JP2012173676A - Light source device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device capable of a smaller size and a prolonged service life.SOLUTION: The light source device 10 includes: a solid light source 20 for generating excitation light; a condenser lens for condensing the excitation light from the solid light source 20; and a fluorescent layer 84 for generating fluorescent light from at least one part of the excitation light from the condenser lens. In this case, the light source device 10 is characterized in that an aspect ratio of a light emission area in the solid light source 20 is greater than one, and that the condenser lens is an anamorphic condenser lens 40 with at least one of an incidence surface or an emission surface comprising an anamorphic surface.

Description

  The present invention relates to a light source device and a projector.

  2. Description of the Related Art Conventionally, a light source device including a solid light source that emits excitation light and a fluorescent layer that converts at least a part of the excitation light into fluorescence is known (see, for example, Patent Document 1). According to a conventional light source device, since a fluorescent layer is provided, it is possible to obtain desired color light (fluorescence or a mixture of fluorescence and excitation light) using a solid light source that generates excitation light of a specific wavelength. Become.

JP 2009-277516 A

  By the way, in the technical field of the light source device, a small light source device is required. Therefore, the inventor of the present invention considered that the excitation light is incident on a smaller range on the fluorescent layer by applying a condensing lens for collecting the excitation light from the solid light source to the conventional light source device. . This is because the fluorescent layer can be reduced in size by such a configuration, and as a result, the light source device can be reduced in size.

However, in the configuration as described above, as shown in a comparative example described later, an excessive thermal load is applied to a part of the region where excitation light is incident on the fluorescent layer, which may cause deterioration or burning of the fluorescent layer. There has been a problem that it may be difficult to extend the life of the light source device. This problem is particularly noticeable in the case of using a high-intensity solid-state light source (a solid-state light source in which the aspect ratio of the light emitting region is often greater than 1). In this case, the light intensity per unit area of light incident on the fluorescent layer ( Hereinafter, the “light intensity per unit area” is simply referred to as “light intensity”), and may sometimes greatly exceed 100 W / mm ² (see FIG. 7C described later).

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a light source device that can be downsized and can have a long lifetime. It is another object of the present invention to provide a projector that includes such a light source device, can be reduced in size, and can reduce the frequency of light source device replacement.

[1] A light source device of the present invention includes a solid-state light source that generates excitation light, a condensing lens that condenses the excitation light from the solid-state light source, and at least a part of the excitation light from the condensing lens. A light source device including a fluorescent layer that generates fluorescence, wherein the aspect ratio of the light emitting region in the solid-state light source is greater than 1, and the condenser lens has an anamorphic surface in which at least one of an incident surface and an exit surface is an anamorphic surface. It is a condensing lens.

  For this reason, according to the light source device of the present invention, since the condensing lens is provided, it is possible to reduce the size of the fluorescent layer by causing excitation light to enter a smaller range on the fluorescent layer. It becomes possible to reduce the size.

  Further, according to the light source device of the present invention, since the condensing lens is an anamorphic condensing lens in which at least one of the incident surface and the exit surface is an anamorphic surface, the solid-state light source is used as shown in an embodiment described later. The excitation light incident on the fluorescent layer can be dispersed by adjusting the range in which the excitation light enters the fluorescent layer, and an excessive thermal load is applied to a part of the region where the excitation light is incident on the fluorescent layer. It is possible to prevent the phosphor layer from being deteriorated or burned out by suppressing the occurrence of light, and as a result, the life of the light source device can be extended.

  Therefore, the light source device of the present invention is a light source device that can be miniaturized and can have a long lifetime.

  Moreover, according to the light source device of the present invention, since the fluorescent layer is provided as in the conventional light source device, it is possible to obtain desired color light using a solid light source that generates excitation light having a specific wavelength.

The “aspect ratio of the light emitting region” is a value obtained by dividing the length of the widest portion of the light emitting region by the length of the narrowest portion. For example, when the light emitting area is a square, “the aspect ratio of the light emitting area is greater than 1” indicates that the light emitting area is not square.
An “anamorphic surface” refers to a surface in which the curvature in one direction (for example, the vertical direction) is different from the curvature in another direction (for example, the horizontal direction).

  In the light source device of the present invention, not only a solid light source that generates only excitation light, but also a solid light source that generates light that serves as both excitation light and color light can be used. That is, in the light source device of the present invention, the light generated by the solid light source may be used not only as excitation light but also as color light.

[2] In the light source device of the present invention, it is preferable that the solid-state light source is composed of a semiconductor laser having an aspect ratio of 3 or more in the light emitting region.

  In semiconductor lasers, the higher the output, the larger the aspect ratio of the light emitting region tends to be, and the emission angle of the excitation light tends to be larger. Therefore, the present invention is preferably applied to such a light source device. Can do.

[3] In the light source device of the present invention, when the range in which the excitation light is incident on the fluorescent layer is an incident range, the maximum width of the incident range is not more than twice the minimum width of the incident range. Is preferred.

  By adopting such a configuration, as shown in an embodiment described later, it is possible to further disperse the incident position of the excitation light incident on the fluorescent layer, and in a part of the region where the excitation light enters the fluorescent layer. It is possible to further suppress the excessive thermal load and prevent the phosphor layer from being deteriorated or burned out. As a result, the life of the light source device can be further extended.

  Further, with such a configuration, since the direction dependency of the region where fluorescence is generated in the fluorescent layer is reduced, it is possible to provide a light source device that emits light that is easy to handle.

  From the above viewpoint, it is preferable that the maximum width of the incident range is closer to the minimum width of the incident range. Specifically, the maximum width of the incident range is more preferably 1.5 times or less, and even more preferably 1.1 times or less the minimum width of the incident range.

[4] The light source device of the present invention is preferably configured such that the excitation light is incident on the fluorescent layer in a defocused state.

  With this configuration, the intensity of the excitation light incident on the fluorescent layer can be further dispersed, and an excessive thermal load is applied to a part of the region where the excitation light is incident on the fluorescent layer. It is possible to further suppress the deterioration and burnout of the fluorescent layer, and as a result, it is possible to further extend the life of the light source device.

[5] In the light source device of the present invention, the anamorphic surface is preferably a cylindrical surface.

  By adopting such a configuration, it is possible to disperse the incident position of the excitation light incident on the fluorescent layer with a relatively simple configuration.

  The “cylindrical surface” is a surface having a curvature of 0 along the generatrix direction (a certain direction), and is a kind of anamorphic surface.

[6] In the light source device of the present invention, the anamorphic surface is preferably a toric surface.

  With such a configuration, the incident position of the excitation light incident on the fluorescent layer can be finely adjusted and dispersed.

  The “toric surface” is a surface in which a curvature in a certain direction (for example, the vertical direction) and a curvature in another direction (for example, the horizontal direction) are different, and neither of the curvatures is 0, and anamorphic A kind of face.

[7] In the light source device of the present invention, it is preferable that both the incident surface and the exit surface of the anamorphic condenser lens are anamorphic surfaces.

  With such a configuration, it is possible to adjust the incident position and range of the excitation light incident on the fluorescent layer using both anamorphic surfaces.

[8] In the light source device of the present invention, the anamorphic condenser lens may be configured such that one of the entrance surface and the exit surface is an anamorphic surface, and the other surface is a rotationally symmetric aspherical surface. preferable.

  With such a configuration, the incident position and range of the excitation light incident on the fluorescent layer can be adjusted by the anamorphic surface and the rotationally symmetric aspheric surface.

[9] In the light source device of the present invention, it is preferable that the optical element subsequent to the anamorphic condenser lens has a shape in which a part including the upper end part and a part including the lower end part are cut off.

  At the upper end and lower end of the optical element, the amount of light passing therethrough is often small and the quality of the light passing therethrough is often poor. A light source device can be obtained.

  The “upper end” refers to the uppermost part when viewed along the direction of gravity in a posture that assumes the use of the light source device, and the “lower end” refers to the use of the light source device. In the assumed posture, it is the lowermost part when viewed along the direction of gravity.

[10] A projector of the present invention includes an illumination device including the light source device of the present invention, a light modulation device that modulates light from the illumination device according to image information, and a projection that projects light from the light modulation device. And an optical system.

  According to the projector of the present invention, since the light source device of the present invention that can be downsized and can have a long lifetime is provided, it can be downsized and the light source device can be replaced. It is possible to reduce the frequency of.

[11] In the projector according to the aspect of the invention, it is preferable that the light modulation device is a single-plate projector including one light modulation device.

  With such a configuration, it is possible to further reduce the size of the projector with a simple configuration.

FIG. 3 is a diagram for explaining a projector 1000 according to the first embodiment. The figure which looked at the solid light source 20 in Embodiment 1 from the anamorphic condensing lens 40 side. 3 is a graph showing the light emission intensity characteristics of the solid-state light source 20 and the light emission intensity characteristics of the phosphor in the first embodiment. The figure shown in order to demonstrate the light source device 10 which concerns on Embodiment 1. FIG. The figure shown in order to demonstrate the light source device 12 which concerns on Embodiment 2. FIG. The figure shown in order to demonstrate the light source device 14 which concerns on Embodiment 3. FIG. The figure shown in order to demonstrate the light source device 16 which concerns on a comparative example. FIG. 10 is a diagram for explaining a projector 1008 according to a fourth embodiment. FIG. 10 is a top view showing an optical system of a projector 1010 according to a modification.

  Hereinafter, a light source device and a projector of the present invention will be described based on the embodiments shown in the drawings.

[Embodiment 1]
FIG. 1 is a diagram for explaining a projector 1000 according to the first embodiment. 1A is a top view showing an optical system of the projector 1000, and FIG. 1B is a side view showing the optical system of the projector 1000. FIG. In FIG. 1, an arrow between the light source device 20 and the fluorescence generation unit 80 roughly represents the extent of the blue light emitted from the center of the solid light source 20. Similar arrows are shown in FIGS. 4 to 9 described later.
FIG. 2 is a diagram of the solid-state light source 20 according to the first embodiment as viewed from the anamorphic condenser lens 40 side.

  FIG. 3 is a graph showing the emission intensity characteristics of the solid-state light source 20 and the emission intensity characteristics of the phosphor in the first embodiment. 3A is a graph showing the emission intensity characteristics of the solid-state light source 20, and FIG. 3B is a graph showing the emission intensity characteristics of the phosphor contained in the fluorescent layer 84. FIG. The light emission intensity characteristic is a characteristic of how much light is emitted with what intensity when a voltage is applied for a light source and excitation light is incident for a phosphor. Say. The vertical axis of the graph represents relative light emission intensity, and the light emission intensity at the wavelength where the light emission intensity is strongest is 1. The horizontal axis of the graph represents the wavelength.

FIG. 4 is a diagram for explaining the light source device 10 according to the first embodiment. 4A is a top view showing the optical system of the light source device 10, FIG. 4B is a side view showing the optical system of the light source device 10, and FIG. 4C is incident on the fluorescent layer 84. FIG. 4D is a graph showing the in-plane light intensity distribution of blue light incident on the fluorescent layer 84. FIG. In addition, the vertical axis | shaft of FIG.4 (c) represents the light intensity of the blue light which injects into the fluorescent layer 84. FIG. The horizontal axis represents the distance from the illumination optical axis 100ax. The unit of light intensity is “W / mm ² ”, and the unit of distance from the illumination optical axis is “mm”. The unit is the same in FIGS. 5 to 7 described later.

In the drawings for explaining the optical system and each optical element, three directions orthogonal to each other are the z-axis direction (illumination optical axis 100ax direction in FIG. 1A) and the x-axis direction (FIG. 1A), respectively. It is displayed as a direction parallel to the paper surface and perpendicular to the z-axis) and a y-axis direction (a direction perpendicular to the paper surface and perpendicular to the z-axis in FIG. 1A).
The solid line graph in FIG. 4C shows the light intensity in a plane parallel to the y axis and the z axis (yz plane), and the broken line graph shows the light intensity in a plane parallel to the x axis and the z axis (xz plane). Show.

As shown in FIG. 1, the projector 1000 according to the first embodiment includes an illumination device 100, a liquid crystal light modulation device 400, and a projection optical system 600. The projector 1000 projects a full color image using red light, green light, and blue light as primary colors. The projector 1000 is a single-plate projector that includes one liquid crystal light modulation device 400 as a light modulation device. The projector 1000 and the light source device 10 (described later) according to the first embodiment are designed so that the y-axis direction is used along the direction of gravity.
The illumination device 100 includes a light source device 10 and a lens integrator optical system 110. The lighting device 100 emits light including red light, green light, and blue light as illumination light (that is, light that can be used as white light).

  The light source device 10 includes a solid light source 20, an anamorphic condenser lens 40, a fluorescence generation unit 80, and a collimator optical system 90.

The solid light source 20 is made of a semiconductor laser. As illustrated in FIGS. 1 and 2, the solid light source 20 includes a substrate 22 and a light emitting unit 24. The output of the solid light source 20 is 1 W, for example.
In the light source device of the present invention, a plurality of solid light sources may be used.

  The substrate 22 has a function of mounting the light emitting unit 24. Although detailed description is omitted, the substrate 22 has a function of mediating supply of power to the light emitting unit 24, a function of radiating heat generated by the light emitting unit 24, and the like.

  The light emitting unit 24 generates blue light that serves as both excitation light and color light (peak of emission intensity: about 460 nm, see FIG. 3A). The solid light source 20 generates excitation light by the light emitting unit 24. As shown in FIG. 2, the light emitting unit 24 has a rectangular light emitting region, and the spread angle along the short side direction of the light emitting region is larger than the spread angle along the long side direction of the light emitting region. It is configured. In the first embodiment, the light emitting region has a size of 18 μm in the vertical direction (y-axis direction) and 2 μm in the horizontal direction (x-axis direction), and thus the aspect ratio is 9. Therefore, the light source device 10 according to the first embodiment satisfies the condition that “the aspect ratio of the light emitting region in the solid light source is greater than 1” and also satisfies the condition that “the aspect ratio of the light emitting region is 3 or more”. The solid light source that can be used in the present invention is not limited to the solid light source 20.

  The anamorphic condenser lens 40 condenses the blue light from the solid light source 20. As shown in FIGS. 1, 4A, and 4B, the anamorphic condenser lens 40 is an anamorphic condenser lens in which both the incident surface 42 and the exit surface 44 are anamorphic surfaces. The anamorphic surfaces of the entrance surface 42 and the exit surface 44 are both cylindrical surfaces having a generatrix along the y-axis direction (that is, along the direction in which the blue light from the solid light source 20 has a small divergence angle). The incident surface 42 is composed of an “aspheric cylindrical surface” where the curvature of the curved surface is different, and the exit surface 44 is composed of a “spherical cylindrical surface” where the curvature of the curved surface is the same at all locations.

For this reason, in the light source device 10 according to the first embodiment, as shown in FIGS. 4C and 4D, the blue light in the direction along the direction in which the divergence angle is large is strongly refracted, so that the fluorescent layer It is possible to disperse the incident position of the excitation light (blue light) incident on 84. The peak intensity at this time (the highest intensity among the light intensity in the light incident on the fluorescent layer) is about 22 W / mm ^{2 as shown} in FIG. Further, as shown in FIG. 4D, the maximum width of the incident range is not more than twice the minimum width of the incident range, more specifically, about 1.0 times.

The fluorescence generation unit 80 includes a transparent member 82 and a fluorescence layer 84. The fluorescence generation unit 80 has a square plate shape as a whole, and is fixed at a predetermined position (see FIG. 1).
The transparent member 82 carries the fluorescent layer 84. The transparent member 82 is made of optical glass, for example. Note that a layer (for example, a dielectric multilayer film) that allows the light from the condenser lens to pass therethrough and reflects the fluorescence may be formed on the transparent member.

The fluorescent layer 84 is disposed at a position where blue light from the anamorphic condenser lens 40 is incident in a defocused state, and red light (peak of emission intensity: about 610 nm) and green light (light emission) from a part of the blue light. Fluorescence including an intensity peak (about 550 nm) is generated (see FIG. 3B).
For this reason, the fluorescence generation unit 80 includes blue light that passes through the fluorescent layer 84 without being involved in generation of fluorescence together with fluorescence (red light and green light) (that is, light that can be used as white light). Will be injected.

The fluorescent layer 84 is composed of a layer containing a YAG phosphor. In addition, as a fluorescent layer, the fluorescent layer containing another fluorescent substance (a silicate type fluorescent substance, a TAG type fluorescent substance, etc.) can also be used. In addition, as a fluorescent layer, a phosphor that converts light from the condensing optical system into red light (for example, CaAlSiN ₃ red phosphor) and a phosphor that converts light from the condensing optical system into green (for example, β sialon green) A fluorescent layer containing (phosphor) can also be used.
A part of the blue light that passes through the fluorescent layer 84 without being involved in the generation of fluorescence is emitted together with the fluorescence. At this time, since the blue light is scattered or reflected in the fluorescent layer 84, the blue light is emitted from the fluorescence generation unit 80 as light having a distribution characteristic (so-called Lambertian distribution) substantially similar to the fluorescence.

The collimator optical system 90 makes the light from the fluorescent layer 84 substantially parallel. As shown in FIG. 1, the collimator optical system 90 includes a first lens 92 and a second lens 94.
The first lens 92 and the second lens 94 are biconvex lenses. In addition, the shape of the first lens and the second lens is not limited to the above shape, and the collimator optical system including the first lens and the second lens substantially parallelizes the light from the fluorescent layer. Any shape can be used. Further, the number of lenses constituting the collimator optical system may be one, or three or more.
The collimator optical system 90 which is an optical element subsequent to the anamorphic condenser lens 40 has a shape in which a part including the upper end part and a part including the lower end part are cut off.

The lens integrator optical system 110 includes a first lens array 120, a second lens array 130, a polarization conversion element 140, and a superimposing lens 150.
Instead of the lens integrator optical system as described above, another integrator optical system, for example, a rod integrator optical system including an integrator rod can be used.

  In the illuminating device 100, the optical elements constituting the lens integrator optical system 110 have a shape in which a part including the upper end part and a part including the lower end part are cut out, as in the collimator optical system 90. For this reason, the illumination device 100 can be a thin illumination device. In addition, the projector 1000 including the illumination device 100 can also be a thin projector.

  As shown in FIG. 1, the first lens array 120 includes a plurality of first small lenses 122 for dividing the light from the light source device 10 into a plurality of partial light beams. The first lens array 120 has a function as a light beam splitting optical element that splits light from the light source device 10 into a plurality of partial light beams, and the plurality of first small lenses 122 are in a plane orthogonal to the illumination optical axis 100ax. It has a configuration arranged in a matrix of multiple rows and multiple columns (2 rows and 6 columns in the first embodiment). Although not illustrated, the outer shape of the first small lens 122 is substantially similar to the outer shape of the image forming area of the liquid crystal light modulation device 400.

  The second lens array 130 has a plurality of second small lenses 132 corresponding to the plurality of first small lenses 122 in the first lens array 120. The second lens array 130 has a function of forming the image of each first small lens 122 together with the superimposing lens 150 in the vicinity of the image forming area of the liquid crystal light modulators 400R, 400G, and 400B. 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 (2 rows and 6 columns in the first embodiment) in a plane orthogonal to the illumination optical axis 100ax. Have.

The polarization conversion element 140 is a polarization conversion element that emits each partial light beam divided by the first lens array 120 as light composed of substantially 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 light source device 10 as it is, and reflects the other linear polarization component in a direction perpendicular to the illumination optical axis 100ax. 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 100ax, and a position that converts the other linearly polarized light component reflected by the reflective layer into one linearly polarized light component. And a phase difference plate.

  The superimposing lens 150 is an optical element that condenses the partial light beams from the polarization conversion element 140 and superimposes them in the vicinity of the image forming area of the liquid crystal light modulation device 400. The superimposing lens 150 is disposed so that the optical axis of the superimposing lens 150 and the illumination optical axis 100ax substantially coincide. The superimposing lens may be composed of a compound lens in which a plurality of lenses are combined.

  A rear-stage condenser lens 300 is disposed between the illumination device 100 and the liquid crystal light modulation device 400. The light from the illumination device 100 passes through the rear condenser lens 300 and enters the liquid crystal light modulation device 400.

  The liquid crystal light modulation device 400 is a liquid crystal light modulation device having a color filter. Although the detailed description of the color filter is omitted, the color filter uses a color separation element such as a dielectric multilayer film to separate the light from the rear condenser lens 300 into red light, green light, and blue light for each pixel. It has a function as a color separation optical system. In addition, other color separation optical systems can be used as the color separation optical system. For example, color separation provided with “three dichroic mirrors corresponding to red light, green light, and blue light and having different angles”. An optical system or the like can also be used.

The liquid crystal light modulation device 400 is a light modulation device that modulates light that has passed through a color filter (originally light from the illumination device 100) according to image information, and modulates incident color light according to image information. A color image is formed. Although not shown, an incident-side polarizing plate is interposed between the rear-stage condenser lens 300 and the liquid crystal light modulation device 400, and the emission side is disposed between the liquid crystal light modulation device 400 and the projection optical system 600. A polarizing plate is interposed. The incident-side polarizing plate, the liquid crystal light modulation device, and the emission-side polarizing plate modulate the light of each incident color light.
The liquid crystal light modulation device is a transmission type liquid crystal light modulation device in which a liquid crystal, which is an electro-optical material, is hermetically sealed in a pair of transparent glass substrates. For example, a polysilicon TFT is used as a switching element in accordance with a given image signal. Thus, the polarization direction of one type of linearly polarized light emitted from the incident side polarizing plate is modulated.

  The color image emitted from the liquid crystal light modulation device 400 is projected by the projection optical system 600 and forms an image on the screen SCR.

  Next, effects of the light source device 10 and the projector 1000 according to the embodiment will be described.

  According to the light source device 10 according to the first embodiment, since the condensing lens (anamorphic condensing lens 40) is provided, excitation light (blue light) is incident on a smaller area on the fluorescent layer 84 to make the fluorescent layer 84 small. As a result, the light source device can be reduced in size.

  Further, according to the light source device 10 according to the first embodiment, the condensing lens is the anamorphic condensing lens 40 in which at least one of the incident surface and the exit surface is an anamorphic surface, and therefore the excitation light from the solid light source is fluorescent. The incident range of excitation light incident on the fluorescent layer can be dispersed by adjusting the range incident on the layer, and an excessive thermal load is suppressed on a part of the region where the excitation light is incident on the fluorescent layer. As a result, the phosphor layer can be prevented from being deteriorated or burned out, and as a result, the life of the light source device can be extended.

  For this reason, the light source device 10 according to the first embodiment is a light source device that can be reduced in size and can have a long lifetime.

  Moreover, according to the light source device 10 according to the first embodiment, since the fluorescent layer 84 is provided as in the conventional light source device, desired color light can be obtained using a solid light source that generates excitation light of a specific wavelength. It becomes possible.

  Further, according to the light source device 10 according to the first embodiment, since the maximum width of the incident range is not more than twice the minimum width of the incident range, the incident position of the excitation light incident on the fluorescent layer can be further dispersed. Therefore, it is possible to further suppress the excessive thermal load on a part of the region where the excitation light is incident on the fluorescent layer and prevent the fluorescent layer from being deteriorated or burned. As a result, the life of the light source device is further increased. It can be made longer.

  Further, according to the light source device 10 according to the first embodiment, since the maximum width of the incident range is not more than twice the minimum width of the incident range, the direction dependency of the region where the fluorescence is generated in the fluorescent layer is reduced. Therefore, a light source device that emits light that is easy to handle can be provided.

  Further, according to the light source device 10 according to the first embodiment, since the excitation light is configured to enter the fluorescent layer 84 in the defocused state, the intensity of the excitation light incident on the fluorescent layer can be further dispersed. It is possible to further suppress the excessive thermal load on a part of the region where the excitation light is incident on the fluorescent layer, and to prevent the fluorescent layer from being deteriorated or burned. The lifetime can be further increased.

  Further, according to the light source device 10 according to the first embodiment, the anamorphic surface is formed of a cylindrical surface, so that the incident positions of the excitation light incident on the fluorescent layer can be dispersed with a relatively simple configuration.

  Further, according to the light source device 10 according to the first embodiment, the anamorphic condenser lens 40 has both the entrance surface 42 and the exit surface 44 made of an anamorphic surface. It is possible to adjust the incident position and range of the incident excitation light.

  Further, according to the light source device 10 according to the first embodiment, a part including the upper end part and a part including the lower end part of the optical element (collimator optical system 90) subsequent to the anamorphic condenser lens 40 are cut off. Since it has a shape, it is possible to obtain a thin light source device without greatly reducing the light utilization efficiency.

  In the light source device 10 according to the first embodiment, the solid light source 20 is composed of a semiconductor laser having an aspect ratio of a light emitting region of 3 or more, and the present invention can be suitably applied to such a light source device.

  The projector 1000 according to the first embodiment includes the light source device 10 according to the first embodiment that can be downsized and can have a long lifetime, and thus can be downsized. In addition, the frequency of light source device replacement can be reduced.

  Further, since the projector 1000 according to the first embodiment is a single-plate projector including one light modulation device as the light modulation device, the projector can be further downsized with a simple configuration.

[Embodiment 2]
FIG. 5 is a diagram for explaining the light source device 12 according to the second embodiment. 5A is a top view showing the optical system of the light source device 12, FIG. 5B is a side view showing the optical system of the light source device 12, and FIG. 5C is incident on the fluorescent layer 84. FIG. FIG. 5D is a graph showing the in-plane light intensity distribution of the blue light incident on the fluorescent layer 84. FIG. In addition, the vertical axis | shaft of FIG.5 (c) represents the light intensity of the blue light which injects into the fluorescent layer 84. FIG. The horizontal axis represents the distance from the illumination optical axis 102ax.

  The light source device 12 according to the second embodiment basically has the same configuration as the light source device 10 according to the first embodiment, but the configuration of the anamorphic condenser lens is different from that of the light source device 10 according to the first embodiment. . That is, in the light source device 12 according to the second embodiment, as shown in FIG. 5A, the anamorphic condenser lens 50 has an exit surface 54 made of an anamorphic surface and an entrance surface 52 made of a rotationally symmetric aspherical surface. Become. Further, the anamorphic surface (exit surface 54) is a concave toric surface.

Therefore, in the light source device 12 according to the second embodiment, as shown in FIGS. 5C and 5D, the blue light in the direction along the direction in which the divergence angle is large is strongly refracted and the divergence angle is increased. It is possible to refract blue light in the direction along the small direction and disperse the incident position of the excitation light (blue light) incident on the fluorescent layer 84. The peak intensity at this time is about 33 W / mm ^{2 as shown} in FIG. Further, as shown in FIG. 5D, the maximum width of the incident range is not more than twice the minimum width of the incident range, and more specifically, about 1.6 times.

  As described above, the light source device 12 according to the second embodiment is different from the light source device 10 according to the first embodiment in the configuration of the anamorphic condenser lens, but includes a condenser lens. Since at least one of the surface and the exit surface is the anamorphic condensing lens 50 formed of an anamorphic surface, it is possible to reduce the size and extend the life as in the light source device 10 according to the first embodiment. It becomes a light source device capable of.

  Further, according to the light source device 12 according to the second embodiment, since the anamorphic surface is a toric surface, the incident position of the excitation light incident on the fluorescent layer can be finely adjusted and dispersed.

  Further, according to the light source device 12 according to the second embodiment, the anamorphic condenser lens 50 has one of the entrance surface and the exit surface made of an anamorphic surface and the other surface made of a rotationally symmetric aspherical surface. The incident position and range of the excitation light incident on the fluorescent layer can be adjusted by the anamorphic surface and the surface composed of the rotationally symmetric aspherical surface.

  The light source device 12 according to the second embodiment has the same configuration as that of the light source device 10 according to the first embodiment except for the configuration of the anamorphic condenser lens. Therefore, the light source device 10 according to the first embodiment has the same configuration. It has the corresponding effect as it is.

[Embodiment 3]
FIG. 6 is a diagram for explaining the light source device 14 according to the third embodiment. 6A is a top view showing the optical system of the light source device 14, FIG. 6B is a side view showing the optical system of the light source device 14, and FIG. 6C is incident on the fluorescent layer 84. FIG. 6D is a graph showing the in-plane light intensity distribution of blue light incident on the fluorescent layer 84. FIG. In addition, the vertical axis | shaft of FIG.6 (c) represents the light intensity of the blue light which injects into the fluorescent layer 84. FIG. The horizontal axis represents the distance from the illumination optical axis 104ax.

  The light source device 14 according to the third embodiment basically has the same configuration as the light source device 12 according to the second embodiment, but the configuration of the anamorphic condenser lens is different from that of the light source device 12 according to the second embodiment. . That is, in the light source device 14 according to the third embodiment, as shown in FIGS. 6A and 6B, the anamorphic surface (the exit surface 64) of the anamorphic condenser lens 60 is formed of a convex toric surface. .

For this reason, in the light source device 14 according to the third embodiment, as shown in FIGS. 6C and 6D, the blue light in the direction along the direction in which the divergence angle is large is strongly refracted and the divergence angle is increased. Blue light in the direction along the small direction is also strongly refracted, and the incident position of excitation light (blue light) incident on the fluorescent layer 84 can be dispersed. The peak intensity at this time is about 26 W / mm ^{2 as shown} in FIG. Further, as shown in FIG. 6D, the maximum width of the incident range is not more than twice the minimum width of the incident range, and more specifically, about 1.0 times.

  As described above, the light source device 14 according to the third embodiment is different from the light source device 12 according to the second embodiment in the configuration of the anamorphic condensing lens, but includes a condensing lens. Since at least one of the surface and the exit surface is the anamorphic condensing lens 60 formed of an anamorphic surface, it is possible to reduce the size and extend the life as in the light source device 12 according to the second embodiment. It becomes a light source device capable of.

  The light source device 14 according to the third embodiment has the same configuration as that of the light source device 12 according to the second embodiment except for the configuration of the anamorphic condenser lens. Therefore, the light source device 12 according to the second embodiment includes the light source device 14 according to the second embodiment. It has the corresponding effect as it is.

[Comparative example]
FIG. 7 is a diagram for explaining the light source device 16 according to the comparative example. FIG. 7A is a top view showing the optical system of the light source device 16, FIG. 7B is a side view showing the optical system of the light source device 16, and FIG. 7C is incident on the fluorescent layer 84. FIG. 7D is a graph showing the in-plane light intensity distribution of the blue light incident on the fluorescent layer 84. FIG. In addition, the vertical axis | shaft of FIG.7 (c) represents the light intensity of the blue light which injects into the fluorescent layer 84. FIG. The horizontal axis represents the distance from the illumination optical axis 106ax.

  The light source device 16 according to the comparative example basically has a configuration similar to that of the light source device 10 according to the first embodiment, but includes a general condenser lens (that is, a condenser lens that is not an anamorphic condenser lens). This is different from the light source device 10 according to the first embodiment. That is, as shown in FIGS. 7A and 7B, the light source device 16 according to the comparative example includes a condensing lens in which both the incident surface 72 and the exit surface 74 are rotationally symmetric aspherical surfaces. 70.

In the light source device 16 according to the comparative example, as illustrated in FIGS. 7C and 7D, the incident position of the blue light incident on the fluorescent layer 84 cannot be dispersed, and the blue light is incident. Part of the area is overheated. In particular, as shown in FIG. 7C, the peak intensity has increased to about 160 W / mm ² .

  As described above, according to the light source device 16 according to the comparative example, the solid-state light source 20 is composed of a high-power semiconductor laser with an aspect ratio of the light emitting region of 3 or more, and the condensing lens has both the entrance surface 72 and the exit surface 74. Since this surface is a condensing lens 70 made of a rotationally symmetric aspherical surface, an excessive thermal load is applied to a part of the region where the excitation light is incident on the fluorescent layer, leading to deterioration or burning of the fluorescent layer. In some cases, it may be difficult to extend the life of the light source device.

[Embodiment 4]
FIG. 8 is a diagram for explaining a projector 1008 according to the fourth embodiment. 8A is a top view showing an optical system of the projector 1008, and FIG. 8B is a side view showing the optical system of the projector 1008.

The projector 1008 according to the fourth embodiment basically has the same configuration as that of the projector 1000 according to the first embodiment, but the configuration of the optical elements subsequent to the anamorphic condenser lens is the same as that of the projector 1000 according to the first embodiment. Is different. That is, in the projector 1000 according to the fourth embodiment, as shown in FIG. 8 (particularly FIG. 8B), each optical element constituting the collimator optical system 98 and the lens integrator optical system 118 includes an upper end portion. A part including a part and a part including a lower end part is formed in a shape that is not cut off.
Accordingly, the plurality of first small lenses 122 in the first lens array 121 and the plurality of second small lenses 132 in the second lens array 131 are arranged in 10 rows and 6 columns.

  Although the projector 1008 having such a configuration cannot be made thinner than the projector 1000 according to the first embodiment, the light utilization efficiency can be improved by effectively using the light from the fluorescent layer 84. Is possible. The light source device 18 according to the fourth embodiment has the same configuration as that of the light source device 10 according to the first embodiment except for the configuration of the collimator optical system. Therefore, the light source device 10 according to the first embodiment has the same configuration. It has the corresponding effect as it is.

  As described above, the projector 1008 according to the fourth embodiment is different from the projector 1000 according to the first embodiment in the configuration of the optical elements subsequent to the anamorphic condenser lens, but can be downsized, and Since the light source device 18 according to the fourth embodiment capable of extending the lifetime is provided, it is possible to reduce the size and reduce the frequency of replacement of the light source device, similarly to the projector 1008 according to the first embodiment. It becomes possible to do.

  Note that the projector 1008 according to the fourth embodiment has the same configuration as that of the projector 1000 according to the first embodiment except for the configuration of the optical elements subsequent to the anamorphic condenser lens, and thus the projector 1000 according to the first embodiment. Among the effects possessed, the corresponding effect is maintained as it is.

  As mentioned above, although this invention was demonstrated based on said embodiment, this invention is not limited to said embodiment. The present invention can be carried out in various modes without departing from the spirit thereof, and for example, the following modifications are possible.

(1) The dimensions, the number, the material, and the shape of each component described in the above embodiments are exemplifications, and can be changed within a range not impairing the effects of the present invention.

(2) In the above embodiments, as the solid light source and the fluorescent layer, the solid light source 20 that generates blue light and the fluorescent layer 84 that generates fluorescence including red light and green light from a part of the blue light are used. However, the present invention is not limited to this. For example, as the solid light source and the fluorescent layer, a solid light source that generates violet light or ultraviolet light and a fluorescent layer that generates color light including red light, green light, and blue light from violet light or ultraviolet light may be used.

(3) In each of the above embodiments, the light source device 10 emits “light that can be used as white light”, but the present invention is not limited to this. A light source device that emits light other than “light that can be used as white light” (for example, light composed of red light and green light, or light including a large amount of specific color light components) may be used.

(4) In each of the above-described embodiments, the solid light source 20 that generates blue light having a light emission intensity peak of about 460 nm is used. However, the present invention is not limited to this. For example, a solid light source that generates blue light having a light emission intensity peak of 440 nm to 450 nm may be used. With such a configuration, it is possible to improve the fluorescence generation efficiency in the phosphor.

(5) In each of the above embodiments, the solid light source 24 made of a semiconductor laser is used as the solid light source, but the present invention is not limited to this. For example, you may use the solid light source which consists of a light emitting diode as a solid light source.

(6) In each of the above embodiments, a transmissive projector is used, but the present invention is not limited to this. For example, a reflective projector may be used. Here, “transmission type” means that a light modulation device as a light modulation means such as a transmission type liquid crystal light modulation device or the like is a type that transmits light, and “reflection type” means This means that the light modulation device as the light modulation means, such as a reflective liquid crystal light modulation device, is a type that reflects light. Even when the present invention is applied to a reflective projector, the same effect as that of a transmissive projector can be obtained.

(7) In each of the above embodiments, the liquid crystal light modulation device is used as the light modulation device of the projector, but the present invention is not limited to this. In general, the light modulation device only needs to modulate incident light according to image information, and a micromirror light modulation device or the like may be used. For example, a DMD (digital micromirror device) (trademark of TI) can be used as the micromirror light modulator.

(8) In the above embodiment, the projector using one light modulation device has been described as an example, but the present invention is not limited to this. The present invention can also be applied to a projector using two or more light modulation devices. The following modification is a specific example. FIG. 9 is a top view showing an optical system of a projector 1010 according to a modification. A projector 1010 according to the modification is a projector including three liquid crystal light modulation devices 400R, 400G, and 400B. Reference numeral 200 denotes a color separation light guide optical system that performs color separation and light guide, and includes dichroic mirrors 210 and 220, reflection mirrors 230, 240 and 250, and relay lenses 260 and 270. Reference numeral 500 denotes a cross dichroic prism that aligns the traveling direction of light. In the above case, a liquid crystal light modulation device without a color filter can be used. For example, the present invention can be applied to such a projector.

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

(10) In each of the above embodiments, the example in which the light source device of the present invention is applied to a projector has been described, but the present invention is not limited to this. For example, the light source device of the present invention can also be applied to other optical devices (for example, an optical disk device, an automobile headlamp, a lighting device, etc.).

DESCRIPTION OF SYMBOLS 10,18 ... Light source device, 20 ... Solid light source, 22 ... Board | substrate, 24 ... Light emission area | region, 40, 50, 60 ... Anamorphic condensing lens, 70 ... Condensing lens, 80 ... Fluorescence production | generation part, 82 ... Transparent member, 84 Fluorescent layer, 90, 98 ... Collimator optical system, 100, 108 ... Illuminator, 100ax, 102ax, 104ax, 106ax, 108ax ... Illumination optical axis, 110, 118 ... Lens integrator optical system, 120, 121 ... First lens Array, 122 ... first small lens, 130,131 ... second lens array, 132 ... second small lens, 140,141 ... polarization conversion element, 150,151 ... superimposed lens, 200 ... color separation light guide optical system, 210 220, dichroic mirror, 230, 240, 250 ... reflection mirror, 260, 270 ... relay lens, 300, 300R 300G, 300B ... subsequent condenser lens, 400,400R, 400G, 400B ... liquid crystal light modulation device, 500 ... cross dichroic prism 600 ... projection optical system, 1000,1008,1010 ... projector, SCR ... screen

Claims (11)

A solid state light source that generates excitation light;
A condensing lens for condensing excitation light from the solid-state light source;
A light source device including a fluorescent layer that generates fluorescence from at least a part of the excitation light from the condenser lens,
The aspect ratio of the light emitting region in the solid state light source is greater than 1,
The light source device, wherein the condensing lens is an anamorphic condensing lens in which at least one of an incident surface and an exit surface is an anamorphic surface. The light source device according to claim 1,
The solid-state light source comprises a semiconductor laser having an aspect ratio of the light emitting region of 3 or more. The light source device according to claim 1 or 2,
When the range in which the excitation light is incident on the fluorescent layer is an incident range,
The maximum width of the incident range is less than twice the minimum width of the incident range. In the light source device in any one of Claims 1-3,
A light source device, wherein the excitation light is configured to enter the fluorescent layer in a defocused state. In the light source device in any one of Claims 1-4,
The light source device, wherein the anamorphic surface is a cylindrical surface. In the light source device in any one of Claims 1-4,
The light source device, wherein the anamorphic surface is a toric surface. In the light source device in any one of Claims 1-6,
In the anamorphic condensing lens, both the incident surface and the exit surface are anamorphic surfaces. In the light source device in any one of Claims 1-6,
The anamorphic condenser lens is characterized in that one of the incident surface and the exit surface is an anamorphic surface and the other surface is a rotationally symmetric aspherical surface. In the light source device in any one of Claims 1-8,
The optical element at the rear stage of the anamorphic condenser lens has a shape in which a part including the upper end part and a part including the lower end part are cut off. An illumination device comprising the light source device according to any one of claims 1 to 9,
A light modulation device that modulates light from the illumination device according to image information;
A projector comprising: a projection optical system that projects light from the light modulation device. The projector according to claim 10.
A projector that is a single-plate projector including one light modulation device as the light modulation device.