodes 50 and 51 can be increased, and as a result, the luminance of the light source device can be increased.

  When the cross-sectional shape of the reflecting surface of the reflecting mirror is an elliptical surface, the light collecting property is higher than that of the parabolic surface. Therefore, when the cross-sectional shape of the reflecting surface is an ellipse, the amount of light dissipated in a direction other than the desired direction is less than that in the case of a parabolic surface. Accordingly, when light of the same brightness as that of a light source device having a parabolic reflecting mirror is to be realized by a light source device having an elliptical reflecting mirror, the lens 44 of this embodiment (ellipsoidal surface) The diameter may be smaller than the diameter of the lens 4 of the first embodiment (parabolic surface). If the diameter of the lens 44 is small, the possibility that the light reflected by the reflecting mirror 43 is refracted by the lens 44 and emitted in a direction other than the desired direction can be suppressed. For this reason, in order for the light reflected by the reflecting portion 45 to be incident on the miniaturized lens 44 with certainty, it is necessary to reduce the area of the reflecting surface of the reflecting portion 45. As a result, the reflecting portion 45 can be reduced in size.

(Fourth embodiment)
FIG. 4 is a cross-sectional view showing a configuration of a light source device according to a fourth embodiment of the present invention.

  This embodiment differs from the second embodiment only in that the cross-sectional shape of the reflecting mirror is an ellipsoid (having a rotationally symmetric axis like the paraboloid of the second embodiment). Therefore, the arrangement relationship between the reflecting mirror and other components, and the actions and effects caused by the arrangement relationship will be mainly described.

  The reflecting mirror 63 has a first focal point F1 and a second focal point F2. Here, along the optical axis of the reflecting mirror 63, the focal point closer to the light source 62 is referred to as a first focal point F1, and the far focal point is referred to as a second focal point F2. On the other hand, the lens 64 has a first focal point F3 and a second focal point F4 on both sides thereof. Here, the focal point on the light incident side of the lens 64 is referred to as a first focal point F3, and the focal point on the light emitting side is referred to as a second focal point F4. The spherical portion 65 has a center C. The first focal point F3 of the lens 64, the first focal point F1 of the reflecting mirror 63, and the center C of the spherical portion 65 coincide with each other, and the second focal point F4 of the lens 64 and the second focal point F2 of the reflecting mirror 63 Are matched with each other so that the lens 64 is provided in the second extension 69 of the light source 62. Further, the center of the light transmitting portion 67 is disposed at a position that is the first focal point F 1 of the reflecting mirror 63, the first focal point F 3 of the lens 64, and the center C of the spherical portion 65.

In the light source device 61 having the reflecting mirror 63 described above, the light reflected by the reflecting mirror 63 (light beams C to I) and the light refracted by the lens 64 (light beams A and B) are rotationally symmetric. The light is emitted from the light source device 61 so as to converge at one point so as to converge at one point toward the optical axis as the axis and the optical axis of the lens 64. This convergence point is the second focal point F2 of the reflecting mirror 63 and also the second focal point F4 of the lens 64. In other words, light that has conventionally been a dissipative component of light output (light in the forward oblique direction D ₆ in FIG. 11) is incident on the lens 64 and refracted in the optical axis direction in this embodiment, so that a desired direction is obtained. Can be emitted. Therefore, the utilization efficiency of light emitted from the light source is improved.

Further, light (light beam) traveling from the center of the light transmitting portion 67 of the light source 62 (the first focal point F1 of the reflecting mirror 63, the first focal point F3 of the lens 64, and the center C of the spherical portion 65) to the base 72 of the reflecting mirror 63. H, I, J) is reflected by the spherical portion 65 (first reflection). The reflected light travels so that the reflection path coincides with the incident path, passes through the center of the light transmission part 67, and passes through the light transmission part 67. Thereafter, a part of the transmitted light (light beams H and I) is reflected by the reflecting mirror 63 (second reflection) and is emitted to the outside of the light source device 61 so as to converge toward the focal point. Since the first reflection in this embodiment is performed by a spherical reflecting surface, the second reflection is closer to the opening of the reflecting mirror 63 than the conventional second reflection (the center of the light transmitting portion 67). At a remote location). For this reason, of the reflected light in the second reflection, the amount of light incident on the tip of the second extending portion 69 of the light source 62 is reduced as compared with the conventional case. Thus, by light such as intensively incident on the tip portion of the second extending portion 69 (see D ₂ in FIG. 10) is reduced, it is possible to avoid disconnection of the light source 62, the breakage. Therefore, the power supplied to the two electrodes 70 and 71 can be increased, and as a result, the luminance of the light source device can be increased.

  On the other hand, a part of the transmitted light (light beam J) enters the lens 64. The incident light is refracted in a desired direction to converge toward the focal point by the lens 64 and is emitted to the outside of the light source device 61. Therefore, light that has conventionally been a dissipative component of light output is reduced, and the light utilization efficiency can be improved.

  In the light source device 41 defined in the third embodiment, a reflecting portion 45 is provided in contact with the light transmitting portion 47 of the light source 42. As a result, when the light source 42 generates heat, heat is directly transmitted to the reflecting portion 45 and the reflecting portion 45 generates heat.

  On the other hand, in the light source device 61 defined in this embodiment, the spherical portion 65 is provided apart from the light transmitting portion 67. Therefore, the distance from the center of the light transmission part 67 to the reflection surface of the spherical part 65 is ensured. Furthermore, from the shape of the base 52 (third embodiment) of the parabolic reflector shown by the broken line in FIG. 4 to the shape of the base 72 (this embodiment) of the spherical reflector shown by the two-dot chain line. It has changed. Therefore, the area of the reflection surface of the spherical portion 65 of this embodiment is larger than that of the reflection portion 45 of the third embodiment. Further, the distance between the center of the light transmission part 67 as the light emitting source and the reflecting surface is larger than the distance in the third embodiment. Therefore, since the density of the light beam incident on the reflecting surface is reduced, the heat generated on the reflecting surface is hardly transmitted to the light source 62, and the temperature rise of the light source 62 can be suppressed. Further, due to the reduction of the light flux density, it is possible to avoid damage to the reflecting surface due to intensive light irradiation on a plurality of layers constituting the reflecting surface of the spherical portion 65. Moreover, since the light (light beam J in FIG. 3) incident on the adhesive 53 in the third embodiment can be captured by the spherical portion 65 in this embodiment, the light utilization efficiency can be further improved.

  Next, a projection display device provided with the light source device of the third embodiment will be described with reference to FIG.

  In general, a projection display device refers to a device that modulates light from a light source according to image information and enlarges and projects a created image on a screen. The projection display device described here emits white light from a light source, then separates the colors into three colors, red, green, and blue, and creates and synthesizes an image using a transmissive liquid crystal modulation element for each color. A three-panel type liquid crystal panel type for display.

  As shown in FIG. 5, the projection display device 81 of the present invention includes an optical unit 82, a power supply unit 83, an electric circuit unit 84, a lamp fan 85 that cools heat-generating components, an exhaust fan 86, and a liquid crystal unit. It is comprised with the liquid crystal part fan 87 which cools.

  In the power supply unit 83, AC power is supplied to the power supply 88 from the external AC power supply 90. Thereafter, electric power is supplied to the ballast 89 and the electric circuit unit 84. The ballast 89 stably causes the light source provided in the optical unit 82 to emit light and supplies power to the light source.

  The electric circuit unit 84 drives the transmissive liquid crystal modulation element in the optical unit 82 in accordance with the video signal 91 input from the outside, and creates an image. The liquid crystal unit fan 87 is mounted on the optical unit 82, and includes optical components that drive the liquid crystal unit fan 87, the lamp fan 85, and the exhaust fan 86, and various electronic components mounted on the power source unit 83. Cool down. Thereby, the optical performance is maintained, and the stability and reliability of the operation are maintained.

  FIG. 6 is a detailed view showing the optical configuration of the optical unit 82 of the projection display apparatus of the present invention.

  The optical unit 82 includes a light source system 821, an illumination optical system 822, a color synthesis optical system 823, and a projection optical system 824. The illumination optical system 822 includes a color separation optical system 825 and a relay optical system 826.

  In the light source system 821, a light source device 827 (for example, an ultrahigh pressure mercury lamp) is turned on by light emission control of the ballast 89. Thereafter, the light emitted from the light source device 827 enters the concave lens 828 positioned forward without loss. The concave lens 828 emits parallel light rays to the first fly-eye lens 829.

  In the illumination optical system 822, the light incident on the first fly-eye lens 829 is divided into a plurality of lens elements. The first fly-eye lens 829 is composed of a plurality of lens elements having a shape similar to the transmission part of the transmission type liquid crystal modulation element. The light divided for each lens element is emitted to a second fly-eye lens 830 having a lens element corresponding to each lens element (the emitted light is transmitted through each optical component, and finally Is superimposed on the liquid crystal display element).

  The light emitted from the second fly-eye lens 830 is aligned with the S-polarized light by the polarization conversion element 831. Thereafter, the S-polarized light travels to the color separation optical system 825 through the field lens 832.

  In the color separation optical system 825, first, the first dichroic mirror 833 reflects and separates only red light (red light path R) and transmits light of other wavelengths. Next, the second dichroic mirror 834 reflects and separates green light (green light path G) and transmits blue light (blue light path B). With this color separation function, S-polarized white light is separated into red, green, and blue. Regarding the blue light path B, the optical path to the transmissive liquid crystal display element 835 is longer than the other light paths, and therefore a relay optical system 826 is provided.

  The relay optical system 826 includes a first relay lens 836, a second relay lens 837, and mirrors 838 and 839 that change the traveling direction of light. Further, the relay optical system 826 adjusts an optical distance longer than the red optical path R and the green optical path G.

  The color-separated light passes through the condenser lens 840, the incident-side polarizing plate 841, the transmissive liquid crystal display element 835, and the emission-side polarizing plate 842 for each color, and is emitted to the color combining optical system 823. The configuration of optical components through which each color is transmitted is almost the same, and the red light path R will be described here. The red light path R separated by the first dichroic mirror 833 is then changed in traveling direction by the mirror 843 and is incident on the condenser lens 840. The light that has entered the condenser lens 840 enters the incident-side polarizing plate 841 as light that is parallel or converges to a focal point. The incident side polarizing plate 841 serves to remove light other than the ideal S-polarized light and improve the contrast. The red light from which unnecessary light has been removed enters the transmissive liquid crystal display element 835, modulates the S-polarized light according to the video signal, and emits it to the color synthesis optical system 823.

  The color synthesis optical system 823 selectively transmits the light modulated by the transmissive liquid crystal display element 835 and emits the light to the cross dichroic prism 844. The cross dichroic prism 844 combines the red light path R, the green light path G, and the blue light path B, and outputs the resultant light to the projection optical system 824.

  The projection optical system 824 projects incident light on a screen by a projection lens 845 composed of a plurality of optical lenses, and displays the enlarged image.

It is sectional drawing which shows the structure of the light source device of the 1st Example of this invention. It is sectional drawing which shows the structure of the light source device of the 2nd Example of this invention. It is sectional drawing which shows the structure of the light source device of the 3rd Example of this invention. It is sectional drawing which shows the structure of the light source device of the 4th Example of this invention. It is a figure which shows the basic composition of the projection type display apparatus provided with the light source device of the 3rd Example of this invention. It is a figure which shows the detailed optical structure of the optical unit of the projection type display apparatus of FIG. It is sectional drawing which shows one form of the conventional light source device which has a parabolic mirror. It is sectional drawing which shows one form of the conventional light source device which has an ellipsoidal mirror. It is sectional drawing which shows another form of the conventional light source device which has a parabolic mirror. It is sectional drawing which shows another form of the conventional light source device which has an ellipsoidal mirror. It is sectional drawing which shows another form of the conventional light source device which has a parabolic mirror.

Explanation of symbols

1, 2, 41, 61 Light source device 2, 22, 42, 62 Light source 3, 23, 43, 63 Reflector 4, 24, 44, 64 Lens 5, 45 Reflector 25, 65 Spherical part 6, 26, 46, 66 Light emitting part 7, 27, 47, 67 Light transmitting part

Claims (11)

A light-emitting unit, a light-transmitting unit that surrounds the light-emitting unit and transmits light generated by the light-emitting unit, and extends linearly from the light-transmitting unit in a direction opposite to the light emitting direction, and is positioned on the light-emitting unit A first extension part sealing a portion other than the tip part of one of the electrodes, and a linear extension from the light transmission part on the opposite side of the first extension part as seen from the light emitting part, A second extension portion sealing a portion other than the tip portion of the other electrode facing the one electrode, and a light source comprising:
It is formed in a rotationally symmetric shape and has an inner space in which the opening area gradually increases in the light emitting direction, the light transmitting portion is housed in the inner space, and the light emitted from the light emitting portion is Reflecting in a direction parallel to the rotational symmetry axis of the rotationally symmetric shape or in a direction converged toward the rotational symmetry axis, the direction in which the first extension part extends and the direction in which the second extension part extends And a reflection mirror in which the rotational symmetry axis is on the same line,
A light refracting means provided on the light emitting direction side of the light transmitting portion and refracting light emitted from the light emitting portion in a direction parallel to the rotational symmetry axis or in a direction converging toward the rotational symmetry axis;
A light reflecting means that is formed on the opposite side of the light emitting direction from the light transmitting portion and is formed as a part of a spherical surface that is substantially centered on the light emitting portion, and reflects the light emitted from the light emitting portion;
A light source device.   The light source device according to claim 1, wherein the light transmission part is substantially spherical, and the light emitting part is located at a center of the light transmission part and in the vicinity thereof.   The light source device according to claim 2, wherein the light reflecting means is a reflecting portion provided on an outer surface of the light transmitting portion.   The light source device according to claim 2, wherein the light reflecting means is a spherical portion provided as a part of the reflecting mirror. The light refracting means has an incident surface on which light emitted from the light emitting unit is incident and an output surface from which light incident on the incident surface is emitted,
5. The light source device according to claim 1, wherein at least one of the entrance surface and the exit surface is formed of an aspherical surface.   The light source device according to claim 1, wherein the light refraction unit is formed integrally with the light source. The reflecting mirror is a parabolic mirror;
The center of the light transmission portion is disposed at the focal point of the reflecting mirror,
The light source device according to claim 3. The reflecting mirror is an ellipsoidal mirror;
The reflecting mirror has a first focal point and a second focal point in order along the light emitting direction, and the light refracting means has the first focal point and the second focal point in order along the light emitting direction. Have
The light refracting means matches the first focus of the light refracting means with the first focus of the reflecting mirror, and the second focus of the light refracting means and the second focus of the reflecting mirror. So that it matches the focus of
The center of the light transmission part is the first focal point of the reflecting mirror, and is disposed at a position that is the first focal point of the light refracting means.
The light source device according to claim 3. The reflecting mirror is a parabolic mirror;
The light reflecting means is provided in the reflecting mirror so that the center of the light reflecting means coincides with the focal point of the reflecting mirror,
The center of the light transmission portion is the center of the light reflecting means, and is disposed at a position that is the focal point of the reflecting mirror.
The light source device according to claim 4. The reflecting mirror is an ellipsoidal mirror;
The reflecting mirror has a first focal point and a second focal point in order along the light emitting direction, and the light refracting means has the first focal point and the second focal point in order along the light emitting direction. And the light reflecting means has a center,
The light refracting means has the first focus of the light refracting means, the first focus of the reflecting mirror, and the center of the light reflecting means being coincident with each other, and the second focus of the light refracting means. And the second focus of the reflecting mirror coincide with each other,
The center of the light transmitting portion is the first focus of the reflecting mirror, the first focus of the light refracting means, and the center of the light reflecting means. ,
The light source device according to claim 4.   A projection display device comprising the light source device according to claim 1.

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