JP2008003125A - Lighting system and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting system for suppressing in-plane light intensity distribution from being nonuniform in an area to be illuminated and suppressing the quality of projected images from deteriorating even when the emission of any LD light source out of a plurality of the LD light sources weakens in the lighting system used preferably for a projector of high brightness. <P>SOLUTION: The lighting system 100 has a first LD light source 10 for emitting an illuminating light flux with a first optical axis 10ax as a center axis; a second LD light source 20 for emitting an illuminating light flux with a second optical axis 20ax as a center axis; and a polarized beam combiner 30 having a polarizing and combining face 32 for reflecting light from the second LD light source 20 and transmitting the light from the first LD light source 10, and combines and emits the light from the first LD light source 10 and the light from the second LD light source 20. The first LD light source 10 is composed so as to emit the light with a P polarized component. The second LD light source 20 is composed so as to emit the light with an S polarized component. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lighting device and a projector.

  Conventionally, a projector with high brightness has been demanded, and a projector having a configuration for combining light from two light source lamps with a triangular prism (hereinafter referred to as a conventional projector) has been proposed as a response to the demand (hereinafter referred to as a conventional projector). For example, see Patent Document 1.)

  According to such a conventional projector, since the illumination device having two light source lamps is used as the illumination device, a projector with higher brightness than the conventional one can be configured.

Japanese Patent Laid-Open No. 2002-72083 (FIG. 4)

  By the way, in order to make the conventional projector more compact, it is conceivable to use two LD light sources instead of the two light source lamps based on the configuration of the conventional projector. A projector using such two LD light sources is a compact projector with high brightness.

  However, in this case, if the light emission of one of the two LD light sources is weakened, there is a problem in that the illuminance in the illuminated area decreases and the brightness of the projected image decreases. Further, when the light emission of one of the two LD light sources is weakened, there is a problem in that the in-plane light intensity distribution in the illuminated area becomes non-uniform and the quality of the projected image is deteriorated.

  Therefore, the present invention has been made to solve the latter problem of the above two problems, and is an illumination device that can be suitably used for a high-intensity projector, and includes a plurality of LD light sources. Provided is an illuminating device capable of suppressing non-uniform in-plane light intensity distribution in an illuminated area and suppressing the quality of a projected image from deteriorating even if the light emission of any LD light source is weakened The purpose is to do. Another object of the present invention is to provide a projector including such an illumination device.

  In order to achieve the above object, the inventor of the present invention has a non-uniform in-plane light intensity distribution in an illuminated area when the light emission of one of the two LD light sources is weakened in a projector using two LD light sources. The cause of becoming a thorough investigation. As a result, because the illumination light beams from the two LD light sources are synthesized by the triangular prism at a predetermined angle, the illumination light beams from the two LD light sources are superimposed in the same illumination range in the illuminated area. However, it was found to be caused by the fact that they were not superimposed at the same angle. Based on this knowledge, the present inventor has conceived that the above problem can be solved by superimposing illumination light beams from two LD light sources at the same angle, and has completed the present invention.

  In other words, the illumination device of the present invention includes a first LD light source that emits an illumination light beam having a first optical axis as a central axis, and a second LD that emits an illumination light beam having a second optical axis as a central axis. A light source and a polarization combining surface that transmits light from the first LD light source and reflects light from the second LD light source; and from the light from the first LD light source and the second LD light source. The first LD light source in a direction parallel to a virtual plane including a normal line of the polarization combining surface and the first optical axis. The second LD light source is configured to emit light having a polarization axis, and the second LD light source has a polarization axis in a direction perpendicular to a virtual plane including a normal line of the polarization combining surface and the second optical axis. It is characterized by emitting the light which has.

  For this reason, according to the illumination device of the present invention, linearly polarized light having different polarization axes is emitted from the first LD light source and the second LD light source, and these linearly polarized light are respectively incident on the polarization beam combiner. From the polarization beam combiner, the illumination light beams from the two LD light sources (the first LD light source and the second LD light source) are emitted in the form of being superimposed at the same angle. For this reason, even if the light emission of any one of the two LD light sources is weakened, the in-plane light intensity distribution in the illuminated area is prevented from being uneven and the quality of the projected image is prevented from being deteriorated. It becomes possible to provide an illuminating device that can do this.

  The illuminating device of the present invention preferably further includes an integrator optical system that is arranged at a later stage of the optical path than the polarization beam combiner and converts the illumination light beam from the polarization beam combiner into light having a more uniform intensity distribution.

  With this configuration, it is possible to make the in-plane light intensity distribution of the illumination light beam applied to the illuminated region more uniform.

  In the illumination device of the present invention, the integrator optical system includes a condenser lens that converts the illumination light beam from the polarization beam combiner into a focused light and emits the light, and a more uniform intensity distribution of the illumination light beam from the condenser lens. It is preferable to have an integrator rod that converts light into light.

  By configuring in this way, it is possible to make the in-plane light intensity distribution of the illumination light beam irradiated to the illuminated region more uniform due to multiple reflection on the inner surface of the integrator rod.

  In the illumination device of the present invention, the integrator rod may be a hollow integrator rod or a solid integrator rod.

  As the hollow integrator rod, for example, a cylindrical light tunnel in which the reflecting surfaces of four reflecting mirrors are bonded inward can be suitably used. In addition, as the solid integrator rod, for example, a solid rod member (glass rod) of an internal total reflection type can be suitably used.

  In the illumination device of the present invention, the integrator optical system includes a first lens array having a plurality of first small lenses that divide an illumination light beam from the polarization beam combiner into a plurality of partial light beams, and the first lens array. It is preferable to include a second lens array having a second small lens corresponding to each first small lens, and a superimposing lens for superimposing light from the second lens array in an illuminated area.

  Even with this configuration, the light from the polarization beam combiner is divided into a plurality of partial luminous fluxes, and then the partial luminous fluxes are superimposed by the superimposing lens, so that the in-plane light of the illumination luminous flux irradiated to the illuminated area is obtained. The intensity distribution can be made more uniform.

  In the illumination device according to the aspect of the invention, it is preferable that the integrator optical system includes a conical prism that converts an illumination light beam from the polarization beam combiner into light having a more uniform intensity distribution.

  Even with this configuration, the light of the relatively bright central part (the part close to the system optical axis) and the relatively dark peripheral part (from the system optical axis) of the illumination light flux from the polarization beam combiner are operated by the action of the conical prism. It becomes possible to mix the light of a distant part), and it is possible to make the in-plane light intensity distribution of the illumination light beam irradiated to the illuminated region more uniform (for details, see Japanese Patent Application Laid-Open No. 2005-2005). -128-563).

  In this specification, the term “conical prism” does not mean only a conical prism, but also includes a structure having a shape obtained by cutting the peripheral portion of the bottom surface of a conical prism into a flat shape. Used.

  In the illuminating device of the present invention, the integrator optical system further includes a light guide member that is disposed on the light exit side of the conical prism and converts the illumination light beam from the conical prism into light having a more uniform intensity distribution. It is preferable.

  With this configuration, it is possible to make the in-plane light intensity distribution of the illumination light beam irradiated to the illuminated region even more uniform by the reflection on the inner surface of the light guide member.

  In the illumination device of the present invention, the light guide member may be a hollow light guide member or a solid light guide member.

  As the hollow light guide member, for example, a cylindrical light tunnel in which the reflection surfaces of four reflection mirrors are bonded inward can be preferably used. Moreover, as a solid light guide member, for example, a solid rod member (glass rod) of an internal total reflection type can be suitably used.

  In the illuminating device of this invention, it is preferable that the light emission surface of the conical prism and the light incident surface of the light guide member are bonded.

  By configuring in this way, undesirable multiple reflection between the conical prism and the light guide member is suppressed, and the light use efficiency does not decrease and the stray light level does not increase. Further, the conical prism and the light guide member can be easily integrated. In addition, it is possible to prevent the occurrence of misalignment after assembly of the device between the conical prism and the light guide member.

  In this case, it is preferable to use an adhesive having substantially the same refractive index as the conical prism and the light guide member.

  The illuminating device of the present invention preferably further includes a light uniformizing optical element that is disposed on the light exit side of the conical prism and converts light from the conical prism into light having a more uniform intensity distribution.

  With this configuration, the in-plane light intensity distribution of the light irradiated to the illuminated region can be made more uniform by the function of the light uniformizing optical element.

  By the way, when a predetermined light uniforming effect is obtained by the conical prism and / or the light guide member, the length of the conical prism and / or the light guide member needs to be relatively long. On the other hand, according to the illuminating device of the present invention, the length of the conical prism and / or the light guide member can be made relatively short due to the light homogenizing effect of the light homogenizing optical element. Can be achieved.

  In the illumination device according to the aspect of the invention, the light uniformizing optical element may include a light transmittance adjusting member whose light transmittance is adjusted according to an in-plane light intensity distribution of light emitted from the conical prism, or the conical prism. A light diffusing member that diffuses emitted light is preferable.

As the light transmittance adjusting member, an ND filter or a dichroic filter having an in-plane light transmittance distribution opposite to the pattern of the in-plane light intensity distribution of light emitted from the conical prism can be suitably used.
As the light diffusing member, a member whose surface is a light diffusing surface, a member containing a granular material having a light diffusing function on the surface or inside, a Fresnel lens, a microprism array, or the like can be suitably used. The microprism array has a plurality of prism-like objects arranged on the surface and has a light diffusion function.

  In the illuminating device of the present invention, the polarization beam combiner is a prism type polarization beam combiner. The polarization beam combiner is disposed in the polarization beam combiner and supplies an acoustic wave including an ultrasonic wave to the polarization beam combiner. An acoustic wave supply device that forms a standing wave in the polarization beam combiner; and a control device that controls the acoustic wave supply device so that a period of the standing wave is modulated at a frequency of 60 Hz or more. preferable.

When the LD light source is used, the laser light has coherence, so that the light from the LD light source interferes with each other to generate speckle noise, and uneven illuminance due to speckle noise in the illuminated area. May occur.
However, according to the illumination device of the present invention, since the polarization beam combiner includes an acoustic wave supply device that forms a standing wave, even if speckle noise occurs due to interference of light from the LD light source, By performing high-speed modulation of such speckle noise at a speed invisible to human eyes, it is possible to reduce illuminance unevenness due to speckle noise in the illuminated area.

  In the illumination device according to the aspect of the invention, it is preferable that the acoustic wave supply device is disposed in close contact with the polarization beam combiner.

  With this configuration, it is possible to efficiently supply an acoustic wave to the polarization beam combiner, and it is possible to reduce illuminance unevenness due to speckle noise in the illuminated area with less energy and greater effect. It becomes.

  In the illuminating device of the present invention, the acoustic wave supply device is disposed on the polarization beam combiner via an ultrasonic good transmission material having a refractive index smaller than that of the medium of the polarization beam combiner. Is preferred.

This configuration also makes it possible to efficiently supply acoustic waves to the polarization beam combiner, and to reduce illuminance unevenness due to speckle noise in the illuminated area with a small amount of energy and a large effect. It becomes possible.
In addition, since the refractive index of the ultrasonic good transmission material is smaller than the refractive index of the medium of the polarization beam combiner, the light from the LD light source is totally reflected at the interface between the polarization beam combiner and the ultrasonic good transmission material, and light leakage occurs. Can be eliminated. For this reason, it becomes possible to suppress generation | occurrence | production of a stray light, and it becomes possible to suppress decline in light utilization efficiency.

  As an ultrasonic good transmission substance, the gel used in the medical / beauty field etc. can be illustrated preferably. In view of long-term stability, it is more preferable to use a gel made of a substance having a low vapor pressure.

  The projector of the present invention includes the above-described illumination device of the present invention, an electro-optic modulation device that modulates light from the illumination device according to image information, and projection optics that projects light modulated by the electro-optic modulation device. And a system.

  Therefore, according to the projector of the present invention, since the above-described excellent illumination device is provided, the projector is a high-intensity projector, and even if the light emission of any one of the plurality of LD light sources is weakened, the projection is performed. This makes it possible to suppress the deterioration of the image quality.

  In the projector according to the aspect of the invention, the illumination device includes a plurality of illumination devices that emit a plurality of color lights, and is disposed between the plurality of illumination devices and the electro-optic modulation device, and is emitted from the plurality of illumination devices. It is preferable to further include a cross dichroic prism that combines the optical paths of the plurality of color lights to be emitted toward the electro-optic modulator.

  In the projector according to the aspect of the invention, the illuminating device includes a plurality of illuminating devices that emit a plurality of color lights, and the electro-optic modulation device is a plurality of devices that respectively modulate light from the plurality of illuminating devices according to image information. It is preferable to further include a cross dichroic prism that combines the plurality of color lights emitted from the plurality of electro-optic modulators.

  By configuring as described above, it is a high-intensity projector, and it is possible to suppress deterioration of the quality of the projected image even if light emission of any one of the plurality of LD light sources is weakened. In addition, a full color projector having excellent image quality (for example, a three-plate type) can be obtained.

  Hereinafter, an illumination device and a projector according to the present invention will be described based on embodiments shown in the drawings.

[Embodiment 1]
FIG. 1 is a diagram illustrating an optical system of the illumination device 100 and the projector 1000 according to the first embodiment. FIG. 2 is a diagram schematically illustrating how the illumination light beams emitted from the first LD light source 10 and the second LD light source 20 in the illumination device 100 are polarized and separated and combined.

  In the following description, three directions orthogonal to each other are defined as a z-axis direction (system optical axis OC direction in FIG. 1), an x-axis direction (direction parallel to the paper surface in FIG. 1 and perpendicular to the z-axis) and y, respectively. An axial direction (a direction perpendicular to the paper surface in FIG. 1 and perpendicular to the z-axis).

  As shown in FIG. 1, the projector 1000 according to the first embodiment has an illumination device 100, a relay optical system 310 that guides light from the illumination device 100 to an illuminated area, and light from the relay optical system 310 as an image. A micromirror light modulator 400 as an electro-optic modulator that modulates according to information, and a projection optical system 600 that projects light modulated by the micromirror light modulator 400 onto a projection surface such as a screen SCR. Projector.

  As shown in FIGS. 1 and 2, the illumination device 100 according to the first embodiment includes a first LD light source 10 that emits an illumination light beam having the first optical axis 10ax as a central axis, and a second optical axis 20ax. A second LD light source 20 that emits an illumination light beam having a central axis as a center axis, and convex lenses 16 and 26 that emit light from the first LD light source 10 and the second LD light source 20 toward the polarization beam combiner 30, respectively. A polarization beam combiner 30 that combines and emits the light from the first LD light source 10 and the light from the second LD light source 20, an acoustic wave supply device 40 disposed in the polarization beam combiner 30, and an acoustic It has a control device (not shown) for controlling the wave supply device 40 and an integrator optical system 700 disposed on the light exit side of the polarization beam combiner 30.

  The first LD light source 10 includes a light emitting unit 12r that emits red light, a light emitting unit 12g that emits green light, a light emitting unit 12b that emits blue light, an LD substrate 14, and a heat dissipation unit (not shown). ). The first LD light source 10 is light having a polarization axis in a direction parallel to a virtual plane including a normal line of a polarization combining surface 32 (to be described later) and the first optical axis 10ax (hereinafter, light related to a P polarization component). It is configured to inject.

  The second LD light source 20 includes a light emitting unit 22r that emits red light, a light emitting unit 22g that emits green light, a light emitting unit 22b that emits blue light, an LD substrate 24, and a heat radiating unit (not shown). ). The second LD light source 20 is light having a polarization axis in a direction perpendicular to a virtual plane including a normal line of the polarization combining surface 32 (to be described later) and the second optical axis 20ax (hereinafter, light related to the S polarization component). It is configured to inject.

  The first LD light source 10 and the second LD light source 20 are connected to a time division drive circuit (not shown), and for example, one frame or an image in an image displayed on the micromirror light modulator 400 by the time division drive circuit. The light emitting units 12r, 12g, 12b, 22r, 22g, and 22b are driven in a time-sharing manner with a period of one field.

  The convex lenses 16 and 26 are made of, for example, aspheric lenses, and have a function of converting the light from the first LD light source 10 and the second LD light source 20 into substantially parallel light and emitting the light.

  The polarization beam combiner 30 has a substantially square shape in plan view in which a triangular prism having the first light incident surface 34 and a triangular prism having the second light incident surface 36 are bonded together, and an interface where the triangular prisms are bonded together. Is formed with a polarization combining surface 32 that transmits light related to the P-polarized component and reflects light related to the S-polarized component. The light related to the P-polarized component emitted from the first LD light source 10 passes through the polarization combining surface 32. The light related to the S-polarized component emitted from the second LD light source 20 is reflected by the polarization combining surface 32. As a result, the light related to the P-polarized component emitted from the first LD light source 10 and the light related to the S-polarized component emitted from the second LD light source 20 are combined, and the integrator optical system is supplied from the polarized beam combiner 30. It is injected toward 700.

  Such a polarization beam combiner 30 has a configuration similar to that of a polarization beam splitter, but the light passing direction is opposite to that of the polarization beam splitter, and two types of straight lines whose polarization directions are perpendicular to each other. Combines polarized light and emits apparently unpolarized light.

  The acoustic wave supply device 40 is disposed on the side surface of the polarization beam combiner 30 through a gel g as a good ultrasonic wave transmission material. Then, a standing wave is formed in the polarization beam combiner 30 by supplying an acoustic wave composed of ultrasonic waves to the polarization beam combiner 30.

As the gel g, a gel having a refractive index smaller than the refractive index of the medium of the polarization beam combiner 30 is used.
Moreover, as gel g, the gel used in the medical / beauty field etc. can be illustrated preferably. In view of long-term stability, it is more preferable to use a gel made of a substance having a low vapor pressure.

  The control device (not shown) controls the acoustic wave supply device 40 so that the period of the standing wave is modulated at a frequency of 60 Hz or more, and sets the frequency of the ultrasonic wave supplied from the acoustic wave supply device 40. Modulate at a frequency of 60 Hz or higher. As a result, for example, by modulating an ultrasonic wave having an oscillation frequency of 200,000 Hz with a modulation frequency of 300 Hz, an acoustic wave composed of an ultrasonic wave modulated at a high speed in the range of 150,000 Hz to 250,000 Hz is converted into a polarization beam combiner. 30 can be supplied. Note that the values of the oscillation frequency and the modulation frequency can be appropriately selected from a predetermined range.

  The integrator optical system 700 includes a conical prism 710 that converts the illumination light beam from the polarization beam combiner 30 into light having a more uniform intensity distribution, and a light guide member 712 that is disposed on the light exit side of the conical prism 710.

The conical prism 710 refracts the illumination light beam from the polarization beam combiner 30 at the light incident surface, so that a relatively bright central portion (portion close to the system optical axis OC) of the illumination light beam from the polarization beam combiner 30 and the light beam. An optical member having a function (light uniformizing function) for mixing and emitting light of a relatively dark peripheral part (part far from the system optical axis OC) to light having a more uniform in-plane light intensity distribution It is.
The conical prism 710 has a shape in which the peripheral portion of the bottom surface is cut into a flat shape. Note that “the shape in which the peripheral portion of the bottom surface is cut into a flat shape” means a shape in which a part of the side surface and the bottom surface of the conical prism 710 is cut into a flat shape.

  The light guide member 712 is an optical member having a function of converting the illumination light beam from the conical prism 710 into light having a more uniform intensity distribution by reflecting the illumination light beam from the conical prism 710 on the inner surface. As the light guide member 712, for example, a cylindrical light tunnel whose inner surface is a reflective surface can be suitably used.

  The relay optical system 310 includes a relay lens 312, a reflection mirror 314, and a condenser lens 316, and has a function of guiding an illumination light beam from the illumination device 100 to an image forming region of the micromirror light modulation device 400. ing.

  The relay lens 312 has a function of forming an image in the vicinity of the image forming region of the micromirror type light modulation device 400 without diverging the illumination light beam from the illumination device 100 together with the condenser lens 316. Note that the relay lens 312 may be formed of a compound lens in which a plurality of lenses are combined.

  The reflection mirror 314 is disposed so as to be inclined with respect to the system optical axis OC of the illumination device 100, bends the illumination light beam from the relay lens 312, and guides it to the micromirror type light modulation device 400. Thereby, a projector can be made compact.

  The condenser lens 316 substantially superimposes the illumination light flux from the relay lens 312 and the reflection mirror 314 on the image forming area of the micromirror light modulator 400 and projects the light modulated by the micromirror light modulator 400. The enlarged projection is performed together with the optical system 600.

  The micromirror-type light modulation device 400 has a function of emitting image light representing an image to the projection optical system 600 by reflecting light from the relay optical system 310 with a micromirror corresponding to each pixel according to image information. Is a reflection direction control type light modulation device. As the micromirror type light modulation device 400, for example, DMD (digital micromirror device) (trademark of TI) can be used.

  The image light emitted from the micromirror light modulator 400 is enlarged and projected by the projection optical system 600 to form a large screen image on the screen SCR.

  The micromirror light modulator 400 and the projection optical system 600 are arranged so that their central axes coincide. When the projector 1000 according to the first embodiment is a projector having a tilting projection configuration, the projection optical axis 600ax of the projection optical system 600 is shifted in the tilting direction with respect to the central axis of the micromirror light modulator 400. It is preferable to configure as described above.

  According to the illuminating device 100 according to Embodiment 1 configured as described above, linearly polarized light having different polarization axes is emitted from the first LD light source 10 and the second LD light source 20, and these linearly polarized light is emitted. By making each incident on the polarization beam combiner 30, the illumination beam from the first LD light source 10 and the second LD light source 20 is emitted from the polarization beam combiner 30 with the same angle superimposed. . For this reason, even if the light emission of any one of the first LD light source 10 and the second LD light source 20 is weakened, the in-plane light intensity distribution in the illuminated area is suppressed from being uneven and projected. It is possible to provide an illumination device capable of suppressing deterioration in image quality.

  In the illumination device according to the first embodiment, the integrator optical system 700 includes the conical prism 710 that converts the illumination light beam from the polarization beam combiner 30 into light having a more uniform intensity distribution. Of the illumination light flux from the polarization beam combiner 30, it is possible to mix light of a relatively bright central portion (portion close to the system optical axis OC) and light of a relatively dark peripheral portion (portion far from the system optical axis OC). As a result, the in-plane light intensity distribution of the illumination light beam applied to the illuminated region can be made more uniform.

  In the illuminating device 100 according to the first embodiment, the integrator optical system 700 further includes a light guide member 712 disposed on the light exit side of the conical prism 710. Therefore, the region to be illuminated is reflected by reflection on the inner surface of the light guide member 712. It is possible to make the in-plane light intensity distribution of the illumination light beam applied to the lens more uniform.

In the illumination device 100 according to the first embodiment, the polarization beam combiner 30 is a prism type polarization beam combiner, and the acoustic wave supply device 40 that forms a standing wave in the polarization beam combiner 30 and the period of the standing wave are to further comprising a control device for controlling the acoustic wave supply unit 40 as modulated at frequencies above 60 Hz, for example, each light emitting unit in the first LD light source 10 at time _{T 1} 12r, 12g, 12b and the second Even if speckle noise is generated in the illuminated area due to interference between the light from the light emitting units 22r, 22g, and 22b in the LD light source 20, the time is at time T ₂ (the time when a predetermined time has elapsed from time T ₁ ). since the speckle noise of different interference patterns occurs as when the T _1, speckle noise Come to averaged over a predetermined time Inconspicuous not. In other words, even if speckle noise occurs in the illuminated area, the illuminance unevenness caused by the speckle noise in the illuminated area is reduced by high-speed modulation of such speckle noise at a speed that is invisible to human eyes. It becomes possible to do.

In the illumination device 100 according to the first embodiment, the acoustic wave supply device 40 is disposed in the polarization beam combiner 30 via the gel g, and therefore can efficiently supply the acoustic wave to the polarization beam combiner 30. It becomes possible to reduce illuminance unevenness due to speckle noise in the illuminated area with a small energy and a large effect.
Further, since the refractive index of the gel g is smaller than the refractive index of the medium of the polarizing beam combiner 30, the light from the first LD light source 10 (convex lens 16) is also received at the interface between the polarizing beam combiner and the ultrasonic good transmission material. It is totally reflected and light leakage can be eliminated. For this reason, generation | occurrence | production of a stray light can be suppressed and it becomes possible to suppress the fall of light utilization efficiency.

  Since the projector 1000 according to the first embodiment includes the excellent illumination device 100 described above, the projector 1000 is a high-intensity projector, and any of the first LD light source 10 and the second LD light source 20 Even if the light emission is weakened, the projector can suppress the deterioration of the quality of the projected image.

[Embodiment 2]
FIG. 3 is a diagram illustrating an optical system of the projector 1002 according to the second embodiment. In FIG. 3, the same members as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 3, the projector 1002 according to the second embodiment is different from the projector 1000 according to the first embodiment in the configuration of the integrator optical system.

  That is, the projector 1002 according to the second embodiment uses an integrator optical system 702 having an integrator rod 722 instead of the integrator optical system 700 having the conical prism 710 described in the first embodiment.

  As shown in FIG. 3, the integrator optical system 702 converts the illumination light beam from the polarization beam combiner 30 into a focused light and emits it, and the illumination light beam from the light collection lens 720 has a more uniform intensity distribution. And an integrator rod 722 that converts light into

  The integrator rod 722 is an optical member having a function of converting light from the condensing lens 720 into light having a more uniform intensity distribution by multiple reflection of light from the condensing lens 720 on the inner surface. The integrator rod 722 is a solid glass rod with a total internal reflection type, but instead of this, a cylindrical light tunnel in which the reflection surfaces of the four reflection mirrors are bonded inward may be used. .

  As described above, the projector 1002 according to the second embodiment is different from the projector 1000 according to the first embodiment in that the configuration of the integrator optical system is different, but the lighting device 102 having the same configuration as that of the lighting device 100 according to the first embodiment. Therefore, as in the case of the projector 1000 according to the first embodiment, the projector is a high-intensity projector, and the light emission of any one of the first LD light source 10 and the second LD light source 20 is weakened. However, the projector can suppress the deterioration of the quality of the projected image.

[Embodiment 3]
FIG. 4 is a diagram illustrating an optical system of the projector 1004 according to the third embodiment. In FIG. 4, the same members as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, the projector 1004 according to the third embodiment is different from the projector 1000 according to the first embodiment in the configuration of the integrator optical system and the type of the electro-optic modulation device.

That is, the projector 1004 according to the third embodiment uses an integrator optical system 704 including a lens array instead of the integrator optical system 700 having the conical prism 710 described in the first embodiment.
In the projector 1004 according to the third embodiment, three liquid crystal devices 402R, 402G, and 402B are used in place of the micromirror light modulation device 400 described in the first embodiment. Incidentally, as the electro-optic modulation device is changed from the micro-mirror type light modulation device 400 to the three liquid crystal devices 402R, 402G, and 402B, the light from the illumination device 104 is changed to three color lights of red light, green light, and blue light. And a color separation light guiding optical system 200 that guides the light to the illuminated area, and a cross dichroic prism 500 that combines the color lights modulated by the liquid crystal devices 402R, 402G, and 402B.

  The integrator optical system 704 includes a first lens array 730 having a plurality of first small lenses 731 that divides the illumination light beam from the polarization beam combiner 30 into a plurality of partial light beams, and each first small lens 731 of the first lens array 730. The second lens array 732 having the second small lens 733 corresponding to the above and a superimposing lens 736 that superimposes the light from the second lens array 732 in the illuminated region. Between the second lens array 732 and the superimposing lens 736, a polarization conversion element 734 for converting the illumination light beam from the second lens array 732 into a light beam having substantially one type of linearly polarized light component is disposed.

  The color separation light guide optical system 200 includes dichroic mirrors 210 and 220, reflection mirrors 230, 240 and 250, an incident side lens 260, and a relay lens 270. The color separation light guide optical system 200 separates the illumination light beam emitted from the superimposing lens 736 into three color lights of red light, green light, and blue light, and each of the three color liquid crystal devices 402R to be illuminated. , 402G, and 402B.

  In front of the optical path of the liquid crystal devices 402R, 402G, and 402B, condenser lenses 300R, 300G, and 300B that convert the partial light beams from the superimposing lens 736 into light beams substantially parallel to the principal rays are disposed.

The liquid crystal devices 402 </ b> R, 402 </ b> G, and 402 </ b> B modulate an illumination light beam according to image information, and are illumination targets of the illumination device 104.
The liquid crystal devices 402R, 402G, and 402B are a pair of transparent glass substrates in which a liquid crystal that is an electro-optical material is hermetically sealed. For example, incident side polarization is performed according to given image information using a polysilicon TFT as a switching element. The polarization direction of one type of linearly polarized light emitted from the plate is modulated.

  Although not shown here, incident-side polarizing plates are interposed between the condenser lenses 300R, 300G, and 300B and the liquid crystal devices 402R, 402G, and 402B, and the liquid crystal devices 402R, 402G, and Between the 402B and the cross dichroic prism 500, an exit-side polarizing plate is interposed. The incident-side polarizing plate, the liquid crystal devices 402R, 402G, and 402B and the emission-side polarizing plate modulate the light of each color light incident thereon.

  The cross dichroic prism 500 is an optical element that forms a color image by synthesizing an optical image modulated for each color light emitted from the exit side polarizing plate. The cross dichroic prism 500 has a substantially square shape in plan view in which four right-angle prisms are bonded together, and a dielectric multilayer film is formed on the substantially X-shaped interface in which the right-angle prisms are bonded together. The dielectric multilayer film formed at one of the substantially X-shaped interfaces reflects red light, and the dielectric multilayer film formed at the other interface reflects blue light. By these dielectric multilayer films, the red light and the blue light are bent and aligned with the traveling direction of the green light, so that the three color lights are synthesized.

  The color image emitted from the cross dichroic prism 500 is enlarged and projected by the projection optical system 610 to form a large screen image on the screen SCR.

  As described above, the projector 1004 according to the third embodiment is different from the projector 1000 according to the first embodiment in the configuration of the integrator optical system and the type of the electro-optic modulation device, but is the same as that of the illumination device 100 according to the first embodiment. Since the illumination device 104 having the configuration is provided, the projector is a high-intensity projector as in the case of the projector 1000 according to the first embodiment, and any one of the first LD light source 10 and the second LD light source 20 is used. Even if the light emission of the LD light source is weakened, the projector can suppress the deterioration of the quality of the projected image.

[Embodiment 4]
FIG. 5 is a diagram illustrating an optical system of the projector 1006 according to the fourth embodiment. In FIG. 5, the same members as those in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5, the projector 1006 according to the fourth embodiment is provided with three illumination devices that each emit different colored light as the illumination device, and is not provided with a color separation light guiding optical system. This is different from the projector 1004 according to the above.

  As shown in FIG. 5, the projector 1006 according to the fourth embodiment includes an illumination device 106 </ b> R that emits red light, an illumination device 106 </ b> G that emits green light, and an illumination device 106 </ b> B that emits blue light as illumination devices. I have.

  The illumination device 106R for red light includes a first LD light source 50R and a second LD light source 60R that emit red light. The first LD light source 50R includes a light emitting unit 52r that emits red light, and is configured to emit light according to the P-polarized component. The second LD light source 60R includes a light emitting unit 62r that emits red light, and is configured to emit light related to the S-polarized component. Then, the light related to the P-polarized component emitted from the first LD light source 50R and the light related to the S-polarized component emitted from the second LD light source 60R are synthesized by the polarization beam combiner 70R, and the liquid crystal device 402R. It will be ejected towards.

  The illumination device 106G for green light includes a first LD light source 50G and a second LD light source 60G that emit green light. The first LD light source 50G includes a light emitting unit 52g that emits green light, and is configured to emit light related to the P-polarized component. The second LD light source 60G includes a light emitting unit 62g that emits green light, and is configured to emit light related to the S-polarized component. Then, by the polarization beam combiner 70G, the light related to the P-polarized component emitted from the first LD light source 50G and the light related to the S-polarized component emitted from the second LD light source 60G are combined to produce a liquid crystal device 402G. It will be ejected towards.

  The blue light illumination device 106B includes a first LD light source 50B and a second LD light source 60B that emit blue light. The first LD light source 50B includes a light emitting unit 52b that emits blue light, and is configured to emit light according to the P-polarized component. The second LD light source 60B includes a light emitting unit 62b that emits blue light, and is configured to emit light related to the S-polarized component. Then, the light related to the P-polarized component emitted from the first LD light source 50B and the light related to the S-polarized component emitted from the second LD light source 60B are synthesized by the polarization beam combiner 70B, and the liquid crystal device 402B. It will be ejected towards.

  These three illuminating devices 106R, 106G, and 106B are arranged in front of the three liquid crystal devices 402R, 402G, and 402B, respectively.

  Note that other configurations of the illumination devices 106R, 106G, and 106B (the convex lenses 56R, 56G, 56B, 66R, 66G, and 66B, the acoustic wave supply devices 80R, 80G, and 80B) are substantially the same as those described in the first embodiment. Since it is the same, detailed description is abbreviate | omitted.

  As described above, the projector 1006 according to the fourth embodiment is different from the projector 1004 according to the third embodiment in that the lighting device includes three lighting devices that emit different color lights and a color separation light guide optical system. Although it differs in that there is no lighting device 106R, 106G, 106B having the same configuration as the lighting devices 100, 104 according to the first and third embodiments, as in the case of the projector 1004 according to the third embodiment, It is a high-intensity projector that can suppress the deterioration of the quality of the projected image even if the light emission of any one of the plurality of LD light sources is weakened.

[Embodiment 5]
FIG. 6 is a diagram illustrating an optical system of the projector 1008 according to the fifth embodiment. In FIG. 6, the same members as those in FIGS. 1 and 5 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 6, projector 1008 according to embodiment 5 includes projector 3 according to embodiment 1 in that it includes three illumination devices that each emit different colored light as an illumination device, and further includes a cross dichroic prism. Is different.

  As shown in FIG. 6, the projector 1008 according to the fifth embodiment includes an illumination device 106R that emits red light, an illumination device 106G that emits green light, and an illumination device 106B that emits blue light as illumination devices. I have.

  Note that the configurations of the lighting devices 106R, 106G, and 106B are the same as those described in the fourth embodiment, and thus detailed description thereof is omitted.

The cross dichroic prism 510 synthesizes the optical paths of the respective color lights emitted from the illumination devices 106R, 106G, and 106B and emits them toward the integrator optical system 706.
Note that the configuration of the cross dichroic prism 510 is the same as that described in the third embodiment, and thus detailed description thereof is omitted. Since the integrator optical system 706 has the same configuration as the integrator optical system 700 of the illumination device 100 according to the first embodiment, a detailed description thereof will be omitted.

  As described above, the projector 1008 according to the fifth embodiment is different from the projector 1000 according to the first embodiment in that the projector 1008 includes three illumination devices each emitting different colored light as the illumination device, and further includes a cross dichroic prism. However, since the illumination devices 106R, 106G, and 106B having the same configuration as the illumination device 100 according to the first embodiment are provided, as in the case of the projector 1000 according to the first embodiment, Even if the light emission of any one of the plurality of LD light sources is weakened, the projector can suppress the deterioration of the quality of the projected image.

  As mentioned above, although the illuminating device and projector of this invention were demonstrated based on said each embodiment, this invention is not limited to said each embodiment, In the range which does not deviate from the summary, it implements in various aspects. For example, the following modifications are possible.

(1) In the illuminating devices 100, 102, 104, 106R, 106G, and 106B of the above embodiments, a prism type polarization beam combiner in which two triangular prisms are bonded is used as the polarization beam combiner. However, the present invention is not limited to this, and a plate-type polarization beam combiner can also be preferably used. As a plate-type polarization beam combiner, a configuration in which a polarization separation film is provided on a translucent substrate can be appropriately employed. When a plate-type polarization beam combiner is used, an acoustic wave supply device is disposed at a position outside the effective incident area of the polarization beam combiner, or an optical element other than the polarization beam combiner (for example, from the polarization beam combiner). Also, it is preferable to dispose it on a conical prism disposed in the subsequent stage.

(2) In the illumination devices 100, 102, 104, 106R, 106G, and 106B of the above embodiments, the acoustic wave supply device is disposed on the light guide member via the gel g. It is not limited to this, and it is also preferable that the light source is disposed in close contact with the polarization beam combiner. In the illumination devices 100, 102, 104, 106R, 106G, and 106B of the above-described embodiments, the acoustic wave supply device is disposed on the side surface (the surface that is neither the light incident surface nor the light exit surface) of the polarization beam combiner. However, the present invention is not limited to this, and may be disposed on the upper surface or the bottom surface of the polarization beam combiner. Furthermore, in the illuminating devices 100, 102, 104, 106R, 106G, and 106B of the above embodiments, one acoustic wave supply device is provided for one polarization beam combiner. However, the present invention is not limited to this, and a plurality of acoustic wave supply devices may be provided for one polarization beam combiner.

(3) In the illumination device 104 according to the third embodiment, a polarization conversion rod that further has a polarization conversion function may be used instead of the integrator rod 722. As a polarization conversion rod, for example, a λ / 4 plate and a reflective polarizing plate are disposed on the light exit surface of the integrator rod, and a polarization conversion element is disposed on the light incident side of the integrator rod. The polarization conversion rod can be used. An illumination device using such a polarization conversion rod is particularly suitable for a projector using an electro-optic modulation device that controls the polarization direction like a liquid crystal device.

(4) In the projector 1008 according to the fifth embodiment, the case where the polarization beam combiners 70R, 70G, and 70B and the cross dichroic prism 510 in each of the illumination devices 106R, 106G, and 106B are spaced apart from each other is illustrated. Although described, the present invention is not limited to this, and the polarization beam combiners 70R, 70G, 70B and the cross dichroic prism 510 may be bonded via an adhesive layer.

(5) In the projectors 1000 and 1008 according to the first and fifth embodiments, the integrator optical systems 700 and 706 having the conical prism and the light guide member have been described as examples. However, the present invention is not limited to this. Alternatively, an integrator optical system having a light uniformizing optical element instead of the light guide member, or an integrator optical system further having a light uniformizing optical element in addition to the conical prism and the light guiding member may be used.

(6) Although the projectors 1004 and 1006 according to the third and fourth embodiments are transmissive projectors, the present invention is not limited to this and can be applied to a reflective projector. Here, “transmission type” means that an electro-optic modulation device as a light modulation means, such as a transmission type liquid crystal device, transmits light, and “reflection type” This means that an electro-optic modulation device as a light modulation means, such as a reflective liquid crystal device, is a type that reflects light. Even when the present invention is applied to a reflective projector, the same effect as that of a transmissive projector can be obtained.

(7) In the projectors 1004 and 1006 according to the third and fourth embodiments, the projector using three liquid crystal devices has been described as an example. However, the present invention is not limited to this, and one, two The present invention can also be applied to a projector using one or four or more liquid crystal devices.

(8) In the projectors 1000, 1002, and 1008 according to the first, second, and fifth embodiments, the projector using one micromirror type light modulation device has been described as an example, but the present invention is limited to this. However, the present invention can be applied to a projector using a plurality of micromirror light modulators.

(9) The present invention can be applied to a rear projection type projector that projects from a side opposite to the side that observes the projected image, even when applied to a front projection type projector that projects from the side that observes the projected image. Is also possible.

FIG. 3 is a diagram illustrating an optical system of the illumination device 100 and the projector 1000 according to the first embodiment. The figure which shows typically a mode that the illumination light beam inject | emitted from the 1st LD light source 10 and the 2nd LD light source 20 in the illuminating device 100 is polarization-separated and combined. FIG. 6 is a diagram showing an optical system of a projector 1002 according to a second embodiment. FIG. 10 shows an optical system of a projector 1004 according to a third embodiment. FIG. 10 shows an optical system of a projector 1006 according to a fourth embodiment. FIG. 10 shows an optical system of a projector 1008 according to a fifth embodiment.

Explanation of symbols

10, 20, 50R, 50G, 50B, 60R, 60G, 60B ... LD light source, 12r, 12g, 12b, 22r, 22g, 22b, 52r, 52g, 52b, 62r, 62g, 62b ... light emitting unit, 14, 24, 54R, 54G, 54B, 64R, 64G, 64B ... LD substrate, 16, 26, 56R, 56G, 56B, 66R, 66G, 66B ... convex lens, 30, 70R, 70G, 70B ... polarization beam combiner, 32 ... polarization combining surface 34... Light entrance surface (of the polarization beam combiner) 36... Light exit surface of the polarization beam combiner 40, 80 R, 80 G, 80 B... Acoustic wave supply device 100, 102, 104, 106 R, 106 G, 106 B. Illumination device, 200 ... color separation light guide optical system, 210, 220 ... dichroic mirror, 230, 240, 250, DESCRIPTION OF SYMBOLS 14 ... Reflection mirror, 260 ... Incident side lens, 270, 312 ... Relay lens, 300R, 300G, 300B, 316, 720 ... Condensing lens, 310 ... Relay optical system, 400 ... Micromirror light modulator, 402R, 402G , 402B ... liquid crystal device, 500, 510 ... cross dichroic prism, 600, 610 ... projection optical system, 600ax ... projection optical axis, 700, 702, 704, 706 ... integrator optical system, 710, 740 ... conical prism, 712, 742 ... light guide member, 722 ... integrator rod, 730 ... first lens array, 731 ... first small lens, 732 ... second lens array, 733 ... second small lens, 734 ... polarization conversion element, 736 ... superimposing lens, 1000 , 1002, 1004, 1006, 1008 ... projector, ... Gel, OC ... the system optical axis, SCR ... screen

Claims (12)

A first LD light source that emits an illumination light beam having a first optical axis as a central axis;
A second LD light source that emits an illumination light beam centered on the second optical axis;
A polarization combining surface that transmits light from the first LD light source and reflects light from the second LD light source; and light from the first LD light source and light from the second LD light source; A polarization beam combiner that synthesizes and emits
The first LD light source is configured to emit light having a polarization axis in a direction parallel to a virtual plane including a normal line of the polarization combining surface and the first optical axis,
The second LD light source is configured to emit light having a polarization axis in a direction perpendicular to a virtual plane including a normal line of the polarization combining surface and the second optical axis. A lighting device. The lighting device according to claim 1.
An illuminating device, further comprising an integrator optical system that is disposed downstream of the polarizing beam combiner and converts an illumination light beam from the polarizing beam combiner into light having a more uniform intensity distribution. The lighting device according to claim 2,
The integrator optical system is
A condensing lens that converts the illumination light beam from the polarization beam combiner into a focused light beam, and
An illuminating device comprising: an integrator rod for converting an illumination light beam from the condenser lens into light having a more uniform intensity distribution. The lighting device according to claim 2,
The integrator optical system is
A first lens array having a plurality of first small lenses for dividing an illumination light beam from the polarization beam combiner into a plurality of partial light beams;
A second lens array having a second small lens corresponding to each first small lens of the first lens array;
An illumination device comprising: a superimposing lens that superimposes light from the second lens array in an illuminated area. The lighting device according to claim 2,
The integrator optical system is
An illuminating device comprising: a conical prism that converts an illumination light beam from the polarization beam combiner into light having a more uniform intensity distribution. The lighting device according to claim 5.
The integrator optical system is
An illuminating device further comprising a light guide member which is disposed on a light exit side of the conical prism and converts an illumination light beam from the conical prism into light having a more uniform intensity distribution. In the illuminating device in any one of Claims 1-6,
The polarization beam combiner is a prism type polarization beam combiner,
An acoustic wave supply device that is disposed in the polarization beam combiner and forms a standing wave in the polarization beam combiner by supplying an acoustic wave composed of ultrasonic waves to the polarization beam combiner;
A lighting device, further comprising: a control device that controls the acoustic wave supply device so that a period of the standing wave is modulated at a frequency of 60 Hz or more. The lighting device according to claim 7.
The acoustic wave supply device is disposed in close contact with the polarization beam combiner. The lighting device according to claim 7.
The illuminating device according to claim 1, wherein the acoustic wave supply device is disposed in the polarization beam combiner via an ultrasonic good transmission material having a refractive index smaller than a refractive index of a medium of the polarization beam combiner. The lighting device according to any one of claims 1 to 9,
An electro-optic modulator that modulates light from the illumination device according to image information;
A projector comprising: a projection optical system that projects light modulated by the electro-optic modulation device. The projector according to claim 10, wherein
As the lighting device, comprising a plurality of lighting devices that emit a plurality of colored light,
A cross dichroic prism disposed between the plurality of illumination devices and the electro-optic modulation device, and combining the optical paths of a plurality of color lights emitted from the plurality of illumination devices and emitting the light toward the electro-optic modulation device; The projector further comprising: The projector according to claim 10, wherein
As the lighting device, comprising a plurality of lighting devices that emit a plurality of colored light,
As the electro-optic modulator, a plurality of electro-optic modulators that respectively modulate light from the plurality of illumination devices according to image information,
A projector further comprising a cross dichroic prism that combines a plurality of color lights emitted from the plurality of electro-optic modulators.