Light source device and image projection device

Abstract

To provide a light source device, an image projection device, and a light source optical system that can be reduced in size and cost.SOLUTION: In a light source device (100) comprising: a light source (101) that emits first color light; an optical member (102) that has a reflection surface (102a) reflecting the first color light emitted from the light source; and a wavelength conversion unit (103) on which the first color light reflected by the optical member is incident and which emits second color light having a different wavelength from that of the first color light, when the center of a projected image of the first color light projected on the reflection surface of the optical member is a point P, and the beam of the first color light emitted from the wavelength conversion unit is a beam Q, the point P and the beam Q are arranged not to intersect each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a light source device. and This relates to an image projection device. [Background technology]

[0002] Nowadays, projectors (image projection devices) that enlarge and project various images are widely used. A projector focuses light emitted from a light source onto a spatial light modulator such as a digital micromirror device (DMD) or a liquid crystal display element, and displays the emitted light from the spatial light modulator modulated by a video signal on a screen as a color image.

[0003] Traditionally, projectors have mainly used high-brightness ultra-high pressure mercury lamps, but due to their short life span, frequent maintenance was required. For this reason, in recent years, projectors that use laser light sources or LED (Light Emitting Diode) light sources instead of ultra-high pressure mercury lamps have been increasing. This is because laser light sources and LED light sources have a longer life span than ultra-high pressure mercury lamps, and also have good color reproducibility due to their monochromaticity.

[0004] In a projector, an image is formed by irradiating an image display element such as a DMD with three primary colors, red, green, and blue. Although it is possible to generate all three colors with a laser light source, this is not preferable because the emission efficiency of green and red lasers is lower than that of blue lasers. For this reason, a method is used in which a blue laser is irradiated onto a phosphor as excitation light, and red and green lights are generated from the fluorescent light that is wavelength-converted by the phosphor.

[0005] Since excitation light of several tens of watts is focused and irradiated onto the phosphor, it is susceptible to burnout or temperature rise, resulting in a decrease in efficiency and deterioration over time. For this reason, a phosphor layer is formed on a disk and rotated to prevent the excitation light from concentrating on one point. This disk is called a phosphor wheel. In a phosphor wheel, the phosphor is formed in a fan shape or annular shape along the outer periphery of the disk.

[0006] As a light source device using the above-mentioned DMD and phosphor wheel, a device has been proposed in which part of the phosphor wheel is used as a transmission plate in order to simplify the entire device (see, for example, Patent Document 1). In the technology described in Patent Document 1, the excitation light transmitted through the phosphor wheel is reflected multiple times by a mirror and guided in the same direction as the fluorescent light. This results in a configuration in which the excitation light and the fluorescent light are combined on the same optical path and irradiated onto the DMD.

[0007] Furthermore, as a light source device using the above-mentioned DMD and phosphor wheel, a device has been proposed in which part of the phosphor wheel is used as a reflector in order to reduce the size of the entire device (see, for example, Patent Document 2). In the technology described in Patent Document 2, the excitation light is reflected by the phosphor wheel in the same direction as the fluorescent light, and the optical path is separated using a phase difference plate (1 / 4 wavelength plate) and a polarization separation element so that the reflected excitation light does not return to the excitation light source. As a result, the excitation light and the fluorescent light are combined into the same optical path and irradiated onto the DMD. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 4711156 [Patent Document 2] Patent No. 5817109 Summary of the Invention [Problem to be solved by the invention]

[0009] However, in the above-mentioned Patent Document 1, the optical path of the excitation light is detouring, which increases the size of the entire device. On the other hand, in the above-mentioned Patent Document 2, the cost is high because a retardation plate and a polarization separation element are used. 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 pass through the same part of the retardation plate and the polarization separation element. For this reason, the light concentration on these optical elements increases, which may cause damage or the like, resulting in a situation in which reliability is reduced.

[0010] The present invention has been completed based on the above-mentioned awareness of the problems, and provides a light source device that can be made smaller and less expensive. and An object of the present invention is to provide an image projection device. [Means for solving the problem]

[0011] The light source device of the present embodiment is a light source device, and includes: an excitation light source that emits a first color light; a first optical member having a first reflecting surface that reflects the first color light emitted from the excitation light source; a second optical member having a second reflecting surface that reflects the first color light reflected from the first reflecting surface of the first optical member; and a rod integrator that mixes the first color light reflected from the second reflecting surface of the second optical member. a center of the first color light in the first optical member is defined as point P, a luminous flux of the first color light reflected from the first reflecting surface of the first optical member and incident on the second reflecting surface of the second optical member is defined as luminous flux Q', and a luminous flux of the first color light reflected from the second reflecting surface of the second optical member is defined as luminous flux Q, the point P and the luminous flux Q do not intersect, and a plane including the luminous flux Q' and the luminous flux Q is disposed approximately parallel to a short side of an entrance opening of the rod integrator. the excitation light source is composed of a light source unit including a plurality of laser diodes arranged in rows and columns and a coupling lens provided on the emission surface side of the laser diode, and the arrangement interval of the laser diodes satisfies the following formula, where θ is the larger divergence angle of the first color light emitted from the laser diodes in the row direction or the column direction, p is the pitch between adjacent laser diodes, and L is the distance from the light emitting point of the laser diode to the coupling lens: It is characterized by the following. 1≦p / Ltanθ≦4 Effect of the Invention

[0012] According to the present invention, a light source device capable of achieving miniaturization and cost reduction is provided. and An image projection device can be provided. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic diagram for explaining an overview of a light source device according to the present invention. [Diagram 2] 1 is a schematic diagram for explaining an overview of a light source device according to the present invention. [Diagram 3] 1 is a schematic diagram for explaining an overview of a light source device according to the present invention. [Figure 4] 1 is a schematic diagram for explaining an overview of a light source device according to the present invention. [Diagram 5] 1 is a schematic diagram for explaining an overview of a light source device according to the present invention. [Figure 6] 1 is a schematic diagram for explaining an overview of a light source device according to the present invention. [Figure 7] 1 is a schematic diagram for explaining an overview of a light source device according to the present invention. [Figure 8] 5A and 5B are schematic diagrams for explaining optical characteristics of a rod integrator included in the light source device according to the present invention. [Figure 9] 5A and 5B are schematic diagrams for explaining the configuration of a rod integrator included in the light source device according to the present invention. [Figure 10] 1 is a schematic configuration diagram showing a projector device 1 including a light source device according to a first embodiment. [Figure 11] 1 is a schematic configuration diagram showing a light source device according to a first embodiment. [Figure 12] 2 is an explanatory diagram of a main part of a light source unit included in the light source device according to the first embodiment. FIG. [Figure 13] 3 is a diagram showing an example of the configuration of a dichroic mirror included in the light source device according to the first embodiment. FIG. [Figure 14] 2 is an explanatory diagram of a configuration of a phosphor unit included in the light source device according to the first embodiment. FIG. [Figure 15] 2 is an explanatory diagram illustrating a schematic configuration of a color wheel included in the light source device according to the first embodiment. FIG. [Figure 16] 2 is a diagram showing an entrance opening of a light tunnel of the light source device according to the first embodiment, as viewed from the direction in which light is incident. FIG. [Figure 17] FIG. 11 is a schematic configuration diagram showing a light source device according to a second embodiment. [Figure 18] 13 is a diagram showing an example of the configuration of a dichroic mirror included in a light source device according to a second embodiment. FIG. [Figure 19] FIG. 11 is a schematic configuration diagram showing a light source device according to a third embodiment. [Figure 20] FIG. 13 is a schematic configuration diagram showing a light source device according to a fourth embodiment. [Figure 21] 13A and 13B are schematic diagrams illustrating the configuration of a phosphor unit included in a light source device according to a fourth embodiment. [Figure 22] FIG. 13 is a schematic configuration diagram showing a light source device according to a fifth embodiment. [Diagram 23] FIG. 13 is a schematic configuration diagram showing a light source device according to a sixth embodiment. [Figure 24] FIG. 13 is a schematic configuration diagram showing a light source device according to a seventh embodiment. [Diagram 25] FIG. 13 is a schematic configuration diagram showing a light source device according to an eighth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Conventionally, a light source device using a digital micromirror device (DMD) and a phosphor wheel has been known in which part of the phosphor wheel is used as a reflector to reduce the size of the entire device. In this light source device, the excitation light is reflected by the phosphor wheel in the same direction as the fluorescent light, and a retardation plate (1 / 4 wavelength plate) and a polarization separation element are placed on the light path to prevent the reflected excitation light from returning to the excitation light source.

[0015] In a light source device having such a configuration, a retardation plate (1 / 4 wavelength plate) and a polarization separation element are arranged on the optical path of the excitation light, which not only restricts the miniaturization of the device but also increases the cost. 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 pass through the same places on the retardation plate and the polarization separation element. This increases the light concentration on these optical elements, which can cause damage and reduce reliability.

[0016] The inventors have noticed that such a structure within the light source device is a factor that hinders the miniaturization and cost reduction of the device body, and is also a factor that reduces reliability. They have discovered that 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 in the light source device so that they do not overlap contributes to miniaturization and cost reduction of the device body, as well as improving reliability, and have arrived at the present invention.

[0017] That is, the present invention provides a light source device including a light source that emits excitation light, an optical element having a reflective surface that reflects the excitation light emitted from the light source, and a wavelength conversion unit having a wavelength conversion element into which the excitation light reflected by the optical element is incident and which converts at least a portion of the excitation light into fluorescent light having a wavelength different from that of the excitation light and emits the fluorescent light, wherein, when the center of the projected image of the excitation light projected onto the reflective surface of the optical element is point P and the luminous flux of the excitation light emitted from the wavelength conversion unit is luminous flux Q, the light source device is arranged so that point P and luminous flux Q do not intersect.

[0018] According to the present invention, since the luminous flux of the excitation light emitted from the wavelength conversion unit does not intersect with the center of the projected image of the excitation light emitted from the light source, it is possible to prevent the excitation light from passing through the same place on the optical member, and therefore it is possible to suppress the damage of the optical member due to the increase in the light concentration, and to improve reliability. In addition, since it is not necessary to prepare special optical elements such as a retardation plate or a polarization separation element to separate the optical path of the excitation light emitted from the wavelength conversion unit, it is possible to reduce the number of parts, reduce the manufacturing cost, and make the device smaller.

[0019] Fig. 1 is a schematic diagram for explaining an overview of a light source device 100 according to the present invention. Fig. 1A is an explanatory diagram of components of the light source device 100 according to the present invention, and Fig. 1B is an explanatory diagram of excitation light projected onto a reflecting surface 102a of a dichroic mirror 102 included in the light source device 100. Fig. 1B shows the reflecting surface 102a from the traveling direction of excitation light from a light source 101.

[0020] As shown in FIG. 1, a light source device 100 according to the present invention includes a light source (excitation light source) 101, a dichroic mirror 102 constituting an example of an optical component, a phosphor unit 103 constituting an example of a wavelength conversion unit, and a rod integrator 104 constituting an example of a light mixing element.

[0021] The configuration of the light source device 100 according to the present invention is not limited to the configuration shown in Fig. 1 and can be modified as appropriate. For example, the light source device 100 may include only the light source 101, the dichroic mirror 102, and the phosphor unit 103. Of the light source device 100 having the light source 101, the dichroic mirror 102, and the phosphor unit 103, the components excluding the light source 101 constitute a "light source optical system."

[0022] The light source 101 emits excitation light (first color light). The dichroic mirror 102 has a reflecting surface 102a that reflects the excitation light emitted from the light source 101 and guides it to the phosphor unit 103. The portions of the dichroic mirror 102 other than the reflecting surface 102a may have optical properties that transmit the excitation light emitted from the light source 101 and the fluorescent light emitted from the phosphor unit 103 described below.

[0023] 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 fluorescent light (second color light) having a wavelength different from that of the excitation light and emits the fluorescent light. When excitation light is incident on phosphor unit 103, phosphor unit 103 sequentially switches between the excitation light and the fluorescent light and emits them to the excitation light incident surface side (upper side shown in FIG. 1). Rod integrator 104 is provided so that the excitation light and fluorescent light emitted from phosphor unit 103 are incident thereon, and mixes (homogenizes) the incident excitation light and fluorescent light and emits them to the outside of light source device 100.

[0024] 1 shows a case where a first region of phosphor unit 103 is placed on the optical path of excitation light emitted from light source 101. The excitation light emitted from light source 101 is reflected toward phosphor unit 103 by reflecting surface 102a of dichroic mirror 102. The excitation light reflected by reflecting surface 102a is reflected toward the incident surface of the excitation light by the first region of phosphor unit 103. Rod integrator 104 is placed at the destination where the excitation light is reflected by phosphor unit 103.

[0025] In light source device 100 in which the optical path of the excitation light is formed in this manner, the center of the excitation light on reflecting surface 102a of dichroic mirror 102 is defined as point P, and the luminous flux of the excitation light emitted from phosphor unit 103 is defined as luminous flux Q. In light source device 100, dichroic mirror 102, phosphor unit 103, and rod integrator 104 are arranged so that point P and luminous flux Q do not intersect.

[0026] Here, the central point P of the excitation light on the reflecting surface 102a (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 reflecting surface 102a is line-symmetric or point-symmetric, the center of the smallest circumscribing circle of the projection range of the excitation light is the center of the projected image. (2) When the light intensity distribution of the projection range of the excitation light projected on the reflecting surface 102a is other than line-symmetric or point-symmetric (i.e., other than the above (1)), as shown in FIG. 1B, when the total energy of the excitation light projected on the reflecting surface 102a is A, the projection range is cut out into a circle of an arbitrary radius r, and the total energy of the light contained within the circle is B, the center of the circle of radius r' where B / A is 93% or more (B / A≧93%) and the energy density within the circle is maximum is the center of the projected image.

[0027] The projection range of the excitation light is defined as 1 / e of the maximum energy in the energy distribution of the excitation light projected onto the reflecting surface 102a. 2 This shows the range of energy that is equal to or greater than 100 times the energy of the object. The energy density can be calculated by dividing the "energy contained within a circle" by the "area of ​​the circle". In other words, the energy density can be calculated using the following formula: Energy density = (energy contained within a circle) / (area of ​​the circle) It should be noted that the center (point P) of the projection image of the excitation light defined in this manner is determined in a state in which all of the light sources 101 provided in the light source device 100 are turned on.

[0028] In addition, the luminous flux (luminous flux Q) of the excitation light emitted from the phosphor unit 103 is 1 / e 2 It refers to a bundle of light rays that pass through a range having an energy equal to or greater than this.

[0029] According to the light source device 100 of the present invention, the luminous flux Q of the excitation light emitted from the phosphor unit 103 does not intersect with the center (center of the projected image of the excitation light) on the reflecting surface 102a of the excitation light emitted from the light source 101, so that it is possible to prevent the excitation light from passing through the same point on the dichroic mirror 102, and therefore it is possible to suppress the dichroic mirror 102 from being damaged due to an increase in the light collection density. Also, since there is no need to prepare special optical elements such as a retardation plate or a polarization separation element to separate the optical path of the excitation light emitted from the phosphor unit 103, it is possible to reduce the number of parts, reduce the manufacturing cost, and make the device more compact.

[0030] 1, the case where the phosphor unit 103 sequentially switches between emitting excitation light and fluorescent light is described. That is, the case where the excitation light and fluorescent light are emitted in a time-division manner is described. However, the configuration of the phosphor unit 103 is not limited to this, and the phosphor unit 103 may be configured to emit excitation light and fluorescent light simultaneously.

[0031] For example, instead of the first and second regions described above, the phosphor unit 103 has a region (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. For example, a wavelength conversion member provided in this region reflects the excitation light and converts it into fluorescent light. This phosphor unit 103 is sometimes called a stationary phosphor unit. When excitation light is incident on the phosphor unit 103, it outputs the excitation light and fluorescent light together toward the excitation light incident surface side (upper side shown in FIG. 1). Even when such a phosphor unit 103 is provided, it is possible to obtain the same effect as when a time-division phosphor unit 103 is used.

[0032] 1 may further include a light guiding means for guiding one or both of the excitation light and the fluorescent light emitted from phosphor unit 103 to rod integrator 104. For example, the light guiding means is composed of a condenser lens or a refractive lens, and is disposed on the optical path between phosphor unit 103 and rod integrator 104. By including a light guiding means in this manner, the excitation light and / or the second color light emitted from phosphor unit 103 can be efficiently guided to rod integrator 104, and the light utilization efficiency can be improved.

[0033] Furthermore, in light source device 100 according to the present invention, the position of rod integrator 104 can be appropriately changed from the viewpoint of improving the efficiency of use of excitation light and / or fluorescent light incident on rod integrator 104. FIG. 2 is a schematic diagram for explaining an overview of light source device 100 according to the present invention. In FIG. 2, the same components as those in FIG. 1 are given the same reference numerals, and their explanation will be omitted. Note that FIG. 2 shows a case where a reflecting surface 102a is formed on the surface of dichroic mirror 102. The same applies to the following drawings.

[0034] 2, consider the case where the center of the projection image of excitation light projected from dichroic mirror 102 onto phosphor unit 103 is point R. In this case, rod integrator 104 is preferably placed on the perpendicular line to point R on exit surface 103a of phosphor unit 103. By placing rod integrator 104 in this manner, when fluorescent light is emitted perpendicularly to exit surface 103a of phosphor unit 103, the fluorescent light can be efficiently incident on rod integrator 104, thereby improving the light utilization efficiency of the fluorescent light.

[0035] Furthermore, the light source device 100 according to the present invention may include a focusing element that is disposed on the optical path between the dichroic mirror 102 and the phosphor unit 103 and focuses the excitation light reflected by the dichroic mirror 102 while substantially collimating the fluorescent light emitted from the phosphor unit 103. For example, the focusing element is formed of a focusing lens. FIG. 3 is a schematic diagram for explaining an overview of the light source device 100 according to the present invention. In FIG. 3, the same reference numerals are given to configurations common to FIG. 1, and the description thereof will be omitted.

[0036] 3 includes a condenser lens 105 as a condensing element 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, while approximately collimating the fluorescent light emitted from the phosphor unit 103.

[0037] Here, a straight line connecting the center of a projected image on the incident surface 105a of the condenser lens 105 projected by the excitation light that is reflected by the reflecting surface 102a of the dichroic mirror 102 and then enters the condenser lens 105 and the point P on the reflecting surface 102a described above is defined as a straight line L1. Also, a point S is defined as an intersection point between the incident surface 103b of the excitation light that is collected by the condenser lens 105 and enters the phosphor unit 103 and the straight line L1. In the light source device 100, the point S and the point R, which is the center of the projected image of the excitation light projected on the phosphor unit 103, are located at different positions. By providing the condenser lens 105 in this manner, the excitation light and the fluorescent light that diverge after being emitted from the phosphor unit 103 are collimated, and therefore these lights can be efficiently incident on the rod integrator 104, thereby improving the light utilization efficiency.

[0038] 3, it is preferable that the above-mentioned straight line L1 perpendicularly intersects with the incident surface 103b of the phosphor unit 103. By arranging the straight line L1 so that it perpendicularly intersects with the incident surface 103b of the phosphor unit 103 in this manner, the distance between the dichroic mirror 102 and the phosphor unit 103 can be shortened, and the overall dimensions of the light source device 100 can be reduced.

[0039] In addition, when light passes through an optical element having a thickness, the surface into which the light enters is the entrance surface, and the surface from which the light exits is the exit surface. For example, as shown in Fig. 3, in condenser lens 105, the surface into which the light enters after being reflected from reflecting surface 102a of dichroic mirror 102 is entrance surface 105a, and the surface from which the light passes through condenser lens 105 from entrance surface 105a and exits toward phosphor unit 103 is exit surface 105b.

[0040] Furthermore, light source device 100 according to the present invention may include a refractive optical element that is disposed in the optical path between condenser lens 105 and rod integrator 104 and condenses the excitation light and / or fluorescent light collimated by the condenser element (condenser lens 105) and guides it to rod integrator 104. For example, the refractive optical element is formed of a refractive lens. Fig. 4 is a schematic diagram for explaining the outline of light source device 100 according to the present invention. In Fig. 4, the same reference numerals are given to the configurations common to Fig. 3, and the description thereof will be omitted.

[0041] 4 includes a refractive lens 106 as a refractive optical element on the optical path between condenser lens 105 and rod integrator 104. The refractive lens 106 condenses (refracts) the excitation light and / or fluorescent light collimated by the condenser element (condenser lens 105) and guides it to the entrance opening 104a of the rod integrator 104. By providing the refractive lens 106 in this manner, the excitation light and / or fluorescent light collimated by the condenser lens 105 can be efficiently incident on the rod integrator 104, thereby improving the light utilization efficiency.

[0042] 4, it is preferable to select the arrangement of rod integrator 104 from the viewpoint of homogenizing (uniformizing) the excitation light and / or fluorescent light incident on rod integrator 104. More specifically, when rod integrator 104 has an inner peripheral cross section in a rectangular shape, it is preferable to arrange rod integrator 104 so that the excitation light, etc. incident on rod integrator 104 is incident on the inner surface corresponding to the long side.

[0043] 4, it is preferable to select the arrangement of the light source 101 from the viewpoint of suppressing vignetting of the excitation light on the reflecting surface 102a of the dichroic mirror 102. More specifically, when the light emitting surface of the light source 101 has a rectangular shape, it is preferable to arrange the light source 101 so that the width of the excitation light is narrow.

[0044] FIG. 5 is a schematic diagram for explaining an overview of a light source device 100 according to the present invention. In FIG. 5, the same reference numerals are given to the configurations common to FIG. 4, and the description thereof will be omitted. FIG. 5A is an explanatory diagram of the components of the light source device 100 according to the present invention, FIG. 5B is an explanatory diagram of an entrance opening 104a of a rod integrator 104 included in the light source device 100, and FIG. 5C is an explanatory diagram of a light source 101 included in the light source device 100. FIG. 5B shows the entrance opening 104a of the rod integrator 104 from the phosphor unit 103 side. FIG. 5C shows the light emitting surface of the light source 101 from the dichroic mirror 102 side.

[0045] In light source device 100 shown in Fig. 5A, the center of a projected image of excitation light and / or fluorescent light collected (refracted) by refractive lens 106 projected onto entrance aperture 104a of rod integrator 104 is defined as point T. A straight line connecting point T and point R, which is the center of a projected image of excitation light projected onto phosphor unit 103, is defined as line L2. On the other hand, as shown in Fig. 5B, entrance aperture 104a of rod integrator 104 has a long side LE 1 and short side SE 1 As shown in FIG. 5C, the light emitting surface 101a of the light source 101 has a rectangular shape having a long side LE2 and short side SE 2 The shape of the rectangular portion is defined as follows:

[0046] In light source device 100, a plane including straight lines L1 and L2 (i.e., a plane including the paper surface shown in FIG. 5A) and a short side SE of entrance opening 104a of rod integrator 104 are aligned parallel to each other. 1 In other words, it is preferable that the short side SE of the rod integrator 104 shown in FIG. 1 It is preferable to arrange the rod integrator 104 so that the long side LE of the entrance aperture 104a of the rod integrator 104 is parallel to the paper surface shown in FIG. 1 Since the excitation light, etc. can be incident so as to hit the inner surface corresponding to the light receiving portion 104, the excitation light, etc. can be made uniform as the number of times the excitation light, etc. is reflected inside rod integrator 104 increases, and the occurrence of color unevenness in the excitation light, etc. can be suppressed.

[0047] In the light source device 100, a plane including the straight lines L1 and L2 (i.e., a plane including the paper surface shown in FIG. 5A) and a short side SE of the light emitting surface 101a of the light source 101 are parallel to each other. 2 In other words, it is preferable that the short side SE of the light emitting surface 101a shown in FIG. 2 It is preferable to arrange light source 101 so that the light beam extending in the direction of extension of the plane including straight lines L1 and L2 is parallel to the paper surface shown in Fig. 5A. By arranging light source 101 in this way, the width of the light beam extending in the extension direction of the plane including straight lines L1 and L2 can be narrowed, so that vignetting on reflecting surface 102a of dichroic mirror 102 can be suppressed, and a decrease in light utilization efficiency can be suppressed. In addition, it is possible to prevent the light reflected by phosphor unit 103 from interfering with dichroic mirror 102, and a decrease in light utilization efficiency can be suppressed.

[0048] Furthermore, in light source device 100 according to the present invention, rod integrator 104 is preferably arranged from the viewpoint of setting the angle between the incidence surface of excitation light incident on incidence opening 104a and incidence opening 104a within a certain range. For example, in light source device 100, rod integrator 104 is preferably arranged so that the angle between the incidence surface of excitation light incident on incidence opening 104a and incidence opening 104a is smaller than a certain angle.

[0049] Fig. 6 is a schematic diagram for explaining an overview of light source device 100 according to the present invention. In Fig. 6, the same components as those in Fig. 5A are given the same reference numerals, and the description thereof will be omitted. Fig. 6A is an explanatory diagram of the components of light source device 100 according to the present invention, and Fig. 6B is an explanatory diagram of the incidence surface of excitation light with respect to incidence opening 104a of rod integrator 104 of light source device 100. Note that Fig. 6A shows the optical path of excitation light in light source device 100.

[0050] 6, the excitation light (incident light) that is collected by the refractive lens 106 and enters the entrance opening 104a is indicated as EL. In the light source device 100, the rod integrator 104 is disposed so that the angle between the entrance opening 104a and the entrance surface of the excitation light EL that enters the entrance opening 104a is smaller than 40°.

[0051] Here, the incident surface is defined as a plane including the normal to a surface (target surface) and the incident light when a light ray is incident on the target surface. When the plane constituting the entrance opening 104a is the target surface, the entrance surface of the excitation light (incident light) EL to the entrance opening 104a is composed of a plane EF including the excitation light EL and the normal 104aL of the entrance opening 104a, as shown in FIG. 6B.

[0052] 6, rod integrator 104 is arranged so that the angle β between excitation light (incident light) EL incident on incidence opening 104a in incidence surface EF and incidence opening 104a is smaller than 40°. By arranging rod integrator 104 in this manner, it is possible to prevent the excitation light from being obliquely incident on rod integrator 104. This allows the excitation light to be sufficiently mixed inside rod integrator 104, thereby suppressing the occurrence of color unevenness and improving light utilization efficiency.

[0053] Furthermore, in light source device 100 according to the present invention, it is preferable to select the arrangement of rod integrator 104 in relation to refractive lens 106. For example, in light source device 100, it is preferable that the center of the projection image of the excitation light projected onto entrance opening 104a of rod integrator 104, the center of the projection image of the fluorescent light projected onto entrance opening 104a of rod integrator 104, and the optical axis of refractive lens 106 intersect at one point.

[0054] Fig. 7 is a schematic diagram for explaining an overview of a light source device 100 according to the present invention. In Fig. 7, the same components as those in Fig. 5A are given the same reference numerals, and their explanation will be omitted. Fig. 7A shows the optical path of excitation light in the light source device 100, and Fig. 7B shows the optical path of fluorescent light in the light source device 100. For convenience of explanation, Fig. 7 shows a pair of condenser lenses 105 arranged along the light propagation direction. 1 , 105 2 This shows that.

[0055] In light source device 100 shown in FIG. 7, the center of the projection image of the excitation light collected by refractive lens 106 on entrance aperture 104a of rod integrator 104 and the center of the projection image of the fluorescent light collected by refractive lens 106 on entrance aperture 104a of rod integrator 104 are the above-mentioned point T. In addition, refractive lens 106 is disposed so that its optical axis LA passes through point T. Therefore, the center of the projection image of the excitation light projected on entrance aperture 104a of rod integrator 104, the center of the projection image of the fluorescent light projected on entrance aperture 104a of rod integrator 104, and the optical axis LA of refractive lens 106 intersect at one point. As a result, the excitation light and the fluorescent light can be incident near the center of entrance aperture 104a of rod integrator 104, so that vignetting of light by entrance aperture 104a of rod integrator 104 can be suppressed and light utilization efficiency can be improved. Furthermore, even if optical elements in the light source device 100 are misaligned due to component tolerances, a decrease in light utilization efficiency can be suppressed.

[0056] Furthermore, in light source device 100 according to the present invention, the arrangement of refractive lens 106 is preferably selected from the viewpoint of setting the angles of excitation light and fluorescent light incident on entrance opening 104a of rod integrator 104 within a certain range. The angle of the light ray with respect to entrance opening 104a refers to the angle between the light ray and the normal to a plane parallel to entrance opening 104a. For example, in light source device 100, it is preferable to set the angle of incidence of the light ray of excitation light incident at the largest angle with respect to entrance opening 104a to be smaller than the angle of incidence of the light ray of fluorescent light incident at the largest angle with respect to entrance opening 104a.

[0057] As shown in FIG. 7, the incident angle of the excitation light beam incident at the largest angle on the entrance aperture 104a is defined as an angle θ 1 is defined as the angle of incidence of the fluorescent light beam incident on the entrance aperture 104a at the largest angle, and the angle of incidence θ 2 In the light source device 100, the angle θ 1 angle θ 2 It is preferable to set the incident angle θ of the excitation light to be smaller than 100 nm.1 is the incident angle θ of the fluorescent light 2 By making it smaller, it is possible to suppress vignetting of light in an optical system arranged downstream of the light source device 100, and it is possible to improve the light utilization efficiency.

[0058] In the light source device 100 according to the present invention, the incidence angle θ of the excitation light described above 1 and the incident angle of the fluorescent light θ 2 The incidence angle θ of these excitation lights may be set to the same angle. 1 is the incident angle θ of the fluorescent light 2 By setting the angle to be the same as that of the excitation light, the light distribution of the fluorescent light projected onto the DMD or the screen can be made substantially the same, and the occurrence of color unevenness in the excitation light etc. can be suppressed.

[0059] Furthermore, in the light source device 100 according to the present invention, the optical characteristics of the rod integrator 104 are such that the incident angle θ of the excitation light described above is 1 and the incident angle of the fluorescent light θ 2 For example, in the light source device 100, the rod integrator 104 is configured as a glass rod integrator, and the total reflection condition of the glass rod integrator is set to the incident angle θ of the excitation light. 1 and the incident angle θ of the second color light 2 It is preferable to set it larger.

[0060] 8 is a schematic diagram for explaining the optical characteristics of rod integrator 104 included in light source device 100 according to the present invention. In light source device 100 shown in FIG. 8, rod integrator 104 is made of a glass rod integrator. The total reflection condition in rod integrator 104 is an angle θ glass In this case, the angle θ glass is the incident angle θ of the excitation light 1 and the incident angle θ of the fluorescent light 2 This makes it possible to prevent loss of excitation light and the like inside rod integrator 104, thereby improving the light utilization efficiency.

[0061] In addition, in light source device 100 according to the present invention, rod integrator 104 constituting the light mixing element preferably has a tapered shape in which entrance opening 104a is smaller than exit opening 104b, as shown in Fig. 9. By tapering rod integrator 104 in this way, the exit angle of light exiting from rod integrator 104 can be reduced, so that vignetting in an optical system arranged downstream of light source device 100 can be suppressed, and light utilization efficiency can be improved.

[0062] A number of embodiments of the present invention will be described below. Note that the following embodiments are merely examples of the light source optical system, the light source device, and the image projection device according to the present invention, and can be modified as appropriate. In addition, each embodiment can be combined as appropriate.

[0063] (First embodiment) 10 is a schematic diagram showing a projector device (image projection device) 1 including a light source device 20 according to the first embodiment. As shown in FIG. 10, the projector device 1 includes a housing 10, a light source device 20, an illumination optical system 30, an image forming element (image display element) 40, a projection optical system 50, and a cooling device 60.

[0064] The housing 10 houses a light source device 20, an illumination optical system 30, an image forming element 40, a projection optical system 50, and a cooling device 60. The light source device 20 emits light including wavelengths corresponding to the respective colors of RGB, for example. The internal configuration of the light source device 20 will be described in detail later.

[0065] The illumination optical system 30 approximately uniformly illuminates the image forming element 40 with light homogenized by a light tunnel 29 of the light source device 20 described below. The illumination optical system 30 has, for example, one or more lenses and one or more reflective surfaces.

[0066] The image forming element 40 forms an image by modulating the light illuminated by the illumination optical system 30 (light from the light source optical system of the light source device 20). The image forming element 40 is composed of, for example, a digital micromirror device (DMD) or a liquid crystal display element. The image forming element 40 drives a micromirror surface in synchronization with the light (blue light, green light, red light, yellow light) irradiated from the illumination optical system 30 to generate a color image.

[0067] The projection optical system 50 enlarges and projects the image (color image) formed by the image forming element 40 onto a screen (projection surface) (not shown). The projection optical system 50 has, for example, one or more lenses. The cooling device 60 cools each element and device that generates heat within the projector device 1.

[0068] Fig. 11 is a schematic diagram showing the configuration of light source device 20 according to the first embodiment. Fig. 11A shows the optical path of blue laser light in light source device 20, and Fig. 11B shows the optical path of fluorescent light in light source device 20.

[0069] As shown in FIG. 11A, the light source device 20 has, arranged in order in the direction of light propagation, a laser light source (excitation light source) 21, a coupling lens 22, a first optical system 23, a dichroic mirror 24 which is an example of an optical component, a second optical system 25, a phosphor unit 26 which is an example of a wavelength conversion unit, a refractive optical system 27, a color wheel 28, and a light tunnel 29 which is an example of a light mixing element.

[0070] For ease of explanation, color wheel 28 is omitted in Fig. 11. For details about color wheel 28, see Fig. 10. In this embodiment, color wheel 28 is described as a component of light source device 20. However, the configuration of light source device 20 is not limited to this, and may be configured without including color wheel 28.

[0071] The laser light source 21 is, for example, an array of light sources that emit a plurality of laser beams. The laser light source 21 emits, for example, light in the blue band (blue laser light) with a center of emission intensity of 455 [nm]. Hereinafter, the blue laser light will be simply referred to as blue light. The blue light emitted from the laser light source 21 is linearly polarized light with a constant polarization direction, and is also used as excitation light for exciting a phosphor in the phosphor unit 26 described later.

[0072] The light emitted from the laser light source 21 may be light of a wavelength capable of exciting a phosphor described later, and is not limited to light in the blue wavelength band. The laser light source 21 has a plurality of light sources, but is not limited to this, and may be configured with a single light source. The laser light source 21 can be configured with a plurality of light sources arranged in an array on a substrate, but is not limited to this, and may be configured in other ways.

[0073] The coupling lens 22 is a lens that receives the blue light emitted from the laser light source 21 and converts it into parallel light (collimated light). In the following, the concept of parallel light is not limited to completely collimated light, but includes approximately collimated light. 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 an increase or decrease in the number of light sources of the laser light source 21.

[0074] In the light source device 20 according to the present embodiment, the laser light source 21 and the coupling lens 22 constitute a light source unit. For example, the laser light source 21 is composed of a plurality of laser diodes arranged in rows and columns. That is, the light source unit is composed of these laser diodes and the coupling lens 22 arranged on the emission surface side of the laser diodes.

[0075] Fig. 12 is an explanatory diagram of a main part of the light source unit included in the light source device 20 according to the first embodiment. As shown in Fig. 12, in the light source unit, the coupling lens 22 is disposed facing the laser diode 21A. In the light source unit, when the divergence angle in the larger direction of the row direction or the column direction of the blue light (excitation light) emitted from each laser diode 21A is θ, the pitch of adjacent laser diodes 21A is P, and the distance from the light emitting point of the laser diode 21A to the coupling lens 22 is L, the arrangement interval (P / Ltanθ) of each laser diode 21A is set so as to satisfy the following (Formula 1). 1 ≦ P / Ltanθ ≦ 4 (Formula 1)

[0076] Most preferably, the arrangement intervals of the laser diodes 21A are set so as to satisfy the following (Equation 2). P / Ltanθ = 2 (Formula 2) By satisfying (Formula 2), the light emitting surface of the laser light source 21 can be made small while the light of each laser diode 21A can be made to enter only the corresponding coupling lens 22, thereby preventing the light from entering an adjacent coupling lens 22 and suppressing a decrease in the light utilization efficiency.

[0077] In addition, it is preferable that the multiple laser diodes 21A included in the light source unit are arranged on the same substrate. By arranging the multiple laser diodes 21A on the same substrate, the area of ​​the light emitted from the light source unit can be made small, so that vignetting of the light in various optical elements on the optical path can be suppressed, and the light utilization efficiency can be improved.

[0078] The first optical system 23 has positive power as a whole, and includes, in this order from the laser light source 21 side to the phosphor unit 26 side, a large-diameter lens 23a and a negative lens 23b. The large-diameter lens 23a constitutes an example of a large-diameter element, has positive power, and is composed of a lens that collects and combines the parallel light emitted from the coupling lens 22. The negative lens 23b constitutes an example of a collimating element, and is composed of a lens that converts the blue light collected by the large-diameter lens 23a into parallel light. The first optical system 23 guides the blue light (excitation light) incident as approximately parallel light from the coupling lens 22 to the dichroic mirror 24 while converging it.

[0079] Dichroic mirror 24 is disposed at an incline with respect to the propagation direction of the blue light emitted from first optical system 23. More specifically, it is disposed with its front end inclined downward along the propagation direction of the blue light emitted from first optical system 23. Dichroic mirror 24 has an optical property of reflecting the blue light that has been made substantially parallel by first optical system 23, while transmitting the fluorescent light (second color light) converted by phosphor unit 26. For example, dichroic mirror 24 is coated with a coating that has the above-mentioned optical property.

[0080] Fig. 13 is a diagram showing an example of the configuration of the dichroic mirror 24 included in the light source device 20 according to the first embodiment. In Fig. 13, the dichroic mirror 24 is shown from the incident direction of the blue light emitted from the first optical system 23. As shown in Fig. 13, the dichroic mirror 24 is divided into two regions 24A and 24B. In the following, for convenience of explanation, the regions 24A and 24B are referred to as the first region 24A and the second region 24B, respectively.

[0081] The first region 24A has an optical property of reflecting blue light emitted from the first optical system 23 (negative lens 23b) while transmitting fluorescent light converted from the blue light by a phosphor of the phosphor unit 26 described below. This first region 24A constitutes the reflecting surface 102a shown in Fig. 1. The second region 24B has an optical property of transmitting the blue light and fluorescent light.

[0082] 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 shifted to a position closer to the first optical system 23 (negative lens 23b) than the optical axis of the second optical system 25. On the other hand, the second region 24B is not disposed on the optical axis of the second optical system 25, and is shifted to a position on the opposite side to the first optical system 23 than the optical axis of the second optical system 25.

[0083] The second optical system 25 has positive power overall, and includes a positive lens 25A and a positive lens 25B in this order from the laser light source 21 side toward the phosphor unit 26 side. The second optical system 25 collects the blue light reflected by the dichroic mirror 24 and guides it to the phosphor unit 26. The second optical system 25 also collimates the fluorescent light emitted from the phosphor unit 26. The second optical system 25 constitutes an example of a light collecting element.

[0084] 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 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 to convert the blue light into fluorescent light of a wavelength range different from that of the blue light by a phosphor. The fluorescent light converted by the phosphor unit 26 is, for example, light in a yellow wavelength range with a center of emission intensity of 550 [nm].

[0085] Fig. 14 is an explanatory diagram of the configuration of the phosphor unit 26 included in the light source device 20 according to the first embodiment. In Fig. 14A, the phosphor unit 26 is shown from the incident direction of blue light, and in Fig. 14B, the phosphor unit 26 is shown from a direction perpendicular to the incident direction of blue light. Note that the configuration of the phosphor unit 26 shown in Fig. 14 is an example, and is not limited to this and can be modified as appropriate.

[0086] 14, the phosphor unit 26 has a disk member (substrate) 26A and a drive motor (drive section) 26C that rotates about a rotation axis 26B that passes through the center of the disk member 26A and is 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 an aluminum substrate), but is not limited thereto.

[0087] The phosphor unit 26 (disk member 26A) has a large portion in the circumferential direction (an angular range greater than 270° in the first embodiment) partitioned into a fluorescent region 26D, and a small portion in the circumferential direction (an angular range smaller than 90° in the first embodiment) partitioned into an excitation light reflecting region 26E. The excitation light reflecting 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 fluorescent region 26D is configured by laminating a reflective coat 26D1, a phosphor layer 26D2, and an anti-reflection coat (AR coat) 26D3 in this order from the lower layer side to the upper layer side.

[0088] The reflective coating 26D1 has a characteristic of reflecting light in the wavelength region of the fluorescent light (emitted light) produced by the phosphor layer 26D2. If the disk member 26A is made of a metal substrate with high reflectivity, the reflective coating 26D1 can be omitted. In other words, the disk member 26A can be given the function of the reflective coating 26D1.

[0089] The phosphor layer 26D2 may be, for example, a phosphor material dispersed in an organic or inorganic binder, a phosphor material crystal formed directly, or a rare earth phosphor such as Ce:YAG. The phosphor layer 26D2 constitutes an example of a wavelength conversion member that converts at least a part of the excitation light into fluorescent light having a wavelength different from that of the excitation light and emits the fluorescent light. The wavelength band of the fluorescent light (emission light) by the phosphor layer 26D2 may be, for example, yellow, blue, green, or red, but in the first embodiment, a case where fluorescent light (emission light) having a yellow wavelength band is used will be described as an example. In addition, although a phosphor is used as the wavelength conversion element in this embodiment, a phosphorescent material, a nonlinear optical crystal, or the like may also be used.

[0090] The anti-reflection coating 26D3 has the property of preventing light reflection on the surface of the phosphor layer 26D2.

[0091] A reflective coat (reflective surface) 26E1 having a characteristic of reflecting light in the wavelength region of blue light guided from the second optical system 25 is laminated on the excitation light reflection region 26E. When the disk member 26A is made of a metal substrate with high reflectivity, the reflective coat 26E1 can be omitted. In other words, the disk member 26A can be given the function of the reflective coat 26E1.

[0092] By rotating disk member 26A by drive motor 26C, the irradiation position of the blue light on phosphor unit 26 moves over time. As a result, a part of the blue light (first color light) incident on phosphor unit 26 is converted into fluorescent light (second color light) having a wavelength different from that of the blue light (first color light) in fluorescent region (wavelength conversion region) 26D and emitted. Meanwhile, the other part of the blue light incident on phosphor unit 26 is reflected as blue light by excitation light reflection region 26E and emitted.

[0093] There is a degree of freedom in the number and range of fluorescent regions 26D and excitation light reflecting regions 26E, and various design modifications are possible. For example, two fluorescent regions and two excitation light reflecting regions may be alternately arranged at 90° intervals in the circumferential direction.

[0094] Returning to Fig. 11, the configuration of light source device 20 will be further described. Refractive optical system 27 is composed of lenses that collect light (blue light and fluorescent light) emitted from second optical system 25. After transmitting through dichroic mirror 24, light (blue light and fluorescent light) emitted from phosphor unit 26 is collected (refracted) by refractive optical system 27 and enters color wheel 28 (see Fig. 9). Color wheel 28 is a member that separates the blue light and fluorescent light generated by phosphor unit 26 into desired colors.

[0095] Fig. 15 is an explanatory diagram of a schematic configuration of color wheel 28 included in light source device 20 according to the first embodiment. In Fig. 15A, color wheel 28 is shown from the incident direction of blue light and fluorescent light, and in Fig. 15B, color wheel 28 is shown from a direction perpendicular to the incident direction of blue light and fluorescent light. As shown in Fig. 15, color wheel 28 has an annular member 28A and a drive motor (drive unit) 28C that rotates and drives annular member 28A around a rotation shaft 28B.

[0096] The annular member 28A is divided into a plurality of regions along the circumferential direction. The annular member 28A has a diffusion region 28D and filter regions 28R, 28G, and 28Y that are partitioned in the circumferential direction. 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 transmits light that includes the wavelength range of the red component of the fluorescent light emitted from the phosphor unit 26. Similarly, the filter regions 28G and 28Y are regions that transmit light that includes the wavelength range of the green component and the yellow component of the fluorescent light emitted from the phosphor unit 26.

[0097] In the above description, color wheel 28 has regions that transmit red, green, and yellow components of the fluorescent light, respectively. However, the configuration of color wheel 28 is not limited to this, and color wheel 28 may have regions that transmit red and green components of the fluorescent light, respectively.

[0098] Moreover, the area ratio of each region in color wheel 28 is based on the design specifications of projector device 1. However, for example, since diffusion region 28D in color wheel 28 transmits blue light emitted from phosphor unit 26, the ratio of the area of ​​excitation light reflection region 26E to the total area of ​​disk member 26A of phosphor unit 26 and the ratio of the area of ​​diffusion region 28D to the total area of ​​color wheel 28 may be made to match.

[0099] As the drive motor 28C is driven to rotate, the annular member 28A rotates in the circumferential direction. As the annular member 28A rotates in the circumferential direction, the blue light emitted from the phosphor unit 26 enters the diffusion region 28D, and the fluorescent light emitted from the phosphor unit 26 enters the filter regions 28R, 28G, and 28Y in sequence. The light (blue light and fluorescent light) emitted from the phosphor unit 26 passes through the color wheel 28, and blue light, green light, red light, and yellow light are emitted in sequence. The light that has passed through each region of the color wheel 28 enters the light tunnel 29.

[0100] Light tunnel 29 is an optical element formed so that four mirrors are inside a rectangular prism, and is an element (light homogenizing element) that homogenizes the distribution of light by reflecting light incident from one end of the rectangular prism multiple times by the internal mirrors. Light tunnel 29 is arranged so that light (blue light and fluorescent light) collected by refractive optical system 27 is incident on it. Note that, although light tunnel 29 is shown in the first embodiment as an example of a light mixing element, the present invention is not limited to this, and a rod integrator, a fly's eye lens, or the like can also be used.

[0101] Fig. 16 is a view of entrance opening 29A of light tunnel 29 of light source device 20 according to the first embodiment, viewed from the light entrance direction. Fig. 16 shows the projection range of blue light on entrance opening 29A of light tunnel 29. As shown in Fig. 16, light tunnel 29 is disposed at a slight incline. The inclination angle of light tunnel 29 varies depending on the performance required of light source device 20.

[0102] In the light source unit of the light source device 20 according to the first embodiment, as described above, the laser light sources 21 (laser diodes 21A) are arranged in an array. As shown in FIG. 16B, the projection range on the entrance opening 29A of the light tunnel 29 onto which the blue light, etc. emitted from the laser diode 21A is projected is configured to have an elliptical shape (see FIG. 16B and FIG. 16C). For example, the projection range of the blue light, etc. on the entrance opening 29A is arranged such that the major axis of the elliptical shape is substantially parallel to the short side of the entrance opening 29A, as shown in FIG. 16B. By setting the projection range of the blue light, etc. on the entrance opening 29A in this manner, it is possible to suppress vignetting of the blue light, etc. by the light tunnel 29. Note that the projection range of the blue light, etc. on the entrance opening 29A may be arranged such that the major axis of the elliptical shape is substantially parallel to the long side of the entrance opening 29A, as shown in FIG. 16B. The elliptical shape referred to here refers to a shape in which there is a difference between the full width at half maximum (FWHM) of the intensity distribution in the vertical direction of the projection range and the full width at half maximum (FWHM) of the intensity distribution in the horizontal direction. In other words, it is a shape that does not have an isotropic intensity distribution.

[0103] The optical path of blue light in light source device 20 having such a configuration (hereinafter referred to as "blue light optical path" where appropriate) will be described with reference to Fig. 11A. The blue light optical path refers to the optical path along which light reflected by excitation light reflection region 26E of phosphor unit 26 travels, out of the excitation light emitted by laser light source 21.

[0104] The blue light emitted from the laser light source 21 is converted into a parallel light by the coupling lens 22. The blue light emitted from the coupling lens 22 is collected and combined by the large-diameter lens 23a of the first optical system 23, and then converted into a parallel light by the negative lens 23b. The blue light emitted from the negative lens 23b is reflected by the first region 24A of the dichroic mirror 24 and travels toward the second optical system 25. The first region 24A constitutes a reflecting surface 102a that reflects the blue light emitted from the laser light source 21 (see FIG. 1). The point P at the center of the projection image of the excitation light described above is formed in the first region 24A.

[0105] As described above, the first region 24A of the dichroic mirror 24 is arranged to be shifted toward the first optical system 23 with respect to the optical axis of the second optical system 25. Therefore, the blue light optical path is incident on a part of the second optical system 25 (more specifically, the positive lens 25A) on the first optical system 23 side. The blue light then travels toward the optical axis of the second optical system 25 at an angle, and is emitted from the second optical system 25 (more specifically, the positive lens 25B). The blue light emitted from the second optical system 25 is incident on the phosphor unit 26.

[0106] Here, the blue light incident on the phosphor unit 26 is incident on the excitation light reflection region 26E. The blue light incident on the excitation light reflection region 26E is specularly reflected. The blue light specularly reflected by the excitation light reflection region 26E is incident on a part of the second optical system 25 (more specifically, the positive lens 25B) on the opposite side to the first optical system 23. The blue light then travels away from the second optical system 25 at an angle to the optical axis of the second optical system 25, and is emitted from the second optical system 25 (more specifically, the positive lens 25A).

[0107] The blue light emitted from the second optical system 25 (more specifically, the positive lens 25A) passes through the second region 24B of the dichroic mirror 24. The blue light beam specularly reflected from the phosphor unit 26, or the blue light beam emitted from the second optical system 25 and transmitted through the second region 24B of the dichroic mirror 24, constitutes the excitation light beam Q emitted from the phosphor unit 103 described above. As described above, the second region 24B of the dichroic mirror 24 has optical properties that transmit the excitation light (and the fluorescent light). Therefore, even when the blue light beam (beam Q) intersects with the dichroic mirror 24, it is possible to suppress a decrease in light utilization efficiency.

[0108] The blue light transmitted through second region 24B of dichroic mirror 24 enters refractive optical system 27. The blue light then travels toward refractive optical system 27 at an angle to the optical axis thereof, and enters light tunnel 29 via color wheel 28. After being reflected multiple times and homogenized inside light tunnel 29, the light enters illumination optical system 30 disposed outside light source device 20.

[0109] Next, the optical path of the fluorescent light in light source device 20 according to this embodiment (hereinafter referred to as the "fluorescent light path" where appropriate) will be described with reference to Fig. 11B. Note that, for ease of explanation, part of the optical path of the fluorescent light is omitted in Fig. 11B. The fluorescent light path refers to the optical path along which light that is wavelength-converted in fluorescent region 26D of phosphor unit 26 out of the excitation light emitted by laser light source 21 travels.

[0110] The fluorescent light path is the same as the above-mentioned blue light light path until the blue light emitted from laser light source 21 is guided to phosphor unit 26. Here, the blue light incident on phosphor unit 26 is assumed to be incident on fluorescent region 26D. The blue light incident on fluorescent region 26D acts as excitation light for the phosphor, and is wavelength-converted by the phosphor to become fluorescent light including, for example, a yellow wavelength range, and is Lambert-reflected by the action of reflective coating 26D1 and phosphor layer 26D2.

[0111] The fluorescent light that has been Lambert-reflected by fluorescent region 26D is converted into parallel light by second optical system 25. The fluorescent light that has exited from second optical system 25 passes through dichroic mirror 24 and enters refractive optical system 27. The fluorescent light then travels toward refractive optical system 27 at an angle to the optical axis thereof, and enters light tunnel 29 via color wheel 28. After being reflected multiple times and homogenized inside light tunnel 29, the light enters illumination optical system 30 disposed outside light source device 20.

[0112] In this way, 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 made different before and after reflection from the phosphor unit 26. More specifically, the blue light optical path is formed so that the point (point P shown in FIG. 1) of the center of the projection image of the blue light projected from the laser light source 21 onto the first region 24A of the dichroic mirror 24 does not intersect with the light flux of the blue light reflected from the phosphor unit 26 (light flux Q shown in FIG. 1). As a result, the light flux of the blue light emitted from the phosphor unit 26 does not intersect with the center of the projection image of the blue light emitted from the laser light source 21, so that the blue light can be prevented from passing through the same place on the dichroic mirror 24, and therefore, the dichroic mirror 24 can be prevented from being damaged due to an increase in the light collection density, and reliability can be improved.

[0113] Also, since there is no need to prepare special optical elements such as a retardation plate or a polarization separation element (polarizing beam splitter) to separate the optical path of the blue light emitted from phosphor unit 26, it is possible to reduce the number of parts, reduce manufacturing costs, and miniaturize light source device 20. Furthermore, since no optical components that manipulate polarized light such as a retardation plate or a polarization separation element are used, it is possible to suppress a decrease in light utilization efficiency due to the reflectance, transmittance, absorptance, etc. of the optical components.

[0114] Furthermore, 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 fixed polarization direction. In addition, the light source unit having a plurality of laser light sources 21 is arranged so that the directions of the linear polarization are all the same. Therefore, the directions of the linear polarization of the light emitted from the light source unit are uniform. The direction of the linear polarization can be determined by the direction in which the light source unit is arranged. As shown in FIG. 16, when the light source unit is tilted in accordance with the inclination of the light tunnel 29, the direction of the linear polarization changes. In such a situation in which the direction of the linear polarization changes, if a configuration is used in which polarization is manipulated by a polarization separation element or the like, the light utilization efficiency may decrease when passing through the polarization separation element. In the light source device 20 according to the first embodiment, since a configuration in which polarization is manipulated is not adopted, it is possible to prevent the light utilization efficiency from decreasing due to the inclination of the laser light source 21.

[0115] Second embodiment The light source device 201 according to the second embodiment differs from the light source device 20 according to the first embodiment in the configuration of the dichroic mirror. The configuration of the light source device 201 according to the second embodiment will be described below, focusing on the differences from the light source device 20 according to the first embodiment. FIG. 17 is a schematic diagram showing the configuration of the light source device 201 according to the second embodiment. FIG. 17A shows the optical path of blue light in the light source device 201, and FIG. 17B shows the optical path of fluorescent light in the light source device 201. In FIG. 17, the same reference numerals are given to the configurations common to FIG. 11, and the description thereof will be omitted. In FIG. 17B, for convenience of explanation, a part of the optical path of the fluorescent light is omitted.

[0116] As shown in Fig. 17, light source device 201 differs from light source device 20 according to the first embodiment only in that it includes a dichroic mirror 241. Dichroic mirror 241 is disposed at an angle similar to dichroic mirror 24, but has a length shorter than dichroic mirror 24. Since dichroic mirror 24 is configured to have a short dimension, light source device 20 can be made compact. Dichroic mirror 241 has optical properties similar to those of a portion (first region 24A) of dichroic mirror 24.

[0117] Fig. 18 is a diagram showing an example of the configuration of a dichroic mirror 241 included in a light source device 201 according to the second embodiment. Note that in Fig. 18, the dichroic mirror 241 is shown from the incident direction of blue light (excitation light) emitted from the first optical system 23. As shown in Fig. 18, the dichroic mirror 241 is composed of only a single region 241A.

[0118] Like the first region 24A, the region 241A has the optical property of reflecting blue light emitted from the first optical system 23 (negative lens 23b) and transmitting fluorescent light converted from the blue light by the phosphor of the phosphor unit 26. Moreover, the region 241A is disposed at the same position as the first region 24A. That is, the region 241A 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 at a position shifted toward the first optical system 23 from the optical axis of the second optical system 25.

[0119] The blue light optical path and the fluorescent light optical path in the light source device 201 having such a configuration will be described with reference to Figs. 17A and 17B. As shown in Fig. 17A, the blue light emitted from the laser light source 21 is reflected by the excitation light reflecting region 26E of the phosphor unit 26 and is emitted to the second optical system 25, and the blue light optical path is the same as that of the first embodiment. In the light source device 201 according to the second embodiment, unlike the first embodiment, the blue light emitted from the second optical system 25 does not pass through the dichroic mirror 241. The blue light beam (beam Q) emitted from the phosphor unit 103 does not intersect with the dichroic mirror 24. On the other hand, the fluorescent light optical path is the same as that of the first embodiment, as shown in Fig. 17B.

[0120] In the light source device 201 of 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, so that, like the light source device 20 of the first embodiment, it is highly reliable and can be made smaller and less expensive.

[0121] In particular, in light source device 201, the width of dichroic mirror 241 can be made smaller than the width of second optical system 25, thereby making it possible to reduce the size of light source device 201. Furthermore, the optical path of the blue light reflected by phosphor unit 26 does not pass through dichroic mirror 241, so that a decrease in light utilization efficiency caused by the transmittance of dichroic mirror 241 can be suppressed.

[0122] Third embodiment The light source device 202 of the third embodiment differs from the light source device 201 of the second embodiment in that, in addition to a light source unit (hereinafter referred to as the "first light source unit") consisting of a laser light source 21 and a coupling lens 22, the light source device 202 has a light source unit (hereinafter referred to as the "second light source unit") consisting of a laser light source 211 and a coupling lens 221, and in that the light source device 202 has a polarizing optical component that combines the excitation light from the second light source unit with the excitation light from the first light source unit.

[0123] The configuration of the light source device 202 according to the third embodiment will be described below, focusing on the differences from the light source device 201 according to the second embodiment. FIG. 19 is a schematic diagram showing the configuration of the light source device 202 according to the third embodiment. FIG. 19A shows the optical path of blue laser light in the light source device 202 according to the third embodiment, and FIG. 19B shows the optical path of fluorescent light in the light source device 202 according to the third embodiment. Note that in FIG. 19, the same reference numerals are given to the configurations common to FIG. 17, and the description thereof will be omitted. Also, in FIG. 19B, for convenience of explanation, a part of the optical path of the fluorescent light is omitted.

[0124] 19, the light source device 202 has a laser light source 211 and a coupling lens 221 which constitute a second light source unit. The second light source unit is disposed so that the laser light emitted from the laser light source 211 is perpendicular to the laser light emitted from the laser light source 21 of the first light source unit.

[0125] The laser light source 211 has the same configuration as the laser light source 21. That is, the laser light source 211 has light sources (laser diodes) that emit a plurality of laser beams arranged in an array, and emits, for example, blue light with a center of emission intensity of 455 [nm]. Here, both of the laser light sources 21 and 211 are configured to emit P-polarized light. Similar to the coupling lens 22, the coupling lens 221 is a lens that receives the blue light emitted from the laser light source 211 and converts it into parallel light (collimated light).

[0126] Light source device 202 has a half-wave plate 222 and a polarization separation element 223 which constitute polarization optical components. Half-wave plate 222 is disposed facing a plurality of coupling lenses 221. Half-wave plate 222 converts the P-polarized component of the blue light emitted from laser light source 211 into an S-polarized component. Polarization separation element 223 is disposed on the optical path of the blue light emitted from laser light source 21 and the blue light emitted from laser light source 211. Polarization separation element 223 has an optical property of reflecting the S-polarized component of the blue light while transmitting the P-polarized component of the blue light.

[0127] The P-polarized component of the blue light emitted from the laser light source 21 passes through the polarization separation element 223 and is incident on the large-diameter lens 23a of the first optical system 23. On the other hand, the P-polarized component of the blue light emitted from the laser light source 211 is converted to S-polarized light by the half-wave plate 222, and then reflected by the polarization separation element 223 and is incident on the large-diameter lens 23a of the first optical system 23. In this way, the excitation light (blue light) from the second light source unit is combined with the excitation light (blue light) from the first light source unit.

[0128] The blue light optical path and the fluorescent light optical path in the light source device 202 having such a configuration will be described with reference to Figures 19A and 19B. As shown in Figures 19A and 19B, the blue light optical path and the fluorescent light optical path after being combined by the polarization separation element 223 and entering the large-diameter lens 23a of the first optical system 23 are the same as those in the second embodiment.

[0129] 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, so that, like the light source device 201 according to the second embodiment, it is highly reliable and can be made compact and inexpensive. In particular, in the light source device 202, the excitation light from the first light source unit is combined with the excitation light from the second light source unit, so that the luminance of the excitation light can be increased and the light utilization efficiency can be improved. In addition, the polarization is manipulated by the half-wave plate 222 and the polarization separation element 223 constituting the polarization optical components, so that the separation and combination of the optical paths can be realized regardless of the presence or absence of a mixture of polarized components of the light emitted from the light source.

[0130] (Fourth embodiment) Light source device 203 according to the fourth embodiment differs from light source device 201 according to the second embodiment in that it has a phosphor unit instead of phosphor unit 26. The configuration of light source device 203 according to the fourth embodiment will be described below, focusing on the differences from light source device 201 according to the second embodiment.

[0131] Fig. 20 is a schematic diagram showing a light source device 203 according to a fourth embodiment. Fig. 20A shows the optical path of blue laser light in light source device 203, and Fig. 20B shows the optical path of fluorescent light in light source device 203. Note that in Fig. 20, the same components as in Fig. 17 are given the same reference numerals and their explanations are omitted. Also, in Fig. 20B, for convenience of explanation, part of the optical path of fluorescent light is omitted.

[0132] Light source device 203 according to the fourth embodiment has a non-rotatable phosphor unit (hereinafter, appropriately referred to as a "stationary phosphor unit") 261, instead of the rotationally driven phosphor unit 26. Stationary phosphor unit 261 reflects a part of the blue light (excitation light) emitted from laser light source 21 as is, while converting the other part of the blue light into fluorescent light and emitting it (emitting it).

[0133] Fig. 21 is a schematic diagram for explaining the configuration of a stationary phosphor unit 261 included in a light source device 203 according to the fourth embodiment. In Fig. 21, the stationary phosphor unit 261 is shown in a direction perpendicular to the incident direction of blue light. As shown in Fig. 21, the stationary phosphor unit 261 is configured by stacking phosphor 261b, which is a wavelength conversion member, on a reflecting member 261a that reflects excitation light. For example, the reflecting member 261a and the phosphor 261b have a rectangular shape in a plan view. The phosphor 261b is applied onto the reflecting member 261a.

[0134] 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 is wavelength-converted by the phosphor 261b. As a result, the light becomes fluorescent light including a yellow wavelength range with a center of emission intensity of 550 [nm], for example, and is Lambert-reflected by the action of the phosphor 261b and the reflecting member 261a.

[0135] On the other hand, for example, 20% of the incident blue light (excitation light) does not act as excitation light and is reflected by the reflecting member 261a. Therefore, when blue light is incident on this stationary phosphor unit 261, blue light and fluorescent light are emitted simultaneously.

[0136] The blue light optical path and the fluorescent light optical path in light source device 203 having such a configuration will be described with reference to Fig. 20A and Fig. 20B. As shown in Fig. 20A and Fig. 20B, the blue light optical path and the fluorescent light optical path in light source device 203 are similar to those in the second embodiment, except for the wavelength conversion and reflection in stationary phosphor unit 261.

[0137] 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, so that, like the light source device 201 according to the second embodiment, it is possible to achieve excellent reliability, miniaturization, and cost reduction. In particular, in the light source device 203, the stationary phosphor unit 261 simultaneously emits blue light and fluorescent light, so there is no need to rotate the phosphor unit, and the manufacturing cost of the device can be reduced. In addition, since the motor for rotation can be omitted, it is possible to achieve quieter operation and prevent a decrease in reliability due to the life of the motor.

[0138] Fifth embodiment Light source device 204 according to the fifth embodiment differs from light source device 201 according to the second embodiment in that it has a mirror instead of dichroic mirror 241 and in the arrangement of components subsequent to first optical system 23. The configuration of light source device 204 according to the fifth embodiment will be described below, focusing on the differences from light source device 201 according to the second embodiment.

[0139] Fig. 22 is a schematic diagram showing a light source device 204 according to a fifth embodiment. Fig. 22A shows the optical path of blue laser light in light source device 204, and Fig. 22B shows the optical path of fluorescent light in light source device 204. Note that in Fig. 22, the same reference numerals are given to configurations common to Fig. 17, and description thereof will be omitted. Also, in Fig. 22B, for convenience of description, part of the optical path of fluorescent light is omitted.

[0140] As shown in Fig. 22A, light source device 204 has, arranged in this order in the light propagation direction, a laser light source (excitation light source) 21, a coupling lens 22, a first optical system 23, a second optical system 25, a phosphor unit 26, a mirror 242, a refractive optical system 27, a color wheel 28, and a light tunnel 29. For convenience of explanation, color wheel 28 is omitted in Fig. 22. Please refer to Fig. 10 for color wheel 28.

[0141] The mirror 242 is disposed at an incline with respect to the propagation direction of the blue light emitted from the second optical system 25. More specifically, the mirror 242 is disposed with its front end inclined upward along the propagation direction of the blue light emitted from the second optical system 25. The mirror 242 has an optical property of reflecting the blue light that has been made substantially parallel by the second optical system 25, and reflecting the fluorescent light converted by the phosphor unit 26. For example, the mirror 242 is coated with a coating that has the optical property described above. The mirror 242 is disposed at an offset from the optical axis of the positive lens 25A that constitutes the second optical system 25. The mirror 242 has an inclined surface 242A on the surface facing the positive lens 25A.

[0142] The blue light optical path in light source device 204 having such a configuration will be described with reference to Fig. 22A. The blue light optical path refers to the optical path along which light reflected by excitation light reflection region 26E of phosphor unit 26 travels, out of the excitation light emitted by laser light source 21.

[0143] The blue light emitted from the laser light source 21 is converted into a parallel light by the coupling lens 22. The blue light emitted from the coupling lens 22 is collected and combined by the large-diameter lens 23a of the first optical system 23, and then converted into a parallel light by the negative lens 23b. The blue light emitted from the negative lens 23b is incident on a part of the second optical system 25 (more specifically, the positive lens 25A) on the refractive optical system 27 side (the upper side shown in FIG. 22). The blue light then travels toward the optical axis of the second optical system 25 at an angle, and is emitted from the second optical system 25 (more specifically, the positive lens 25B). The blue light emitted from the second optical system 25 is incident on the phosphor unit 26.

[0144] Here, the blue light incident on the phosphor unit 26 is incident on the excitation light reflection region 26E. The blue light incident on the excitation light reflection region 26E is specularly reflected. The blue light specularly reflected by the excitation light reflection region 26E is incident on a part of the second optical system 25 (more specifically, the positive lens 25B) on the opposite side to the refractive optical system 27 (the lower side shown in FIG. 22). The blue light then travels away from the optical axis of the second optical system 25 at an angle, and is emitted from the second optical system 25 (more specifically, the positive lens 25A).

[0145] The blue light emitted from second optical system 25 (more specifically, positive lens 25A) is reflected by reflective surface 242A of mirror 242 and enters refractive optical system 27. The blue light then travels at an angle so as to approach the optical axis of refractive optical system 27, and enters light tunnel 29 via color wheel 28. After being reflected multiple times and homogenized inside light tunnel 29, the blue light enters illumination optical system 30 arranged outside light source device 20.

[0146] Next, the fluorescent light path in light source device 204 according to the present embodiment will be described with reference to Fig. 22B. The fluorescent light path refers to the light path along which light that is wavelength-converted in fluorescent region 26D of phosphor unit 26, out of the excitation light emitted by laser light source 21, travels.

[0147] The fluorescent light path is the same as the above-mentioned blue light light path until the blue light emitted from laser light source 21 is guided to phosphor unit 26. Here, the blue light incident on phosphor unit 26 is assumed to be incident on fluorescent region 26D. The blue light incident on fluorescent region 26D acts as excitation light for the phosphor, and is wavelength-converted by the phosphor to become fluorescent light including, for example, a yellow wavelength range, and is Lambert-reflected by the action of reflective coating 26D1 and phosphor layer 26D2.

[0148] The fluorescent light that has been subjected to Lambertian reflection by fluorescent region 26D is converted into parallel light by second optical system 25. The fluorescent light that has exited from second optical system 25 is reflected by reflecting surface 242A of mirror 242, and enters refractive optical system 27. The fluorescent light then travels at an angle so as to approach the optical axis of refractive optical system 27, and enters light tunnel 29 via color wheel 28. After being reflected multiple times and homogenized inside light tunnel 29, the fluorescent light enters illumination optical system 30 arranged outside light source device 20.

[0149] In this way, in the light source device 204 of the fifth 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, so that, like the light source device 20 of the first embodiment, it is highly reliable and can be made smaller and less expensive.

[0150] Sixth embodiment Light source device 205 according to the sixth embodiment differs from light source device 204 according to the fifth embodiment in that a dichroic mirror is provided in addition to mirror 242. The configuration of light source device 205 according to the sixth embodiment will be described below, focusing on the differences from light source device 204 according to the fifth embodiment.

[0151] Fig. 23 is a schematic diagram showing a light source device 205 according to a sixth embodiment. Fig. 23A shows the optical path of blue laser light in light source device 205, and Fig. 23B shows the optical path of fluorescent light in light source device 205. Note that in Fig. 23, the same reference numerals are given to configurations common to Fig. 22, and descriptions thereof will be omitted. Also, in Fig. 23B, for convenience of explanation, a part of the optical path of fluorescent light is omitted.

[0152] As shown in FIG. 23A, the light source device 205 has a dichroic mirror 243 in the vicinity of the mirror 242. The dichroic mirror 243 has an optical property of transmitting the blue light that has been made into a substantially parallel light by the second optical system 25, while reflecting the fluorescent light converted by the phosphor unit 26. For example, the dichroic mirror 243 is coated with a coating that has the above-mentioned optical property. The dichroic mirror 243 is disposed parallel to the mirror 242 on the side of the reflecting surface 242A of the mirror 242. That is, the dichroic mirror 243 is disposed inclined with respect to the propagation direction of the blue light emitted from the second optical system 25, similar to the mirror 242. Preferably, the dichroic mirror 243 is disposed on the optical axis of the second optical system 25. More preferably, the dichroic mirror 243 is disposed on the optical axis of the second optical system 25 and on the optical axis of the refractive optical system 27.

[0153] The blue light optical path in light source device 205 having such a configuration will be described with reference to Fig. 23A. The blue light optical path in light source device 205 differs from that of light source device 204 according to the fifth embodiment only in that blue light emitted from second optical system 25 is reflected by reflecting surface 242A of mirror 242 after transmitting through dichroic mirror 243. Therefore, detailed description thereof will be omitted.

[0154] Next, the fluorescent light path in the light source device 205 according to the present embodiment will be described with reference to FIG. 23B. After the blue light emitted from the laser light source 21 is converted into fluorescent light, the fluorescent light path is the same as that of the light source device 204 according to the fifth embodiment until it is converted into parallel light by the second optical system 25. In the light source device 205, the fluorescent light emitted from the second optical system 25 is reflected by the dichroic mirror 243, not the mirror 242, and enters the refractive optical system 27. The fluorescent light then travels at an angle so as to approach the optical axis of the refractive optical system 27, and enters the light tunnel 29 via the color wheel 28. After being reflected multiple times and homogenized inside the light tunnel 29, it enters the illumination optical system 30 arranged outside the light source device 20.

[0155] In this way, in light source device 205 according to the sixth embodiment, the optical path of the blue light emitted from laser light source 21 is made different before and after reflection by phosphor unit 26, so that, like light source device 20 according to the first embodiment, it is possible to achieve excellent reliability, miniaturization, and cost reduction. In particular, in light source device 205, by arranging dichroic mirror 243 on the optical axis of second optical system 25 and on the optical axis of refractive optical system 27, it is possible to improve the light utilization efficiency of fluorescent light.

[0156] Seventh embodiment The light source device 206 according to the seventh embodiment differs from the light source device 205 according to the sixth embodiment in that it has a light source unit (second light source unit) consisting of a laser light source 211 and a coupling lens 221 in addition to a light source unit (first light source unit) consisting of a laser light source 21 and a coupling lens 22, and in that it has a polarizing optical component that combines the excitation light from the second light source unit with the excitation light from the first light source unit. The configuration of the light source device 206 according to the seventh embodiment will be described below, focusing on the differences from the light source device 205 according to the sixth embodiment.

[0157] Fig. 24 is a schematic diagram showing a light source device 206 according to the seventh embodiment. Fig. 24A shows the optical path of blue laser light in light source device 206, and Fig. 24B shows the optical path of fluorescent light in light source device 206. Note that in Fig. 24, the same reference numerals are given to configurations common to Figs. 19 and 23, and descriptions thereof will be omitted. Also, in Fig. 24B, for convenience of explanation, part of the optical path of fluorescent light is omitted.

[0158] 24A, light source device 206 differs from light source device 205 according to the sixth embodiment in that light source device 206 has laser light source 211 and coupling lens 221 constituting a second light source unit, and has half-wave plate 222 and polarization separation element 223 constituting polarization optical components. For the configurations of the second light source unit, half-wave plate 222, and polarization separation element 223, please refer to light source device 202 according to the third embodiment shown in FIG.

[0159] The blue light optical path in light source device 206 having such a configuration will be described with reference to Fig. 24A. As shown in Fig. 24A, in light source device 206, the blue light optical path from laser light source 21 and laser light source 211 to first optical system 23 is the same as that of light source device 202 of the third embodiment (see Fig. 19A). In addition, the blue light optical path from first optical system 23 to incidence on light tunnel 29 is the same as that of light source device 205 of the sixth embodiment (see Fig. 23A). For this reason, detailed description thereof will be omitted.

[0160] Next, the fluorescent light path in light source device 206 according to the present embodiment will be described with reference to Fig. 24B. In light source device 206, the fluorescent light path from the laser light source 21 and the laser light source 211 to the first optical system 23 is the same as that of light source device 202 according to the third embodiment. In addition, the fluorescent light path from the first optical system 23 to the light tunnel 29 is the same as that of light source device 205 according to the sixth embodiment (see Fig. 23A). Therefore, detailed description thereof will be omitted.

[0161] In the light source device 206 according to the seventh 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, so that, like the light source device 20 according to the first embodiment, it is possible to achieve excellent reliability, miniaturization, and cost reduction. In particular, in the light source device 206, the excitation light from the first light source unit is combined with the excitation light from the second light source unit, so that the luminance of the excitation light can be increased and the light utilization efficiency can be improved. In addition, the polarization is manipulated by the half-wave plate 222 and the polarization separation element 223 constituting the polarization optical components, so that the separation and combination of the optical paths can be realized regardless of the presence or absence of a mixture of polarized components of the light emitted from the light source.

[0162] Eighth embodiment Light source device 207 according to the eighth embodiment differs from light source device 204 according to the fifth embodiment in that it has a phosphor unit that is not rotated (stationary phosphor unit) instead of the rotationally driven phosphor unit 26. The configuration of light source device 207 according to the eighth embodiment will be described below, focusing on the differences from light source device 204 according to the fifth embodiment.

[0163] Fig. 25 is a schematic diagram showing a light source device 207 according to an eighth embodiment. Fig. 25A shows the optical path of blue laser light in light source device 207, and Fig. 25B shows the optical path of fluorescent light in light source device 207. Note that in Fig. 25, the same components as those in Figs. 20 and 23 are given the same reference numerals and their explanations are omitted. Also, in Fig. 24B, for the sake of convenience, part of the optical path of fluorescent light is omitted.

[0164] 25A, light source device 206 differs from light source device 204 according to the fifth embodiment in that light source device 206 has a phosphor unit (stationary phosphor unit) 261 that is not rotated, instead of phosphor unit 26 that is rotated. For the configuration of stationary phosphor unit 261, please refer to light source device 203 according to the fourth embodiment shown in FIG.

[0165] The optical path of blue light in light source device 207 having such a configuration will be described with reference to Fig. 25A. As shown in Fig. 25A, in light source device 207, the optical path of blue light from laser light source 21 to stationary phosphor unit 261 is the same as that of light source device 205 of the sixth embodiment. In addition, the optical path of blue light from stationary phosphor unit 261 to incidence on light tunnel 29 is the same as that of light source device 205 of the sixth embodiment. Therefore, detailed description thereof will be omitted.

[0166] Next, the fluorescent light path in light source device 207 according to the present embodiment will be described with reference to Fig. 24B. In light source device 207, the fluorescent light path from laser light source 21 to stationary phosphor unit 261 is the same as that in light source device 205 of the sixth embodiment. In addition, the fluorescent light path from stationary phosphor unit 261 to incidence on light tunnel 29 is the same as that in light source device 205 according to the sixth embodiment. For this reason, detailed description thereof will be omitted.

[0167] In the light source device 207 according to the eighth 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, so that, like the light source device 20 according to the first embodiment, it is possible to achieve excellent reliability, miniaturization, and cost reduction. In particular, in the light source device 207, the stationary phosphor unit 261 simultaneously emits blue light and fluorescent light, so there is no need to rotate the phosphor unit, and the manufacturing cost of the device can be reduced. In addition, since the motor for rotation can be omitted, it is possible to achieve quieter operation and prevent a decrease in reliability due to the life of the motor.

[0168] In addition, although each of the above-mentioned embodiments shows a preferred embodiment of the present invention, the present invention is not limited to the contents thereof. In particular, the specific shapes and numerical values ​​of each part exemplified in each embodiment are merely examples of the embodiment of the present invention, and the technical scope of the present invention should not be interpreted in a limited manner based on these. Thus, the present invention is not limited to the contents described in the present embodiment, and can be appropriately modified within the scope of the gist of the present invention. [Explanation of symbols]

[0169] 1: Projector device 10: Housing 20:Light source device 21: Laser light source 21A: Laser diode 22: Coupling lens 23: First optical system 23a: Large aperture lens 23b: Negative lens 24:Dichroic mirror 24A: Area (first area) 24B: Area (first area) 25: Second optical system 25A, 25B: Positive lens 26: Phosphor unit 27: Refractive optical system 28: Color Wheel 29: Light Tunnel 29A:Incidence aperture 30: Illumination optical system 40: Image forming element 50: Projection optical system 60: Cooling device 100: Light source device 101 :Light source 101a: Light emitting surface 102:Dichroic mirror 102a: Reflective surface 103: Phosphor unit 103a: Output surface 103b:Incidence surface 104: Rod Integrator 104a:Incidence aperture 104b: Output aperture 105: Condenser lens 105a:Incidence surface 105b: Output surface 106: Refractive lens 201, 202, 203, 204, 205, 206, 207: Light source device 211: Laser light source 221: Coupling lens 222 :1 / 2 wavelength plate 223: Polarization separation element 241, 243: Dichroic mirror 241A :Area 242: Mirror 261: Phosphor unit (static phosphor unit) 261a: Reflective material 261b: Phosphor

Claims

1. A light source device, an excitation light source that emits a first color light; a first optical member having a first reflecting surface that reflects the first color light emitted from the excitation light source; a second optical member having a second reflecting surface that reflects the first color light reflected from the first reflecting surface of the first optical member; a rod integrator that mixes the first color light reflected from the second reflecting surface of the second optical member; Equipped with A center of the first color light on the first reflecting surface of the first optical member is defined as point P, a light flux of the first color light reflected from the first reflecting surface of the first optical member and incident on the second reflecting surface of the second optical member is defined as a light flux Q′; When a luminous flux of the first color light reflected from the second reflecting surface of the second optical member and incident on the rod integrator is defined as a luminous flux Q, The point P and the light beam Q do not intersect, a plane including the light beam Q′ and the light beam Q is disposed approximately parallel to a short side of an entrance opening of the rod integrator, the excitation light source is composed of a light source unit including a plurality of laser diodes arranged in rows and columns and a coupling lens provided on the emission surface side of the laser diodes; a divergence angle in a row direction or a column direction, which is larger, of the divergence angles of the first color light emitted from the laser diode is defined as θ; The pitch between adjacent laser diodes is p, When the distance from the light emitting point of the laser diode to the coupling lens is L, the arrangement interval of the laser diode satisfies the following formula: A light source device characterized by: 1≦p / L tan θ≦4

2. 2. The light source device according to claim 1, wherein when a center of a projected image of the first color light projected onto the second optical member is defined as point R, the rod integrator is disposed on a perpendicular line to the point R on the second reflecting surface of the second optical member.

3. 3. The light source device according to claim 1, wherein an angle β formed between the first color light on an incident surface of the first color light with respect to the incident opening of the rod integrator and the incident opening of the rod integrator is smaller than 40°.

4. 4. The light source device according to claim 1, wherein the rod integrator has an entrance opening smaller than an exit opening.

5. The excitation light source includes a plurality of laser diodes arranged in an array, a projection range on an entrance opening of the rod integrator onto which the first color light emitted from the laser diode is projected is elliptical, 5. The light source device according to claim 1, wherein a major axis of the elliptical shape is disposed approximately parallel to a long side or a short side of an entrance opening of the rod integrator.

6. 6. The light source device according to claim 5, wherein the plurality of laser diodes are disposed on the same substrate.

7. a large-aperture element having a positive power and a collimating element having a negative power are disposed on an optical path between the excitation light source and the first optical member in accordance with a traveling direction of the first color light, 7. A light source device as described in any one of claims 1 to 6, characterized in that the first color light emitted from the excitation light source is concentrated by the large-diameter element, then converted into approximately parallel light by the collimating element, and enters the first optical member.

8. A light source device according to any one of claims 1 to 7, an illumination optical system that guides light emitted from the light source device to an image display element; a projection optical system that projects an image generated by the image display element using the light guided by the illumination optical system.

Images