Light source device, image projection device, and light source optical system

Abstract

A light source device includes: an excitation light source configured to emit first-color light; an optical component having a reflection surface configured to reflect the first-color light; a wavelength conversion unit including a wavelength conversion component onto which the first-color light reflected by the optical component is incident, the wavelength conversion component being configured to convert at least a part of the first-color light into second-color light having a wavelength different from that of the first-color light and emit the second-color light; and a condenser element configured to condense the first-color light emitted from the wavelength conversion unit. A straight line including a first optical path does not intersect a light beam condensed by the condenser element, and the first optical path is an optical path from the center of the light beam emitted from the excitation light source to the center of the first-color light on the reflection surface.

Description

Technical Field

[0001] Embodiments disclosed in the present invention relate to a light source device, an image projection device, and a light source optical system. Background Art

[0002] Currently, projectors (or image projection devices) for magnifying and projecting various images or moving images are widely used. A projector focuses light emitted from a light source onto a spatial light modulation element such as a digital micromirror device (DMD) or a liquid crystal display, and displays the emitted light from the spatial light modulation element modulated by an image signal as a color image on a screen.

[0003] In the prior art, for example, a high-brightness ultra-high pressure mercury lamp is used as a light source of a projector, but due to its short lifespan, frequent maintenance is required. Therefore, in recent years, the number of projectors using a laser light source or an LED light source instead of an ultra-high pressure mercury lamp is increasing. This is because, compared with an ultra-high pressure mercury lamp, the laser light source and the LED light source have a long lifespan, and in addition, due to their monochromaticity, the color reproducibility is also good.

[0004] In a projector, an image is formed by irradiating an image display element such as a DMD with, for example, three primary colors of light, namely red, green, and blue. Although all three colors can be generated using a laser light source, since the luminous efficiency of green laser and red laser is lower than that of blue laser, it is not preferred. Therefore, the method used is to irradiate a phosphor with blue laser as excitation light, and generate red light and green light from the fluorescent light after wavelength conversion by the phosphor.

[0005] Since the excitation light of several tens of W is converged and irradiated in the phosphor, it causes burnout, a decrease in efficiency due to temperature rise, and secular change. Therefore, by forming a phosphor layer on a disk and rotating it, the irradiation position of the excitation light is not concentrated at a single point. This disk is called a phosphor wheel. In the phosphor wheel, the phosphor is formed in a sector shape or a ring shape along the outer periphery of the disk.

[0006] As an example of a light source device using the DMD and the phosphor wheel as described above, JP-4711156-B (JP-2011-013320-A) proposes a device in which a part of the phosphor wheel is used as a transmissive plate in order to simplify the entire device. In the technology disclosed in JP-4711156-B, the excitation light penetrating the phosphor wheel is reflected multiple times by a mirror and guided in the same direction as the fluorescent light. As a result, a structure is formed in which the excitation light and the fluorescent light are synthesized in the same optical path and irradiated onto the DMD.

[0007] In addition, as another example of a light source device using the DMD and the phosphor wheel as described above, JP-5817109-B (JP-2012-123179-A) proposes a device in which, in order to miniaturize the entire device, a part of the phosphor wheel is used as a reflector. In the technology disclosed in JP-5817109-B, a phase retarder (quarter-wave plate) and a polarization beam splitter are used to separate the optical path, so that the excitation light is reflected in the same direction as the fluorescence light by the phosphor wheel, so that the reflected excitation light does not return to the excitation light source. Thus, a structure is formed in which the excitation light and the fluorescence are synthesized in the same optical path and irradiated onto the DMD.

[0008] Citation List

[0009] Patent Document

[0010] [Patent Document 1] JP-4711156-B (JP-2011-013320-A)

[0011] [Patent Document 2] JP-5817109-B (JP-2012-123179-A) Summary of the Invention

[0012] Technical Problem

[0013] However, in the above-mentioned JP-4711156-B, since the optical path of the excitation light is circuitous, the entire device becomes large-sized. On the other hand, in the above-mentioned JP-5817109-B, since a phase retarder and a polarization beam splitter are used, the cost becomes high. In addition, the optical path of the excitation light toward the phosphor wheel and the optical path of the excitation light reflected from the phosphor wheel penetrate the same part of the phase retarder or the polarization beam splitter. Therefore, the condensing density on these optical elements increases, which causes breakage or the like, and may lead to a decrease in reliability.

[0014] An object of the present invention is to provide a light source device capable of achieving miniaturization and low cost, an image projection device having the light source device, and a light source optical system having the light source device.

[0015] Solution to the Problem

[0016] According to one aspect of the present invention, a light source device includes an excitation light source, an optical component, a wavelength conversion unit, and a condenser element. The excitation light source emits first-color light. The optical component has a reflecting surface that reflects the first-color light. The wavelength conversion unit includes a wavelength conversion component, and the first-color light reflected by the optical component is incident on the wavelength conversion component. The wavelength conversion component converts at least a part of the first-color light into second-color light having a wavelength different from that of the first-color light and emits the second-color light. The condenser element condenses the first-color light emitted from the wavelength conversion unit. A straight line including a first optical path does not intersect with the light beam condensed by the condenser element, where the first optical path is the optical path from the center of the light beam emitted from the excitation light source to the center of the first-color light on the reflecting surface.

[0017] Advantages of the present invention

[0018] Embodiments of the present invention can provide a light source device capable of achieving miniaturization and cost reduction, an image projection device having the light source device, and a light source optical system having the light source device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings are intended to depict embodiments of the present invention and should not be construed as limiting its scope. The drawings are not to be regarded as drawn to scale unless otherwise clearly noted. Also, the same or similar reference numerals denote the same or similar components in multiple views.

[0020] Figure 1A and 1B are schematic views of a light source device according to an embodiment of the present invention, where Figure 1A is a schematic view of the optical configuration of the light source device, Figure 1B is the light emitted onto Figure 1A a dichroic mirror of the light source device, and is a schematic view of an example of the excitation light.

[0021] Figure 2 is a schematic view of the optical configuration of a light source device according to another embodiment of the present invention.

[0022] Figure 3 is a schematic view of the optical configuration of a light source device according to another embodiment of the present invention.

[0023] Figure 4 is a schematic view of the optical configuration of a light source device according to another embodiment of the present invention.

[0024] Figure 5A , 5B and 5C are schematic views of a light source device according to still another embodiment of the present invention, where Figure 5A is a schematic view of the optical configuration of the light source device, Figure 5Bis a front view of the rod integrator in the light source device as viewed from the incident opening side, Figure 5C is a front view of the rod integrator as viewed from the exit opening surface.

[0025] Fig. 6A and 6B is a schematic diagram of a light source device according to another embodiment of the present invention, wherein, Fig. 6A is a schematic diagram of the optical configuration of the excitation light optical path, Figure 6B is a schematic diagram of the optical configuration of the fluorescence optical path in the embodiment.

[0026] Figure 7 is a schematic diagram of the optical characteristics of the rod integrator according to an embodiment of the present invention.

[0027] Figure 8 is a schematic diagram of a rod integrator according to another embodiment of the present invention.

[0028] Fig. 9 is a schematic diagram of the optical configuration of a light source device according to a first embodiment of the present invention and a projector including the light source device according to an embodiment of the present invention.

[0029] Fig. 10A and 10B is a schematic diagram of a light source device according to the first embodiment, wherein, Fig. 10A is a schematic diagram of the optical configuration of the blue laser optical path, Fig. 10B is a schematic diagram of the optical configuration of the fluorescence optical path.

[0030] Fig.11 is a diagram showing the main part of the light source unit included in the light source device according to the first embodiment.

[0031] Fig.12 is a front view of an example of the configuration of the dichroic mirror of the light source device according to the first embodiment.

[0032] Fig.13A and 13B is a diagram showing the structure of the phosphor unit included in the light source device according to the first embodiment, wherein, Fig.13A is a front view of the phosphor unit as viewed from the blue light incident direction, Fig. 13B is a side view of the phosphor unit as viewed from a direction orthogonal to the blue light incident direction.

[0033] Fig.14A and 14B is a diagram showing the structure of the color wheel included in the light source device according to the first embodiment, wherein, Fig.14A is a front view of the color wheel as viewed from the incident direction of blue light and fluorescence, Fig. 14B is a side view of the color wheel as viewed from a direction orthogonal to the incident direction of blue light and fluorescence.

[0034] Fig.15A and 15B are diagrams of the light tunnel of the light source device according to the first embodiment, where, Fig.15A is a schematic diagram of an example of the mode in which light enters the incident opening of the light tunnel, Fig. 15B is a schematic diagram of another example of the mode in which light enters the incident opening of the light tunnel.

[0035] Fig.16A and 16B are schematic diagrams of the optical path of the light source device according to the second embodiment of the present invention, where, Fig.16A is a schematic diagram of the optical configuration of the optical path of blue light, Fig. 16B is a schematic diagram of the optical configuration of the optical path of fluorescence.

[0036] Fig.17 is a front view of an example of the configuration of a dichroic mirror applicable to the light source device according to the second embodiment.

[0037] Fig.18A and 18B are schematic diagrams of the light source device according to the third embodiment of the present invention, where, Fig.18A is a schematic diagram of the optical configuration of the blue laser optical path, Fig.18B is a schematic diagram of the optical configuration of the fluorescence optical path.

[0038] Fig.19A and 19B are schematic diagrams of the light source device according to the fourth embodiment of the present invention, where, Fig.19A is a schematic diagram of the optical configuration of the blue laser optical path, Fig.19B is a schematic diagram of the optical configuration of the fluorescence optical path.

[0039] Fig. 20 is a schematic side view of the structure of the phosphor unit of the light source device according to the fourth embodiment.

[0040] Fig.21A and 21B are schematic diagrams of the light source device according to the fifth embodiment of the present invention, where, Fig.21A is an optical configuration diagram of the light source device viewed from the direction facing the light emitting surface of the light source, Fig. 21B is the optical configuration diagram of the light source device obtained by rotating the light source device of Fig.21A 90 degrees around the vertical axis.

[0041] Fig.22A and 22B show a part of the light source device according to the fifth embodiment of the present invention, where, Fig.22A is an optical path diagram showing the state of blue light incident on the dichroic mirror, Fig. 22BIt is an optical path diagram showing the state of blue light incident on a phosphor unit.

[0042] Fig.23A And 23B It is a schematic diagram of a light source device according to a sixth embodiment of the present invention, wherein Fig.23A It is an optical configuration diagram of the light source device viewed from the lateral side direction, Fig. 23B It is an optical configuration diagram of the light source device viewed from the planar direction.

[0043] Fig.24A And 24B It is a schematic diagram of a light source device according to a second embodiment for comparison with the sixth embodiment, wherein Fig.24A It is an optical configuration diagram of the light source device viewed from the lateral side direction, Fig. 24B It is an optical configuration diagram of the light source device viewed from the planar direction.

[0044] Fig.25 It is a front view of a light source device according to a seventh embodiment of the present invention.

[0045] Fig.26 It is a front view of a light source device according to a comparative example of the seventh embodiment.

[0046] Fig. 27 It is a perspective view of an example of a light mixing element according to an embodiment of the present invention, showing an example of the occurrence of luminance non-uniformity.

[0047] Fig.28A And 28B It is a perspective view of a rod integrator in a light source device according to an eighth embodiment of the present invention, Fig.28C And 28D It is an illustration of an example of the occurrence of luminance non-uniformity of the rod integrator.

[0048] Fig.29A And 29B It is a diagram of a light source device according to a ninth embodiment of the present invention.

[0049] Fig.30 It is a diagram of a light source device according to a tenth embodiment of the present invention.

[0050] Fig.31 It is a diagram of a light source device according to an eleventh embodiment of the present invention.

[0051] Fig.32 It is a diagram of a light source device according to a twelfth embodiment of the present invention.

[0052] Fig.33 It is a diagram of a light source device according to a twelfth embodiment of the present invention.

[0053] Fig.34It is a diagram of a light source device according to the twelfth embodiment of the present invention. Detailed implementation mode

[0054] The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly indicates otherwise.

[0055] When describing the embodiments shown in the drawings, specific terms are adopted for clarity. However, the disclosure of this specification is not intended to be limited to the specific terms so selected, and it should be understood that each specific element includes all technical equivalents having similar functions, operating in a similar manner and obtaining similar results.

[0056] Some embodiments disclosed in the present invention are described below, but no limitations are indicated here, and various applications and modifications can be made without departing from the scope of the present invention. In the following-mentioned drawings, the same reference codes are used for common elements, and their descriptions are appropriately omitted.

[0057] As a light source device using a digital micromirror device (DMD) and a phosphor wheel, in order to miniaturize the entire device, a device in which a part of the phosphor wheel is used as a reflector is known. In this light source device, a phase retarder (quarter-wave plate) and a polarization beam splitter are arranged on the optical path to reflect the excitation light in the same direction as the fluorescence light through the phosphor wheel, so that the reflected excitation light does not return to the excitation light source.

[0058] In a light source device having such a configuration, since a phase difference plate and a polarization beam splitter are arranged on the optical path of the excitation light, not only the miniaturization of the device is restricted, but also the cost becomes high. In addition, the optical path of the excitation light toward the phosphor wheel and the optical path of the excitation light reflected from the phosphor wheel penetrate the same part of the phase difference plate or the polarization beam splitter. Therefore, the condensing density on these optical elements increases, which causes breakage and the like, and may lead to a decrease in reliability.

[0059] The workers of the present invention focused on the fact that the structure in such a light source device becomes a factor hindering the miniaturization and low cost of the device main body, and also focused on the problem of becoming a factor reducing reliability. Then, it was found that in the light source device, forming the optical path of the excitation light toward the phosphor wheel and the optical path of the excitation light reflected from the phosphor wheel so as not to overlap would contribute to the miniaturization and low cost of the device main body and the improvement of reliability, and the present invention was conceived.

[0060] At least one embodiment of the present invention provides a light source device, including a light source that emits excitation light, an optical component having a reflecting surface that reflects the excitation light emitted by the light source, and a wavelength conversion unit having a wavelength conversion component that allows the excitation light reflected by the optical component to enter and converts at least a part of the excitation light into fluorescence light having a different wavelength from the excitation light and emits the fluorescence light. In such a light source device, when the center of the projected image of the excitation light on the reflecting surface of the optical component is set as point P and the light beam of the excitation light emitted from the wavelength conversion unit is set as light beam Q, point P and light beam Q are configured not to intersect.

[0061] According to at least one embodiment of the present invention, the light beam of the excitation light emitted from the wavelength conversion unit does not intersect the center of the projected image of the excitation light emitted from the light source. Therefore, it is possible to prevent the excitation light from passing through the same part of the optical component, and thus it is possible to suppress the breakage of the optical component due to the increase in the condensing density, and the reliability can be improved. In addition, there is no need to prepare special optical elements such as a phase difference plate or a polarization beam splitter for separating the optical path of the excitation light emitted from the wavelength conversion unit. Therefore, the number of components can be reduced, the manufacturing cost can be lowered, and the device can be miniaturized.

[0062] Figure 1A and Figure 1B The figure shows a schematic diagram of a light source device 100 according to an embodiment of the present invention. Figure 1A The figure shows an explanatory diagram of the components of a light source device 100 according to an embodiment of the present invention. Figure 1B The figure shows an explanatory diagram of the excitation light projected onto the reflecting surface 102a of a dichroic mirror 102 of a light source device 100. Figure 1B The figure shows the reflecting surface 102a as viewed from the traveling direction of the excitation light from a light source 101.

[0063] As Figure 1A shown, the light source device 100 includes a light source 101 as an excitation light source and a dichroic mirror 102 as an example of an optical component. The light source device 100 further includes a phosphor unit 103 as an example of a wavelength conversion unit (wavelength converter) and a rod integrator 104 as an example of a light mixing element.

[0064] The light source device 100 according to an embodiment of the present invention is not limited to the structure shown in FIG. 1 and can be appropriately changed. For example, the light source device 100 may only include a light source 101, a dichroic mirror 102, and a phosphor unit 103. In the light source device 100 having these light source 101, dichroic mirror 102, and phosphor unit 103, the light source optical system is constituted by the components after removing the light source 101.

[0065] The light source 101 emits excitation light (hereinafter, also referred to as "first color light"). The dichroic mirror 102 has a reflection surface 102a that reflects the excitation light emitted by the light source 101 and guides it to the phosphor unit 103. For parts other than the reflection surface 102a of the dichroic mirror 102, it may have the optical property of allowing the excitation light emitted by the light source 101 and the fluorescence emitted from the phosphor unit 103 to penetrate.

[0066] The phosphor unit 103 has a first region that reflects or diffusely reflects the excitation light, and a second region that converts at least a part of the excitation light into fluorescence light (also referred to as "second color light") having a wavelength different from that of the excitation light and emits it. When the excitation light enters the phosphor unit 103, the phosphor unit 103 alternately emits the excitation light and the fluorescence light in sequence to the side of the incident surface of the excitation light ( Figure 1A the upper side shown). The rod integrator 104 is arranged such that the excitation light and the fluorescence emitted from the phosphor unit 103 are directed to and enter the rod integrator 104. The rod integrator 104 mixes and homogenizes the incident excitation light and fluorescence light, and emits the mixed light to the outside of the light source device 100.

[0067] Figure 1A Shown is a case where the first region of the phosphor unit 103 is arranged on the optical path of the excitation light emitted by the light source 101. The excitation light emitted by the light source 101 is reflected by the reflection surface 102a of the dichroic mirror 102 to the side of the phosphor unit 103. The excitation light reflected by the reflection surface 102a is reflected by the incident surface side of the first region of the phosphor unit 103. The rod integrator 104 is arranged in the reflection direction of the excitation light of the phosphor unit 103.

[0068] In the light source device 100 configured to form the optical path of the excitation light in this way, the center of the excitation light on the reflection surface 102a of the dichroic mirror 102 is set as point P, and the light beam of the excitation light emitted from the phosphor unit 103 is set as light beam Q. In the light source device 100, the dichroic mirror 102, the phosphor unit 103, and the rod integrator 104 are arranged such that these points P and the light beam Q do not intersect.

[0069] Regarding the center point P of the excitation light on the reflection surface 102a, in other words, the center of the projected image of the projected excitation light is defined as follows. (1) When the light intensity distribution of the projection range of the excitation light projected on the reflection surface 102a is line-symmetric or point-symmetric, the center of the minimum circumscribed circle of the projection range of the excitation light is taken as the center of the projected image. (2) When the light intensity distribution of the projection range of the excitation light projected on the reflection surface 102a is other than line-symmetric or point-symmetric, that is, in a case other than the above (1), just as Figure 1BAs shown, when the total energy of the excitation light projected onto the reflecting surface 102a is set as A, and a circle with an arbitrary radius r is used to cut out its projection range and the total energy of the light contained within the circle is set as B, the center of the circle with a radius r' when B / A is 93% or more (B / A ≥ 93%) and the energy density within the circle is the maximum is defined as the center of the projected image.

[0070] The projection range of the excitation light refers to the range of 1 / e or more of the energy with the maximum energy in the energy distribution of the excitation light projected onto the reflecting surface 102a. The energy density is obtained by dividing the "energy contained within the circle" by the "area of the circle", that is, the energy density is obtained by the following formula: 2 The projection range of the excitation light refers to the range of 1 / e or more of the energy with the maximum energy in the energy distribution of the excitation light projected onto the reflecting surface 102a. The energy density is obtained by dividing the "energy contained within the circle" by the "area of the circle", that is, the energy density is obtained by the following formula:

[0071] Energy density = (energy contained within the circle) / (area of the circle)

[0072] The center point P of the projected image of the excitation light defined in this way is determined in the state of all the light sources 101 included in the lighting light source device 100.

[0073] In addition, the light beam Q of the excitation light emitted from the phosphor unit 103 refers to the light beam within the range of 1 / e or more of the energy with the maximum energy in the energy distribution of the excitation light on the plane perpendicular to the propagation direction of the excitation light. 2 The center point P of the projected image of the excitation light defined in this way is determined in the state of all the light sources 101 included in the lighting light source device 100.

[0074] According to the light source device 100 according to the embodiment of the present invention, the light beam Q of the excitation light emitted from the phosphor unit 103 does not intersect with the center (the center of the projected image of the excitation light) of the excitation light emitted from the light source 101 on the reflecting surface 102a. Therefore, it is possible to prevent the excitation light from penetrating the same part of the dichroic mirror 102, and it is possible to suppress the breakage of the dichroic mirror 102 due to the increase in the condensing density. In addition, there is no need to prepare special optical elements such as a phase difference plate or a polarization separation element in order to separate the optical path of the excitation light emitted from the phosphor unit 103. Therefore, it is possible to reduce the number of parts, reduce the manufacturing cost, and at the same time miniaturize the device.

[0075] In Figure 1A and 1B In the light source device 100 shown, the case where the phosphor unit 103 sequentially switches the excitation light and the fluorescent light to emit, that is, the case where the excitation light and the fluorescence are emitted in a time-division manner is described. However, the configuration of the phosphor unit 103 is not limited to this, and it may be configured to emit the excitation light and the fluorescence simultaneously.

[0076] For example, instead of the first and second regions described above, the phosphor unit 103 has a region, i.e., a third region, that reflects a part of the excitation light and converts the other part of the excitation light into fluorescent light different from the excitation light. The reflection of the excitation light and the conversion of the fluorescent light are performed by the wavelength conversion member provided in the third region. The phosphor unit 103 is sometimes referred to as a stationary phosphor unit. When the excitation light is incident, the phosphor unit 103 emits the excitation light and the fluorescent light together to the side of the incident surface of the excitation light ( Figure 1A the upper side shown in). Even when such a phosphor unit 103 is provided, the same effect as when using a time-division type phosphor unit 103 can be obtained.

[0077] In some embodiments, in the light source device 100 shown in FIG. 1, a light guiding mechanism for guiding one or both of the excitation light and the fluorescent light emitted from the phosphor unit 103 to the rod integrator 104 may be provided. For example, the light guiding mechanism is composed of a condenser lens or a refractive lens and is disposed on the optical path between the phosphor unit 103 and the rod integrator 104. By providing such a light guiding mechanism, at least one of the excitation light and the second color light emitted from the phosphor unit 103 can be effectively guided to the rod integrator 104, and the light utilization efficiency can be improved.

[0078] In the light source device 100 according to the present embodiment, in order to improve the utilization efficiency of at least one of the incident excitation light and the fluorescence, the position of the rod integrator 104 can be appropriately changed. Figure 2 Another embodiment of the light source device according to the present invention is shown. In Figure 2 the same components as those in Figure 1A and Figure 1B are given the same reference numerals and their descriptions are omitted. In Figure 2 it shows a case where a reflecting surface 102a is formed on the surface of the dichroic mirror 102. The same applies to the following drawings.

[0079] As Figure 2 shown, it is considered a case where the center of the projected image of the excitation light projected from the dichroic mirror 102 onto the phosphor unit 103 is the point R. At this time, the rod integrator 104 is preferably disposed on the perpendicular line of the point R on the emission surface 103a of the phosphor unit 103. By disposing the rod integrator 104 in this way, when the fluorescent light is emitted perpendicularly to the emission surface 103a of the phosphor unit 103, since the fluorescent light can be effectively incident on the rod integrator 104, the light utilization efficiency of the fluorescent light can be improved.

[0080] In the light source device 100 according to the present embodiment, a condensing element may also be disposed on the optical path between the dichroic mirror 102 and the phosphor unit 103. The condensing element condenses the excitation light reflected by the dichroic mirror 102 so that the fluorescent light emitted from the phosphor unit 103 is substantially parallelized. For example, the condensing element may be constituted by a condenser lens.

[0081] Figure 3 It shows a light source device according to another embodiment of the present invention. In Figure 3 the same components as those in FIG. 1 are given the same reference numerals and their descriptions are omitted. In Figure 3 the light source device 100 shown, a condenser lens 105 as a condensing element is provided on the optical path between the dichroic mirror 102 and the phosphor unit 103. The condenser lens 105 condenses the excitation light reflected by the dichroic mirror 102 so that the fluorescent light emitted from the phosphor unit 103 is substantially parallelized.

[0082] Figure 3 It represents a straight line L1 connecting a point P on the reflecting surface 102a and the center of the projection image on the incident surface 105a of the condenser lens 105a. The excitation light reflected by the reflecting surface 102a of the dichroic mirror 102 and incident on the condenser lens 105 projects a projection image on the incident surface 105a. In addition, Figure 3 it also represents a point S, which is the intersection of the straight line L1 and the incident surface 103b of the phosphor unit 103, and the excitation light condensed by the condenser lens 105 is incident on the incident surface 103b of the phosphor unit 103. In the light source device 100, the point S and the center of the projection image of the excitation light projected on the phosphor unit 103, that is, the point R, are arranged at different positions. By such an arrangement of the condenser lens 105, the excitation light and the fluorescent light diverging from the phosphor unit 103 can be parallelized, so that the parallelized excitation light and fluorescent light can be effectively incident on the rod integrator 104, improving the light utilization efficiency.

[0083] In Figure 3 the light source device 100 shown, the straight line L1 preferably intersects perpendicularly with the incident surface 103b of the phosphor unit 103. By making the straight line L1 intersect perpendicularly with the incident surface 103b of the phosphor unit 103, the distance between the dichroic mirror 102 and the phosphor unit 103 can be shortened, and the overall size of the light source device 100 can be miniaturized.

[0084] When light passes through an optical element with a certain thickness, the incident surface is the surface where the light enters, and the exit surface is the surface where the light exits. For example, in Figure 3In the condenser lens 105 shown, the surface on which the light is incident after being reflected from the reflecting surface 102a of the dichroic mirror 102 is the incident surface 105a, and the surface that penetrates the condenser lens 105 from the incident surface 105a and exits to the phosphor unit 103 side is the exit surface 105b.

[0085] In the light source device 100 according to the present embodiment, a refractive optical element may be provided, and the refractive optical element is disposed between the condenser lens 105 and the rod integrator 104. The refractive optical element condenses at least one of the excitation light and the fluorescence light that parallelizes the condenser lens 105 as a condensing element, and guides the condensed light to the rod integrator 104. The refractive optical element is, for example, a refractive lens. Figure 4 Describe the light source device 100 according to an embodiment of the present invention having such a structure. In Figure 4 In, the same components as those in the Figure 3 shown embodiment are denoted by the same reference numerals, and repeated descriptions are omitted.

[0086] In Figure 4 the shown light source device 100, a refractive lens 106 as a refractive optical element is provided on the optical path between the condenser lens 105 and the rod integrator 104. The refractive lens 106 condenses at least one of the excitation light and the fluorescence light parallelized by the condenser element, that is, the condenser lens 105, and guides it to the incident opening 104a of the rod integrator 104. By providing the refractive lens 106 in this way, since at least one of the excitation light and the fluorescence light parallelized by the condenser lens 105 can be effectively incident on the rod integrator 104, the light utilization efficiency is improved.

[0087] In Figure 4 the shown light source device 100, from the viewpoint of homogenizing and averaging at least one of the excitation light and the fluorescence light incident on the rod integrator 104, it is preferable to select the arrangement position of the rod integrator 104. More specifically, when the inner peripheral cross-section of the rod integrator 104 has a rectangular shape, the long side of the elliptical cross-section of the excitation light incident on the rod integrator 104 can be arranged corresponding to the long side of the inner peripheral cross-section of the rod integrator 104.

[0088] Furthermore, in Figure 4 the shown light source device 100, from the viewpoint of suppressing the vignetting of the excitation light on the reflecting surface 102a of the dichroic mirror 102, it is preferable to select the arrangement of the light source 101. More specifically, when the light emitting surface of the light source 101 has a rectangular shape, it is preferably arranged in such a way that the width of the excitation light becomes narrower.

[0089] Figure 5A 、 5B and 5C describe a light source device according to another embodiment of the present invention. In Figure 5A 、5B In 5C, components identical to those of the Figure 4 embodiment shown are given the same reference numerals and their description is omitted. Figure 5A The light source device 100 according to the present embodiment will be described. Figure 5B FIG. is an explanatory view of the incident opening 104a of the rod integrator 104 included in the light source device 100, Figure 5C FIG. is an explanatory view of the light source 101 included in the light source device 100. Figure 5B Shown is the incident opening 104a of the rod integrator 104 as viewed from the phosphor unit 103 side. Figure 5C Shown is the light emitting surface of the light source 101 as viewed from the dichroic mirror 102 side.

[0090] In Figure 5A the light source device 100 shown, the center of the projected image on the incident opening 104a of the rod integrator 104 on which at least one of the excitation light and the fluorescence light refracted and condensed by the refractive lens 106 is projected is set as point T. The straight line connecting this point T and the center of the projected image of the excitation light projected on the phosphor unit 103, that is, point R, is set as straight line L2. As Figure 5B shown, the incident opening 104a of the rod integrator 104 is rectangular with a long side LE1 and a short side SE1. Further, as Figure 5C shown, the light emitting surface 101a of the light source 101 is rectangular with a long side LE2 and a short side SE2.

[0091] In the light source device 100, it is preferable that the plane including the straight lines L1 and L2, that is, the plane including the Figure 5A paper surface shown and the short side SE1 of the incident opening 104a of the rod integrator 104 are substantially parallel. That is, it is preferable to arrange the rod integrator 104 in such a manner that Figure 5B the short side SE1 of the rod integrator 104 shown is parallel to the Figure 5A paper surface shown. By arranging the rod integrator 104 in this way, the excitation light etc. can be incident in such a manner as to hit the inner side surface corresponding to the long side LE1 of the incident opening 104a of the rod integrator 104. Therefore, the number of reflections of the excitation light etc. inside the rod integrator 104 can be increased, making the excitation light etc. uniform, and the occurrence of color unevenness in the excitation light etc. can be suppressed.

[0092] In the light source device 100, it is preferable that the plane including the straight lines L1 and L2, that is, the plane including the Figure 5A paper surface shown and the short side SE2 of the light emitting surface 101a of the light source 101 are substantially parallel. That is, it is preferable to arrange the light emitting surface 101a in such a manner that Figure 5C the short side SE2 of the light emitting surface 101a shown is parallel to the Figure 5AThe light source 101 is arranged in a manner parallel to the paper surface shown. By arranging the light source 101 in this way, it is possible to narrow the width of the light beam extending in the extending direction of the plane including the straight line L1 and the straight line L2, suppress the vignetting on the reflecting surface 102a of the dichroic mirror 102, and suppress the reduction of light utilization efficiency. In addition, it is possible to prevent the light reflected by the phosphor unit 103 from interfering with the dichroic mirror 102, thereby suppressing the reduction of light utilization efficiency.

[0093] In the light source device 100 according to an embodiment of the present invention, the rod integrator 104 is preferably arranged according to the relative positions of the refractive lens 106 and the rod integrator 104. For example, it is preferable that the center of the projected image projected onto the incident opening 104a of the rod integrator 104, the center of the projected image of the fluorescent light projected onto the incident opening 104a of the rod integrator 104, and the optical axis of the refractive lens 106 intersect at one point.

[0094] Fig. 6A and 6B The outline of a light source device 100 according to another embodiment of the present invention is depicted. In Fig. 6A and 6B , the same components as those in the embodiments shown in Figure 5A , 5B and 5C are given the same reference numerals and their descriptions are omitted. Fig. 6A Depicts the optical path of the excitation light in the light source device 100, Figure 6B Depicts the optical path of the fluorescent light in the light source device 100. For ease of explanation, Fig. 6A and 6B Also depicts a pair of condenser lenses 1051 and 1052 arranged along the light propagation direction.

[0095] In Fig. 6A and 6B In the light source device 100 shown, for at least one of the excitation light and the fluorescent light condensed by the refractive lens 106, the center of the projected image projected onto the incident opening 104a of the rod integrator 104 is the above-mentioned point T. Moreover, the refractive lens 106 is arranged such that the optical axis LA of the refractive lens 106 passes through this point T. Therefore, the center of the projected image of the excitation light and the fluorescent light projected onto the incident opening 104a of the rod integrator 104 intersects with the optical axis LA of the refractive lens 106 at one point. Such an arrangement allows the excitation light and the fluorescent light to enter the center of the incident opening 104a of the rod integrator 104, thereby suppressing vignetting on the incident opening 104a of the rod integrator 104 and improving the light utilization efficiency. In addition, it is also possible to suppress the reduction of light utilization efficiency caused by the misalignment of the optical elements in the light source device 100 due to part tolerances.

[0096] In the light source device 100 according to the present embodiment, the arrangement of the refractive lens 106 is preferably selected from the viewpoint of setting the angles of the excitation light and the fluorescence incident on the incident opening 104a of the rod integrator 104 within a certain range. Note that the angle of the light with respect to the incident opening 104a refers to the angle between the light and the normal to the plane parallel to the incident opening 104a. For example, in the light source device 100, it is preferable that the maximum incident angle of the excitation light with respect to the incident opening 104a is smaller than the maximum incident angle of the fluorescence with respect to the incident opening 104a.

[0097] As Fig. 6A shown, the angle θ1 is the maximum incident angle of the excitation light with respect to the incident opening 104a. As Figure 6B shown, the angle θ2 is the maximum incident angle of the fluorescence with respect to the incident opening 104a. In the light source device 100, it is preferable that the angle θ1 is set smaller than the angle θ2. Setting the incident angle θ1 of the excitation light smaller than the incident angle θ2 of the fluorescence light can suppress the occurrence of vignetting in the optical system downstream of the light source device 100, thereby improving the light utilization efficiency.

[0098] In the light source device 100 according to an embodiment of the present invention, the incident angle θ1 of the excitation light and the incident angle θ2 of the fluorescence light can be set to be equal to each other. By setting the incident angle θ1 of the excitation light to be equal to the incident angle θ2 of the fluorescence light, the distribution of the excitation light projected onto the DMD or the screen can be made substantially the same as the distribution of the fluorescence light projected onto the DMD or the screen. Therefore, color non-uniformity of the excitation light and the like can be suppressed.

[0099] In the light source device 100 of the present embodiment, it is preferable to select the optical characteristics of the rod integrator 104 according to the relationship between the incident angle θ1 of the excitation light and the incident angle θ2 of the fluorescence light. For example, it is preferable that the rod integrator 104 of the light source device 100 is composed of a glass rod integrator, and the total reflection condition is set to be greater than the incident angle θ1 of the excitation light and the incident angle θ2 of the second color light.

[0100] The optical characteristics of the rod integrator 104 included in the light source device 100 of the present invention are described with reference to Figure 7 In Figure 7 , the rod integrator 104 is a glass rod integrator. The total reflection condition of the rod integrator 104 is set as the angle θglass. In this case, the angle θglass is set to be greater than the incident angle θ1 of the excitation light and the incident angle θ2 of the fluorescence. Thereby, since the loss of the excitation light and the like inside the rod integrator 104 can be prevented, the light utilization efficiency can be improved.

[0101] In the light source device 100 of the present embodiment, the rod integrator 104 constituting the light mixing element is as Figure 8As shown, it is preferable that the light incident opening 104a is smaller than the light emitting opening 104b in a conical shape. By forming the rod integrator 104 in such a conical shape, since the emission angle of the light emitted from the rod integrator 104 can be reduced, vignetting in the optical system disposed at the subsequent stage of the light source device 100 can be suppressed, and the light utilization efficiency can be improved.

[0102] Hereinafter, a light source optical system, a light source device, and an image projection device according to some embodiments of the present invention will be described. The light source optical system, the light source device, and the image projection device according to some embodiments of the present invention are examples of the embodiments of the present invention and can be appropriately changed. In addition, the respective embodiments can be appropriately combined.

[0103] First Embodiment

[0104] Fig. 9 is a schematic configuration diagram of a projector (also referred to as an "image projection device") 1 provided with a light source device 20 according to the first embodiment of the present invention. As Fig. 9 shown, the projector 1 includes a housing 10, a light source device 20, an illumination optical system 30, an image forming element (also referred to as an "image display element") 40, a projection optical system 50, and a cooling device 60.

[0105] The housing 10 houses the light source device 20, the illumination optical system 30, the image forming element 40, the projection optical system 50, and the cooling device 60. The light source device 20 emits, for example, light including wavelengths corresponding to the respective colors of RGB. The internal structure of the light source device 20 will be described in detail later.

[0106] The illumination optical system 30 substantially uniformly illuminates the image forming element 40 with the light homogenized by the light tunnel 29 of the light source device 20 described later. The illumination optical system 30 has, for example, one or more lenses and one or more reflecting surfaces.

[0107] The image forming element 40 forms an image by modulating the light illuminated by the illumination optical system 30, that is, the light from the light source optical system of the light source device 20. The image forming element 40 is constituted by, for example, a digital micromirror device (DMD) or a liquid crystal display element. The image forming element 40 drives the micromirrors synchronously with the blue light, green light, red light, and yellow light irradiated by the illumination optical system 30 to generate a color image.

[0108] The projection optical system 50 magnifies and projects the color image formed by the image forming element 40 onto a screen (not shown), that is, a projection surface. The projection optical system 50 includes, for example, one or more lenses. The cooling device 60 cools the respective elements and devices with heat inside the projector 1.

[0109] Fig. 10A and Fig. 10B depicts a light source device 20 according to the first embodiment. Fig. 10A depicts the optical path of the blue laser in the light source device 20, Fig. 10B depicts the optical path of the fluorescent light in the light source device 20.

[0110] As Fig.11 shown in FIG. 10A, the light source device 20 includes a laser light source (excitation light source) 21, a coupling lens 22, a first optical system 23, and a dichroic mirror 24 as an example of an optical component, which are sequentially arranged in the light propagation direction. The light source device 20 further includes a second optical system 25, a phosphor unit 26 as an example of a wavelength conversion unit, a refractive optical system 27, a color ring 28, and an optical tunnel 29 as an example of a light mixing element.

[0111] In FIG. 10, for ease of explanation, the color ring 28 is omitted. Regarding the color ring 28, refer to Fig. 9 , the color ring 28 is arranged between the refractive optical system 27 and the optical tunnel 29. As Fig. 9 shown, in this embodiment, the color ring 28 is described as a component of the light source device 20. However, the configuration of the light source device 20 is not limited thereto, and it may also be a configuration that does not include the color ring 28.

[0112] As Fig. 10A and 10B shown, the laser light source 21, for example, arranges a plurality of light sources that emit laser light in an array. The laser light source 21, for example, emits light in a blue frequency band (blue laser) with a center of the emission intensity at 455 nm. Hereinafter, the blue laser is simply referred to as blue light. The blue light emitted from the laser light source 21 is linearly polarized light with a polarization direction in a certain direction, and is also used as excitation light for exciting the phosphor included in the phosphor unit 26 described later.

[0113] The light emitted from the laser light source 21 only needs to be light with a wavelength capable of exciting the phosphor described later, and is not limited to light in the blue wavelength band. In addition, in the first embodiment, the laser light source 21 includes a plurality of light sources, but is not limited thereto, and may also be composed of one light source. In addition, the laser light source 21 may be configured to arrange a plurality of light sources in an array on a substrate, but is not limited thereto, and may also be other configurations.

[0114] The coupling lens 22 is a lens that enters the blue light emitted from the laser light source 21 and converts it into parallel light, that is, collimated light. The "parallel light" mentioned below is not limited to the light that is completely parallelized, but includes the concept of light that is approximately parallelized. The number of coupling lenses 22 only needs to correspond to the number of light sources of the laser light source 21, and can be increased or decreased according to the increase or decrease in the number of light sources of the laser light source 21.

[0115] In the light source device 20 of the present embodiment, a light source unit is constituted by these laser light sources 21 and coupling lenses 22. For example, the laser light source 21 is constituted by a plurality of laser diodes arranged in rows and columns. That is, the light source unit is constituted by these laser diodes and the coupling lens 22 arranged on the light emitting surface side of the laser diodes.

[0116] Fig.11 FIG. showing the main part of the light source unit of the light source device 20 in the first embodiment. As Fig.11 shown, in the light source unit, the coupling lens 22 is arranged facing the laser diode 21A. In the light source unit, among the divergence angles of the blue light emitted from each laser diode 21A, the divergence angle in the larger direction in the row direction or the column direction is set as θ. The pitch between adjacent laser diodes 21A is set as P, and the distance from the light emitting point of the laser diode 21A to the coupling lens 22 is set as L. The arrangement interval (P / Ltanθ) of each laser diode 21A is set to satisfy the following (Equation 1).

[0117] 1 ≤ P / Ltanθ ≤ 4 (Equation 1)

[0118] More preferably, the arrangement interval of each laser diode 21A is set to satisfy the following (Equation 2).

[0119] P / Ltanθ = 2 (Equation 2)

[0120] By satisfying (Equation 2), since it is possible to reduce the light emitting surface of the laser light source 21 while allowing the light of each laser diode 21A to be incident only on the corresponding coupling lens 22, it is possible to prevent the light from being incident on the adjacent coupling lens 22 and suppress the reduction of the light utilization efficiency.

[0121] The plurality of laser diodes 21A included in the light source unit are preferably arranged on the same substrate. By arranging the plurality of laser diodes 21A on the same substrate, since it is possible to reduce the area of the light emitted from the light source unit, it is possible to suppress the light halo in various optical elements on the optical path and improve the light utilization efficiency.

[0122] In Fig. 9 the first optical system 23 has a positive power as a whole and is arranged with a large-aperture lens 23a and a negative lens 23b in order from the laser light source 21 side toward the phosphor unit 26 side. The large-aperture lens 23a constitutes a large-aperture element, which is a lens having a positive power and condensing and synthesizing the parallel light emitted from the coupling lens 22. The first optical system 23 constituted by the large-aperture lens 23a and the negative lens 23b converges the light beam of the blue light incident as substantially parallel light from the coupling lens 22 while guiding it to the dichroic mirror 24.

[0123] The dichroic mirror 24 is disposed obliquely with respect to the propagation direction of the blue light emitted from the first optical system 23. More specifically, along the propagation direction of the blue light emitted from the first optical system 23, the front end side is disposed in a state of being inclined downward. The optical characteristic of the dichroic mirror 24 is that, in addition to reflecting the blue light that has become substantially parallel light through the first optical system 23, it also transmits the fluorescent light converted by the phosphor unit 26, that is, the second color light. For example, a coating is applied to the dichroic mirror 24 so that it has the above optical characteristics.

[0124] Fig.12 Shown is an example of the configuration of the dichroic mirror 24 included in the light source device 20 of the first embodiment. In Fig.12 this, the dichroic mirror 24 is represented by the incident direction of the blue light emitted from the first optical system 23 side. As Fig.12 shown, the dichroic mirror 24 is divided into two regions 24A and 24B. Hereinafter, for the sake of convenience of explanation, the regions 24A and 24B are referred to as the first region 24A and the second region 24B, respectively.

[0125] The optical characteristic of the first region 24A is that, in addition to reflecting the blue light emitted from the negative lens 23b of the first optical system 23, it also transmits the fluorescent light converted from the blue light by the phosphor of the phosphor unit 26 described later. The first region 24A constitutes the reflecting surface 102a shown in FIG. 1. The optical characteristic of the second region 24B is that it transmits these blue light and fluorescent light.

[0126] The first region 24A is disposed on the optical axis of the first optical system 23, but is not disposed on the optical axis of the second optical system 25, and is disposed in a posture close to the first optical system 23 side. On the other hand, the second region 24B is not disposed on the optical path of the second optical system 25, and is disposed in a posture farther from the first optical system 23 than the optical path of the second optical system 25.

[0127] The second optical system 25 has a positive optical power as a whole, and sequentially includes a positive lens 25A and a positive lens 25B from the laser light source 21 side toward the phosphor unit 26 side. The second optical system 25 condenses the blue light reflected by the dichroic mirror 24 and guides it to the phosphor unit 26. In addition, the second optical system 25 parallelizes the fluorescent light emitted from the phosphor unit 26. In addition, the second optical system 25 constitutes an example of a condensing element.

[0128] The blue light guided from the second optical system 25 is incident on the phosphor unit 26. The phosphor unit 26 is a unit that switches between the following functions: a function of reflecting the blue light emitted from the second optical system 25, and a function of using the blue light as excitation light and converting it into fluorescent light in a wavelength region different from that of the blue light through a phosphor. The fluorescent light converted by the phosphor unit 26 is, for example, light in a yellow wavelength region with a center of luminous intensity at 550 nm.

[0129] Fig.13A And 13B Describe the phosphor unit 26 included in the light source device 20 according to the first embodiment. In Fig.13A , the phosphor unit 26 is shown from the incident direction of the blue light, and in Fig. 13B , the phosphor unit 26 is shown from a direction orthogonal to the incident direction of the blue light. The configuration of the phosphor unit 26 shown in FIG. 13 is an example and is not limited thereto, and can be appropriately changed.

[0130] As Fig.13A And 13B shown, the phosphor unit 26 includes a disk member 26A as a substrate, and a drive motor 26C as a drive unit that rotates and drives about a rotation axis 26B passing through the center of the disk member 26A and perpendicular to the plane of the disk member 26A. The disk member 26A can be, for example, a transparent substrate or a metal substrate such as aluminum, but is not limited thereto.

[0131] In the first embodiment, most of the circumferential direction of the disk member 26A of the phosphor unit 26 is divided into a fluorescent region 26D in an angular range greater than 270°. A small part of the circumferential direction is divided into an excitation light reflection region 26E in an angular range less than 90° in the first embodiment. The excitation light reflection region 26E constitutes an example of a first region that reflects or diffusely reflects the excitation light reflected by the dichroic mirror 24. The fluorescent region 26D constitutes an example of a region that converts the excitation light reflected by the dichroic mirror 24 and emits fluorescent light. The configuration of the fluorescent region 26D is such that a reflection coating 26D1, a phosphor layer 26D2, and an antireflection coating (AR coating) 26D3 are sequentially stacked from the lower layer side to the upper layer side.

[0132] The reflection coating 26D1 has the property of reflecting light in the wavelength region of the fluorescent light of the phosphor layer 26D2. When the disk member 26A is made of a metal substrate with a high reflectivity, the reflection coating 26D1 can be omitted. In other words, the disk member 26A can also have the function of the reflection coating 26D1.

[0133] As the phosphor layer 26D2, for example, a phosphor material can be dispersed in an organic / inorganic binder, a crystal of the phosphor material can be directly formed, or a rare-earth phosphor such as a Ce:YAG system can be used. The phosphor layer 26D2 constitutes an example of a wavelength conversion component that converts at least a part of the excitation light into fluorescence light having a wavelength different from that of the excitation light and emits it. The wavelength band of the fluorescence light of the phosphor layer 26D2 can be, for example, a yellow, blue, green, or red wavelength band. In the first embodiment, the case of using fluorescence light having a yellow wavelength band is taken as an example for explanation. In addition, in the present embodiment, a phosphor is used as the wavelength conversion element, but a phosphorescent substance, a nonlinear optical crystal, etc. can also be used.

[0134] The antireflection coating 26D3 has the property of preventing light from being reflected on the surface of the phosphor layer 26D2.

[0135] A reflection coating 26E1 is laminated on the excitation light reflection region 26E, and the reflection coating 26E1 has the property of reflecting light in the wavelength region of the blue light guided from the second optical system 25. Therefore, the excitation light reflection region 26E is a reflecting surface. When the disk member 26A is made of a metal substrate having a high reflectivity, the reflection coating 26E1 can be omitted. That is, the disk member 26A itself can also have the function of the reflection coating 26E1.

[0136] If the disk member 26A is rotated by the drive motor 26C while irradiating the phosphor unit 26 with blue light (referred to as "first color light"), the irradiation position of the blue light with respect to the phosphor unit 26 moves with time. As a result, a part of the blue light incident on the phosphor unit 26 is converted into fluorescence light (referred to as "second color light") having a wavelength different from that of the blue light in the fluorescence region 26D, which is a wavelength conversion region, and is emitted. On the other hand, the other part of the blue light incident on the phosphor unit 26 is directly reflected as blue light in the excitation light reflection region 26E and is emitted. Here, the "part of the blue light" and the "other part of the blue light" mean a part and the other part distinguished on the time axis.

[0137] The number, range, etc. of the fluorescence region 26D and the excitation light reflection region 26E have degrees of freedom, and various design changes can be made. For example, two fluorescence regions and two excitation light reflection regions can be alternately arranged at intervals of 90° in the circumferential direction.

[0138] Back to Fig. 10A and 10B, the structure of the light source device 20 will be further described. The refractive optical system 27 is composed of lenses that condense the blue light and fluorescent light emitted from the second optical system 25. The blue light and fluorescent light emitted from the phosphor unit 26 pass through the dichroic mirror 24 and are refracted and condensed by the refractive optical system 27, and then enter the color wheel 28 (see Fig. 9 ). The color wheel 28 is a component that separates the blue light and fluorescent light generated by the phosphor unit 26 into desired colors.

[0139] Fig.14A And 14B are explanatory diagrams of the schematic configuration of the color wheel 28 included in the light source device 20 according to the first embodiment. Fig.14A shows the color wheel 28 from the incident direction of the blue light and fluorescent light, Fig. 14B and Fig.14A shows the color wheel 28 from a direction orthogonal to the incident direction of the blue light and fluorescent light. As shown in 14B , the color wheel 28 has an annular member 28A and a drive motor 28C that rotates and drives the annular member 28A around the rotation axis 28B as a drive unit.

[0140] The annular member 28A has a plurality of regions defined in the circumferential direction, that is, a diffusion region 28D, and three filter regions 28R, 28G, and 28Y. The diffusion region 28D is a region for transmitting and diffusing the blue light emitted from the phosphor unit 26. The filter region 28R is a region that allows light in the wavelength region containing the red component among the fluorescent light emitted from the phosphor unit 26 to pass through. Similarly, the filter regions 28G and 28Y are regions that allow light in the wavelength regions containing the green component and the yellow component among the fluorescent light emitted from the phosphor unit 26 to pass through, respectively.

[0141] In the above description, the color wheel 28 has regions that allow the light of the red component, green component, and yellow component in the fluorescent light to pass through, respectively. However, the structure of the color wheel 28 is not limited thereto. For example, it may also have regions that allow the light of the red component and green component in the fluorescence to pass through, respectively.

[0142] The area ratio of each region in the color wheel 28 is based on the design specifications of the projector 1. However, for example, since the diffusion region 28D in the color wheel 28 transmits the blue light emitted from the phosphor unit 26, it is only necessary to make the ratio of the area of the excitation light reflection region 26E to the entire area of the disk member 26A of the phosphor unit 26 the same as the ratio of the area of the diffusion region 28D to the entire area of the color wheel 28.

[0143] The drive motor 28C drives the rotation of the ring-shaped member 28A in the circumferential direction. If the ring-shaped member 28A rotates in the circumferential direction, the blue light emitted from the phosphor unit 26 is sequentially incident on the diffusion region 28D, the filtering regions 28R, 28G, and 28Y. The blue light and the fluorescent light emitted from the phosphor unit 26 penetrate the color ring 28, and blue light, green light, red light, and yellow light are sequentially emitted. The light passing through each region of the color ring 28 is incident on the light tunnel 29.

[0144] The light tunnel 29 is an optical element formed in such a manner that the inner side of a quadrangular prism is formed by four reflectors, and is a light homogenizing element that homogenizes the distribution of light by reflecting the light incident from one end of the quadrangular prism multiple times by the internal reflectors. The light tunnel 29 is arranged such that the blue light and the fluorescent light condensed by the refractive optical system 27 are incident. In the first embodiment, the light tunnel 29 is used as an example of the light mixing element, but it is not limited thereto, and a rod integrator, a fly-eye lens, etc. described above may also be used.

[0145] Fig.15A and 15B Examples of the incident opening 29A of the light tunnel 29 included in the light source device 20 of the first embodiment as seen from the light incident direction are shown. Fig.15A and 15B The projection range of the blue light on the incident opening 29A of the light tunnel 29 is shown. As Fig.15A and 15B shown, the light tunnel 29 is arranged slightly inclined. The inclination angle of the light tunnel 29 varies according to the performance required for the light source device 20.

[0146] As described above, the light source unit of the light source device 20 according to the first embodiment includes the laser light source 21 in which the laser diodes 21A are arranged in an array. As Fig.15A and 15B shown, the projection cross section of the blue light etc. emitted from the laser diode 21A and projected on the incident opening 29A of the light tunnel 29 has an elliptical shape. In the example as Fig.15A shown, the major axis of the elliptical projection cross section of the blue light etc. projected onto the incident opening 29A is substantially parallel to the short side of the incident opening 29A. Thus, by setting the projection range of the blue light etc. on the incident opening 29A, vignetting of the blue light etc. caused by the light tunnel 29 can be suppressed.

[0147] As Fig. 15BAs shown, the projection range of blue light or the like incident on the opening 29A may also be configured such that the major axis of the elliptical projection cross-section is substantially parallel to the long side of the opening 29A into which the light is incident. The elliptical shape referred to here means a shape in which there is a difference between the full width at half maximum (FWHM) of the intensity distribution in the longitudinal direction of the projection range and the full width at half maximum (FWHM) of the intensity distribution in the transverse direction. That is, it is a shape that does not have an isotropic intensity distribution.

[0148] The optical path of the blue light in the light source device 20 having such a configuration (hereinafter, appropriately referred to as the "blue light optical path") will be described. The blue light optical path refers to Fig. 10A Among the excitation light emitted from the laser light source 21 shown, the optical path traveled by the light reflected by the excitation light reflection region 26E of the phosphor unit 26 (see Fig.13A ).

[0149] The blue light emitted from the laser light source 21 is converted into parallel light by the coupling lens 22. The blue light emitted from the coupling lens 22 is condensed and synthesized by the large-diameter lens 23a of the first optical system 23, and then enters the dichroic mirror 24 as condensed light through the negative lens 23b. The dichroic mirror 24 reflects the incident light in the first region 24A, and the reflected light is directed toward the second optical system 25. The first region 24A constitutes a reflection surface 102a that reflects the blue light emitted from the laser light source 21 (see Figure 1A and Figure 1B ). The point P at the center of the projection image of the above excitation light is formed in the first region 24A.

[0150] As described above, the first region 24A of the dichroic mirror 24 is arranged to deviate to the first optical system 23 side with respect to the optical axis of the second optical system 25. Therefore, the blue light optical path enters the second optical system 25. More specifically, it enters a part of the positive lens 25A on the first optical system 23 side. Then, the blue light travels approaching with an angle with respect to the optical axis of the second optical system 25 and exits from the second optical system 25. More specifically, it exits from the positive lens 25B. The blue light emitted from the second optical system 25 enters the phosphor unit 26.

[0151] When the blue light incident on the phosphor unit 26 enters the excitation light reflection region 26E, the blue light is specularly reflected in the excitation light reflection region 26E. The blue light specularly reflected in the excitation light reflection region 26E enters the second optical system 25. More specifically, it enters a part of the positive lens 25B on the side opposite to the first optical system 23 side. Then, the blue light travels away with an angle with respect to the optical axis of the second optical system 25 and exits from the second optical system 25. More specifically, it exits from the positive lens 25A.

[0152] The blue light emitted from the positive lens 25A of the second optical system 25 penetrates the second region 24B of the dichroic mirror 24. The light beam of the blue light specularly reflected from the phosphor unit 26, or the light beam of the blue light emitted from the second optical system 25 and transmitted through the second region 24B of the dichroic mirror 24 constitutes the light beam Q of the excitation light. As described above, the second region 24B of the dichroic mirror 24 has the optical property of transmitting the excitation light and the fluorescent light. Therefore, even when the light beam of the blue light (light beam Q) intersects the dichroic mirror 24, a reduction in light utilization efficiency can be suppressed.

[0153] The blue light transmitted through the second region 24B of the dichroic mirror 24 enters the refractive optical system 27. The blue light travels approaching with an angle with respect to the optical axis of the refractive optical system 27 and, via Fig. 9 the color ring 28 shown, enters the light tunnel 29. After the blue light is reflected multiple times and homogenized inside the light tunnel 29, it enters the illumination optical system 30 disposed outside the light source device 20.

[0154] Next, with reference to Fig. 10B the optical path of the fluorescent light (hereinafter appropriately referred to as the "fluorescent optical path") in the light source device 20 according to the present embodiment will be described. In Fig. 10B for ease of explanation, a part of the optical path of the fluorescent light is omitted. The fluorescent optical path refers to the optical path traveled by the light wavelength-converted in the fluorescent region 26D of the phosphor unit 26 among the excitation light emitted from the laser light source 21.

[0155] Before the blue light emitted from the laser light source 21 is guided to the phosphor unit 26, the fluorescent optical path is the same as the above-described blue light optical path. Here, the blue light incident on the phosphor unit 26 is assumed to be incident on the fluorescent region 26D. The blue light incident on the fluorescent region 26D becomes the excitation light for the phosphor and is wavelength-converted by the phosphor. For example, while becoming fluorescent light in a wavelength region including yellow, it undergoes Lambertian reflectance by the reflection coating 26D1 and the phosphor layer 26D2.

[0156] The fluorescent light Lambertian-reflected by the fluorescent region 26D is converted into parallel light by the second optical system 25. The fluorescent light emitted from the second optical system 25 passes through the dichroic mirror 24 and enters the refractive optical system 27. The fluorescent light travels approaching with an angle with respect to the optical axis of the refractive optical system 27 and enters the light tunnel 29 via the color ring 28. After the fluorescent light is reflected multiple times and homogenized inside the light tunnel 29, it enters the illumination optical system 30 disposed outside the light source device 20.

[0157] Thus, in the light source device 20 according to the first embodiment, the optical path of the blue light emitted from the laser light source 21 is different before and after reflection by the phosphor unit 26. More specifically, it is described as follows. Determine the point that is the center of the projected image of the blue light projected from the laser light source 21 onto the first region 24A of the dichroic mirror 24. This point of the projected image center is represented by point P in FIG. 1. Form the optical path of the blue light such that this point P and the light beam of the blue light reflected from the phosphor unit 26 (the light beam Q shown in FIG. 1) do not intersect. By configuring in this way, it is possible to prevent the blue light from passing through the same part of the dichroic mirror 24, suppress the breakage of the dichroic mirror 24 caused by the increase in the condensing density, and improve the reliability.

[0158] In addition, there is no need to prepare special optical elements such as a retardation plate or a polarization beam splitter composed of a polarization separation element for separating the optical path of the excitation light emitted from the phosphor unit 26. Therefore, the number of components can be reduced, the manufacturing cost can be lowered, and at the same time, the light source device 20 can be miniaturized. Furthermore, since polarization optical components such as a retardation plate or a polarization separation element are not used, it is possible to suppress the reduction in the light utilization efficiency caused by the reflectance, transmittance, absorption rate, etc. of the optical components.

[0159] In the light source device 20 according to the first embodiment, the blue light emitted from the laser light source 21 is linearly polarized light with a certain polarization direction. In addition, the light source unit having a plurality of laser light sources 21 is configured such that the orientations of the linearly polarized lights are all the same, and the directions of the linearly polarized lights of the light emitted from the light source unit are consistent. The orientation of the linearly polarized light can be determined by the orientation of the light source unit.

[0160] As Fig.15A and 15B shown, when the light source unit is tilted so as to be consistent with the inclination of the light tunnel 29, the orientation of the linearly polarized light changes. In the case where the orientation of the linearly polarized light changes, in the case of operating the polarized light by a polarization separation element or the like, the light utilization efficiency may be reduced when passing through the polarization separation element. In the light source device 20 according to the first embodiment, a configuration for operating the polarized light is not adopted, so it is possible to prevent the reduction in the light utilization efficiency caused by the tilt of the laser light source 21.

[0161] Second Embodiment

[0162] The configuration of the dichroic mirror of the light source device 201 according to the second embodiment is different from that of the light source device 20 according to the first embodiment. Hereinafter, the configuration of the light source device 201 according to the second embodiment shown in Fig.16A and 16B will be described, centering on the differences from the light source device 20 according to the first embodiment. Fig.16A Represents the optical path of the blue light of the light source device 201 Fig. 16B Indicates the optical path of the fluorescent light in the light source device 201. In Fig.16A and 16B , the same components as those in the first embodiment are given the same reference numerals and their descriptions are omitted. In Fig. 16B , for ease of explanation, a part of the optical path of the fluorescent light is omitted.

[0163] Fig.16A and 16B The light source device 201 shown is different from the light source device 20 according to the first embodiment only in that it is composed only of the dichroic mirror 241. The dichroic mirror 241 is arranged obliquely in the same manner as the dichroic mirror 24 in the first embodiment. On the other hand, it has a shorter length than the dichroic mirror 24. Since the size of the dichroic mirror 241 is short, the light source device 20 can be miniaturized. The dichroic mirror 241 has the same optical characteristics as the first region 24A which is a part of the dichroic mirror 24.

[0164] Fig.17 An example showing the configuration of the dichroic mirror 241 included in the light source device 201 according to the second embodiment. Fig.17 Shows the dichroic mirror 241 as seen from the incident direction of the blue light (excitation light) emitted from the first optical system 23 side. The dichroic mirror 241 is composed of only a single region 241A.

[0165] The region 241A, like the first region 24A in the second embodiment, has the optical characteristics of reflecting the blue light emitted from the first optical system 23 and allowing the fluorescent light converted from the blue light by the phosphor in the phosphor unit 26 to pass through. The region 241A is arranged at the same position as the first region 24A. That is, the region 241A is arranged on the optical path of the first optical system 23. However, the region 241A is arranged at a position biased toward the first optical system 23 side compared with the optical axis of the second optical system 25.

[0166] Refer to Fig.16A and Fig. 16B to describe the blue light optical path and the fluorescent optical path in the light source device 201 having such a configuration. As Fig.16A shown, the blue light emitted from the laser light source 21 is reflected by the excitation light reflection region 26E of the phosphor unit 26 and emitted to the second optical system 25. Before that, it is the same as the blue light optical path in the first embodiment. In the light source device 201 according to the second embodiment, the blue light emitted from the second optical system 25 does not pass through the dichroic mirror 241. The light beam of the blue light emitted from the phosphor unit 26 (corresponding to the light beam Q shown in Figure 1A ) does not intersect the dichroic mirror 24. On the other hand, as Fig. 16B shown, the fluorescent optical path is the same as or similar to the fluorescent optical path in the first embodiment even if it is not the same.

[0167] In the light source device 201 according to the second embodiment, the optical path of the blue light emitted from the laser light source 21 is different before and after reflection by the phosphor unit 26. Therefore, similarly to the light source device 20 according to the first embodiment, miniaturization and cost reduction can be achieved while excellent reliability is ensured.

[0168] In particular, in the light source device 201, the width of the dichroic mirror 241 can be made smaller than the width of the second optical system 25, so that the size of the light source device 201 can be reduced. Further, since the optical path of the blue light reflected by the phosphor unit 26 does not pass through the dichroic mirror 241, a decrease in light utilization efficiency due to the transmittance of the dichroic mirror 241 can be suppressed.

[0169] Third Embodiment

[0170] Hereinafter, a description will be given of a light source device 202 according to a third embodiment shown in Fig.18A and 18B The light source device 202 is different from the light source device 201 according to the second embodiment in that it includes a first light source unit and a second light source unit, and has a polarization optical component that combines the excitation light from the second light source unit with the excitation light from the first light source unit. The first light source unit includes a laser light source 21 and a coupling lens 22. The second light source unit includes a laser light source 211 and a coupling lens 221.

[0171] Fig.18A represents the optical path of the blue laser in the light source device 202 according to the third embodiment, Fig.18B represents the optical path of the fluorescence in the light source device 202 according to the third embodiment. In Fig.18A and Fig.18B components that are the same as those in the second embodiment described above are given the same reference numerals and their descriptions are omitted. In Fig.18B for ease of explanation, a part of the optical path of the fluorescence light is omitted.

[0172] As shown in Fig.18A and 18B the light source device 202 is provided with a laser light source 211 and a coupling lens 221 that constitute the second light source unit. The second light source unit is arranged such that the laser emitted from the laser light source 211 is orthogonal to the laser emitted from the laser light source 21 of the first light source unit.

[0173] The laser light source 211 has the same configuration as the laser light source 21. That is, the laser light source 211 arranges laser diodes in an array, and serves as a plurality of light sources that emit laser light. For example, it emits blue light with the center of the emission intensity at 455 nm. Both the laser light sources 21 and 211 are configured to emit P-polarized light. Similar to the above-mentioned coupling lens 22, the coupling lens 221 is a lens that makes the blue light emitted from the laser light source 211 incident and converts it into parallel light, i.e., collimated light.

[0174] The light source device 202 includes a 1 / 2 wavelength plate 222 and a polarization beam splitter 223 that constitute polarization optical components. The 1 / 2 wavelength plate 222 is arranged facing a plurality of coupling lenses 221. The 1 / 2 wavelength plate 222 converts the P-polarized light component of the blue light emitted from the laser light source 211 into an S-polarized light component. The polarization beam splitter 223 is arranged on the optical paths of the blue light emitted from the laser light source 21 and the blue light emitted from the laser light source 211. The polarization beam splitter 223 has an optical characteristic of reflecting the S-polarized light component of the blue light while transmitting the P-polarized light component of the blue light.

[0175] The P-polarized light component of the blue light emitted from the laser light source 21 passes through the polarization beam splitter 223 and enters the large-aperture lens 23a of the first optical system 23. On the other hand, the P-polarized light component of the blue light emitted from the laser light source 211 is converted into S-polarized light by the 1 / 2 wavelength plate 222, reflected by the polarization beam splitter 223, and enters the large-aperture lens 23a of the first optical system 23. In this way, the blue excitation light from the second light source unit is synthesized with the blue excitation light from the first light source unit.

[0176] Refer to Fig.18A and Fig.18B The blue light optical path and the fluorescence optical path of the light source device 202 having such a configuration will be described. As Fig.18A and Fig.18B shown, the blue light optical path and the fluorescence optical path after being synthesized by the polarization beam splitter 223 and entering the large-aperture lens 23a of the first optical system 23 are similar even if they are different from those of the second embodiment.

[0177] In the light source device 202 according to the third embodiment, the optical path of the blue light emitted from the laser light source 21 is different before and after reflection by the phosphor unit 26. Therefore, similar to the light source device 201 according to the second embodiment, miniaturization and cost reduction can be achieved while excellent reliability is maintained. In particular, in the light source device 202, the excitation light from the second light source unit is synthesized into the excitation light from the first light source unit, so that the brightness of the excitation light can be increased and the light utilization efficiency can be improved. In addition, the polarized light is operated by the half-wave plate 222 and the polarization beam splitter 223 constituting the polarized light optical component, so that the separation and synthesis of the optical path can be achieved regardless of whether the light emitted from the light source contains a polarized light component.

[0178] Fourth Embodiment

[0179] Hereinafter, the light source device 203 according to the fourth embodiment shown in FIG. 19 will be described. The light source device 203 is different from the light source device 201 according to the second embodiment in that a phosphor unit 261 different from the above-described phosphor unit 26 is provided. Hereinafter, the configuration of the light source device 203 according to the fourth embodiment will be described centering on the differences from the light source device 201 according to the second embodiment.

[0180] Fig.19A Indicates the optical path of the blue laser in the light source device 203. Fig.19B Indicates the optical path of the fluorescence in the light source device 203. In Fig.19A and Fig.19B The same reference numerals are given to the components having the same configuration as those in the second embodiment described above, and the description thereof is omitted. In Fig.19B For ease of explanation, a part of the optical path of the fluorescence light is omitted.

[0181] The light source device 203 according to the fourth embodiment is provided with a phosphor unit (hereinafter, appropriately referred to as a "fixed phosphor unit") 261 that does not rotate, instead of the above-described phosphor unit 26 that rotates. The stationary phosphor unit 261 reflects a part of the blue light (excitation light) emitted from the laser light source 21 as it is, and converts the other part of the blue light into fluorescence light and emits it.

[0182] Fig. 20 Indicates the configuration of the stationary phosphor unit 261 included in the light source device 203 according to the fourth embodiment. Fig. 20 The stationary phosphor unit 261 is shown from a direction orthogonal to the incident direction of the blue light. As Fig. 20As shown, the stationary phosphor unit 261 is configured such that a phosphor 261b, which is a wavelength conversion member, is laminated on a reflection member 261a that reflects excitation light. For example, the reflection member 261a and the phosphor 261b have a rectangular shape in a plan view. The phosphor 261b is coated on the reflection member 261a.

[0183] The phosphor 261b converts, for example, 80% of the incident blue light (excitation light) into fluorescent light. When blue light is incident on the stationary phosphor unit 261, 80% of the blue light acts as excitation light for the phosphor 261b, and wavelength conversion is performed by the phosphor 261b. As a result, for example, fluorescent light in a wavelength region of yellow with the center of the emission intensity at 550 nm is obtained, and Lambert reflection occurs due to the action of the phosphor 261b and the reflection member 261a.

[0184] For example, 20% of the blue light (excitation light) incident on the stationary phosphor unit 261 does not act as excitation light and is reflected by the reflection member 261a. Therefore, when blue light is incident on the stationary phosphor unit 261, blue light and fluorescent light are emitted simultaneously.

[0185] Refer to Fig.19A and Fig.19B to describe the blue light optical path and the fluorescent optical path in the light source device 203 having such a configuration. As Fig.19A and Fig.19B shown, the blue light optical path and the fluorescent optical path in the light source device 203 are the same as those in the second embodiment except for wavelength conversion and reflection in the stationary phosphor unit 261.

[0186] In the light source device 203 according to the fourth embodiment, the optical path of the blue light emitted from the laser light source 21 is different before and after reflection by the stationary phosphor unit 261. Therefore, similar to the light source device 201 according to the second embodiment, high reliability can be achieved while miniaturization and cost reduction can be realized. In particular, in the light source device 203, blue light and fluorescent light are emitted simultaneously by the stationary phosphor unit 261. Therefore, there is no need to drive the phosphor unit to rotate, and the manufacturing cost of the device can be reduced. The motor for rotation driving can be omitted, so that quiet operation can be achieved and a reduction in reliability due to the motor life can be prevented.

[0187] Fifth Embodiment

[0188] Next, the fifth embodiment shown in Fig.21A and 21B will be described. Since the basic configuration is the same as that of the second embodiment, the characteristic configuration parts will be described. Fig.21A and 21B both show the structure of this embodiment. In Fig.21A and 21BIn this case, the vertical direction is set as the X direction, the direction orthogonal to the X direction and along the light emission direction of the light from the light source unit is set as the Y direction, and the direction orthogonal to both the X direction and the Y direction is set as the Z direction. Fig. 21B Indicates the configuration as seen from the direction obtained by Fig.21A rotating 90° around the X axis.

[0189] In Fig.21A and 21B when the straight line connecting the approximate center of the light beam emitted from the light source unit and the above-mentioned point P is set as the straight line L0, the straight line L0 is configured to perpendicularly intersect the plane including the straight line L1 and the light beam Q. This configuration can reduce the Fig.21A dimension in the Z-axis direction in . In addition, the conditions 1 and 2 for the polarization direction of the polarized light described later can be achieved simultaneously, and the light utilization efficiency can be improved.

[0190] Fig.22A Indicates the state when blue light is incident on the dichroic mirror 102 in this embodiment. Fig. 22B Indicates the state when blue light is incident on the phosphor unit 26. As Fig.22A shown, it is preferable that the blue light is incident on the dichroic mirror 102 as S-polarized light. This is set as the "polarized light condition 1". As Fig. 22B shown, it is preferable that the blue light is incident on the phosphor unit 26 as P-polarized light. This is set as the "polarized light condition 2". This is because generally when light is incident on a surface at an angle, the reflectivity of S-polarized light is high. Thus, at the dichroic mirror 102, the S-polarized light is reflected, so that the reflectivity is further increased, and surface reflection is suppressed in the phosphor region. By incidenting as P-polarized light, more blue light is incident on the phosphor.

[0191] The structure of this embodiment rotates the polarization direction of the polarized light by 90° using the dichroic mirror 102 and the fluorescent unit 26. Therefore, the polarized light condition 1 and the polarized light condition 2 are satisfied, and the light utilization efficiency is improved.

[0192] Sixth Embodiment

[0193] FIG. 23 shows a light source device according to the sixth embodiment of the present invention. Fig.23A is a side view of the light source device according to this embodiment, Fig. 23B is the top view of the light source device obtained by Fig.23A rotating the light source device around the Z axis by 90°. Fig.24A and 24B represent the above-mentioned second embodiment for comparison with the sixth embodiment. Fig.24A is a side view of the light source device according to the sixth embodiment of the present invention, Fig. 24B is the top view of the light source device obtained by Fig.24A rotating the light source device around the Z axis by 90°.

[0194] In this embodiment, as Fig.23A and 23B As shown in 23B , the mirror 110 is disposed in front of the dichroic mirror 102 so that the optical path of the illumination light from the light source is bent. Thereby, the size in the Z-axis direction can be reduced. The size in the Y-axis direction is almost the same as that of the second embodiment shown in Fig. 24B . Fig. 24B the same as that of the second embodiment shown in Fig. 24B .

[0195] In this embodiment, the diameter φ of the rotary phosphor unit 26 is 50 to 60 mm. In a small light source device, the phosphor unit 26 becomes a large component. Therefore, the size of the phosphor unit 26 dominates the sizes in the Y-axis and Z-axis directions. Therefore, by using the projection space in the plane direction of the phosphor unit 26 generated by folding the optical path with the mirror 110 and arranging the constituent components in this projection space, the light source device can be miniaturized significantly.

[0196] Fig. 23B shows such a structure. As shown in Fig. 23B , when viewed from the X-axis direction, if all the surface vertices T of the lenses are arranged within the projection plane of the disk-shaped phosphor unit 26, the entire light source device becomes small and close to a cube. Fig. 23B As shown in Fig. 23B , when viewed from the X-axis direction, if all the surface vertices T of the lenses are arranged within the projection plane of the disk-shaped phosphor unit 26, the entire light source device becomes small and close to a cube.

[0197] In addition, the mirror 110 can also be made to have a function of adjusting the degree of condensing of the blue light on the surface of the phosphor unit 26. For example, when the mirror 110 is a diffuse reflection surface, the mirror 110 can diffuse the blue light irradiated onto the phosphor unit 26, make the degree of condensing of the blue light on the phosphor unit 26 uniform, and improve the conversion efficiency of the phosphor unit 26.

[0198] Seventh Embodiment

[0199] Fig.25 shows a light source device according to the seventh embodiment of the present invention. Fig.26 shows a comparative example relative to the seventh embodiment. The light source device 20 according to the seventh embodiment is connected to the radiator 120 through a heat pipe 125 and is cooled by it. In this embodiment, the optical axis of the projection optical system 50 and the emission direction of the excitation light emitted from the light source device 20 are perpendicular to each other.

[0200] In Fig.26 In the comparative example shown in Fig.26 , when the space where the light source device 20 and the radiator 120 can be disposed is connected by the heat pipe 125, the heat pipe 125 needs to be bent, resulting in a reduction in cooling efficiency. Therefore, in order to obtain a predetermined heat dissipation amount, the radiator 120 becomes larger.

[0201] On the other hand, according to this embodiment, since the heat pipe 125 can be connected to the radiator 120 without being greatly bent, the cooling efficiency is not reduced so much, and thus the light source device 20 can be effectively cooled.

[0202] As Fig.25 shown, since the radiator 120 can be arranged in the space adjacent to the projection optical system 50, this space can be effectively utilized, and thus the entire projector can be further miniaturized. In the present embodiment, a heat pipe is used as an example of the cooling device, but for example, a loop heat pipe can also be used, or a heat dissipation component such as a radiator can be directly arranged on the light source.

[0203] In the light source device according to the embodiment of the present invention, since the excitation light is incident on the light mixing element obliquely, sometimes due to the size of the light mixing element, brightness non-uniformity is generated at the light tunnel exit. Since the brightness non-uniformity directly becomes the brightness non-uniformity on the screen, it is preferable to generate the brightness non-uniformity so that the image on the screen can be easily viewed. For example, generally speaking, the brightness non-uniformity appearing in the projected image is preferably in the vertical direction compared with the horizontal direction. And when the lower side closer to the human line of sight is brighter, the projected image is easier to see. Therefore, as Fig. 27 shown, it is preferable to make the excitation light incident on the light mixing element so that the lower direction on the screen becomes brighter.

[0204] Eighth Embodiment

[0205] Refer to Fig.28A , 28B , 28C and 28D to describe the eighth embodiment. The basic structure of the eighth embodiment is the same as that of the first embodiment, so the characteristic part will be described. The light source device according to the embodiment of the present invention can be configured such that the excitation light incident on the rod integrator is incident on the inner side corresponding to the long side. This structure can reduce the brightness non-uniformity at the exit of the rod integrator, which may cause brightness non-uniformity on the screen. By reducing the brightness non-uniformity, an "image with uniform brightness" can be viewed. As described above, generally, it is preferable to "reduce the brightness non-uniformity on the screen".

[0206] However, in some cases, by "utilizing the brightness non-uniformity", the image projected on the screen can be easily viewed. For example, when the image is projected onto a screen above the height of a person's eyes, in other words, when the audience looks up at the screen to view the image, when the "lower side of the screen" closer to the person's eyes is brighter, the image is easier to view. Therefore, in this case, it is preferable to make the excitation light incident on the rod integrator so that the lower side of the screen becomes brighter.

[0207] As Figures 28A to 28D shown, when the excitation light is incident on the "surface of the long side having a length LE1", brightness non-uniformity is generated in the vertical direction of the screen. When the excitation light is incident on the rod integrator from the Fig.28A left side, the upper side of the screen becomes brighter as Fig.28C shown, and when the excitation light is from Fig.28B When incident from the right side onto the rod integrator, the lower side of the screen becomes brighter as shown in Fig.28D . Whether the upper side or the lower side becomes brighter depends on the length Lint of the rod integrator, the structure of the illumination optical system, and "the structure of the projection optical system that projects the light beam emitted from the rod integrator". Therefore, appropriate design is required, but the illumination optical system can be designed according to which of the upper side and the lower side of the screen is brighter.

[0208] Hereinafter, four other embodiments of the present invention are described as the ninth to twelfth embodiments. In the ninth to twelfth embodiments, the three-dimensional configuration of the optical paths of the excitation light and the fluorescence light in the above embodiments. As described above, in Figure 5A , the plane including the straight line L1 and the straight line L2, that is, the plane including the Figure 5A paper surface shown in is substantially parallel to the short side SE1 of the incident opening 104a of the rod integrator 104. However, in some embodiments, the plane including the straight line L1 and the straight line L2 is not necessarily parallel to the short side SE1 of the incident opening 104a of the rod integrator 104. In other words, the rod integrator 104 can make several rotations around the straight line L2.

[0209] Ninth Embodiment

[0210] In the light source device according to the ninth embodiment shown in Fig.29A and 29B , the long side of the incident opening of the rod integrator 104 is parallel to the plane including the straight line L1 and the straight line L2. The feature of this embodiment is that the plane including the optical path of the excitation light incident on the optical component and the optical path of the excitation light reflected by the optical component toward the condenser element (the optical paths before and after the optical component) is not parallel to the plane including the optical path of the excitation light between the condenser element and the wavelength conversion unit (the optical paths before and after the wavelength conversion unit).

[0211] Fig.29A The structure shown in Figure 5A is similar if not the same as the structure shown in Figure 5A . In Figure 5A , the plane including the straight line L1 and the straight line L2 is located within the plane including the Figure 5A paper surface. In other words, in

[0212] , the straight line L2 intersects with the extension of the straight line L1. However, in the ninth embodiment described here, the extension of the straight line L1 does not intersect with the straight line L2. Fig.29AThe reference numerals in the figure. L0 represents the optical path (a straight line) from the approximate center of the light beam emitted from the light source 101 to point P. L1 represents the optical path (a straight line) connecting the center of the projected image on the incident surface 105a of the condenser lens 105 where the excitation light is projected onto the condenser lens 105 to point P on the reflecting surface 102a. L12 represents the optical path (a straight line) of the light ray passing through the approximate center point of the light beam forming the projected image on the incident surface 105a and exiting from the exit surface 105b of the condenser lens 105 and traveling towards the reflection point R. Q represents the light beam of the excitation light emitted from the phosphor unit 103. Q1 represents the optical path of the light beam reflected at the reflection point R and traveling towards the condenser lens 105. Q2 represents the optical path of the light beam refracted by the refractive lens 106 and traveling towards point T where it is incident on the rod integrator 104. The optical paths Q1 and Q2 are the optical paths representing the central light rays of the light beam, and they are also referred to as the light rays Q1 and Q2. Assuming that the central light ray is the representative light ray of the light beam Q, the central light ray of the light beam Q can also be referred to as the light ray Q. In addition, Q, Q1, and Q2 can also be referred to as the light beam Q, the light beam Q1, and the light beam Q2, as the light beams containing the light rays Q, Q1, and Q2. U represents the imaginary intersection point of the light ray L1 and the light ray L2. V represents the imaginary intersection point of the light ray Q1 and the light ray Q2. W represents the imaginary intersection point of the light ray Q and the light ray Q2.

[0213] To clarify the three-dimensional positional relationship, the direction in which light is incident on the reflecting surface 102a is defined as the Z-axis, and the X, Y, and Z coordinate axes of the right-handed system are defined as shown in Fig.29A and 29B shown. Fig.29A is a view of the YZ plane as seen from the negative side of the X-axis, Fig.29B is a view of the state as seen from the side of the rod integrator 104, Fig.29A in other words, a view of the ZX plane as seen from the positive side of the Y-axis.

[0214] As Fig.29A and 29B shown, the light rays emitted from the light source 101 either go directly or are reflected back (in Fig.29AIn the middle, it is directly) guided to the dichroic mirror 102, and the light incident on the dichroic mirror 102 travels along the straight line L0. The straight line L0 itself can be regarded as light. The light emitted from the light source 101 is treated as "a light beam propagating with a constant width or discretely", and the "optical path of the approximate center of the light beam" is defined as the straight line L0. The light source is composed of a single or multiple light-emitting parts arranged in an array facing a certain surface. If it is single, the optical path of its center becomes the straight line L0. If it is multiple, the optical path of the approximate center of the multiple arranged light-emitting parts becomes the straight line L0. It is not limited that the straight line L0 is the center of the light-emitting part or the light-emitting part group, and it is set as the optical path of the approximate center of the light beam. The light traveling along the straight line L0 is reflected at the point P and incident on the condenser lens 105, and travels to the point R due to the refraction of the condenser lens 105. At this time, the point R on the phosphor unit 103 becomes the reflection area, and regular reflection occurs at the point R. The regularly reflected light beam Q1 is directed to the condenser lens 105 again. The light beam Q1 is refracted due to the refraction of the condenser lens 105 and becomes the light beam Q. The light beam Q is refracted due to the condensing action of the refracting lens 106 and becomes the light beam Q2, and travels to the point T.

[0215] Originally, the light passing through the condenser lens 105 is refracted at the lens boundary and travels to the point R (the condensing point in this example). However, in Fig.29A it is shown that the light is refracted at the point U inside the lens. This is to simplify the explanation in order to correctly express the characteristics of this embodiment. In fact, the light is refracted when passing through the lens interface (for example, Figure 3 105a or 105b in ). The same applies to the bending point V where the light beam Q1 reflected at the point R is refracted to become the light beam Q, and the bending point W where the light beam Q is refracted to become the light beam Q2 due to the refraction of the condenser lens 106 is also the same.

[0216] In the light source device 100 of this embodiment, as Fig.29B shown, the plane PL1 containing the straight line L0 and the straight line L1 and the plane PL2 containing the straight line L12 and the light beam (light ray) Q1 "are not in a parallel relationship (not parallel to each other)". Moreover, it is configured that "the straight line (the extension of the straight line L1) along which the light ray traveling straight along the straight line L1 does not intersect the straight line L2 (the perpendicular line to the point R) due to the refraction force of the condenser lens 105". In the light source device 100 of the ninth embodiment, the long side of the incident opening of the rod-shaped integrator 104 is parallel to the plane PL1.

[0217] Tenth Embodiment

[0218] Fig.30 The light source device of the tenth embodiment shown is a modification of the above ninth embodiment. The long side of the incident opening of the rod-shaped integrator 104 is rotated clockwise by a certain amount with respect to the plane PL1, which is different from the ninth embodiment, and is the same as the ninth embodiment in other aspects.

[0219] Eleventh Embodiment

[0220] Fig.31 The light source device of the eleventh embodiment shown is also a modified example of the above-described ninth embodiment. The long side of the incident opening of the rod integrator 104 is rotated counterclockwise by a certain amount with respect to the plane PL1, which is different from the ninth embodiment, and is the same as the ninth embodiment in other aspects.

[0221] In the tenth and eleventh embodiments, as Fig.30 and 31 shown, the long side of the incident opening of the rod integrator 104 is "substantially parallel" to the plane PL1, so that most of the light incident on the rod integrator 104 is incident on the long side of the rod integrator 104. The light source device according to the ninth to eleventh embodiments is further characterized in that the light source unit and the phosphor unit 103 are arranged such that when the rotation center axis of the phosphor unit 103 is determined, the position relationship is such that the rotation center axis does not intersect the light ray L0. Here, the light emitted from the light source 101 is treated as a light beam traveling with a constant width or discretely, and the optical path of the approximate center of the above-described light beam is defined as the straight line L0. Since the light beam has a constant width (thickness), the eccentric end may intersect the rotation center axis. In the present invention, for the light emitted from the light source 101, the optical path (straight line) of the light ray (optical path) along the approximate center of the light beam traveling with a constant width or discretely is set as L0 or L1.

[0222] In Fig.29B , 30 and 31, the state where the rotation center axis and the light ray L0 do not intersect is magnified. With such a configuration, excitation light or the like can be incident on the inner side surface corresponding to the long side of the incident opening 104a of the rod integrator 104. Therefore, as the number of reflections of the excitation light or the like inside the rod integrator 104 increases, the excitation light can be homogenized, and the occurrence of color unevenness of the excitation light or the like can be suppressed. Further, in the tenth and eleventh embodiments, when the straight line connecting the connection point R and the center of the projection image on the incident opening of the rod integrator that projects the first color light is defined as the straight line L2, the plane including the straight line L1 and the straight line L2 is not parallel to the short side direction of the incident opening of the rod integrator. In other words, the rod integrator 104 is rotated around the straight line L2. This structure can further increase the number of reflections on the internal reflection surface, and thus, a great effect of homogenization can be obtained.

[0223] Specifically, in the embodiment shown in Fig.30 , a large number of light rays of the excitation light reaching the rod integrator 104 are likely to irradiate the internal reflection region on the long side of the rod integrator 104. In other words, when the beam width of the excitation light increases, Fig.30 the tenth embodiment on the long side has a ratio compared to Fig.31 The eleventh embodiment has a wider internal reflection area. Therefore, Fig.30 the tenth embodiment is better. On the other hand, if the planes PL1 and PL2 are arranged parallel to each other, light enters from the short side of the rod integrator, making it difficult to achieve uniformity. Therefore, for example, by making the planes PL1 and PL2 non-parallel, preferably greater than 45 degrees and less than 135 degrees, that is, set to a "positional relationship of approximately 90 degrees", when the plane PL1 is aligned with the long side direction of the rod integrator 104, without changing the configuration of the rod integrator 104, the incident direction of the excitation light is deflected to "approximately 90 degrees", and a large amount of light can be directed to the internal reflection area located on the long side of the rod integrator 104. Therefore, it is effective in terms of homogenization. Even if the angle formed by the planes PL1 and PL2 is small, but there is an angle, that is, non-parallel, it can bend the optical path in the formed angle direction, resulting in the effect of miniaturizing the device. To further reduce the device volume, a greater effect can be obtained by appropriately setting the angle formed by the planes PL1 and PL2. As described above, when the angle formed by the planes PL1 and PL2 is set to approximately 90 degrees (at least within the range of greater than 45 degrees and less than 135 degrees), the optical path can be bent more cubically, making the optical system compact.

[0224] In Fig.32 , the light rays emitted from the same light source LT as the light source 101 in Fig.29A travel in the + direction of the X-axis in the depth direction of the paper surface, pass through the lenses LN1 and LN2, are reflected back in the Z direction by the folding mirror BM, and travel towards the reflecting surface 102a of the mirror DM (refer to Figure 1A ). The light rays reflected back by the folding mirror BM are equivalent to the optical path L0 shown in Fig.29A , 29B , 30, and 31, and their functions are basically the same. That is, Figures 29A to 31 the dichroic mirror (reflecting mirror) 102 in Fig.32 , 33 , 34 is equivalent to the mirror DM.

[0225] The light rays reflected back by the mirror BM become the light rays L1 traveling in the Z direction, that is, Fig.32 the direction from right to left in Fig.29BThe left-to-right direction in the figure is reversed. Then, it is reflected back downward by the mirror DM, travels along the optical path L1, is condensed by the condenser lenses LN3 and LN4, passes through the optical path L12, and is condensed at point R on the phosphor unit PW. In the reflection area of the phosphor unit PW, the condensed light source light is reflected to become high-speed Q, is condensed again by the lens LN4 and the lens LN3, passes near the mirror DM without interfering with the mirror DM (because the light passes through the front side of the paper and has different positions in the depth direction of the paper), and travels toward the lens LN5. The light source light (excitation light) condensed by the lens LN5 reaches the rod integrator LT. Here, the rod integrator LT is arranged such that the direction parallel to the YZ plane (the plane of the paper) is along the long side of the incident surface. In practice, there are cases where it rotates somewhat around the perpendicular line of point R, so it is described as along the long side. In addition, it is along the direction perpendicular to the plane of the paper. At this time, the light (excitation light) incident on the rod integrator LT is incident on the rod integrator LT from the depth direction of the paper relative to Fig.32 of the paper. In other words, there is more light incident on the long side direction of the rod integrator LT.

[0226] Fig.33 is such that Fig.32 is a figure obtained by rotating Fig.32 90 degrees around the Y axis. The light reflected back downward by the mirror DM is reflected by the reflection surface of the phosphor unit PW and travels upward. As Fig.33 shown, the respective lights travel without interfering with each other, are condensed by the lens LN5, and pass through the color ring CW and travel toward the rod integrator LT. Here, the rod integrator LT is arranged such that the direction parallel to the XY plane ( Fig.33 the plane of the paper depicted in Fig.33 is along the short side. The light (excitation light) incident on the rod integrator LT becomes light incident on the rod integrator LT from a direction parallel to the plane of the paper in

[0227] Fig.34 is a view of the phosphor unit observed from the side of the rod integrator, corresponding to Fig.31 etc., and only the direction of observing the phosphor unit is 180 degrees different. As Fig.32 , 33 shown, the plane PL1 and the plane PL2 are set to approximately 90 degrees. By approximately 90 degrees is meant an angular range greater than 45 degrees and less than 135 degrees. This structure can separate the optical path of the light L1 from the optical path of the light beam Q including the excitation light emitted from the phosphor unit PW. The light beam Q is easily separated from the mirror DM. Even if the plane PL1 is along the long side of the rod integrator LT, when observed from the incident position of the rod integrator LT, the incident direction of the excitation light is rotated by approximately 90 degrees, so the excitation light can be incident from the short-axis direction of the rod integrator LT.

[0228] The above structure does not require a polarization beam splitter (PBS) or a wavelength plate, which is necessary in the conventional technology. Therefore, the structure is simplified, and the optical path is three-dimensionally bent. Therefore, the direction of the light when it reaches the rod integrator can be freely changed. For example, the excitation light can be incident on the long side LE1 corresponding to the incident opening 104a of the rod integrator 104 (see Figure 5B ) As a result, as the number of reflections of the excitation light etc. inside the rod integrator 104 increases, the excitation light etc. can be made uniform, and the occurrence of color non-uniformity of the excitation light etc. can be suppressed.

[0229] In the above-mentioned embodiments, suitable embodiments of the present invention are shown, but the present invention is not limited to the contents. In particular, the specific shapes and numerical values ​​of each part illustrated in each embodiment are only examples of the embodiment performed when the present invention is implemented, and the technical scope of the present invention is not interpreted as limited by them. Thus, the present invention is not limited to the contents described in the present embodiment, and can be appropriately changed within the scope of the main purpose.

[0230] This patent application is based upon and claims the benefit of priority from Japanese Patent Application No. 2019-200035 filed on November 1, 2019, Japanese Patent Application No. 2019-200042 filed on November 1, 2019, and Japanese Patent Application No. 2019-200043 filed on November 1, 2019, the disclosures of which are incorporated herein by reference in their entirety.

[0231] Reference numerals list

[0232] 1 Projector

[0233] 10 Frame

[0234] 20 Light source device

[0235] 21. Laser light source

[0236] 22 Coupling lens

[0237] 23. First optical system

[0238] 23a Large aperture lens

[0239] 23b Negative lens

[0240] 24 Dichroic Mirror

[0241] Area 24A (First Area)

[0242] Area 24B (Second Area)

[0243] 25 Second optical system

[0244] 25A, 25B positive lens

[0245] 26 phosphor unit

[0246] 27 refractive optical system

[0247] 28 color ring

[0248] 29 light tunnel

[0249] 29A incident opening

[0250] 30 illumination optical system

[0251] 40 image forming element

[0252] 50 projection optical system

[0253] 60 cooling device

[0254] 100 light source device

[0255] 101 light source

[0256] 101a light emitting surface

[0257] 102 dichroic mirror

[0258] 102a reflecting surface

[0259] 103 phosphor unit

[0260] 103a emitting surface

[0261] 103b incident surface

[0262] 104 rod integrator

[0263] 104a incident opening

[0264] 104b emitting opening

[0265] 105 condenser lens

[0266] 105a incident surface

[0267] 105b emitting surface

[0268] 106 refractive lens

[0269] 201, 202, 203 light source device

[0270] 211 laser light source

[0271] 221 coupling lens

[0272] 222 half-wave retarder

[0273] 223 polarization beam splitter

[0274] 241 Dichroic mirror

[0275] 241A Region

[0276] 261 Phosphor unit (fixed phosphor unit)

[0277] 261a Reflective element

[0278] 261b Phosphor

Claims

1. A light source device, comprising: An excitation light source configured to emit first-color light; An optical component having a reflecting surface configured to reflect the first-color light; A wavelength conversion unit including a wavelength conversion component, the first-color light reflected by the optical component being incident on the wavelength conversion component, the wavelength conversion component being configured to convert at least a part of the first-color light into second-color light having a wavelength different from that of the first-color light and emit the second-color light; And A condenser configured to condense the first-color light emitted from the wavelength conversion unit, wherein a straight line (L0) including a first optical path does not intersect a light beam (Q) condensed by the condenser and a perpendicular line to a point on an emission surface of the wavelength conversion unit, where the first optical path is an optical path from the beam center of a light ray emitted from the excitation light source to the center of the first-color light on the reflecting surface; wherein the straight line including the first optical path does not parallel but intersects a plane formed by a second optical path and the light beam, where the second optical path is an optical path from the center of the first-color light on the reflecting surface to the condenser; 2. The light source device according to claim 1, further comprising: A light mixing element configured to perform light mixing on at least one of the first-color light and the second-color light emitted from the wavelength conversion unit; A light guide configured to guide at least one of the first-color light and the second-color light emitted from the wavelength conversion unit; 3. The light source device according to claim 2, Among them, wherein the light mixing element is located on a line perpendicular to a point on the emission surface of the wavelength conversion unit, the point being the center of a projection image of the first-color light projected on the wavelength conversion unit; 4. The light source device according to claim 1, further comprising: Another condenser provided on an optical path between the optical component and the wavelength conversion unit, configured to condense the first-color light reflected by the optical component and make the second-color light emitted from the wavelength conversion unit substantially parallel, Among them, wherein the point on the emission surface of the wavelength conversion unit is different in position from an intersection point, where L1 represents a straight line connecting the center of the first-color light on the reflecting surface of the optical component and the center of a projection image of the first-color light incident on the other condenser after being reflected by the reflecting surface and projected on an incident surface of the other condenser, the intersection point being an intersection point of L1 and an incident surface of the wavelength conversion unit, and the first-color light condensed by the other condenser being incident on the incident surface of the wavelength conversion unit; 5. A light source device, comprising: An excitation light source configured to emit first-color light; An optical component having a reflecting surface configured to reflect the first-color light; A wavelength conversion unit, including a wavelength conversion component, the first color light reflected by the optical component is incident on the wavelength conversion component, and the wavelength conversion component is configured to convert at least a part of the first color light into a second color light having a wavelength different from that of the first color light and emit the second color light; A condenser element, configured to condense the first color light emitted from the wavelength conversion unit, wherein, a straight line (L0) of the first optical path does not intersect with the light beam (Q) condensed by the condenser element and the perpendicular line of the point on the emission surface of the wavelength conversion unit. Here, the first optical path is the optical path from the beam center of the light rays emitted from the excitation light source to the center of the first color light on the reflection surface; A light mixing element, configured to perform light mixing on at least one of the first color light and the second color light emitted from the wavelength conversion unit; A light guide, configured to guide at least one of the first color light and the second color light emitted from the wavelength conversion unit, wherein, the light mixing element is a rod-shaped integrator, wherein, when the first color light is incident on the rod-shaped integrator, the first color light first enters the surface with the long side of the incident opening of the rod-shaped integrator, The light source device further includes a refractive optical element, configured to guide at least one of the first color light and the second color light emitted from the wavelength conversion unit to the incident opening of the rod-shaped integrator, wherein, the center of the projected image of the first color light projected onto the incident opening of the rod-shaped integrator, the center of the projected image of the second color light projected onto the incident opening of the rod-shaped integrator, and the optical axis of the refractive optical element intersect at one point.

6. The light source device according to claim 5, Among them, The first incident angle is smaller than the second incident angle, The first incident angle is the incident angle of the light ray of the first color light that enters the incident opening of the rod-shaped integrator at the maximum angle among the light rays of the first color light, The second incident angle is the incident angle of the light ray of the second color light that enters the incident opening of the rod-shaped integrator at the maximum angle among the light rays of the second color light.

7. The light source device according to claim 6, Among them, The rod-shaped integrator is a glass rod-shaped integrator, wherein, the third incident angle is the incident angle that satisfies the total reflection condition of the rod-shaped integrator, The third incident angle is greater than each of the first incident angle and the second incident angle.

8. The light source device according to claim 5, Among them, The excitation light source includes a plurality of laser diodes configured in an array, wherein, the projection area of the first color light emitted from the plurality of laser diodes onto the incident opening of the rod-shaped integrator is an elliptical shape, wherein, the major axis of the elliptical shape is substantially parallel to the long side or the short side of the incident opening of the rod-shaped integrator.

9. The light source device according to claim 5, Among them, The excitation light source includes a light source unit, The light source unit includes: a plurality of laser diodes arranged in rows and columns; and A plurality of coupling lenses are respectively disposed on the light emitting surface side of the laser diode. Among them, the arrangement interval of the laser diodes satisfies the relationship of 1 ≤ p / Ltanθ ≤ 4. Here, θ is the larger of the divergence angles of the first color light emitted from the laser diode in the row direction and the column direction, p is the pitch between adjacent laser diodes, and L is the distance from the light emitting point of each laser diode to the corresponding one coupling lens.

10. The light source device according to claim 5. Each light ray emitted from two laser diodes located outside the light source composed of a plurality of laser diodes intersects between the second optical system and the refractive optical element.

11. A light source device, comprising: An excitation light source configured to emit a first color light; An optical component having a reflecting surface configured to reflect the first color light; A wavelength conversion unit including a wavelength conversion component, the first color light reflected by the optical component is incident on the wavelength conversion component, and the wavelength conversion component is configured to convert at least a part of the first color light into a second color light having a wavelength different from that of the first color light and emit the second color light; A condensing element configured to condense the first color light emitted from the wavelength conversion unit; Wherein, The straight line (L0) including the first optical path does not intersect the light beam (Q) condensed by the condensing element and the perpendicular line of the point on the emission surface of the wavelength conversion unit. Here, the first optical path is the optical path from the beam center of the light ray emitted from the excitation light source to the center of the first color light on the reflecting surface; A light mixing element configured to perform light mixing on at least one of the first color light and the second color light emitted from the wavelength conversion unit; A light guide configured to guide at least one of the first color light and the second color light emitted from the wavelength conversion unit; Wherein, the light mixing element is located on the line perpendicular to the point on the emission surface of the wavelength conversion unit; The point is the center of the projection image of the first color light projected on the wavelength conversion unit; Wherein, the first plane including the first optical path and the second optical path is not parallel to the second plane including the third optical path and the fourth optical path; Here, the first optical path is the optical path from the approximate center of the light beam of the light ray emitted from the excitation light source to the center of the first color light on the reflecting surface; The second optical path is the optical path from the center of the first color light on the reflecting surface to the condensing element; The third optical path is the optical path from the condensing element to the point on the emission surface of the wavelength conversion unit; The fourth optical path is the optical path from the point on the emission surface of the wavelength conversion unit to the condensing element.

12. The light source device according to claim 11. Among them, The angle formed by the first plane and the second plane is approximately 90 degrees.

13. An image projection device, comprising: The light source device according to claim 5 or 11; An illumination optical system configured to direct the light emitted from the light source device to an image display element; And A projection optical system that projects an image generated by the image display element using light guided by the illumination optical system.

14. The image projection device according to claim 13, Among them, An optical axis common to a plurality of lenses of the projection optical system and an emission direction of the first color light emitted from the excitation light source are not in the same plane.

Images