JP2012103615A - Illumination device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination device capable of preventing lowering of luminous efficiency of a fluorescent layer even when output of an excitation light source device is enhanced.SOLUTION: An illumination device 101 of the invention includes a first light source device 10a for emitting a first light beam La, a second light source device 10b for emitting a second light beam Lb, a fluorescent layer 42 excited by the first light beam La and the second light beam Lb, a light diffusion member 26a disposed on an optical path of the first light beam La between the first light source device 10a and the fluorescent layer 42 to diffuse the light beam La, and a light collection optical system 21 for projecting the first light beam La and the second light beam Lb onto the fluorescent layer 42 so that at least a part of the first light beam La and at least a part of the second light beam Lb are overlapped with each other on the fluorescent layer 42.

Description

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

  As a lighting device for a projector, a lighting device described in Patent Document 1 is known. The illumination device of Patent Document 1 includes a light source that emits excitation light (blue light), and a fluorescent plate that is formed by forming two types of fluorescent layers (a red fluorescent layer and a green fluorescent layer) on a disc that is rotated by a motor. It is equipped with. On the disk, three segment regions are formed along the rotation direction. Two of the three segment areas are formed with two types of fluorescent layers that emit different colored light (red light and green light), and the remaining segment areas scatter excitation light (blue light). A scatterer is formed. According to the illuminating device of patent document 1, the illuminating device which can radiate | emit three color lights sequentially using excitation light and two types of fluorescent layers can be provided.

JP 2009-277516 A

  In the illumination device of Patent Document 1, a laser light source is used as a light source device for excitation. When increasing the light intensity of radiated light in the illumination device of Patent Document 1, it is necessary to concentrate and irradiate high-power laser light (excitation light) on a small area of the fluorescent layer. However, the higher the output of the laser light that irradiates a small area of the fluorescent layer, the lower the luminous efficiency of the fluorescent layer. This is because the temperature of the part irradiated with the excitation light suddenly rises, and when the light density of the excitation light increases, the decrease in the number density of the absorption levels due to absorption of the excitation light cannot be ignored. It can be considered that the light absorption rate decreases. The former is called a temperature quenching phenomenon, and the latter is called a saturation excitation phenomenon.

  The present invention has been made in view of such circumstances, and provides an illumination device and a projector capable of suppressing a decrease in the luminous efficiency of the fluorescent layer even when the output of the excitation light source device is increased. With the goal.

  In order to solve the above-described problems, an illumination device according to the present invention includes a first light source device that emits first light, a second light source device that emits second light, the first light, and the light source device. A fluorescent layer excited by second light, a light diffusing member disposed on the optical path of the first light between the first light source device and the fluorescent layer, and diffusing the first light; The first light and the second light are applied to the fluorescent layer such that at least a part of the first light and at least a part of the second light overlap each other on the fluorescent layer. And a condensing optical system for irradiation.

  According to this configuration, in the light intensity distribution on the fluorescent layer of the light irradiated to the fluorescent layer as excitation light, the occurrence of a portion having a large light intensity is suppressed. Therefore, a decrease in luminous efficiency that occurs when the output of the excitation light source device is increased is suppressed, and a bright illumination device is provided.

  The condensing optical system includes a collimating lens on which the first light diffused by the light diffusing member is incident, and a condensing lens on which the first light emitted from the collimating lens is incident. It is desirable.

  According to this configuration, the excitation light diffused by the light diffusing member can be efficiently incident on the condenser lens.

  The light diffusing member is preferably a hologram element.

  According to this structure, compared with the light-diffusion member which made the base material which consists of resin contain the scattering fine particle, a highly uniform light intensity distribution can be formed.

  The light intensity distribution of the first light diffused by the light diffusing member is preferably a light intensity distribution having a flat portion across the central axis of the first light.

  According to this configuration, a highly uniform light intensity distribution can be formed.

  The light diffusing member is preferably a plate having the fluorescent layer formed on one side.

  According to this configuration, since the excitation light is diffused in the vicinity of the fluorescent layer, the fluorescent layer can emit light in a small region. Therefore, the luminous efficiency of the fluorescent layer can be increased, and a bright illumination device is provided.

  The fluorescent layer is preferably formed continuously on a plate material rotated by a motor along the rotation direction of the plate material.

  According to this configuration, the heat of the fluorescent layer generated by the excitation light irradiation can be dissipated in a wide region along the rotation direction of the plate material. Therefore, a decrease in luminous efficiency that occurs when the output of the excitation light source device is increased is suppressed, and a bright illumination device is provided.

  It is desirable that the first light source device is a laser light source that emits laser light as the first light, and the second light source device is a laser light source that emits laser light as the second light. .

  According to this configuration, since the highly condensing laser light source is used as the light source device, the fluorescent layer can emit light in a small area. Therefore, the luminous efficiency of the fluorescent layer can be increased, and a bright illumination device is provided.

  The projector according to the present invention includes the illumination device according to the present invention, a light modulation device that modulates illumination light from the illumination device according to image information, and a projection optical system that projects the modulated light from the light modulation device as a projection image. And.

  According to this configuration, a projector capable of displaying a bright projection image is provided.

FIG. 2 is a top view showing an optical system of the projector according to the first embodiment. It is a graph which shows the light emission characteristic of the light source device of 1st Embodiment, and a fluorescent layer. It is explanatory drawing of the rotation fluorescent screen of 1st Embodiment. It is a figure which shows light intensity distribution of a laser beam. It is a top view which shows the optical system of the projector of 2nd Embodiment. It is a top view which shows the optical system of the projector of 3rd Embodiment. It is a top view which shows the optical system of the projector of 4th Embodiment. It is a graph which shows the light emission characteristic of a 2nd light source device.

[First Embodiment]
FIG. 1 is a top view showing an optical system of the projector 1001 according to the first embodiment. FIG. 2 is a graph showing the light emission characteristics of the light source device 10 and the fluorescent layer 42 provided in the projector 1001. FIG. 2A is a graph showing the light emission characteristics of the light source device 10, and FIG. 2B is a graph showing the light emission characteristics of the fluorescent layer 42. The light emission characteristic of the light source device 10 refers to a characteristic of how much light is emitted with what intensity when a voltage is applied. Further, the light emission characteristic of the fluorescent layer 42 refers to a characteristic of how much light is emitted with what intensity when excitation light is incident. The vertical axis of the graph represents the relative light emission intensity, and the light emission intensity at the wavelength with the highest light emission intensity is 1. The horizontal axis of the graph represents the wavelength. FIG. 3 is an explanatory diagram of the rotating fluorescent plate 30 provided in the projector 1001. 3A is a front view of the rotating fluorescent plate 30, and FIG. 3B is a cross-sectional view taken along line A1-A1 of FIG.

  As shown in FIG. 1, the projector 1001 includes an illumination device 101, a color separation light guide optical system 200, a liquid crystal light modulation device 400R as a light modulation device, a liquid crystal light modulation device 400G, a liquid crystal light modulation device 400B, and a cross dichroic prism 500. And a projection optical system 600.

  The illumination device 101 includes a light source device 10a, a light source device 10b, a light source device 10c, a condensing optical system 21, a rotating fluorescent plate 30, a motor 50, a collimating optical system 60, a first lens array 120, a second lens array 130, and a polarization conversion element. 140 and a superimposing lens 150 are provided.

  Each of the light source device 10a, the light source device 10b, and the light source device 10c is a laser light source that emits blue laser light (emission intensity peak: about 445 nm, see FIG. 2A). In this specification, the light source device 10a, the light source device 10b, and the light source device 10c may be collectively referred to as the light source device 10, and the laser light La emitted from the light source device 10a and the laser light Lb emitted from the light source device 10b. And the laser beam Lc emitted from the light source device 10c may be collectively referred to as a laser beam L. The light source device 10a corresponds to the first light source device, the light source device 10b corresponds to the second light source device, the laser light La corresponds to the first light, and the laser light Lb corresponds to the second light.

  In FIG. 2A, the symbol B is a color light component of the laser light L emitted from the light source device 10. The illumination device 101 illustrated in FIG. 1 includes three light source devices 10 (light source device 10a, light source device 10b, and light source device 10c), but the number of light source devices 10 is not limited to this, and two or four or more. But you can. A light source device that emits blue light having a wavelength other than 445 nm (for example, 460 nm) as excitation light can also be used. The laser light La emitted from the light source device 10a, the laser light Lb emitted from the light source device 10b, and the laser light Lc emitted from the light source device 10c are superimposed on each other on the fluorescent layer 42 by the condensing optical system 21. Thus, excitation light for exciting the fluorescent layer 42 is formed.

  The condensing optical system 21 includes a light diffusing member 26a, a light diffusing member 26b, a light diffusing member 26c, a first lens 23a, a first lens 23b, a first lens 23c, and a second lens 25. ing. The light diffusion member 26a and the first lens 23a are provided corresponding to the light source device 10a, the light diffusion member 26b and the first lens 23b are provided corresponding to the light source device 10b, and the light diffusion member 26c and the first lens 23c are provided. It is provided corresponding to the light source device 10c. The condensing optical system 21 is disposed in the optical path from the light source device 10 to the rotating fluorescent plate 30 and causes the laser light La, the laser light Lb, and the laser light Lc to enter the fluorescent layer 42 in a substantially condensed state. In this specification, the light diffusing member 26a, the light diffusing member 26b, and the light diffusing member 26c are collectively referred to as the light diffusing member 26, and the first lens 23a, the first lens 23b, and the first lens 23c are collectively referred to as the first. Sometimes referred to as a lens 23.

  The light diffusion member 26 is made of, for example, a transparent resin plate provided with scattering particles that scatter the laser light L emitted from the light source device 10. The light diffusion member 26 diffuses the laser light L emitted from the light source device 10. Specifically, the light diffusion member 26a diffuses the laser light La, the light diffusion member 26b diffuses the laser light Lb, and the light diffusion member 26c diffuses the laser light Lc. In FIG. 1, one light diffusing member 26 is provided for one light source device 10, but it is also possible to provide one common light diffusing member for the light source device 10a, the light source device 10b, and the light source device 10c. It is.

  The first lens 23 is a collimating lens, and the second lens 25 is a condenser lens. The first lens 23 and the second lens 25 are, for example, convex lenses.

  The rotating fluorescent plate 30 is a so-called transmission type rotating fluorescent plate. As shown in FIGS. 1 and 3, the rotating fluorescent plate 30 is formed by continuously forming a single fluorescent layer 42 along the rotation direction of the plate 40 on a part of the plate 40 that can be rotated by the motor 50. . The region where the fluorescent layer 42 is formed includes a region where excitation light is incident. The rotating fluorescent plate 30 emits red light and green light toward the side opposite to the side on which excitation light (blue light) is incident.

  The rotating fluorescent plate 30 rotates at 7500 rpm when in use. Although the detailed description is omitted, the diameter of the rotating fluorescent plate 30 is 50 mm, and the optical axis of the excitation light incident on the rotating fluorescent plate 30 is located at a position about 22.5 mm away from the rotation center of the rotating fluorescent plate 30. ing. That is, the rotating fluorescent plate 30 rotates at such a rotational speed that the condensed spot of the excitation light moves on the fluorescent layer 42 at about 18 m / sec.

  The plate member 40 is made of a material that transmits excitation light. In FIG. 3, the plate member 40 is a disc, but the plate member 40 is not limited to a disc. As a material of the plate member 40, for example, quartz glass, crystal, sapphire, optical glass, transparent resin, or the like can be used. The laser light La, the laser light Lb, and the laser light Lc emitted from the light source device 10 are substantially condensed by the condensing optical system 21 and irradiated to the rotating fluorescent plate 30 as excitation light from the plate material 40 side.

  The fluorescent layer 42 is formed on the plate member 40 via a dichroic film 44 that transmits excitation light and reflects fluorescence emitted from the fluorescent layer 42. The dichroic film 44 is made of, for example, a dielectric multilayer film.

  The fluorescent layer 42 converts, for example, a part of the laser light L (blue light) as excitation light emitted from the light source device 10 into light including red light and green light, and the excitation light (blue light). Let the rest pass through without conversion. Specifically, the fluorescent layer 42 is efficiently excited by excitation light having a wavelength of 445 nm, and a part of the excitation light emitted from the light source device 10 is converted into red light and green light as shown in FIG. It is converted into yellow fluorescence containing light and emitted. Of the yellow fluorescence, the short wavelength component is used as green light, and among the yellow fluorescence, the long wavelength component is used as red light.

The fluorescent layer 42 is made of, for example, a layer containing (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce, which is a YAG phosphor. As the fluorescent layer 42, a layer containing another phosphor that emits fluorescence including red light and green light may be used. Further, as the fluorescent layer 42, a layer containing a mixture of a phosphor that converts excitation light (blue light) into red light and a phosphor that converts excitation light (blue light) into green light may be used.

  The laser light La emitted from the light source device 10a is condensed on the fluorescent layer 42 via the light diffusion member 26a, the first lens 23a, and the second lens 25, and the laser light Lb emitted from the light source device 10b is obtained. The laser light Lc collected on the fluorescent layer 42 via the light diffusing member 26b, the first lens 23b, and the second lens 25 and emitted from the light source device 10c is transmitted to the light diffusing member 26c and the first lens 23c. The light is condensed on the fluorescent layer 42 via the second lens 25.

  As already described, the light diffusing member 26 diffuses the laser light L emitted from the light source device 10 and makes the light intensity distribution of the laser light L uniform. FIG. 4 is a diagram showing the effect of the light diffusing member 26. Here, a case where laser light having a Gaussian light intensity distribution is used will be described as an example. La1 indicates the light intensity distribution in a cross section perpendicular to the optical axis of the laser light La before the laser light La passes through the light diffusion member 26a, and La2 indicates the light intensity distribution after the laser light La passes through the light diffusion member 26a. The light intensity distribution is shown. In the cross section perpendicular to the optical axis of the laser beam La, the portion close to the central axis of the laser beam La is the high-intensity region C having the highest light intensity, and the periphery of the high-intensity region C is an attenuation in which the light intensity gradually attenuates Region D. As can be seen from FIG. 4, the laser light La is diffused by the light diffusion member 26a, whereby the light intensity of the high intensity region C is reduced and the light intensity of the attenuation region D is increased. Thereby, the light intensity distribution of the laser light La in a plane perpendicular to the optical axis of the laser light La is made more uniform than before entering the light diffusing member 26a. The same applies to the laser beam Lb and the laser beam Lc.

  After the laser light La, the laser light Lb, and the laser light Lc are made uniform by the light diffusion member 26, the beam spot of the laser light La, the beam spot of the laser light Lb, and the beam spot of the laser light Lc on the fluorescent layer 42 Are irradiated onto the fluorescent layer 42 through the first lens 23 and the second lens 25 so as to overlap each other. For this reason, the light intensity distribution of the excitation light on the fluorescent layer 42 is made more uniform than when the light diffusion member 26 is not used. Here, in order to improve the uniformity of the light intensity distribution in the high intensity region C of the excitation light on the fluorescent layer 42, the beam spot of the laser light La, the beam spot of the laser light Lb, and the laser light on the fluorescent layer 42. It is preferable that the beam spot of Lc is exactly overlapped with each other.

  The same applies when the laser light L having a light intensity distribution other than the Gaussian distribution type is used. The light diffusing member 26 diffuses the laser light L emitted from the light source device 10, thereby reducing the light intensity in the high intensity region and increasing the light intensity in the attenuation region. As a result, the distribution of the light intensity of the laser light L in a plane perpendicular to the optical axis of the laser light L is made more uniform than before entering the light diffusing member 26. For this reason, the light intensity distribution of the excitation light on the fluorescent layer 42 is made more uniform than when the light diffusing member 26 is not used.

  In this way, the light intensity distribution on the fluorescent layer 42 of the excitation light applied to the fluorescent layer 42 is made uniform, and the occurrence of a portion having a large light intensity protruding on the fluorescent layer 42 is suppressed. . Therefore, a decrease in luminous efficiency that occurs when the output of the excitation light source device is increased is suppressed, and a bright illumination device 101 is provided.

  Returning to FIG. 1, the collimating optical system 60 includes a first lens 62 that suppresses the spread of light from the rotating fluorescent plate 30, and a second lens 64 that substantially collimates the light incident from the first lens 62. Yes. The collimating optical system 60 has a function of making the light from the rotating fluorescent plate 30 substantially parallel as a whole. The second lens 62 and the second lens 64 are, for example, convex lenses.

  The first lens array 120 has a plurality of first small lenses 122 for dividing the light from the collimating optical system 60 into a plurality of partial light beams. The first lens array 120 functions as a light beam splitting optical element that splits light from the collimating optical system 60 into a plurality of partial light beams. The first lens array 120 has a configuration in which a plurality of first small lenses 122 are arranged in a matrix of a plurality of rows and a plurality of columns in a plane orthogonal to the illumination optical axis 101ax. Although not illustrated, the outer shape of the first small lens 122 is substantially similar to the outer shapes of the image forming regions of the liquid crystal light modulation device 400R, the liquid crystal light modulation device 400G, and the liquid crystal light modulation device 400B.

  The second lens array 130 has a plurality of second small lenses 132 corresponding to the plurality of first small lenses 122 of the first lens array 120. The second lens array 130, together with the superimposing lens 150, causes the images of the first small lenses 122 of the first lens array 120 to be in the vicinity of the image forming areas of the liquid crystal light modulation device 400R, the liquid crystal light modulation device 400G, and the liquid crystal light modulation device 400B. It has a function to form an image. The second lens array 130 has a configuration in which a plurality of second small lenses 132 are arranged in a matrix of a plurality of rows and a plurality of columns in a plane orthogonal to the illumination optical axis 101ax.

  The polarization conversion element 140 is an optical element that emits each partial light divided by the first lens array 120 as approximately one type of linearly polarized light having a uniform polarization direction. The polarization conversion element 140 transmits one linear polarization component of the polarization components included in the light from the rotating fluorescent plate 30 as it is, and reflects the other linear polarization component in a direction perpendicular to the illumination optical axis 101ax. A reflection layer that reflects the other linearly polarized light component reflected by the polarization separation layer in a direction parallel to the illumination optical axis 101ax, and a position that converts the other linearly polarized light component reflected by the reflective layer into one linearly polarized light component. A phase difference plate.

  The superimposing lens 150 is an optical element that condenses each partial light beam from the polarization conversion element 140 and superimposes it in the vicinity of the image forming region of the liquid crystal light modulation device 400R, the liquid crystal light modulation device 400G, and the liquid crystal light modulation device 400B. . The superimposing lens 150 is arranged so that the optical axis of the superimposing lens 150 and the optical axis of the illumination device 100 substantially coincide with each other. The superimposing lens 150 may be composed of a compound lens obtained by combining a plurality of lenses. The first lens array 120, the second lens array 130, and the superimposing lens 150 constitute an integrator optical system that makes the in-plane light intensity distribution of the light from the rotating fluorescent plate 30 uniform.

  Instead of the lens integrator optical system using the first lens array 120 and the second lens array 130, a rod integrator optical system using a rod lens may be used.

  The color separation light guide optical system 200 includes dichroic mirrors 210 and 220, reflection mirrors 230, 240 and 250, and relay lenses 260 and 270. The color separation light guide optical system 200 separates the light from the illumination device 100 into red light, green light, and blue light, and the respective color lights of red light, green light, and blue light are liquid crystal light modulation devices 400R that are illumination targets. , And has a function of guiding light to the liquid crystal light modulation device 400G and the liquid crystal light modulation device 400B. A condensing lens 300R, a condensing lens 300G, and a condensing lens 300B are disposed between the color separation light guide optical system 200 and the liquid crystal light modulation devices 400R, 400G, and 40B.

  The dichroic mirrors 210 and 220 are mirrors in which a wavelength selective transmission film that reflects light in a predetermined wavelength region and passes light in other wavelength regions is formed on a substrate. The dichroic mirror 210 is a dichroic mirror that transmits a red light component and reflects a green light component and a blue light component. The dichroic mirror 220 is a dichroic mirror that reflects a green component and transmits a blue light component. The reflection mirror 230 is a mirror that reflects a red light component. The reflection mirrors 240 and 250 are mirrors that reflect blue light components.

  The red light that has passed through the dichroic mirror 210 is reflected by the reflecting mirror 230, passes through the condenser lens 300R, and enters the image forming area of the liquid crystal light modulation device 400R for red light. The green light reflected by the dichroic mirror 210 is further reflected by the dichroic mirror 220, passes through the condenser lens 300G, and enters the image forming area of the green light liquid crystal light modulation device 400G. The blue light that has passed through the dichroic mirror 220 passes through the relay lens 260, the incident-side reflecting mirror 240, the relay lens 270, the exit-side reflecting mirror 250, and the condensing lens 300B to form an image of the liquid crystal light modulation device 400B for blue light. Incident into the area. The relay lenses 260 and 270 and the reflection mirrors 240 and 250 function as a relay optical system that guides the blue light component that has passed through the dichroic mirror 220 to the liquid crystal light modulation device 400B.

  The liquid crystal light modulation device 400R, the liquid crystal light modulation device 400G, and the liquid crystal light modulation device 400B modulate incident color light according to image information to form a color image. The liquid crystal light modulation device 400R, the liquid crystal light modulation device 400G, and the liquid crystal light modulation device 400B are illumination targets of the illumination device 100. Although not shown, an incident-side polarizing plate is disposed between each condenser lens 300R, 300G, 3000B and each liquid crystal light modulator 400R, liquid crystal light modulator 400G, and liquid crystal light modulator 400B. Between the light modulation device 400R, the liquid crystal light modulation device 400G, the liquid crystal light modulation device 400B, and the cross dichroic prism 500, an exit side polarizing plate is disposed. The incident side polarizing plate, the liquid crystal light modulation device 400R, the liquid crystal light modulation device 400G, the liquid crystal light modulation device 400B, and the emission side polarizing plate modulate the light of each incident color light.

  The liquid crystal light modulation device 400R, the liquid crystal light modulation device 400G, and the liquid crystal light modulation device 400B are transmissive liquid crystal light modulation devices in which liquid crystal that is an electro-optical material is hermetically sealed between a pair of transparent glass substrates. The liquid crystal light modulation device 400R, the liquid crystal light modulation device 400G, and the liquid crystal light modulation device 400B include, for example, a polysilicon TFT as a switching element, and one type of straight line emitted from the incident-side polarizing plate according to a given image signal. Modulates the polarization direction of polarized light.

  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 emission 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. A dielectric multilayer film is formed on the substantially X-shaped interface where the right-angle prisms are bonded together. The dielectric multilayer film formed at one of the substantially X-shaped interfaces is a dielectric multilayer film that transmits green light and blue light and reflects red light, and the dielectric multilayer film formed at the other interface is A dielectric multilayer film that transmits red light and green light and reflects blue light. The red light and the blue light are bent by the two types of dielectric multilayer films formed on the substantially X-shaped interface, and the three color lights are synthesized by aligning with the traveling direction of the green light.

  The color image emitted from the cross dichroic prism 500 is enlarged and projected by the projection optical system 600 to form an image on the screen SCR.

  According to the projector 1001 having the above configuration, the fluorescent layer 42 is excited by the laser light L as the excitation light emitted from the light source device 10, and a plurality of color lights are emitted. Therefore, a plurality of color lights can be obtained while using the single color light source device 10.

  Light intensity distribution of the laser light La emitted from the light source device 10a, the laser light Lb emitted from the light source device 10b, and the laser light Lc emitted from the light source device 10c is made uniform by the light diffusion member 26. Therefore, the light intensity distribution of the excitation light on the fluorescent layer 42 is made uniform, and the occurrence of a portion having a high light intensity protruding on the fluorescent layer 42 is suppressed. Further, since the fluorescent layer 42 is formed on the plate member 40 rotated by the motor 50, the heat of the fluorescent layer 42 generated by the irradiation of the excitation light is dissipated in a wide region along the rotation direction of the plate member 40. . Therefore, a decrease in light emission efficiency that occurs when the output of the excitation light source device, that is, the light source device 10 is increased, is suppressed, and a bright illumination device 101 is provided.

[Second Embodiment]
FIG. 5 is a top view showing the optical system of the projector 1002 of the second embodiment. In FIG. 5, the same code | symbol is attached | subjected about the component which is common in the illuminating device 101 of 1st Embodiment, and detailed description is abbreviate | omitted. These components will be described with reference to FIGS. 2 and 3 as necessary.

  The projector 1002 is different from the projector 1001 of the first embodiment in the configuration of the illumination device 102. The configuration of the color separation light guide optical system 200, the liquid crystal light modulation device 400R as the light modulation device, the liquid crystal light modulation device 400G, the liquid crystal light modulation device 400B, the cross dichroic prism 500, and the projection optical system 600 is the projector 1001 of the first embodiment. Is the same.

  In the illuminating device 101 of the first embodiment, a resin light diffusing member 26 containing scattered fine particles is disposed on the optical path between the light source device 10 and the first lens 23, and the laser light L is emitted by the light diffusing member 26. By diffusing, the light intensity distribution of the excitation light on the fluorescent layer 42 was made uniform. On the other hand, in the illumination device 102 of the second embodiment, fine unevenness 41A is formed on the light incident surface of the rotating fluorescent plate 31, and the excitation light is diffused by the unevenness 41A, so that the light intensity distribution of the excitation light is uniform. It has become.

  The rotating fluorescent plate 31 is a so-called transmission type rotating fluorescent plate. As shown in FIGS. 5 and 3, the rotating fluorescent plate 31 has a single fluorescent layer 42 continuously along the rotation direction of the light diffusing member 41 on a part of the light diffusing member 41 that can be rotated by the motor 50. Formed. The region where the fluorescent layer 42 is formed includes a region where excitation light is incident. The rotating fluorescent plate 31 emits red light and green light toward the side opposite to the side on which excitation light (blue light) is incident.

  The rotating fluorescent plate 31 rotates at 7500 rpm during use. Although the detailed description is omitted, the diameter of the rotating fluorescent plate 31 is 50 mm, and the optical axis of the excitation light incident on the rotating fluorescent plate 31 is located at a position about 22.5 mm away from the rotation center of the rotating fluorescent plate 31. ing. That is, the rotating fluorescent plate 31 rotates at such a rotational speed that the excitation light condensing spot moves on the fluorescent layer 42 at about 18 m / sec.

  The light diffusion member 41 is made of a plate material that transmits excitation light. As a material of the light diffusing member 41, for example, quartz glass, crystal, sapphire, optical glass, transparent resin, or the like can be used. The laser light L emitted from the light source device 10 enters the rotating fluorescent plate 31 from the light diffusion member 41 side as excitation light. On the light incident surface of the light diffusion member 41, fine irregularities 41A are formed. The unevenness 41A is formed at random, and the laser light L emitted from the condensing optical system 27 is diffused by the unevenness 41A.

  The condensing optical system 27 includes a first lens 23 a, a first lens 23 b, a first lens 23 c, a second lens 25, and a light diffusion member 41. The condensing optical system 27 is disposed in the optical path from the light source device 10 to the fluorescent layer 42, and is emitted from the laser light La emitted from the light source device 10a, the laser light Lb emitted from the light source device 10b, and the light source device 10c. The laser light Lc to be incident on the fluorescent layer 42 in a substantially condensed state.

  The laser light La emitted from the light source device 10a, the laser light Lb emitted from the light source device 10b, and the laser light Lc emitted from the light source device 10c are superimposed on each other on the fluorescent layer 42 by the condensing optical system 27. Thus, excitation light for exciting the fluorescent layer 42 is formed.

  The laser light La is condensed on the fluorescent layer 42 via the first lens 23a, the second lens 25, and the light diffusion member 41, and the laser light Lb is condensed to the first lens 23b, the second lens 25, and the light diffusion member 41. The laser light Lc is condensed on the fluorescent layer 42 via the first lens 23c, the second lens 25, and the light diffusion member 41. Since the fine irregularities 41A are formed on the light incident surface of the light diffusion member 41, the laser light L is diffused by the irregularities 41A. As a result, as described with reference to FIG. 4 in the first embodiment, the light intensity distribution of the laser light L in a plane perpendicular to the optical axis of the laser light L is more than that before entering the light diffusion member 41. It is made uniform.

  After the laser light La, the laser light Lb, and the laser light Lc are made uniform by the light diffusion member 41, the beam spot of the laser light La, the beam spot of the laser light Lb, and the beam spot of the laser light Lc on the fluorescent layer 42 Are irradiated on the fluorescent layer 42 so as to overlap each other. For this reason, the light intensity distribution of the excitation light on the fluorescent layer 42 is made more uniform than when the light diffusion member 41 is not used. Here, in order to improve the uniformity of the light intensity distribution in the high intensity region C of the excitation light on the fluorescent layer 42, the beam spot of the laser light La, the beam spot of the laser light Lb, and the laser light on the fluorescent layer 42. It is preferable that the beam spot of Lc is exactly overlapped with each other.

  In this way, the light intensity distribution on the fluorescent layer 42 of the excitation light applied to the fluorescent layer 42 is made uniform, and the occurrence of a portion having a large light intensity protruding on the fluorescent layer 42 is suppressed. . Therefore, a decrease in light emission efficiency that occurs when the output of the excitation light source device, that is, the light source device 10 is increased, is suppressed, and a bright illumination device 102 is provided.

[Third Embodiment]
FIG. 6 is a top view showing the optical system of the projector 1003 of the third embodiment. In FIG. 6, the same reference numerals are given to components common to the illumination device 101 of the first embodiment, and detailed description thereof is omitted. These components will be described with reference to FIGS. 2 and 3 as necessary.

  The projector 1003 is different from the projector 1001 of the first embodiment in the configuration of the illumination device 103. The configuration of the color separation light guide optical system 200, the liquid crystal light modulation device 400R as the light modulation device, the liquid crystal light modulation device 400G, the liquid crystal light modulation device 400B, the cross dichroic prism 500, and the projection optical system 600 is the projector 1001 of the first embodiment. Is the same.

  In the illuminating device 101 of the first embodiment, a resin light diffusing member 26 containing scattered fine particles is disposed on the optical path between the light source device 10 and the first lens 23, and the laser light L is emitted by the light diffusing member 26. By diffusing, the light intensity distribution of the excitation light on the fluorescent layer 42 was made uniform. On the other hand, in the illumination device 103 of the third embodiment, the laser light L is diffused by the light diffusing member 29 made of a hologram element instead of the resin light diffusing member 26 containing the scattering fine particles, so that the excitation light The light intensity distribution is made uniform.

  The illumination device 103 includes a light source device 10a, a light source device 10b, a light source device 10c, a condensing optical system 28, a rotating fluorescent plate 30, a motor 50, a collimating optical system 60, a first lens array 120, a second lens array 130, and a polarization conversion element 140. And a superimposing lens 150.

  The condensing optical system 28 includes a first lens 23a, a first lens 23b, a first lens 23c, a light diffusing member 29a, a light diffusing member 29b, a light diffusing member 29c, and a second lens 25. ing. The light diffusing member 29a and the first lens 23a are provided corresponding to the light source device 10a, the light diffusing member 29b and the first lens 23b are provided corresponding to the light source device 10b, and the light diffusing member 29c and the first lens 23c are provided. It is provided corresponding to the light source device 10c. The condensing optical system 28 is disposed in the optical path from the light source device 10 to the rotating fluorescent plate 30, and is emitted from the laser light La emitted from the light source device 10a, the laser light Lb emitted from the light source device 10b, and the light source device 10c. The laser light Lc to be incident on the fluorescent layer 42 in a substantially condensed state. In this specification, the light diffusing member 29a, the light diffusing member 29b, and the light diffusing member 29c may be collectively referred to as the light diffusing member 29.

  The light diffusing member 29 is, for example, a computer generated hologram (CGH) in which a concavo-convex structure artificially produced by calculation with a computer is formed on a glass substrate. The light diffusing member 29 diffuses the laser light L emitted from the light source device 10 and causes the excitation light having a uniform light intensity distribution to enter the fluorescent layer 42. In FIG. 6, one light diffusing member 29 is provided for one light source device 10, but it is also possible to provide one common light diffusing member for the light source device 10a, the light source device 10b, and the light source device 10c. It is.

  A computer-generated hologram is a wavefront conversion element that converts the wavefront of incident light using a diffraction phenomenon. In particular, a phase-modulated computer-generated hologram can be wavefront converted with almost no loss of incident light wave energy. The computer-generated hologram can generate a uniform light intensity or a light intensity distribution with a simple shape. Therefore, for example, a light intensity distribution having a flat portion across the central axis of the laser light L can be formed, and thereby a highly uniform light intensity distribution can be realized.

  The first lens 23 is a collimating lens, and the second lens 25 is a condenser lens. The first lens 23 and the second lens 25 are, for example, convex lenses.

  The laser light La emitted from the light source device 10a is condensed on the fluorescent layer 42 via the first lens 23a, the light diffusion member 29a, and the second lens 25, and the laser light Lb emitted from the light source device 10b is The laser light Lc collected on the fluorescent layer 42 via the first lens 23b, the light diffusion member 29b, and the second lens 25 and emitted from the light source device 10c is the first lens 23c, the light diffusion member 29c, and the second lens. The light is condensed on the fluorescent layer 42 through the lens 25. As the laser light L is diffused by the light diffusing member 29, the light intensity distribution of the laser light L in a plane perpendicular to the optical axis of the laser light L is made more uniform than before entering the light diffusing member 29. The

  After the laser light La, the laser light Lb, and the laser light Lc are made uniform by the light diffusing member 29, the beam spot of the laser light La, the beam spot of the laser light Lb, and the beam spot of the laser light Lc on the fluorescent layer 42 Are irradiated onto the fluorescent layer 42 through the second lens 25 so as to overlap each other. For this reason, the light intensity distribution of the excitation light on the fluorescent layer 42 is made more uniform than when the light diffusion member 29 is not used. Here, in order to improve the uniformity of the light intensity distribution in the high intensity region C of the excitation light on the fluorescent layer 42, the beam spot of the laser light La, the beam spot of the laser light Lb, and the laser light on the fluorescent layer 42. It is preferable that the beam spot of Lc is exactly overlapped with each other.

  In this way, the light intensity distribution on the fluorescent layer 42 of the excitation light applied to the fluorescent layer 42 is made uniform, and the occurrence of a portion having a large light intensity protruding on the fluorescent layer 42 is suppressed. . Therefore, a decrease in light emission efficiency that occurs when the output of the excitation light source device is increased is suppressed, and a bright illumination device 102 is provided.

[Fourth Embodiment]
FIG. 7 is a top view showing an optical system of the projector 1004 of the fourth embodiment. FIG. 8 is a graph showing the light emission characteristics of the second light source device 710 provided in the projector 1004. The vertical axis of the graph represents the relative light emission intensity, and the light emission intensity at the wavelength with the highest light emission intensity is 1. The horizontal axis of the graph represents the wavelength. In FIG. 7, components common to the projector 1001 of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. These components will be described with reference to FIGS. 2, 3 and 4 as necessary.

  As shown in FIG. 7, the projector 1004 includes an illumination device 104, a second illumination device 700, a color separation light guide optical system 202, a liquid crystal light modulation device 400R as a light modulation device, a liquid crystal light modulation device 400G, and a liquid crystal light modulation device. 400B, a cross dichroic prism 500, and a projection optical system 600 are provided.

  In the projector 1001 of the first embodiment, a part of the blue light emitted from the light source device 10 is transmitted through the fluorescent layer and used as illumination light for the liquid crystal light modulation device 400B. On the other hand, in the projector 1004 according to the fourth embodiment, all the blue light emitted from the light source device 10 is used as the excitation light for the fluorescent layer 46, and the blue light used as the illumination light for the liquid crystal light modulation device 400B is The light is emitted from a second lighting device 700 provided separately from the lighting device 104.

  The illumination device 104 includes a light source device 10a, a light source device 10b, a light source device 10c, a condensing optical system 21, a rotating fluorescent plate 32, a motor 50, a collimating optical system 60, a first lens array 120, a second lens array 130, and a polarization conversion element. 140 and a superimposing lens 150 are provided. The configurations of the light source device 10, the condensing optical system 21, the motor 50, the collimating optical system 60, the first lens array 120, the second lens array 130, the polarization conversion element 140, and the superimposing lens 150 are the same as in the first embodiment. Detailed description will be omitted.

  The rotating fluorescent plate 32 is a so-called transmission type rotating fluorescent plate. The rotating fluorescent plate 32 is formed by continuously forming a single fluorescent layer 46 along the rotation direction of the plate 40 on a part of the plate 40 that can be rotated by the motor 50. The region where the fluorescent layer 46 is formed includes a region where excitation light is incident. The rotating fluorescent plate 32 emits red light and green light toward the side opposite to the side on which excitation light (blue light) is incident.

  The rotating fluorescent plate 32 rotates at 7500 rpm during use. Although a detailed description is omitted, the diameter of the rotating fluorescent plate 32 is 50 mm, and the optical axis of the excitation light incident on the rotating fluorescent plate 32 is located at a position about 22.5 mm away from the rotation center of the rotating fluorescent plate 32. ing. That is, the rotating fluorescent plate 32 rotates at such a rotational speed that the excitation light condensing spot moves on the fluorescent layer 46 at about 18 m / sec.

  The fluorescent layer 46 is formed on the plate member 40 via a dichroic film 44 that transmits excitation light and reflects fluorescence emitted from the fluorescent layer 46. The dichroic film 44 is made of, for example, a dielectric multilayer film.

  For example, the fluorescent layer 46 converts substantially all of the laser light L (blue light) as excitation light emitted from the light source device 10 into light including red light and green light. The fluorescent layer 46 is formed thicker than the fluorescent layer 42 of the first embodiment, and there is almost no excitation light that passes through the fluorescent layer 46 as it is. The fluorescent layer 46 is efficiently excited by excitation light having a wavelength of 445 nm, and the excitation light emitted from the light source device 10 is converted into yellow fluorescence including red light and green light, as shown in FIG. And inject. Of the yellow fluorescence, the short wavelength component is used as green light, and among the yellow fluorescence, the long wavelength component is used as red light.

The fluorescent layer 46 is made of a layer containing (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce, which is a YAG phosphor, for example. As the fluorescent layer 46, a layer containing another phosphor that emits fluorescence including red light and green light may be used. Further, as the fluorescent layer 46, a layer containing a mixture of a phosphor that converts excitation light (blue light) into red light and a phosphor that converts excitation light (blue light) into green light may be used.

  Similarly to the first embodiment, the laser light La emitted from the light source device 10a is condensed on the fluorescent layer 46 via the light diffusion member 26a, the first lens 23a, and the second lens 25, and is emitted from the light source device 10b. The emitted laser light Lb is condensed on the fluorescent layer 46 via the light diffusion member 26b, the first lens 23b, and the second lens 25, and the laser light Lc emitted from the light source device 10c is the light diffusion member 26c. The light is condensed on the fluorescent layer 46 through the first lens 23 c and the second lens 25. The laser light La, the laser light Lb, and the laser light Lc are superimposed on each other on the fluorescent layer 46 by the condensing optical system 21, thereby forming excitation light that excites the fluorescent layer 46.

  The light diffusing member 26a diffuses the laser light La to make the light intensity distribution of the laser light La uniform. The light diffusing member 26b diffuses the laser light Lb to make the light intensity distribution of the laser light Lb uniform. The light diffusing member 26c diffuses the laser light Lc to make the light intensity distribution of the laser light Lc uniform. Thereby, the light intensity distribution on the fluorescent layer 46 of the excitation light applied to the fluorescent layer 46 is made uniform, and the occurrence of a portion having a large light intensity protruding on the fluorescent layer 46 is suppressed. Therefore, a decrease in light emission efficiency that occurs when the output of the excitation light source device is increased is suppressed, and a bright illumination device 104 is provided.

  The second illumination device 700 includes a second light source device 710, a condensing optical system 720, a scattering plate 730, a polarization conversion integrator rod 740, and a condensing lens 750.

  The second light source device 710 is a laser light source that emits blue light (peak of emission intensity: about 445 nm, see FIG. 8) made of laser light as color light. In FIG. 8, reference numeral B indicates a color light component emitted by the second light source device 710 as blue light. Although one light source device 710 is illustrated in FIG. 7, the number of light source devices 710 is not limited to this, and a plurality of light source devices 710 may be used. A light source device that emits blue light having a wavelength other than 445 nm (for example, 460 nm) can also be used.

  The condensing optical system 720 includes a first lens 722 and a second lens 724. As a whole, the condensing optical system 720 causes blue light to be incident on the scattering plate 730 in a substantially condensed state. The first lens 722 and the second lens 724 are, for example, convex lenses.

  The scattering plate 730 scatters the blue light from the second light source device 710 with a predetermined degree of scattering to obtain blue light having a light distribution similar to fluorescence (red light and green light emitted from the rotating fluorescent plate 33). . As the scattering plate 730, for example, polished glass made of optical glass can be used.

  The polarization conversion integrator rod 740 is an optical element that makes the in-plane light intensity distribution of the blue light from the second light source device 710 uniform and makes the blue light approximately one type of linearly polarized light with the same polarization direction. . The polarization conversion integrator rod 740 is not described in detail, but the integrator rod, the reflector disposed on the incident surface side of the integrator rod, and having a small hole through which blue light is incident, and the reflection disposed on the exit surface side. A type polarizing plate.

  A lens integrator optical system using a lens array and a polarization conversion element can also be used instead of the polarization conversion integrator rod using a rod lens.

  The condensing lens 750 condenses the light from the polarization conversion integrator rod 740 and causes it to enter the vicinity of the image forming area of the liquid crystal light modulator 400B.

  The color separation light guide optical system 202 includes a dichroic mirror 210 and reflection mirrors 222, 230, and 250. The color separation light guide optical system 202 separates light from the illumination device 102 into red light and green light, and each of red light and green light from the illumination device 102 and blue light from the second illumination device 700. The color light is guided to the liquid crystal light modulation device 400R, the liquid crystal light modulation device 400G, and the liquid crystal light modulation device 400B to be illuminated. A condensing lens 300R, a condensing lens 300G, and a condensing lens 300B are disposed between the color separation light guide optical system 200 and the liquid crystal light modulation device 400R, the liquid crystal light modulation device 400G, and the liquid crystal light modulation device 40B. .

  The red light that has passed through the dichroic mirror 210 is reflected by the reflecting mirror 230, passes through the condenser lens 300R, and enters the image forming area of the liquid crystal light modulation device 400R for red light. The green light reflected by the dichroic mirror 210 is further reflected by the reflection mirror 222, passes through the condenser lens 300G, and enters the image forming region of the green light liquid crystal light modulation device 400G. The blue light from the second illumination device 700 is reflected by the reflection mirror 250, passes through the condenser lens 300B, and enters the image forming region of the liquid crystal light modulation device 400B for blue light.

  According to the projector 1004 having the above configuration, the fluorescent layer 46 is excited by the excitation light emitted from the light source device 10, and a plurality of color lights are emitted. Therefore, a plurality of color lights can be obtained while using the single color light source device 10.

  The light diffusing member 26a diffuses the laser light La to make the light intensity distribution of the laser light La uniform. The light diffusing member 26b diffuses the laser light Lb to make the light intensity distribution of the laser light Lb uniform. The light diffusing member 26c diffuses the laser light Lc to make the light intensity distribution of the laser light Lc uniform. Thereby, the light intensity distribution on the fluorescent layer 46 of the excitation light applied to the fluorescent layer 46 is made uniform, and the occurrence of a portion having a large light intensity protruding on the fluorescent layer 46 is suppressed. Further, since the fluorescent layer 46 is formed on the plate member 40 rotated by the motor 50, the heat of the fluorescent layer 46 generated by the irradiation of the excitation light is dissipated in a wide region along the rotation direction of the plate member 40. . Therefore, a decrease in light emission efficiency that occurs when the output of the excitation light source device is increased is suppressed, and a bright illumination device 104 is provided.

[Deformation]
In the projector of the fourth embodiment, the second illumination device is separately provided as the illumination light source for the liquid crystal light modulation device 400B. However, such a configuration is also applicable to the projectors of the first to third embodiments. Can do.

  The illumination devices of the first to fourth embodiments include a light source device 10a, a light source device 10b, a light source device 10c, and at least one light diffusing member. The laser light La, the laser light Lb, and the laser light Lc are It is made uniform before entering the fluorescent layer. Although it is preferable to make all the laser beams L uniform, it is not always necessary to make all the laser beams L uniform.

  Although the example which radiates | emits red light and green light by blue excitation light was demonstrated as a fluorescent layer formed in a rotation fluorescent plate, a fluorescent layer is not limited to such a thing. For example, a fluorescent layer that uses violet light or ultraviolet light as excitation light and emits three color lights of red light, green light, and blue light by the excitation light may be used.

  Although the example in which the fluorescent layer is continuously formed along the rotation direction of the plate material has been described, the configuration of the fluorescent layer is not limited thereto. As in the rotating fluorescent plate of Patent Document 1, a plurality of types of fluorescent layers may be formed along the rotation direction of the plate material, and a plurality of color lights may be sequentially emitted. A plurality of color lights sequentially emitted from the rotating fluorescent plate are modulated by one light modulation device to form a color image.

  Such a rotating fluorescent plate also has a condensing optical system that makes the light intensity distribution of a plurality of excitation lights emitted from a plurality of light source devices 10 uniform and collects the light on the fluorescent layer, thereby protruding on the fluorescent layer. Generation of a portion having a large light intensity is suppressed. This suppresses a decrease in light emission efficiency that occurs when the output of the excitation light source device is increased, and provides a bright illumination device.

DESCRIPTION OF SYMBOLS 10 ... Light source device, 21, 27, 28 ... Condensing optical system, 26, 26a, 26b, 26c, 41, 29, 29a, 29b, 29c ... Light diffusion member, 23, 23a, 23b, 23c ... 1st lens ( Collimating lens), 25 ... second lens (condensing lens), 40 ... plate material, 42, 46 ... fluorescent layer, 50 ... motor, 101, 102, 103, 104 ... illumination device, 400R, 400G, 400B ... light modulation device , 600 ... projection optical system, 1001, 1002, 1003, 1004 ... projector, BS ... beam spot of excitation light on the fluorescent layer, C ... high intensity region, D ... attenuation region

Claims (8)

A first light source device that emits first light;
A second light source device that emits second light;
A fluorescent layer excited by the first light and the second light;
A light diffusing member disposed on an optical path of the first light between the first light source device and the fluorescent layer and diffusing the first light;
Irradiating the fluorescent layer with the first light and the second light so that at least part of the first light and at least part of the second light overlap each other on the fluorescent layer. And an optical condensing optical system.   The condensing optical system includes a collimating lens on which the first light diffused by the light diffusing member is incident, and a condensing lens on which the first light emitted from the collimating lens is incident. The lighting device according to claim 1, wherein:   The illumination device according to claim 1, wherein the light diffusion member is a hologram element.   The light intensity distribution of the first light diffused by the light diffusing member is a light intensity distribution having a flat portion across a central axis of the first light. Lighting device.   The lighting device according to claim 1, wherein the light diffusing member is a plate material on which the fluorescent layer is formed on one surface side.   The lighting device according to claim 1, wherein the fluorescent layer is continuously formed on a plate member rotated by a motor along a rotation direction of the plate member.   The first light source device is a laser light source that emits laser light as the first light, and the second light source device is a laser light source that emits laser light as the second light. The illumination device according to any one of claims 1 to 6. The lighting device according to any one of claims 1 to 7,
A light modulation device that modulates illumination light from the illumination device according to image information;
And a projection optical system that projects the modulated light from the light modulation device as a projection image.

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