JP2009058716A - Illuminating device, monitoring device and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illuminating device which can convert the wavelength of fundamental wave light and reduce emission of the fundamental wave light, and has stable output and high reliability, and to provide a monitoring device and an image display device each using the illuminating device. <P>SOLUTION: The illuminating device has: a light source device 11 provided with a light source part emitting light having a first wavelength, a wavelength conversion element converting a portion of light emitted from the light source part and having the first wavelength to light having a second wavelength different from the first wavelength and a casing for a light source housing at least the light source part and the wavelength conversion element; and a collimator lens 13 to be a wavelength selecting and absorbing part absorbing light emitted from the light source device 11 and having the first wavelength and advancing light having the second wavelength to an object I to be irradiated, wherein the wavelength selecting and absorbing part is provided outside the casing for the light source. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lighting device, a monitor device, and an image display device, and more particularly to a technology of a lighting device using a wavelength conversion element.

  In recent years, a technique using a laser light source as a light source device of a projector has been proposed. Laser light sources have been developed as light sources for projectors with higher output and more colors. Compared with UHP lamps conventionally used as projector light sources, laser light sources have advantages such as high color reproducibility, instant lighting, and long life. As the laser light source, there is known a laser light source that emits the fundamental wave light from the light source with the same wavelength, and a laser light source that converts the wavelength of the fundamental wave light and emits it. As a wavelength conversion element that converts the wavelength of fundamental light, for example, a second-harmonic generation (SHG) element is known. By using the SHG element, it is possible to supply laser light having a desired wavelength and a sufficient amount of light using a general-purpose light source that can be easily obtained.

  The wavelength conversion element emits harmonic light after wavelength conversion, and simultaneously emits fundamental wave light that has not been wavelength-converted. The fundamental light may be emitted from the light source device through the same optical path as the harmonic light or after being scattered in the package of the light source device. For example, when light having a wavelength other than a desired wavelength is mixed in an optical disk device or the like, optical performance may be degraded. In addition, the high-power laser beam may cause a problem that causes discomfort to the human body, particularly the eyes. For this reason, it is desirable for a light source device using a wavelength conversion element to block emission of fundamental wave light to the outside. Conventionally, a technique has been proposed in which only fundamental light is reflected by a window that transmits harmonic light to the outside of the package, thereby blocking emission of the fundamental light to the outside of the package. FIG. 5 of Patent Document 1 shows a configuration for reflecting fundamental light from a window in a direction other than the direction of the laser light source.

JP-A-7-104332

  A semiconductor element used as a light source has a property that its output decreases as temperature rises. In order to obtain a high output and a stable output, high heat dissipation performance is required to reduce the temperature rise of the semiconductor element. In the configuration in which the fundamental wave light is confined in the light source device, the fundamental wave light is finally converted into heat in the light source device. In this case, in order to dissipate the heat generated in the light source device, higher heat dissipation performance is required. A significant temperature change of the semiconductor element causes instability of the fundamental wave light from the semiconductor element, wavelength shift, shortening of the lifetime, and the like. A remarkable temperature change of the wavelength conversion element causes a decrease in wavelength conversion efficiency in the wavelength conversion element. Therefore, in order to obtain a stable output and high reliability, high-precision temperature control of the light source device, particularly the semiconductor element and the wavelength conversion element is necessary. On the other hand, temperature control of a semiconductor element and a wavelength conversion element becomes difficult, so that the heat storage in a light source device is remarkable. As described above, according to the conventional technique, it is difficult to reduce the emission of the fundamental wave light and to obtain a stable output and high reliability. The present invention has been made in view of the above-described problems. An illumination device that converts the wavelength of fundamental wave light, reduces emission of the fundamental wave light, has a stable output, and has high reliability. An object is to provide a monitor device and an image display device to be used.

  In order to solve the above-described problems and achieve the object, a light source device according to the present invention includes a light source unit that emits light of a first wavelength and a part of light of a first wavelength emitted from the light source unit. A light source device comprising: a wavelength conversion element that converts light having a wavelength different from the first wavelength into light having a second wavelength; and a light source casing that houses at least the light source unit and the wavelength conversion element; A wavelength selective absorption unit that absorbs light of the first wavelength and advances light of the second wavelength to the irradiated object, and the wavelength selective absorption unit is provided outside the light source housing. To do.

  By using the wavelength selective absorption unit, it is possible to reduce the emission of the fundamental wave light having the first wavelength from the illumination device. By absorbing the fundamental wave light outside the light source casing, the fundamental wave light is not confined in the light source casing, and the temperature rise of the light source device can be reduced. As a result, it is possible to convert the wavelength of the fundamental wave light, reduce the emission of the fundamental wave light, and obtain a lighting device having a stable output and high reliability.

  As a preferred embodiment of the present invention, it is desirable that the first wavelength light is infrared light and the second wavelength light is visible light. Thereby, visible light can be supplied by wavelength-converting infrared light. In the present invention, the emission of infrared light from the lighting device can be reduced, and the temperature rise due to the infrared light can be reduced.

  Moreover, as a preferable aspect of the present invention, it is desirable that the wavelength selective absorption section includes an optical element that transmits light of the second wavelength. Thereby, harmonic light can be advanced to the irradiated object.

  Moreover, as a preferable aspect of the present invention, it is desirable that the wavelength selective absorption unit includes an optical element that reflects light of the second wavelength. Thereby, harmonic light can be advanced to the irradiated object.

  Moreover, as a preferable aspect of the present invention, a diffusion unit that diffuses the light emitted from the light source device is included, and the wavelength selective absorption unit absorbs the first wavelength light diffused by the diffusion unit, and the second wavelength. It is desirable to advance the light of the object to the irradiated object. By diffusing light using the diffusing unit, the area of the wavelength selective absorption unit that is irradiated with light of the first wavelength is expanded. Since the amount of energy per unit area received by the wavelength selective absorption unit is reduced by increasing the area of the region irradiated with the light of the first wavelength, it is possible to reduce the temperature rise for each unit area of the wavelength selective absorption unit It becomes. Thereby, the temperature rise of the wavelength selection absorption part by absorption of fundamental wave light can be reduced.

  Moreover, as a preferable aspect of the present invention, it is desirable that the optical element collimates the light diffused by the diffusing section. Thereby, the light diffused by the diffusing portion can be collimated and advanced to the irradiated object. By providing the optical element that collimates the light with the function of the wavelength selective absorption unit, the lighting device can have a smaller number of components than when the wavelength selective absorption unit is separately provided. This facilitates downsizing and space saving of the optical system.

  Furthermore, a monitor device according to the present invention includes the above-described illumination device and an imaging unit that captures an image of a subject illuminated by the illumination device. By using the illumination device described above, emission of fundamental light can be reduced, and high reliability can be obtained with a stable output. As a result, it is possible to obtain a monitor device that can reduce emission of fundamental wave light unnecessary for illumination of a subject and monitor a bright and stable image.

  Furthermore, an image display device according to the present invention includes the above-described illumination device, and displays an image using light from the illumination device. By using the illumination device described above, emission of fundamental light can be reduced, and high reliability can be obtained with a stable output. As a result, it is possible to obtain an image display apparatus that can reduce emission of fundamental wave light unnecessary for image formation and display a bright and stable image.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of a lighting apparatus 10 according to Embodiment 1 of the present invention. The illumination device 10 illuminates the irradiation object I such as a spatial light modulator. The illumination device 10 includes a light source device 11 that emits laser light.

FIG. 2 shows a schematic configuration of the light source device 11. The light source device 11 is a semiconductor laser pumped solid state (DPSS) laser oscillator. For example, the semiconductor element 21 emits light having a wavelength of 808 nm. A first resonance mirror 22 is provided on the emission side of the semiconductor element 21. Light from the semiconductor element 21 passes through the first resonance mirror 22 and then enters the laser crystal 23. The laser crystal 23 is excited by light from the semiconductor element 21 and emits fundamental light having a first wavelength. As the laser crystal 23, for example, an Nd: YVO ₄ crystal or an Nd: YAG (Y ₃ Al ₅ O ₁₂ ) crystal can be used. The semiconductor element 21 and the laser crystal 23 function as a light source unit that emits fundamental wave light. The fundamental light of the first wavelength is, for example, infrared light. The first wavelength is, for example, 1064 nm.

  The SHG element 24 is provided in the optical path between the laser crystal 23 and the second resonance mirror 25. The SHG element 24 emits harmonic light of the second wavelength by making the fundamental light of the first wavelength incident. The harmonic light is, for example, visible light. The SHG element 24 is a wavelength conversion element that converts a part of the fundamental wave light having the first wavelength emitted from the light source unit into the harmonic light having the second wavelength. The second wavelength is half the first wavelength and is, for example, 532 nm.

  The second resonance mirror 25 resonates light with the first resonance mirror 22. The first resonance mirror 22 and the second resonance mirror 25 selectively reflect the fundamental wave light having the first wavelength and transmit light having a wavelength (including the second wavelength) different from the first wavelength. The fundamental light reflected by the first resonant mirror 22 and the second resonant mirror 25 resonates with the fundamental light newly emitted from the laser crystal 23 and is amplified. The light transmitted through the second resonance mirror 25 travels in the direction of the window 26.

  The light source casing 27 is a casing that houses a configuration for generating laser light. The light source casing 27 houses the semiconductor element 21, the first resonance mirror 22, the laser crystal 23, the SHG element 24, and the second resonance mirror 25, and seals the inside. Each part from the semiconductor element 21 to the second resonance mirror 25 is positioned and arranged in the light source casing 27. For example, the laser crystal 23 and the SHG element 24 are provided on a common fixing portion 28, so that positioning with respect to other configurations is performed. The fixing portion 28 is a plate-like member. With respect to configurations other than the laser crystal 23 and the SHG element 24, positioning with respect to other configurations may be performed by using a member such as a fixed portion.

  The window 26 is provided at a position where light transmitted through the second resonance mirror 25 enters the light source casing 27. The window 26 is provided so as to completely close the opening formed in the light source casing 27. The window 26 transmits the light from the second resonance mirror 25 and emits the light to the outside of the light source casing 27. The window 26 is configured using a transparent member such as glass. An antireflection (AR) film (not shown) is provided on the surface of the window 26 on the inside of the light source casing 27. By providing the AR film, it is possible to reduce a decrease in light transmittance in the window 26. The light source device 11 may be configured to emit light from an opening formed in the light source casing 27 instead of the configuration of emitting light using the window 26.

  Returning to FIG. 1, the diffusion lens 12 is a diffusion unit that diffuses light emitted from the light source device 11. The diffusion lens 12 expands the illumination area by diffusing light from the light source device 11. The collimator lens 13 collimates the light diffused by the diffusion lens 12. The first integrator lens 14 divides the light flux from the collimator lens 13 into a plurality of parts by using a plurality of lens elements 15 arranged in an array. Each lens element 15 has a rectangular shape substantially similar to the irradiated object I. Each lens element 15 of the first integrator lens 14 condenses the light beam from the collimator lens 13 in the vicinity of the lens element 17 of the second integrator lens 16. The second integrator lens 16 forms an image of the lens element 15 of the first integrator lens 14 on the irradiated object I using a plurality of lens elements 17 arranged in an array.

  The superimposing lens 18 superimposes the image of each lens element 15 of the first integrator lens 14 on the irradiation object I. The first integrator lens 14, the second integrator lens 16, and the superimposing lens 18 perform shaping of the illumination area and equalization of the light amount distribution. The illumination device 10 is not limited to the configuration described in the present embodiment as long as the illumination area can be shaped, enlarged, and the light amount distribution can be made uniform.

  The collimator lens 13 is an optical element that functions as a wavelength selective absorption unit. After being emitted from the light source device 11, the collimator lens 13 absorbs the fundamental wave light having the first wavelength diffused by the diffusion lens 12 and transmits the harmonic light having the second wavelength. The collimator lens 13 is provided outside the light source casing 27. The collimator lens 13 is configured by coating a surface of a transparent member such as glass with a wavelength selection film, for example, a dielectric multilayer film.

  The SHG element 24 emits the harmonic light after the wavelength conversion, and also emits the fundamental wave light that has not been wavelength-converted. Even if the second resonant mirror 25 has high wavelength selectivity, it is difficult to reflect all of the fundamental light from the SHG element 24 by the second resonant mirror 25, and some fundamental light is The light passes through the two-resonance mirror 25. The fundamental light and the harmonic light transmitted through the second resonance mirror 25 are transmitted through the window 26 and then enter the collimator lens 13 through the diffusion lens 12. Thus, the light source device 11 emits the fundamental wave light and the harmonic light to the outside of the light source casing 27.

  The harmonic light incident on the collimator lens 13 passes through the collimator lens 13. The harmonic light transmitted through the collimator lens 13 travels to the first integrator lens 14, the second integrator lens 16, the superimposing lens 18, and the irradiated object I. The fundamental wave light incident on the collimator lens 13 is absorbed by the collimator lens 13.

  By using the collimator lens 13 that functions as the wavelength selective absorption unit, it is possible to reduce the emission of the fundamental wave light from the illumination device 10. By absorbing the fundamental wave light outside the light source casing 27, the fundamental light is not confined in the light source casing 27, and the temperature rise of the light source device 11 can be reduced. Thereby, the wavelength of the fundamental wave light is converted, the emission of the fundamental wave light can be reduced, and high reliability can be obtained with a stable output. Since the temperature change of the light source device 11 can be reduced, the structure for heat dissipation and temperature control of the light source device 11 can be simplified and miniaturized.

  If the fundamental wave light from the light source device 11 is incident on the collimator lens 13 without diffusing, the temperature of the collimator lens 13 where the fundamental wave light is concentrated rises. On the other hand, by diffusing the fundamental wave light using the diffusing lens 12, the area of the collimator lens 13 irradiated with the fundamental wave light is expanded. Since the amount of energy per unit area received by the collimator lens 13 is reduced by increasing the area of the region irradiated with the fundamental wave light, the temperature rise for each unit area of the collimator lens 13 can be reduced. Thereby, the temperature rise of the collimator lens 13 by absorption of fundamental wave light can be reduced. Since the temperature rise of the collimator lens 13 can be reduced, the heat radiation of the collimator lens 13 can be easily performed.

  In order to obtain visible light by wavelength conversion of the SHG element 24, it is common to use infrared light as fundamental wave light. In the case of infrared light, it is more difficult to evacuate by a repellent reaction than in the case of visible light. Therefore, leakage of high-power infrared light may cause a problem that causes discomfort to the human body, particularly the eyes. According to the present invention, the emission of infrared light from the illumination device 10 can be reduced.

  By providing the collimator lens 13 with the function of a wavelength selective absorption unit, the illumination device 10 can reduce the number of components compared to the case where a wavelength selective absorption unit is separately provided. This facilitates downsizing and space saving of the optical system. The illumination device 10 is not limited to the case where the collimator lens 13 functions as a wavelength selective absorption unit. At least an optical element provided outside the light source casing 27 can function as a wavelength selective absorption unit.

  The configuration of the light source device may be changed as appropriate. For example, the light source device 30 shown in FIG. 3 includes a semiconductor laser 31 that oscillates laser light. The semiconductor laser 31 that is a light source unit emits a fundamental laser beam having a first wavelength. The first wavelength is, for example, 920 nm. The first collimator lens 32 collimates the fundamental laser beam that diverges from the semiconductor laser 31. The focus lens 33 condenses the light collimated by the first collimator lens 32 by the SHG element 34.

  The SHG element 34, which is a wavelength conversion element, converts a part of the fundamental wave light having the first wavelength into harmonic light having the second wavelength. The second wavelength is a half wavelength of the first wavelength and is, for example, 460 nm. Of the fundamental wave light, the light that has not been converted into the harmonic light is emitted from the SHG element 34 together with the harmonic light. The SHG element 34 can be configured to have a waveguide that transmits light, for example. Condensing light to the position of the waveguide by the focus lens 33 enables efficient wavelength conversion. By providing the SHG element 34 on the fixed portion 36, positioning with respect to another configuration is performed. The second collimator lens 35 collimates the light diverging from the SHG element 34. The light transmitted through the second collimator lens 35 is emitted from the window 26 to the outside of the light source casing 27. As described above, similarly to the light source device 11 described above, the light source device 30 of the present modification also emits fundamental wave light and harmonic light to the outside of the light source casing 27. The light source device 30 is not limited to the configuration using the first collimator lens 32, the focus lens 33, and the second collimator lens 35, and may be appropriately modified.

  FIG. 4 shows another modification of the light source device. The light source device 40 shown in FIG. 4 resonates fundamental light using a mirror layer (not shown) of the semiconductor element 41 and an external resonator 43. The semiconductor element 41 which is a light source unit emits fundamental wave light having a wavelength of 1064 nm, for example. The SHG element 42, which is a wavelength conversion element, converts a part of the fundamental wave light having the first wavelength into harmonic light having the second wavelength. The second wavelength is half the first wavelength and is, for example, 532 nm. Of the fundamental wave light, the light that has not been converted into the harmonic light is emitted from the SHG element 42 together with the harmonic light. By providing the SHG element 42 on the fixed portion 36, positioning with respect to another configuration is performed. The external resonator 43 selectively reflects the fundamental wave light having the first wavelength, and transmits light having a wavelength (including the second wavelength) different from the first wavelength. Similar to the second resonance mirror 25 provided in the light source device 11 described above, the external resonator 43 transmits a part of the fundamental wave light. Therefore, like the light source device 11, the light source device 40 of this modification also emits fundamental wave light and harmonic light to the outside of the light source casing 27.

  FIG. 5 shows a schematic configuration of the illumination device 50 according to the second embodiment of the present invention. The same parts as those in the above embodiment are denoted by the same reference numerals, and redundant description is omitted. The collimator lens 51 transmits both the fundamental wave light of the first wavelength and the harmonic light of the second wavelength emitted from the light source device 11. The fundamental light and the harmonic light transmitted through the collimator lens 51 are transmitted through the first integrator lens 14, the second integrator lens 16 and the superimposing lens 18.

  The reflection mirror 52 is disposed at a position where light from the superimposing lens 18 enters. The reflection mirror 52 is disposed with an inclination with respect to the light from the superimposing lens 18. The reflection mirror 52 is an optical element that functions as a wavelength selective absorption unit. The reflection mirror 52 absorbs the fundamental wave light of the first wavelength emitted from the light source device 11 and diffused by the diffusion lens 12, and reflects the harmonic light of the second wavelength. The reflection mirror 52 is provided outside the light source casing 27 (see FIG. 2). The reflection mirror 52 is configured by coating a surface of a highly reflective member such as aluminum with a wavelength selection film, for example, a dielectric multilayer film.

  The harmonic light incident on the reflection mirror 52 is reflected by the reflection mirror 52. The harmonic light reflected by the reflection mirror 52 travels toward the irradiated object I with its optical path bent. The fundamental light incident on the reflection mirror 52 is absorbed by the reflection mirror 52. By using the reflection mirror 52 functioning as a wavelength selective absorption unit, it is possible to reduce the emission of the fundamental wave light, and to obtain high reliability with a stable output. By causing the fundamental wave light diffused by the diffusing lens 12 to enter the reflection mirror 52, it is possible to reduce the temperature rise of the reflection mirror 52 due to absorption of the fundamental wave light. Accordingly, the heat radiation of the reflection mirror 52 can be facilitated.

  By providing the reflection mirror 52 with the function of a wavelength selective absorption unit, the illumination device 50 can reduce the number of components compared to the case where a wavelength selective absorption unit is separately provided. This facilitates downsizing and space saving of the optical system. The reflection mirror 52 functioning as a wavelength selective absorption unit may be disposed at any position in the optical path outside the light source casing 27. The configuration of the light source device may be appropriately changed as in the above embodiment.

  FIG. 6 shows a schematic configuration of a projector 60 according to Embodiment 3 of the present invention. The projector 60 is a front projection type projector that views light by supplying light to the screen 68 and observing light reflected by the screen 68. The projector 60 includes a red (R) light illumination device 61R, a green (G) light illumination device 61G, and a blue (B) light illumination device 61B. The projector 60 is an image display device that displays an image using light from each color light illumination device 61R, 61G, 61B.

  Each of the color light illumination devices 61R, 61G, and 61B has the same configuration as the illumination device 10 of the first embodiment. The R light illumination device 61R is a light device that supplies R light. The R light illumination device 61R includes, for example, an R light light source device 62R that emits harmonic light having a wavelength of 660 nm. The G light illumination device 61G is a light device that supplies G light. The G light illumination device 61G includes, for example, a G light source device 62G that emits harmonic light having a wavelength of 532 nm. The illumination device 61B for B light is an illumination device that supplies B light. The B light illumination device 61B includes, for example, a B light source device 62B that emits harmonic light having a wavelength of 460 nm.

  The R light from the R light illumination device 61R is incident on the R light spatial light modulation device 63R, which is an object to be irradiated by the R light illumination device 61R. The R light spatial light modulation device 63R is a spatial light modulation device that modulates the R light from the R light illumination device 61R according to an image signal, and is a transmissive liquid crystal display device. The R light modulated by the R light spatial light modulator 63R is incident on a cross dichroic prism 64 which is a color synthesis optical system.

  The G light from the G light illumination device 61G is incident on the G light spatial light modulation device 63G, which is an irradiation object of the G light illumination device 61G. The G light spatial light modulation device 63G is a spatial light modulation device that modulates the G light from the G light illumination device 61G according to an image signal, and is a transmissive liquid crystal display device. The G light modulated by the G light spatial light modulator 63G is incident on a surface of the cross dichroic prism 64 that is different from the surface on which the R light is incident.

  The B light from the B light illumination device 61B is incident on the B light spatial light modulation device 63B, which is an object to be irradiated by the B light illumination device 61B. The B light spatial light modulation device 63B is a spatial light modulation device that modulates the B light from the B light illumination device 61B according to an image signal, and is a transmissive liquid crystal display device. The B light modulated by the B light spatial light modulation device 63B is incident on a surface of the cross dichroic prism 64 that is different from the surface on which the R light is incident and the surface on which the G light is incident. As the transmissive liquid crystal display device, for example, a high temperature polysilicon TFT liquid crystal panel (HTPS) can be used.

  The cross dichroic prism 64 has two dichroic films 65 and 66 arranged substantially orthogonal to each other. The first dichroic film 65 reflects R light and transmits G light and B light. The second dichroic film 66 reflects B light and transmits R light and G light. The cross dichroic prism 64 combines the R light, G light, and B light incident from different directions, and emits the light toward the projection lens 67. The projection lens 67 projects the light synthesized by the cross dichroic prism 64 toward the screen 68.

  By using each color light illumination device 61R, 61G, 61B having the same configuration as the illumination device 10 described above, emission of the fundamental wave light can be reduced, and high reliability can be obtained with a stable output. Thereby, it is possible to reduce the emission of the fundamental wave light unnecessary for image formation and to display a bright and stable image. Each of the color light illumination devices 61R, 61G, and 61B may have the same configuration as the illumination device 50 of the second embodiment.

  The optical element functioning as the wavelength selective absorption unit is desirably provided on the light source device 62R, 62G, 62B side in the optical path from the spatial light modulation devices 63R, 63G, 63B. By absorbing the fundamental light before the spatial light modulators 63R, 63G, 63B, it is possible to reduce the deterioration of the spatial light modulators 63R, 63G, 63B. Further, the optical element functioning as the wavelength selective absorption unit may be one in which a plurality of color lights are incident in addition to the one color light incident thereon. For example, when a plurality of color lights are separated by a wavelength selection mirror, the wavelength selection mirror may have a function of absorbing fundamental light.

  The projector 60 is not limited to the case where each of the color light illumination devices 61R, 61G, and 61B has the same configuration as that of any of the illumination devices of the above-described embodiments. For example, the R light illumination device 61R may be a light source device that emits the fundamental wave light from the light source unit without using an SHG element.

  The projector is not limited to the case where a transmissive liquid crystal display device is used as the spatial light modulation device. As the spatial light modulator, a reflective liquid crystal display (Liquid Crystal On Silicon; LCOS), DMD (Digital Micromirror Device), GLV (Grating Light Valve), or the like may be used. The projector is not limited to a configuration including a spatial light modulator for each color light. The projector may be configured to modulate two or three or more color lights with one spatial light modulator. The projector is not limited to the case where the spatial light modulator is used. The projector may be a laser scanning projector that scans the laser light from the light source device by scanning means such as a galvanometer mirror and displays an image on the irradiated surface. The projector may be a slide projector that uses a slide having image information. The projector may be a so-called rear projector that supplies light to one surface of the screen and observes an image by observing light emitted from the other surface of the screen.

  FIG. 7 shows a schematic configuration of a monitor device 70 according to the fourth embodiment of the present invention. The monitor device 70 includes a device main body 71 and an optical transmission unit 72. The apparatus main body 71 includes the light source device 11 (see FIG. 2) described in the first embodiment. The light transmission unit 72 includes two light guides 74 and 75. A diffusion plate 76 and an imaging lens 77 are provided at the end of the light transmission unit 72 on the subject (not shown) side. The configuration of the light source device may be appropriately changed as in the above embodiment.

  The focus lens 78 condenses the light from the light source device 11 on the incident surface of the first light guide 74. The focus lens 78 is an optical element that functions as a wavelength selective absorption unit. The focus lens 78 absorbs the fundamental light having the first wavelength emitted from the light source device 11 and transmits the harmonic light having the second wavelength. The first light guide 74 transmits the harmonic light from the light source device 11 to the subject. The diffusion plate 76 is provided on the emission side of the first light guide 74. The light propagating through the first light guide 74 is diffused on the subject side by passing through the diffusion plate 76. Each part in the optical path from the light source device 11 to the diffusion plate 76 constitutes an illumination device that illuminates the subject.

  The second light guide 75 transmits light from the subject to the camera 73. The imaging lens 77 is provided on the incident side of the second light guide 75. The imaging lens 77 condenses light from the subject on the incident surface of the second light guide 75. Light from the subject enters the second light guide 75 through the imaging lens 77, then propagates through the second light guide 75 and enters the camera 73.

  As the first light guide 74 and the second light guide 75, a bundle of many optical fibers can be used. By using an optical fiber, light can be transmitted far away. The camera 73 is provided in the apparatus main body 71. The camera 73 is an imaging unit that captures an image of a subject illuminated by the illumination device. By making the light incident from the second light guide 75 enter the camera 73, the subject can be imaged by the camera 73.

  Also in this embodiment, the emission of fundamental light can be reduced, and high reliability can be obtained with a stable output. As a result, it is possible to reduce the emission of fundamental light unnecessary for illumination of the subject and to monitor a bright and stable image. The monitor device 70 is not limited to the case where the focus lens 78 functions as a wavelength selection / absorption unit. At least an optical element provided outside the light source casing can function as a wavelength selective absorption unit. The monitor device 70 may function an optical element that reflects harmonic light as a wavelength selective absorption unit.

  The illumination device of the present invention may be applied to a liquid crystal display that is an image display device. A liquid crystal panel can be illuminated by using a light guide plate for the lighting device of the present invention. Also in this case, a bright and stable image can be displayed. The illumination device of the present invention is not limited to being applied to a monitor device or an image display device. The illumination device of the present invention may be used for an optical system such as an exposure device for exposure using laser light or a laser processing device, for example.

  As described above, the illumination device according to the present invention is suitable for use in an image display device or a monitor device.

The figure which shows schematic structure of the illuminating device which concerns on Example 1 of this invention. The figure which shows schematic structure of a light source device. The figure which shows the light source device which has a semiconductor laser which oscillates a laser beam. The figure which shows the light source device which resonates fundamental wave light using a semiconductor element and an external resonator. The figure which shows schematic structure of the illuminating device which concerns on Example 2 of this invention. FIG. 6 is a diagram illustrating a schematic configuration of a projector according to a third embodiment of the invention. The figure which shows schematic structure of the monitor apparatus which concerns on Example 4 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Illuminating device, 11 Light source device, 12 Diffuse lens, 13 Collimator lens, 14 1st integrator lens, 15, 17 Lens element, 16 2nd integrator lens, 18 Superimposing lens, I Irradiated object, 21 Semiconductor element, 22 1st Resonant mirror, 23 Laser crystal, 24 SHG element, 25 Second resonant mirror, 26 Window, 27 Light source casing, 28 Fixed part, 30 Light source device, 31 Semiconductor laser, 32 First collimator lens, 33 Focus lens, 34 SHG Element, 35 Second collimator lens, 36 Fixed part, 40 Light source device, 41 Semiconductor element, 42 SHG element, 43 External resonator, 50 Illumination device, 51 Collimator lens, 52 Reflection mirror, 60 Projector, 61R R light illumination device , 61G G light illumination device, 6 BB light illumination device, 62R R light source device, 62G G light light source device, 62B B light source device, 63R R light spatial light modulation device, 63G G light spatial light modulation device, 63B for B light Spatial light modulator, 64 cross dichroic prism, 65 first dichroic film, 66 second dichroic film, 67 projection lens, 68 screen, 70 monitor device, 71 device body, 72 light transmission unit, 73 camera, 74 first light guide 75 Second light guide, 76 Diffuser, 77 Imaging lens, 78 Focus lens

Claims (8)

A light source unit that emits light of a first wavelength, and wavelength conversion that converts part of the light of the first wavelength emitted from the light source unit into light of a second wavelength that is a wavelength different from the first wavelength A light source device comprising: an element; and a light source housing that houses at least the light source unit and the wavelength conversion element;
A wavelength selective absorption unit that absorbs the light of the first wavelength emitted from the light source device and advances the light of the second wavelength to the irradiation object,
The wavelength selective absorption unit is provided outside the light source casing.   The lighting device according to claim 1, wherein the first wavelength light is infrared light, and the second wavelength light is visible light.   The illumination apparatus according to claim 1, wherein the wavelength selective absorption unit includes an optical element that transmits light of the second wavelength.   The illumination device according to claim 1, wherein the wavelength selective absorption unit includes an optical element that reflects the light of the second wavelength. A diffusion unit that diffuses the light emitted from the light source device;
The said wavelength selection absorption part absorbs the light of the said 1st wavelength diffused by the said spreading | diffusion part, and advances the light of the said 2nd wavelength to the said to-be-irradiated object, The any one of Claims 1-4 characterized by the above-mentioned. The lighting device according to claim 1.   The illumination device according to claim 5, wherein the optical element collimates the light diffused by the diffusion unit. The lighting device according to any one of claims 1 to 6,
An image pickup unit for picking up an image of a subject illuminated by the illumination device.   An image display device comprising the illumination device according to claim 1 and displaying an image using light from the illumination device.

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