JP2021071693A - Light source device, image projection device, and light source optical system - Google Patents

Abstract

To provide a light source device and an image projection device that can reduce size and cost.SOLUTION: A light source device comprises: an excitation light source that emits first color light; an optical member having a reflection surface that reflects the first color light; and a wavelength conversion unit having a wavelength conversion member on which the first color light reflected by the optical member is incident and converts at least part of the first color light into second color light having a wavelength different from that of the first color light and emits the color light; and a condensation element that condenses the first color light emitted from the wavelength conversion unit. When the center of the first color light on the reflection surface of the optical member is point P, a light beam condensed by the condensation element is Q, a light path from the center of the bundle of rays emitted from the excitation light source to the point P is LO, and a light path from the point P to the condensation element is L1, the point P and the light beam Q do not intersect with each other, and a straight line including the light path L0 intersects with a plane formed by the light path L1 and the light beam Q at substantially 90 degrees.SELECTED DRAWING: Figure 21

Description

The present invention relates to a light source device, an image projection device, and a light source optical system.

Today, projectors (image projection devices) that magnify and project various images are widely used. The projector collects the light emitted from the light source on a spatial light modulation element such as a digital micromirror device (DMD) or a liquid crystal display element, and emits light from the spatial light modulation element modulated by a video signal on the screen. Is displayed as a color image.

Conventionally, a high-brightness ultra-high pressure mercury lamp or the like has been mainly used as a light source of a projector, but since the life is short, it is necessary to perform maintenance frequently. In recent years, the number of projectors that use a laser light source, an LED (Light Emitting Diode) light source, or the like instead of an ultra-high pressure mercury lamp is increasing. Laser light sources and LED light sources have a longer life than ultra-high pressure mercury lamps, and their monochromaticity has good color reproducibility.

In a projector, an image is formed by irradiating an image display element such as a DMD with three-color light of, for example, red, green, and blue, which are the three primary colors of colors. It is possible to generate all of these three colors with a laser light source, but this is not preferable because the luminous efficiency of the green laser and the red laser is lower than that of the blue laser. Therefore, a method is used in which a phosphor is irradiated with a blue laser as excitation light to generate red light and green light from the fluorescent light whose wavelength is converted by the phosphor.

Since the phosphor is irradiated with the excitation light of several tens [W], the efficiency decreases and the aging changes due to burning or temperature rise. Therefore, by rotating the disk on which the phosphor layer is formed, the irradiation position of the excitation light is prevented from being concentrated at one point. This disk is called a phosphor wheel. In the phosphor wheel, the phosphor is formed in a fan shape or an annulus shape along the outer circumference of the disk.

As a light source device using the DMD and the phosphor wheel as described above, it has been proposed to use a part of the phosphor wheel as a transmission plate in order to simplify the entire device (see, for example, Patent Document 1). .. In the technique described in Patent Document 1, the excitation light transmitted through the phosphor wheel is reflected by a mirror a plurality of times and guided in the same direction as the fluorescent light. As a result, the excitation light and the fluorescent light are combined in the same optical path and irradiated to the DMD.

Further, as a light source device using the DMD and the phosphor wheel as described above, it has been proposed to use a part of the phosphor wheel as a reflector in order to reduce the size of the entire device (for example, Patent Document 2). reference). In the technique described in Patent Document 2, the excitation light is reflected by the phosphor wheel in the same direction as the fluorescent light, and a retardation plate such as a 1/4 wave plate is used so that the reflected excitation light does not return to the excitation light source. And the light path is separated by using a polarization separation element. As a result, the excitation light and the fluorescent light are combined in the same optical path and irradiated to the DMD.

Japanese Patent No. 471156 Japanese Patent No. 5817109

However, in the above-mentioned Patent Document 1, since the optical path of the excitation light is bypassed, the entire device becomes large. On the other hand, in the above-mentioned Patent Document 2, since the retardation plate and the polarizing separation element are used, the cost is high. Further, the optical path of the excitation light directed to the phosphor wheel and the optical path of the excitation light reflected from the phosphor wheel pass through the same portion in the retardation plate or the polarization separating element. For this reason, the light collection density on these optical elements increases, causing damage and the like, and the reliability decreases.

An object of the present invention is to provide a light source device, an image projection device, and a light source optical system capable of reducing the size and cost.

In the light source device according to the present invention, an excitation light source that emits first colored light, an optical member having a reflecting surface that reflects the first colored light, and the first colored light reflected by the optical member are incident. A wavelength conversion unit having a wavelength conversion member that converts at least a part of the first color light into a second color light having a wavelength different from that of the first color light and emits the light, and a second color light emitted from the wavelength conversion unit. A light collecting element for condensing 1 colored light is provided, the center of the first colored light on the reflecting surface of the optical member is a point P, the light source collected by the condensing element is Q, and the excitation is performed. Assuming that the center of the light flux emitted by the light source and the optical path leading to the point P are LO, and the optical path from the point P to the condensing element is L1, the point P and the light beam Q do not intersect and include the optical path L0. The straight line is characterized in that it intersects the plane formed by the light path L1 and the light source Q at approximately 90 degrees.

According to the present invention, it is possible to provide a light source device, an image projection device, and a light source optical system that can be miniaturized and reduced in cost.

An embodiment of the light source device according to the present invention is schematically shown. FIG. 1A is an optical layout diagram, and FIG. 1B is a schematic diagram showing an example of excitation light projected on a dichroic mirror included in the light source device. It is an optical layout diagram which schematically shows another embodiment of the light source apparatus which concerns on this invention. It is an optical layout diagram which shows still another Embodiment of the light source apparatus which concerns on this invention. It is an optical layout diagram which shows still another Embodiment of the light source apparatus which concerns on this invention. Yet another embodiment of the light source device according to the present invention is schematically shown. FIG. 5A is an optical layout view, FIG. 5B is a face-to-face view of a rod integrator in the light source device as viewed from the incident aperture surface side, and FIG. It is a face-to-face view which looked at the rod integrator from the exit opening surface. Yet another embodiment of the light source device according to the present invention, FIG. 6A is an optical layout diagram showing an optical path of excitation light, and FIG. 6B is an optical layout diagram showing an optical path of fluorescent light in the present embodiment. It is a schematic diagram for demonstrating the optical characteristic of the rod integrator. It is a schematic diagram which shows another example of the rod integrator applicable to this invention. It is an optical layout diagram which shows typically the 1st Embodiment of the light source apparatus which concerns on this invention, and the embodiment of the projector apparatus provided with this. The light source device according to the first embodiment is shown, FIG. 10A is an optical arrangement diagram showing an optical path of a blue laser light, and FIG. 10B is an optical arrangement diagram showing an optical path of a fluorescent light. It is explanatory drawing of the main part of the light source unit which the light source apparatus which concerns on 1st Embodiment has. It is a front view which shows an example of the structure of the dichroic mirror which the light source apparatus which concerns on 1st Embodiment has. The configuration of the phosphor unit included in the light source device according to the first embodiment is shown. FIG. 13A is a front view showing from the incident direction of blue light, and FIG. 13B is a side view showing from a direction orthogonal to the incident direction of blue light. is there. A schematic configuration of a color wheel included in the light source device according to the first embodiment is shown, FIG. 14A is a front view showing from the incident direction of blue light and fluorescent light, and FIG. 14B is orthogonal to the incident direction of blue light and fluorescent light. It is a side view which shows from a direction. A light tunnel included in the light source device according to the first embodiment is shown, FIG. 15A is a schematic view showing an example of light incident on an incident opening, and FIG. 15B is an incident light on an incident opening of the light tunnel. It is a schematic diagram which shows another example of. The optical path of the second embodiment of the light source device according to the present invention is shown, FIG. 16A is an optical arrangement diagram showing an optical path of blue light, and FIG. 16B is an optical arrangement diagram showing an optical path of fluorescent light. It is a front view which shows an example of the structure of the dichroic mirror applicable to the light source apparatus which concerns on 2nd Embodiment. A third embodiment of the light source device according to the present invention is shown. FIG. 18A is an optical arrangement diagram showing an optical path of a blue laser light, and FIG. 18B is an optical arrangement diagram showing an optical path of a fluorescent light. A fourth embodiment of the light source device according to the present invention is shown. FIG. 19A is an optical arrangement diagram showing an optical path of a blue laser light, and FIG. 19B is an optical arrangement diagram showing an optical path of a fluorescent light. It is a side view which shows typically the structure of the phosphor unit which the light source apparatus which concerns on 4th Embodiment has. A fifth embodiment of the light source device according to the present invention is schematically shown. FIG. 21A is an optical arrangement diagram viewed from a direction facing the exit surface of the light source, and FIG. 21B is a diagram 21B around a vertical axis. It is an optical arrangement drawing rotated by 90 degrees. A part of the fifth embodiment of the light source device is shown. FIG. 22A is an optical path diagram showing how blue light is incident on a dichroic mirror, and FIG. 22B is an optical path diagram showing how blue light is incident on a phosphor unit. A sixth embodiment of the light source device according to the present invention is schematically shown, and FIG. 23A is an optical layout view seen from the side direction, and FIG. 23B is an optical layout view seen from the plane direction. The second embodiment is schematically shown for comparison with the sixth embodiment. FIG. 24A is an optical layout view seen from the side surface direction, and FIG. 24B is an optical layout view seen from the plane direction. The seventh embodiment of the light source apparatus which concerns on this invention is a front view. It is a front view which shows the comparative example with respect to the said 7th Embodiment. It is a perspective view which shows the example of the optical mixing element applicable to this invention together with the appearance of the luminance unevenness.

As a light source device using a digital micromirror device (DMD) and a phosphor wheel, a device in which a part of the phosphor wheel is used as a reflector in order to reduce the size of the entire device is known. In this light source device, the phosphor wheel reflects the excitation light in the same direction as the fluorescence light, and a retardation plate such as a 1/4 wave plate and polarized light are placed on the optical path so that the reflected excitation light does not return to the excitation light source. Separation elements are arranged.

In the light source device having such a configuration, since the retardation plate and the polarization separating element are arranged on the optical path of the excitation light, the miniaturization of the device is restricted and the cost is high. Further, the optical path of the excitation light directed to the phosphor wheel and the optical path of the excitation light reflected from the phosphor wheel pass through the same portion of the retardation plate and the polarization separating element. For this reason, the light collection density on these optical elements increases, causing damage and the like, and the reliability of the light source device decreases.

The present inventors have focused on the fact that the structure inside the light source device is a factor that hinders the miniaturization and cost reduction of the device body and is a factor that lowers the reliability. Further, preventing the optical path of the excitation light directed to the phosphor wheel from overlapping with the optical path of the excitation light reflected by the phosphor wheel contributes to miniaturization, cost reduction, and improvement of reliability of the apparatus main body. This led to the present invention.

In the present invention, a light source that emits excitation light, an optical member having a reflecting surface that reflects the excitation light emitted from the light source, and the excitation light reflected by the optical member are incident to excite at least a part of the excitation light. In a light source device including a wavelength conversion unit having a wavelength conversion member that converts light into fluorescent light having a wavelength different from that of light and emits the light, the center of the projected image of the excitation light projected on the reflection surface of the optical member is pointed at point P. When the light source of the excitation light emitted from the wavelength conversion unit is the light source Q, the main point is to arrange the points P so that the light source Q does not intersect.

According to the present invention, since the luminous flux of the excitation light emitted from the wavelength conversion unit does not intersect the center of the projected image of the excitation light emitted from the light source, the excitation light is transmitted through the same location on the optical member. Can be prevented. Therefore, it is possible to suppress damage to the optical member due to an increase in the light collection density, and it is possible to improve the reliability of the apparatus. Further, it is not necessary to prepare a special optical element such as a retardation plate or a polarization separating element in order to separate the optical path of the excitation light emitted from the wavelength conversion unit. Therefore, the number of parts can be reduced, the manufacturing cost can be reduced, and the device can be miniaturized.

FIG. 1 shows an outline of the light source device 100 according to the present invention. FIG. 1A shows the components of the light source device 100 according to the present invention. FIG. 1B shows the state of the excitation light projected on the reflection surface 102a of the dichroic mirror 102 included in the light source device 100. FIG. 1B looks at the reflection surface 102a along the traveling direction of the excitation light from the light source 101.

As shown in FIG. 1A, the light source device 100 includes a light source 101 made of an excitation light source and a dichroic mirror 102 constituting an example of an optical member. The light source device 100 also includes a phosphor unit 103, which is an example of a wavelength conversion unit, and a rod integrator 104, which is an example of an optical mixing element.

The light source device 100 according to the present invention is not limited to the configuration shown in FIG. 1, and can be appropriately changed. For example, the light source device 100 may include only the light source 101, the dichroic mirror 102, and the phosphor unit 103. Among the light source devices 100 having the light source 101, the dichroic mirror 102, and the phosphor unit 103, the "light source optical system" is composed of the components excluding the light source 101.

The light source 101 emits excitation light (sometimes referred to as "first color light" in a later description). 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 portion of the dichroic mirror 102 other than the reflecting surface 102a may have optical characteristics of transmitting the excitation light emitted from the light source 101 and the fluorescent light emitted from the phosphor unit 103 described later.

The phosphor unit 103 converts the excitation light into a first region that reflects or diffusely reflects the excitation light, and at least a part of the excitation light into fluorescent light having a wavelength different from that of the excitation light (sometimes referred to as “second color light”). It has a second region to emit light. When the excitation light is incident, the phosphor unit 103 sequentially switches between the excitation light and the fluorescent light and emits the excitation light to the incident surface side (upper side shown in FIG. 1). The rod integrator 104 is provided so that the excitation light and the fluorescent light emitted from the phosphor unit 103 are incident, and the incident excitation light and the fluorescent light are mixed and homogenized and emitted to the outside of the light source device 100.

FIG. 1A shows a case where the first region of the phosphor unit 103 exists on the optical path of the excitation light emitted from the light source 101. The excitation light emitted from the light source 101 is reflected on the reflecting surface 102a of the dichroic mirror 102 toward the phosphor unit 103. The excitation light reflected by the reflection surface 102a is reflected to the incident surface side of the excitation light in the first region of the phosphor unit 103. The rod integrator 104 is arranged at the reflection destination of the excitation light by the phosphor unit 103.

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

The center point P of the excitation light on the reflection surface 102a, that is, the projected image center of the projected excitation light is defined as follows.
(1) When the light intensity distribution in the projection range of the excitation light projected on the reflection surface 102a is line-symmetrical or point-symmetrical.
The center of the minimum circumscribed circle in the projection range of the excitation light is the center of the projected image.
(2) When the light intensity distribution in the projection range of the excitation light projected on the reflecting surface 102a is other than line symmetry or point symmetry, that is, when it is other than the above (1).
As shown in FIG. 1B, the total energy of the excitation light projected on the reflecting surface 102a is defined as A, the projection range is cut out by a circle having an arbitrary radius r, and the total energy of the light contained in the circle is defined as B. To do. The center of the circle having a B / A of 93% or more (B / A ≧ 93%) and the energy density in the circle having the maximum energy density is defined as the center of the projected image.

Note that the projection range of the excitation light, in the energy distribution of the excitation light projected onto the reflective surface 102a, indicating the range with a 1 / e ² or more of the energy of the maximum energy. The energy density is obtained by dividing "energy contained in a circle" by "area of a circle", that is,
Energy density = Energy contained in a circle / Area of a circle. The projected image center P of the excitation light defined in this way is determined in a state where all the light sources 101 provided in the light source device 100 are lit.

Light beam Q of the excitation light emitted from the phosphor unit 103, the energy distribution of the excitation light on the propagation direction and the plane perpendicular to the excitation light, of the light beam passing through the range with a 1 / e ² or more of the energy of the maximum energy flux It means that.

According to the light source device 100 according to the embodiment of the present invention, the luminous flux Q of the excitation light emitted from the phosphor unit 103 is the center on the reflection surface 102a of the excitation light emitted from the light source 101, and the projection of the excitation light. It does not intersect the center of the statue. Therefore, it is possible to prevent the excitation light from passing through the same portion on the dichroic mirror 102, and it is possible to suppress damage to the dichroic mirror 102 due to an increase in the focusing density. Further, it is not necessary to prepare a special optical element such as a retardation plate or a polarization separating element in order to separate the optical path of the excitation light emitted from the phosphor unit 103. Therefore, the number of parts can be reduced, the manufacturing cost can be reduced, and the device can be miniaturized.

In the light source device 100 shown in FIG. 1, a case where the phosphor unit 103 sequentially switches and emits the excitation light and the fluorescent light, that is, a case where the excitation light and the fluorescent light are time-divided and emitted is described. However, the phosphor unit 103 is not limited to such a configuration, and may be configured to emit excitation light and fluorescent light at the same time.

For example, the phosphor unit 103 is a 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, that is, the first region, instead of the first and second regions described above. It has 3 regions. The wavelength conversion member provided in this third region reflects the excitation light and converts it into fluorescent light. The phosphor unit 103 is sometimes called a static phosphor unit. When the excitation light is incident, the phosphor unit 103 together emits the excitation light and the fluorescent light to the incident surface side (upper side shown in FIG. 1) of the excitation light. Even when such a phosphor unit 103 is provided, the same effect as when the time-division type phosphor unit 103 is used can be obtained.

Further, the light source device 100 shown in FIG. 1 may include a light guide means for guiding one or both of the excitation light and the fluorescent light emitted from the phosphor unit 103 to the rod integrator 104. For example, the light guide means is composed of a condenser lens or a refraction lens, and is arranged on an optical path between the phosphor unit 103 and the rod integrator 104. By providing the light guide means, the excitation light and / or the second color light emitted from the phosphor unit 103 can be efficiently guided to the rod integrator 104, and the light utilization efficiency can be enhanced.

In the light source device 100 according to the embodiment of the present invention, the position of the rod integrator 104 can be appropriately changed in order to improve the utilization efficiency of the incident excitation light and / or fluorescent light. FIG. 2 shows another embodiment of the light source device according to the present invention. In FIG. 2, the same reference numerals are given to the configurations common to those of the embodiment shown in FIG. 1, and the description thereof will be simplified. FIG. 2 shows a case where a reflecting surface 102a is formed on the surface of the dichroic mirror 102. The same applies to the drawings shown below.

As shown in FIG. 2, consider a case where the center of the projected image of the excitation light projected from the dichroic mirror 102 onto the phosphor unit 103 is the point R. In this case, the rod integrator 104 is preferably arranged on the perpendicular line of the point R on the exit surface 103a of the phosphor unit 103. When the rod integrator 104 is arranged in this way, when the fluorescent light is emitted perpendicularly to the emission surface 103a of the phosphor unit 103, the fluorescent light is efficiently incident on the rod integrator 104 on the fluorescent light side, and the light utilization efficiency of the fluorescent light is improved.

In the light source device 100 according to the embodiment of the present invention, the condensing element may be arranged on the optical path between the dichroic mirror 102 and the phosphor unit 103. This condensing element collects the excitation light reflected by the dichroic mirror 102 and substantially parallelizes the fluorescent light emitted from the phosphor unit 103. The condensing element can be composed of, for example, a condensing lens.

FIG. 3 shows yet another embodiment of the light source device according to the present invention. In FIG. 3, the same reference numerals are given to the configurations common to those of the embodiment shown in FIG. 1, and the description thereof will be omitted. The light source device 100 shown in FIG. 3 includes a condensing lens 105 as a condensing element on the optical path between the dichroic mirror 102 and the phosphor unit 103. The condenser lens 105 collects the excitation light reflected by the dichroic mirror 102, while substantially parallelizing the fluorescence light emitted from the phosphor unit 103.

Here, the center of the projected image on the incident surface 105a of the condensing lens 105, which is reflected by the reflecting surface 102a of the dichroic mirror 102 and projected by the excitation light incident on the condensing lens 105, and the point P on the reflecting surface 102a. Let L1 be the straight line connecting the above. Further, the intersection of the incident surface 103b of the excitation light collected by the condenser lens 105 and incident on the phosphor unit 103 and the straight line L1 is defined as the point S. 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 arranged at different positions. By providing the condenser lens 105 in this way, the excitation light and the fluorescent light emitted after being emitted from the phosphor unit 103 are parallelized. Therefore, these lights can be efficiently incident on the rod integrator 104, and the light utilization efficiency can be improved.

In the light source device 100 shown in FIG. 3, it is preferable that the straight line L1 intersects the incident surface 103b of the phosphor unit 103 perpendicularly. When the straight line L1 is configured to intersect the incident surface 103b of the phosphor unit 103 perpendicularly, the distance between the dichroic mirror 102 and the phosphor unit 103 can be shortened, and the dimensions of the entire light source device 100 can be reduced.

When light is transmitted through a thick optical element, the surface on which the light is incident is the incident surface, and the surface on which the light is emitted is the exit surface. For example, in the condensing lens 105 shown in FIG. 3, the surface on which the reflected light from the reflecting surface 102a of the dichroic mirror 102 is incident is the incident surface 105a, which is transmitted through the condensing lens 105 from the incident surface 105a and is a phosphor. The surface that emits light to the unit 103 side is the exit surface 105b.

In the light source device 100 according to the embodiment of the present invention, a refraction optical element may be arranged between the condenser lens 105 and the rod integrator 104. The refraction optical element collects the excitation light and / or the fluorescent light parallelized by the condensing lens 105, which is a condensing element, and guides it to the rod integrator 104. The refracting optical element is composed of, for example, a refracting lens. FIG. 4 shows a light source device 100 according to an embodiment of the present invention having such a configuration. In FIG. 4, the same reference numerals are given to the configurations common to the embodiments shown in FIG. 3, and the description thereof will be omitted.

In the light source device 100 shown in FIG. 4, a refraction lens 106 as a refraction optical element is provided on the optical path between the condenser lens 105 and the rod integrator 104. The refracting lens 106 refracts the excitation light and / or the fluorescent light parallelized by the condensing lens 105, which is a condensing element, and condenses the light, and guides the light to the incident opening 104a of the rod integrator 104. By providing the refracting lens 106 in this way, the excitation light and / or the fluorescent light parallelized by the condenser lens 105 can be efficiently incident on the rod integrator 104, and the light utilization efficiency is improved.

In the light source device 100 shown in FIG. 4, it is preferable to select the arrangement position of the rod integrator 104 from the viewpoint of homogenization and homogenization of the excitation light and / or the fluorescent light incident on the rod integrator 104. Specifically, when the inner peripheral cross section of the rod integrator 104 is rectangular, the long side of the elliptical cross section such as the excitation light incident on the rod integrator 104 is arranged so as to correspond to the long side of the inner peripheral cross section of the rod integrator 104. It is good to do.

Further, in the light source device 100 shown in FIG. 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 reflection surface 102a of the dichroic mirror 102. Specifically, when the light emitting surface of the light source 101 is rectangular, it is preferable to arrange the light source 101 so that the width of the excitation light is narrow.

FIG. 5 shows yet another embodiment of the light source device according to the present invention. In FIG. 5, the same reference numerals are given to the configurations common to the embodiments shown in FIG. 4, and the description thereof will be omitted. FIG. 5B is an explanatory view of the incident opening 104a of the rod integrator 104 included in the light source device 100, and FIG. 5C is an explanatory diagram of the light source 101 included in the light source device 100. FIG. 5B is a view of the incident opening 104a of the rod integrator 104 as viewed from the phosphor unit 103 side. FIG. 5C is a view of the light emitting surface of the light source 101 viewed from the dichroic mirror 102 side.

In the light source device 100 shown in FIG. 5, the center of the projected image on the incident opening 104a of the rod integrator 104 on which the excitation light and / or the fluorescent light refracted and condensed by the lens 106 is projected is defined as a point T. A straight line L2 is a straight line connecting this point T and the point R which is the center of the projected image of the excitation light projected on the phosphor unit 103. On the other hand, as shown in FIG. 5B, the incident opening 104a of the rod integrator 104 has a rectangular shape having _{a long side LE 1} and a short side SE _1. Further, as shown in FIG. 5C, the light emitting surface 101a of the light source 101 has a rectangular shape having _{a long side LE 2} and a short side SE _2.

In the light source device 100, it is preferable that the plane including the straight line L1 and the straight line L2, that is, the plane including the paper surface shown in FIG. 5A, and the short side SE _{1 of the incident opening 104a of the rod integrator 104 are substantially parallel. That is, it is preferable to arrange the rod integrator 104 so that the short side SE 1} of the rod integrator 104 shown in FIG. 5B is parallel to the paper surface in the figure shown in FIG. 5A. By arranging the rod integrator 104 in this way, the excitation light or the like can be incident so as to hit the inner side surface corresponding to _{the long side LE 1 of the incident opening 104a of the rod integrator 104.} Therefore, the number of reflections of the excitation light or the like inside the rod integrator 104 can be increased to make the excitation light or the like uniform, and the occurrence of color unevenness in the excitation light or the like can be suppressed.

Further, in the light source device 100, it is preferable that the surface including the straight line L1 and the straight line L2, that is, the plane including the paper surface of FIG. 5A and the short side SE ₂ of the light emitting surface 101a of the light source 101 are substantially parallel. _{That is, it is preferable to arrange the light source 101 so that the short side SE 2} of the light emitting surface 101a shown in FIG. 5C is parallel to the paper surface in the figure shown in FIG. 5A. When the light source 101 is arranged in this way, the width of the light flux extending in the extending direction of the surface including the straight line L1 and the straight line L2 can be narrowed, vignetting on the reflecting surface 102a of the dichroic mirror 102 can be suppressed, and a decrease in light utilization efficiency can be suppressed. it can. Further, it is possible to avoid interference of the light reflected by the phosphor unit 103 with the dichroic mirror 102 and suppress a decrease in light utilization efficiency.

In the light source device 100 according to the embodiment of the present invention, it is preferable to select the arrangement of the rod integrator 104 in relation to the refracting lens 106. For example, it is preferable that the center of the projected image of the rod integrator 104 on the incident opening 104a, the center of the projected image of the fluorescent light on the incident opening 104a of the rod integrator 104, and the optical axis of the refracting lens 106 intersect at one point.

FIG. 6 shows an outline of the light source device 100 according to still another embodiment of the present invention. In FIG. 6, the same reference numerals are given to the configurations common to the embodiments shown in FIG. 5, and the description thereof will be omitted. FIG. 6A shows the optical path of the excitation light in the light source device 100, and FIG. 6B shows the optical path of the fluorescent light in the light source device 100. In FIG. 6, for convenience of explanation, a pair of condenser lenses 105 ₁ and 105 ₂ arranged along the light propagation direction are shown.

In the light source device 100 shown in FIG. 6, the center of the projected image of the excitation light and the fluorescent light collected by the refraction lens 106 on the incident opening 104a of the rod integrator 104 is assumed to be the above-mentioned point T. Further, the refraction lens 106 is arranged so that its optical axis LA passes through the point T. Therefore, the center of the projected image of the excitation light and the fluorescent light projected on the incident opening 104a of the rod integrator 104 intersects with the optical axis LA of the refracting lens 106 at one point. As a result, the excitation light and the fluorescent light can be incident on the vicinity of the center of the incident opening 104a of the rod integrator 104, suppress the vignetting of the light by the incident opening 104a of the rod integrator 104, and improve the light utilization efficiency. .. Further, even when the optical elements in the light source device 100 are displaced due to the tolerance of the parts, the decrease in the light utilization efficiency can be suppressed.

The arrangement of the refracting lens 106 in the light source device 100 according to the embodiment of the present invention can be selected from the viewpoint of setting the angles of the excitation light and the fluorescent light incident on the incident opening 104a of the rod integrator 104 within a certain range. preferable. The angle of the light ray with respect to the incident opening 104a means the angle formed by the normal line of the surface parallel to the incident opening 104a and the light ray. In the light source device 100, the incident angle of the excitation light ray incident on the incident opening 104a at the largest angle is smaller than the incident angle of the fluorescent light ray incident on the incident opening 104a at the largest angle. It is preferable to set it.

As shown in FIG. 6A, the angle of incidence of the light beam of the excitation light incident on the incident opening 104a at the largest angle is defined as the angle θ ₁ . As shown in FIG. 6B, the angle of incidence of the light beam of the fluorescent light incident on the incident opening 104a at the largest angle is defined as the angle θ ₂ . In the light source device 100, it is preferable to set the _{angle θ 1} to be smaller than the angle θ _2. By setting the incident angle θ ₁ of the excitation light to be smaller than the incident angle θ ₂ of the fluorescent light, vignetting of light in the optical system arranged after the light source device 100 can be suppressed, and the light utilization efficiency can be improved.

Incidentally, in the light source apparatus 100 according to the present invention, the incident angle theta ₂ of the incidence angle theta ₁ and the fluorescent light of the excitation light may be set to the same angle. By setting the incident angle θ ₁ of the excitation light to the same angle as the incident angle θ ₂ of the fluorescent light, the distribution of the excitation light and the fluorescent light projected on the DMD or the screen can be made substantially the same, and the distribution of the excitation light and the like can be made substantially the same. The occurrence of color unevenness can be suppressed.

In the light source apparatus 100 according to an embodiment of the present invention, the optical properties of the rod integrator 104 is preferably set in relation to the incident angle theta ₂ of the incidence angle theta ₁ and the fluorescent light of the excitation light described above. For example, the rod integrator 104 of the light source apparatus 100 configured with a glass rod integrator, it is preferable that the total reflection condition is set to be larger than the incident angle theta ₂ of the incidence angle theta ₁ and the second color light of the excitation light.

The optical characteristics of the rod integrator 104 included in the light source device 100 according to the embodiment of the present invention will be described with reference to FIG. 7. In FIG. 7, the rod integrator 104 is a glass rod integrator. It is assumed that the total reflection condition in the rod integrator 104 is an angle θ _glass. In this case, the angle theta _Glass is set larger than the incident angle theta ₂ of the incidence angle theta ₁ and fluorescence light of the excitation light. As a result, the loss of excitation light or the like inside the rod integrator 104 can be prevented, so that the light utilization efficiency can be improved.

In the light source device 100 according to the embodiment of the present invention, the rod integrator 104 constituting the optical mixing element preferably has a tapered shape in which the incident opening 104a is smaller than the exit opening 104b, as shown in FIG. When the rod integrator 104 has a tapered shape in this way, the light emission angle from the rod integrator 104 becomes small, vignetting of light in the optical system at the subsequent stage of the light source device 100 is suppressed, and the light utilization efficiency is improved.

Next, some embodiments of the light source optical system, the light source device, and the image projection device according to the present invention will be described. The plurality of embodiments shown below show an example of the light source optical system, the light source device, and the image projection device according to the present invention, and can be changed as appropriate. It is also possible to appropriately combine the respective embodiments.

(First Embodiment)
FIG. 9 is a schematic configuration diagram showing a projector device (also referred to as an “image projection device”) 1 provided with a light source device 20 according to the first embodiment of the present invention. As shown in FIG. 9, the projector device 1 includes a housing 10, a light source device 20, an illumination optical system 30, an image forming element (also referred to as an “image display element”) 40, a projection optical system 50, and cooling. It has a device 60.

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

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

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

The projection optical system 50 magnifies and projects a color image formed by the image forming element 40 onto a screen (not shown), that is, a projected surface. The projection optical system 50 has, for example, one or more lenses. The cooling device 60 cools each of the heat-bearing elements and devices in the projector device 1.

FIG. 10 shows the light source device 20 according to the first embodiment. FIG. 10A shows the optical path of the blue laser light in the light source device 20, and FIG. 10B shows the optical path of the fluorescent light in the light source device 20.

As shown in FIG. 10A, the light source device 20 includes a laser light source (excitation light source) 21, a coupling lens 22, a first optical system 23, and a dichroic mirror 24, which is an example of an optical member, arranged in order in the light propagation direction. Has. The light source device 20 further includes a second optical system 25, a phosphor unit 26 which is an example of a wavelength conversion unit, a refractive optics system 27, and a light tunnel 29 which is an example of an optical mixing element.

In FIG. 10, the color wheel is omitted for convenience of explanation. As shown in FIG. 9, the color wheel 29 is arranged between the bending optical system 27 and the light tunnel 29. As shown in FIG. 9, in the present embodiment, the color wheel 28 is described as a component of the light source device 20. However, the configuration of the light source device 20 is not limited to this, and the configuration may not include the color wheel 28.

As shown in FIG. 10, in the laser light source 21, for example, light sources that emit a plurality of laser beams are arranged in an array. The laser light source 21 emits, for example, light in the blue band having a center of emission intensity of 455 [nm], that is, blue laser light. Hereinafter, the blue laser light is simply referred to as blue light. The blue light emitted from the laser light source 21 is linearly polarized light whose polarization direction is a constant direction, and is also used as excitation light for exciting the phosphor contained in the phosphor unit 26 described later.

The light emitted from the laser light source 21 may be light having a wavelength capable of exciting a phosphor, which will be described later, and is not limited to light in the blue wavelength band. Further, the laser light source 21 is assumed to have a plurality of light sources, but the present invention is not limited to this, and the laser light source 21 may be composed of one light source. The laser light source 21 can be configured by arranging a plurality of light sources in an array on the substrate, but the present invention is not limited to this, and other arrangement configurations may be used.

The coupling lens 22 is a lens that incidents blue light emitted from a laser light source 21 and converts it into parallel light, that is, collimated light. In the following, parallel light is not limited to completely parallelized light, but includes substantially parallelized light. The number of coupling lenses 22 corresponds to the number of light sources of the laser light source 21, and increases or decreases according to the increase or decrease of the number of light sources of the laser light source 21.

In the light source device 20 according to the present embodiment, the light source unit is composed of these laser light sources 21 and the coupling lens 22. For example, the laser light source 21 is composed of a plurality of laser diodes arranged in rows and columns. The light source unit is composed of these laser diodes and a coupling lens 22 arranged on the exit surface side of the laser diode.

FIG. 11 shows a main part of the light source unit included in the light source device 20 according to the first embodiment. As shown in FIG. 11, in the light source unit, the coupling lens 22 is arranged so as to face the laser diode 21A. In the light source unit, among the divergence angles of blue light emitted from each laser diode 21A, the divergence angle in the larger direction in the row direction or the column direction is defined as θ. Let P be the pitch of the adjacent laser diodes 21A, and let L be the distance from the light emitting point of the laser diodes 21A to the coupling lens 22. The arrangement interval (P / Ltanθ) of each laser diode 21A is set so as to satisfy the following (Equation 1).
1 ≤ P / Ltan θ ≤ 4 ... (Equation 1)

Most preferably, the arrangement interval of each laser diode 21A is set so as to satisfy the following (Equation 2).
P / Ltan θ = 2 ... (Equation 2)
By satisfying (Equation 2), the light of each laser diode 21A can be incidented only on the corresponding coupling lens 22 while reducing the light emitting surface of the laser light source 21. As a result, it is possible to prevent incident on the adjacent coupling lens 22, and it is possible to suppress a decrease in light utilization efficiency.

The plurality of laser diodes 21A included in the light source unit are preferably arranged on the same substrate. By arranging a plurality of laser diodes 21A on the same substrate, the region of light emitted from the light source unit can be reduced, vignetting of light in various optical elements on the optical path can be suppressed, and light utilization efficiency can be improved. ..

In FIG. 9, the first optical system 23 has a positive power as a whole, and has a large-diameter lens 23a and a negative lens 23b arranged in order from the laser light source 21 side toward the phosphor unit 26 side. Have. The large-diameter lens 23a is a lens that constitutes a large-diameter element, has positive power, and collects and synthesizes parallel light emitted from the coupling lens 22. The first optical system 23 composed of the large-diameter lens 23a and the negative lens 23b guides the dichroic mirror 24 to the dichroic mirror 24 while converging the light flux of the blue light incident on the coupling lens 22 as substantially parallel light.

The dichroic mirror 24 is arranged so as to be inclined with respect to the propagation direction of the blue light emitted from the first optical system 23. Specifically, the blue light emitted from the first optical system 23 is arranged in a state in which the front end side in the propagation direction is lowered downward and inclined. The dichroic mirror 24 has an optical property of reflecting blue light which is substantially parallel light by the first optical system 23, and transmitting fluorescent light converted by the phosphor unit 26, that is, second color light. The dichroic mirror 24 is provided with, for example, an optical coating in order to have the above-mentioned optical characteristics.

FIG. 12 shows an example of the configuration of the dichroic mirror 24 included in the light source device 20 according to the first embodiment. FIG. 12 shows a dichroic mirror 24 viewed from the incident direction of blue light emitted from the first optical system 23 side. As shown in FIG. 12, the dichroic mirror 24 is divided into two regions 24A and 24B. Hereinafter, for convenience of explanation, the regions 24A and 24B will be referred to as a first region 24A and a second region 24B, respectively.

The first region 24A reflects the blue light emitted from the negative lens 23b of the first optical system 23, while transmitting the fluorescent light converted from the blue light by the phosphor of the phosphor unit 26 described later. It has characteristics. The first region 24A constitutes the reflection surface 102a shown in FIG. The second region 24B has an optical property of transmitting these blue light and fluorescent light.

The first region 24A is arranged on the optical axis of the first optical system 23, but is not arranged on the optical axis of the second optical system 25, and is arranged so as to approach the first optical system 23 side. Has been done. On the other hand, the second region 24B is not arranged on the optical axis of the second optical system 25, and is arranged so as to be farther from the first optical system 23 than the optical axis of the second optical system 25. ..

The second optical system 25 has a positive power as a whole, and has a positive lens 25A and a positive lens 25B in this order from the side of the laser light source 21 toward the side of the phosphor unit 26. The second optical system 25 collects the blue light reflected by the dichroic mirror 24 and guides it to the phosphor unit 26. Further, the second optical system 25 parallelizes the fluorescent light emitted from the phosphor unit 26. The second optical system 25 constitutes an example of a condensing element.

Blue light guided from the second optical system 25 is incident on the phosphor unit 26. The phosphor unit 26 has a function of reflecting blue light emitted from the second optical system 25 and a function of causing blue light to act as excitation light and converting it into fluorescent light having a wavelength range different from that of blue light by the phosphor. To switch between. The fluorescent light converted by the phosphor unit 26 is, for example, light in the yellow wavelength region having a center of emission intensity of 550 [nm].

FIG. 13 shows a phosphor unit 26 included in the light source device 20 according to the first embodiment. FIG. 13A shows the phosphor unit 26 from the incident direction of the blue light, and FIG. 13B shows the phosphor unit 26 from the direction orthogonal to the incident direction of the blue light. FIG. 13 shows an example of the configuration of the phosphor unit 26, and the present invention is not limited to this, and can be appropriately changed.

As shown in FIG. 13, the phosphor unit 26 includes a disk member 26A forming a substrate and a drive motor 26C forming a drive unit. The drive motor 26C has a straight line passing through the center of the disk member 26A and perpendicular to the plane of the disk member 26A as the rotation shaft 26B. The material of the disk member 26A is arbitrary, but for example, a transparent substrate or a metal substrate such as aluminum can be used.

The disk member 26A of the phosphor unit 26 is divided into a fluorescent region 26D for most of the circumferential direction, that is, an angle range larger than 270 ° in the first embodiment. A small portion of the disk member 26A in the circumferential direction, in the first embodiment, an angle range smaller than 90 ° is defined in the excitation light reflection region 26E. The excitation light reflection region 26E constitutes an example of a first region that reflects or diffusely reflects the excitation light reflected by the dichroic mirror 24. The fluorescence region 26D constitutes an example of a region in which the excitation light reflected by the dichroic mirror 24 is converted to emit the fluorescence light. The fluorescence region 26D is composed of a reflection coat 26D1, a phosphor layer 26D2, and an antireflection coat (AR coat) 26D3, which are laminated in order from the lower layer side to the upper layer side.

The reflection coat 26D1 has a property of reflecting light in the wavelength region of the fluorescent light emitted from the phosphor layer 26D2. When the disk member 26A is made of a metal substrate having a high reflectance, the reflective coating 26D1 can be omitted. In other words, it is also possible to give the disk member 26A the function of the reflective coating 26D1.

As the phosphor layer 26D2, for example, one in which the phosphor material is dispersed in an organic / inorganic binder, one in which crystals of the phosphor material are directly formed, and a rare earth phosphor such as Ce: YAG type can be used. .. 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 light. The wavelength band of the fluorescent light emitted from the phosphor layer 26D2 can be, for example, a wavelength band of yellow, blue, green, or red. In the first embodiment, fluorescent light having a yellow wavelength band is used. Further, although a phosphor is used as the wavelength conversion element in this embodiment, a phosphorescent body, a nonlinear optical crystal, or the like may be used.

The antireflection coat 26D3 has a property of preventing the reflection of light on the surface of the phosphor layer 26D2.

A reflection coat 26E1 having a property of reflecting light in a wavelength region of blue light derived from the second optical system 25 is laminated on the excitation light reflection region 26E. Therefore, the excitation light reflection region 26E is a reflection surface. When the disk member 26A is made of a metal substrate having a high reflectance, the reflective coating 26E1 can be omitted. In other words, it is also possible to give the disk member 26A itself the function of the reflective coating 26E1.

When the disk member 26A is rotationally driven by the drive motor 26C while irradiating the phosphor unit 26 with blue light (referred to as “first color light”), the irradiation position of the blue light on the phosphor unit 26 moves with time. As a result, a part of the blue light incident on the phosphor unit 26 is converted into fluorescent light (referred to as "second color light") having a wavelength different from that of the blue light in the fluorescence region 26D, which is the wavelength conversion region, and emitted. .. On the other hand, the other portion of the blue light incident on the phosphor unit 26 is reflected and emitted as the blue light in the excitation light reflection region 26E. Here, "a part of blue light" and "another part of blue light" mean a part and another part divided on the time axis.

There is a degree of freedom in the number and range of the fluorescence region 26D and the excitation light reflection region 26E, and various design changes are possible. For example, each of the two fluorescence regions and the excitation light reflection region may be alternately arranged at intervals of 90 ° in the circumferential direction.

Returning to FIG. 10, the description of the configuration of the light source device 20 will be continued. The refractive optics system 27 is composed of a lens that collects blue light and fluorescent light emitted from the second optical system 25. The light emitted from the phosphor unit 26 passes through the dichroic mirror 24, is refracted by the folding optics system 27, is condensed, and is incident on the color wheel 28 (see FIG. 9). The color wheel 28 separates the blue light and the fluorescent light generated by the phosphor unit 26 into desired colors.

FIG. 14 shows a schematic configuration of a color wheel 28 included in the light source device 20 according to the first embodiment. FIG. 14A shows the color wheel 28 from the incident direction of the blue light and the fluorescent light, and FIG. 14B shows the color wheel 28 from the direction orthogonal to the incident direction of the blue light and the fluorescent light. As shown in FIG. 14, the color wheel 28 includes a ring-shaped member 28A and, as a driving unit thereof, a drive motor 28C that rotationally drives the ring-shaped member 28A around a rotating shaft 28B.

The ring-shaped member 28A has a plurality of regions partitioned along the circumferential direction, that is, a diffusion region 28D, and three filter regions 28R, 28G, and 28Y. The diffusion region 28D is a region for transmitting and diffusing the blue light emitted from the phosphor unit 26. The filter region 28R is a region for transmitting light including the wavelength region of the red component among the fluorescent light emitted from the phosphor unit 26. Similarly, the filter regions 28G and 28Y are regions that transmit light including the wavelength regions of the green component and the yellow component of the fluorescent light emitted from the phosphor unit 26, respectively.

In the above description, it is assumed that the color wheel 28 has a region for transmitting the red component, the green component, and the yellow component of the fluorescent light, respectively. However, the configuration of the color wheel 28 is not limited to this, and may have, for example, a region for transmitting the light of the red component and the green component of the fluorescent light.

The area ratio of each region in the color wheel 28 is based on the design specifications of the projector device 1. Blue light emitted from the phosphor unit 26 is transmitted through the diffusion region 28D of the color wheel 28. Therefore, it is preferable to match the ratio of the area of the excitation light reflection region 26E to the total area of the disk member 26A of the phosphor unit 26 and the ratio of the area of the diffusion region 28D to the total area of the color wheel 28.

The drive motor 28C rotationally drives the annular member 28A in the circumferential direction. When the annular member 28A rotates in the circumferential direction, the blue light emitted from the phosphor unit 26 sequentially enters the diffusion region 28D, the filter regions 28R, 28G, and 28Y. The blue light and the fluorescent light emitted from the phosphor unit 26 pass through the color wheel 28, so that the blue light, the green light, the red light, and the yellow light are sequentially emitted. The light transmitted through each region of the color wheel 28 is incident on the light tunnel 29.

The light tunnel 29 is an optical element formed so that four mirrors are inside the quadrangular prism, and the light incident from one end of the quadrangular prism is reflected by the internal mirror multiple times to make the distribution of light uniform. It is an optical mixing element. The light tunnel 29 is arranged so that the light blue light and the fluorescent light collected by the refractive optics 27 are incident. In the first embodiment, the light tunnel 29 is used as an example of the optical mixing element, but the present invention is not limited to this, and a rod integrator, a fly-eye lens, or the like described above can also be used.

FIG. 15 shows two examples of the light tunnel 29 included in the light source device 20 according to the first embodiment, showing the incident opening 29A from the incident direction of light. FIG. 15 shows the projection range of blue light on the incident opening 29A of the light tunnel 29. As shown in FIG. 15, the light tunnel 29 is arranged at a slight inclination. The tilt angle of the light tunnel 29 varies depending on the performance required for the light source device 20.

As described above, the light source unit of the light source device 20 according to the first embodiment has the laser light source 21 in which the laser diodes 21A are arranged in an array. As shown in FIGS. 15A and 15B, the projected cross section of blue light or the like emitted from the laser diode 21A and projected onto the incident opening 29A of the light tunnel 29 has an elliptical shape. In the example shown in FIG. 15A, the long axis of the elliptical projected cross section such as blue light projected on the incident opening 29A is arranged so as to be substantially parallel to the short side of the incident opening 29A. By setting the projection range of blue light or the like on the incident opening 29A in this way, vignetting of blue light or the like due to the light tunnel 29 can be suppressed.

As shown in FIG. 15B, the projection range of blue light or the like on the incident opening 29A may be arranged so that the long axis of the elliptical projected cross section is substantially parallel to the long side of the incident opening 29A. 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 and the full width at half maximum (FWHM) of the intensity distribution in the horizontal direction. That is, it is a shape that does not have an isotropic intensity distribution.

The blue light optical path (hereinafter, appropriately referred to as “blue light path”) in the light source device 20 having such a configuration will be described as follows. The blue optical path refers to an optical path in which the light reflected by the excitation light reflection region 26E (see FIG. 13A) of the phosphor unit 26 travels among the excitation lights emitted by the laser light source 21 shown in FIG. 10A.

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

As described above, the first region 24A of the dichroic mirror 24 is arranged so as to be offset from the optical axis of the second optical system 25 toward the first optical system 23. Therefore, the blue optical path is incident on the second optical system 25, specifically, a part of the positive lens 25A on the first optical system 23 side. Then, the blue light travels so as to approach the optical axis of the second optical system 25 at an angle, and is emitted from the second optical system 25, specifically, the positive lens 25B. The blue light emitted from the second optical system 25 is incident on the phosphor unit 26.

When the blue light directed to the phosphor unit 26 is incident on the excitation light reflection region 26E, the blue light is specularly reflected in the excitation light reflection region 26E. The blue light that is specularly reflected by the excitation light reflection region 26E is incident on a part of the second optical system 25, specifically, a part of the positive lens 25B opposite to the first optical system 23 side. Then, the blue light travels away from the optical axis of the second optical system 25 at an angle, and is emitted from the second optical system 25, specifically, the positive lens 25A.

The blue light emitted from the positive lens 25A of the second optical system 25 passes through the second region 24B of the dichroic mirror 24. The luminous flux of blue light specularly reflected from the phosphor unit 26 or the luminous flux of blue light emitted from the second optical system 25 and transmitted through the second region 24B of the dichroic mirror 24 constitutes the luminous flux Q of the excitation light. To do. As described above, the second region 24B of the dichroic mirror 24 has an optical property of transmitting excitation light and fluorescent light. Therefore, even when the luminous flux (luminous flux Q) of blue light intersects with the dichroic mirror 24, it is possible to suppress a decrease in light utilization efficiency.

The blue light transmitted through the second region 24B of the dichroic mirror 24 is incident on the refractive optics system 27. The blue light travels so as to approach the optical axis of the refractive optics system 27 at an angle, and enters the light tunnel 29 via the color wheel 28 shown in FIG. The blue light is reflected a plurality of times inside the light tunnel 29, homogenized, and then incident on the illumination optical system 30 arranged outside the light source device 20.

Next, the optical path of the fluorescent light (hereinafter, appropriately referred to as “fluorescent optical path”) in the light source device 20 according to the present embodiment will be described with reference to FIG. 10B. In FIG. 10B, a part of the optical path of the fluorescent light is omitted for convenience of explanation. The fluorescent optical path refers to an optical path in which light whose wavelength is converted in the fluorescence region 26D of the phosphor unit 26 travels among the excitation light emitted by the laser light source 21.

The fluorescent optical path is the same as the blue optical path described above until the blue light emitted from the laser light source 21 is guided to the phosphor unit 26. Here, it is assumed that the blue light incident on the phosphor unit 26 is incident on the fluorescence region 26D. The blue light incident on the fluorescence region 26D becomes excitation light for the phosphor and is wavelength-converted by the phosphor to become fluorescent light including, for example, a yellow wavelength region, and is Lambert-reflected by the reflection coat 26D1 and the phosphor layer 26D2. Will be done.

The fluorescent light Lambertian reflected by the fluorescent region 26D is converted into parallel light by the second optical system 25. The fluorescent light emitted from the second optical system 25 passes through the dichroic mirror 24 and enters the refractive optical system 27. The fluorescent light travels so as to approach the optical axis of the refractive optics system 27 at an angle, and enters the light tunnel 29 via the color wheel 28. The fluorescent light is reflected a plurality of times inside the light tunnel 29 and homogenized, and then enters the illumination optical system 30 arranged outside the light source device 20.

As described above, in the light source device 20 according to the first embodiment, the optical path of the blue light emitted from the laser light source 21 is different between before and after the reflection of the phosphor unit 26. More specifically, it is as follows. A point at the center of the projected image of blue light projected from the laser light source 21 onto the first region 24A of the dichroic mirror 24 is determined. The point at the center of this projected image is indicated by point P in FIG. A blue optical path is formed so that this point P and the luminous flux of blue light reflected from the phosphor unit 26 (luminous flux Q shown in FIG. 1) do not intersect. With this configuration, it is possible to prevent blue light from passing through the same location on the dichroic mirror 24, prevent the dichroic mirror 24 from being damaged due to an increase in the light collection density, and improve reliability. be able to.

Further, in order to separate the optical path of blue light emitted from the phosphor unit 26, it is not necessary to prepare a special optical element such as a polarization separating element including a retardation plate or a polarization beam splitter. Therefore, the number of parts can be reduced, the manufacturing cost can be reduced, and the light source device 20 can be miniaturized. Further, since an optical component such as a retardation plate or a polarization separating element that manipulates polarization is not used, it is possible to suppress a decrease in light utilization efficiency due to the reflectance, transmittance, absorption rate, etc. of the optical component.

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 whose polarization direction is a constant direction. Further, the light source units having the plurality of laser light sources 21 are arranged so that the directions of linearly polarized light are all the same, and the directions of linearly polarized light of the light emitted from the light source unit are aligned. The direction of linearly polarized light can be determined by the direction in which the light source unit is arranged.

As can be seen in FIGS. 15A and 15B, if the light source unit is tilted according to the tilt of the light tunnel 29, the direction of linearly polarized light changes. In a situation where the direction of linearly polarized light changes, when the polarization is manipulated by a polarization separating element or the like, the light utilization efficiency may decrease when transmitting through the polarization separating element. Since the light source device 20 according to the first embodiment does not employ a configuration in which polarization is manipulated, it is possible to prevent the light utilization efficiency from being lowered due to the inclination of the laser light source 21.

(Second Embodiment)
The light source device 201 according to the second embodiment has a dichroic mirror configuration different from that of the light source device 20 according to the first embodiment. Hereinafter, the configuration of the light source device 201 according to the second embodiment shown in FIG. 16 will be described focusing on the differences from the light source device 20 according to the first embodiment. FIG. 16A shows the optical path of blue light in the light source device 201, and FIG. 16B shows the optical path of fluorescent light in the light source device 201. In FIG. 16, the same reference numerals are given to the configurations common to those of the first embodiment, and the description thereof will be omitted. In FIG. 16B, a part of the optical path of the fluorescent light is omitted for convenience of explanation.

The light source device 201 shown in FIG. 16 differs from the light source device 20 according to the first embodiment only in the configuration of the dichroic mirror 241. The dichroic mirror 241 is arranged at an angle like the dichroic mirror 24 of the first embodiment, but is shorter in length than the dichroic mirror 24. Since the size of the dichroic mirror 24 is short, the light source device 20 can be miniaturized. The dichroic mirror 241 has the same optical characteristics as the first region 24A which is a part of the dichroic mirror 24.

FIG. 17 shows an example of the configuration of the dichroic mirror 241 included in the light source device 201 according to the second embodiment. FIG. 17 shows a dichroic mirror 241 viewed from the incident direction of blue light (excitation light) emitted from the first optical system 23 side. The dichroic mirror 241 is composed of only a single region 241A.

Similar to the first region 24A in the second embodiment, the region 241A reflects the blue light emitted from the first optical system 23, and the fluorescence converted from the blue light by the phosphor of the phosphor unit 26. It has optical properties that allow light to pass through. The region 241A is arranged at the same position as the first region 24A. That is, the region 241A is arranged on the optical axis of the first optical system 23. However, the region 241A is arranged at a position deviated from the optical axis of the second optical system 25 toward the first optical system 23.

The blue optical path and the fluorescent optical path in the light source device 201 having such a configuration will be described with reference to FIGS. 16A and 16B. As shown in FIG. 16A, the blue light emitted from the laser light source 21 is reflected by the excitation light reflection region 26E of the phosphor unit 26 and is emitted to the second optical system 25. Up to this point, it is the same as the blue optical path of the first embodiment. In the light source device 201 according to the second embodiment, the blue light emitted from the second optical system 25 does not pass through the dichroic mirror 241. The luminous flux of blue light emitted from the phosphor unit 26 (corresponding to the luminous flux Q shown in FIG. 1A) does not intersect with the dichroic mirror 24. On the other hand, as shown in FIG. 16B, the fluorescent optical path is the same as that of the fluorescent optical path of the first embodiment.

In the light source device 201 according to the second embodiment, the optical path of blue light emitted from the laser light source 21 is different between before and after reflection of the phosphor unit 26. Therefore, similarly to the light source device 20 according to the first embodiment, the reliability of the light source device can be improved, and the size and cost can be reduced.

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

(Third Embodiment)
Next, the light source device 202 according to the third embodiment shown in FIG. 18 will be described. The second embodiment is that the light source device 202 has a first light source unit and a second light source unit, and has a polarized optical component that synthesizes excitation light from the second light source unit with excitation light from the first light source unit. It is different from the light source device 201 according to the above. The first light source unit includes a laser light source 21 and a coupling lens 22. The second light source unit includes a laser light source 211 and a coupling lens 221.

FIG. 18A shows the optical path of the blue laser light in the light source device 202 according to the third embodiment, and FIG. 18B shows the optical path of the fluorescent light in the light source device 202 according to the third embodiment. In FIG. 18, the same reference numerals are given to the configurations common to those of the second embodiment, and the description thereof will be omitted. In FIG. 18B, a part of the optical path of the fluorescent light is omitted for convenience of explanation.

As shown in FIG. 18, the light source device 202 includes a laser light source 211 and a coupling lens 221 that form a second light source unit. The second light source unit is arranged so that the laser light emitted from the laser light source 211 is orthogonal to the laser light emitted from the laser light source 21 of the first light source unit.

The laser light source 211 has the same configuration as the laser light source 21. That is, in the laser light source 211, laser diodes are arranged in an array as a light source for emitting a plurality of laser beams, and for example, blue light having a center of emission intensity of 455 [nm] is emitted. Both 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 incidents blue light emitted from the laser light source 211 and converts it into parallel light, that is, collimated light.

The light source device 202 includes a 1/2 wavelength plate 222 and a polarization separating element 223 that form a polarizing optical component. The 1/2 wave plate 222 is arranged so as to face the plurality of coupling lenses 221. The 1/2 wave plate 222 converts the P-polarized light component of the blue light emitted from the laser light source 211 into the S-polarized light component. The polarization separating element 223 is arranged on the optical path of the blue light emitted from the laser light source 21 and the blue light emitted from the laser light source 211. The polarization separating element 223 has an optical property of reflecting the S-polarizing component of blue light while transmitting the P-polarizing component of blue light.

The P-polarized light component of the blue light emitted from the laser light source 21 passes through the polarization separating element 223 and is incident on the large-diameter lens 23a of the first optical system 23. On the other hand, the P-polarized light component of the blue light emitted from the laser light source 211 is converted into S-polarized light by the 1/2 wave plate 222 and then reflected by the polarization separating element 223, which is a large-diameter lens of the first optical system 23. It is incident on 23a. In this way, the blue excitation light from the second light source unit is combined with the blue excitation light from the first light source unit.

The blue optical path and the fluorescent optical path of the light source device 202 having such a configuration will be described with reference to FIG. As shown in FIGS. 18A and 18B, the blue optical path and the fluorescent optical path after being synthesized by the polarizing separation element 223 and incident on the large-diameter lens 23a of the first optical system 23 are the same as those in the second embodiment. is there.

In the light source device 202 according to the third embodiment, the optical path of blue light emitted from the laser light source 21 is different between before and after reflection of the phosphor unit 26. Therefore, as with 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 202, since the excitation light from the first light source unit is combined with the excitation light from the second light source unit, the brightness of the excitation light can be increased and the light utilization efficiency can be improved. Further, since the polarization is manipulated by the 1/2 wavelength plate 222 and the polarization separation element 223 that constitute the polarization optical component, the optical path can be separated and synthesized regardless of the presence or absence of the polarization component of the light emitted from the light source. It can be realized.

(Fourth Embodiment)
Next, the light source device 203 according to the fourth embodiment shown in FIG. 19 will be described. The light source device 203 is different from the light source device 201 according to the second embodiment in that it has a phosphor unit 261 different from the phosphor unit 26. Hereinafter, the configuration of the light source device 203 according to the fourth embodiment will be described focusing on the differences from the light source device 201 according to the second embodiment.

FIG. 19A shows the optical path of the blue laser light in the light source device 203, and FIG. 19B shows the optical path of the fluorescent light in the light source device 203. 19A and 19B, the same reference numerals are given to the configurations common to those of the second embodiment, and the description thereof will be omitted. In FIG. 19B, a part of the optical path of the fluorescent light is omitted for convenience of explanation.

The light source device 203 according to the fourth embodiment has a phosphor unit (hereinafter, appropriately referred to as “static phosphor unit”) 261 that is not rotationally driven, instead of the phosphor unit 26 that is rotationally driven. The static phosphor unit 261 reflects a part of the blue light (excitation light) emitted from the laser light source 21 as it is, and converts the other part of the blue light into fluorescent light and emits it.

FIG. 20 shows the configuration of the static phosphor unit 261 included in the light source device 203 according to the fourth embodiment. FIG. 20 shows the static phosphor unit 261 from a direction orthogonal to the incident direction of blue light. As shown in FIG. 20, the resting phosphor unit 261 is configured by laminating a phosphor 261b, which is a wavelength conversion member, on a reflecting member 261a that reflects excitation light. For example, the reflective member 261a and the phosphor 261b have a rectangular shape in a plan view. The phosphor 261b is applied onto the reflective member 261a.

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 on the phosphor 261b, and the wavelength is converted by the phosphor 261b. As a result, for example, the center of the emission intensity becomes fluorescent light including a yellow wavelength region of 550 [nm], and Lambertian reflection is performed by the action of the phosphor 261b and the reflection member 261a.

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

The blue optical path and the fluorescent optical path in the light source device 203 configured in this way will be described with reference to FIG. As shown in FIG. 19, the blue optical path and the fluorescent optical path in the light source device 203 are the same as those in the second embodiment except for the wavelength conversion and reflection in the static phosphor unit 261.

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 between before and after the reflection of the static phosphor unit 261. Therefore, similarly to the light source device 201 according to the second embodiment, the reliability is excellent, and the size and cost can be reduced. In particular, in the light source device 203, since the static phosphor unit 261 simultaneously emits blue light and fluorescent light, it is not necessary to drive the phosphor unit to rotate, and the manufacturing cost of the device can be reduced. Since the rotation drive motor can be omitted, it is possible to reduce the noise and prevent the reliability from being lowered due to the life of the motor.

(Fifth Embodiment)
Next, the fifth embodiment shown in FIG. 21 will be described. Since the basic configuration is the same as that of the second embodiment, characteristic components will be described. 21A and 21B both show the configuration of this embodiment. In FIG. 21, the vertical direction is the X direction and the direction orthogonal to the X direction, the emission direction of the light beam from the light source unit is the Y direction, and the direction orthogonal to both the X direction and the Y direction is the Z direction. FIG. 21B shows a configuration seen from a direction in which FIG. 21A is rotated by 90 ° around the X axis.

In FIG. 21, when the straight line connecting the substantially center of the light beam bundle emitted from the light source unit and the point P is a straight line L0, the straight line L0 is configured to intersect the plane including the straight line L1 and the luminous flux Q perpendicularly. .. By doing so, the size can be reduced in the Z-axis direction in the drawing. Further, conditions 1 and 2 in the polarization direction, which will be described later, can be achieved at the same time, and the light utilization efficiency can be improved.

FIG. 22A shows a state when blue light is incident on the dichroic mirror 102 in the present embodiment. FIG. 22B shows a state when blue light is incident on the phosphor unit 26. As shown in FIG. 22A, it is preferable that the blue light is incident on the dichroic mirror 102 with S polarization. This is referred to as "polarization condition 1". Further, as shown in FIG. 22B, it is preferable that the blue light is incident on the phosphor unit 26 with P-polarized light. This is referred to as "polarization condition 2". The reason for this is that, in general, when light is incident on a surface at an angle, S-polarized light has a higher reflectance. From this, the dichroic mirror 102 reflects with S-polarized light so that the reflectance is further increased, and in the phosphor region, surface reflection is suppressed and more blue light is incident with P-polarized light so as to be incident on the phosphor.

In the configuration of the present embodiment, since the polarization direction of the dichroic mirror 102 and the phosphor unit 26 is rotated by 90 °, it is possible to improve the light utilization efficiency by achieving both the polarization condition 1 and the polarization condition 2.

(Sixth Embodiment)
FIG. 23 shows a sixth embodiment of the light source device according to the present invention. FIG. 23A is a view of the present embodiment viewed from the side surface side, and FIG. 23B is a view of FIG. 23A rotated by 90 ° around the Z axis and viewed from above. FIG. 24 shows the second embodiment for comparison with the sixth embodiment. FIG. 24A is a view seen from the side surface side, and FIG. 24B is a view of FIG. 24A rotated by 90 ° around the Z axis and viewed from above.

In the present embodiment, as shown in FIGS. 23A and 23B, the mirror 110 is inserted in front of the dichroic mirror 102 to bend the optical path of the illumination light from the light source. Thereby, the dimension in the Z-axis direction can be reduced. The size in the Y-axis direction is almost the same as that of the second embodiment shown in FIG. 24.

In the present embodiment, the diameter of the rotary phosphor unit 26 is φ50 to 60 mm, which is a large component in a small light source device. Therefore, the sizes in the Y-axis direction and the Z-axis direction are the phosphor unit 26. The size of is dominant. Therefore, the light source device can be significantly miniaturized by arranging the components in the projection space in the plane direction of the phosphor unit 26 generated by folding the optical path with the mirror 110.

FIG. 23B shows this. As shown in FIG. 23B, when the surface vertices T of all the lenses are arranged in the projection plane of the disk-shaped phosphor unit 26 when viewed from the X-axis direction, the entire light source device becomes smaller and closer to a cube. ..

Further, the mirror 110 may be provided with a function of adjusting the degree of focusing of blue light on the surface of the phosphor unit 26. For example, when the mirror 110 is used as a diffuse reflection surface, the blue light irradiating the phosphor unit 26 can be diffused to make the degree of concentration of the blue light on the phosphor unit 26 uniform and improve the conversion efficiency of the phosphor unit 26. it can.

(7th Embodiment)
FIG. 25 shows a seventh embodiment of the light source device according to the present invention. FIG. 26 is a comparative example with respect to the seventh embodiment. In the seventh embodiment, the light source device 20 is connected to the heat radiating unit 120 via the heat pipe 125 and cooled. In the present embodiment, the optical axis of the projection optical system 50 and the emission direction of the excitation light emitted from the light source device 20 are arranged so as to be perpendicular to each other.

In the comparative example as shown in FIG. 26, if the heat pipe 125 is used to connect the space where the light source position 20 and the heat radiating unit 120 can be arranged, the heat pipe 125 needs to be bent and the cooling efficiency is lowered. Therefore, the heat radiating unit 120 becomes large in order to obtain a predetermined heat radiating amount.

On the other hand, according to the present embodiment, since the heat pipe 125 can be coupled to the heat radiating unit 120 without bending too much, the cooling efficiency is less likely to decrease, and the light source device 20 can be cooled efficiently.

Further, as shown in FIG. 25, since the heat radiating unit 120 can be arranged in the space adjacent to the projection optical system 50, the space can be effectively used and the entire projector device can be further miniaturized. In the present embodiment, a heat pipe is used as an example of the cooling means, but a loop heat pipe may also be used, or a heat radiating member such as a heat sink may be provided directly to the light source.

In the embodiment of the light source device according to the present invention, the excitation light is obliquely incident on the optical mixing element, so that the brightness unevenness may occur at the exit of the light tunnel depending on the size of the optical mixing element. Since this becomes the brightness unevenness on the screen as it is, it is preferable to generate the brightness unevenness so as to make the image on the screen easier to see. For example, in general, the brightness unevenness that occurs in a projected image is preferably in the vertical direction rather than in the horizontal direction, and it is easier to see the lower side close to the human eye. Therefore, as shown in FIG. 27, it is preferable that the excitation light is incident on the optical mixing element so that the downward direction on the screen becomes bright.

Each of the embodiments described above shows preferred embodiments of the present invention, and the present invention is not limited to the configurations of these embodiments. In particular, the specific shapes and numerical values of each part illustrated in each embodiment are merely examples of the embodiment of the present invention, and the technical scope of the present invention is not limited thereto. The present invention can be appropriately modified without departing from the technical concept described in each claim of the claims.

1: Projector device (image projection device)
10: Housing 20: Light source device 21: Laser light source 22: Coupling lens 23: First optical system 23a: Large-diameter lens 23b: Negative lens 24: Dichroic mirror 24A: Region (first region)
24B: Area (first area)
25: Second optical system 26: Phosphorant unit 27: Refractive optical system 28: Color wheel 29: Light tunnel 29A: Incident opening 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: Reflecting surface 103: Phosphorant unit 103a: Exit surface 103b: Incident surface 104: Rod integrator 104a: Incident opening 104b: Exit opening 105: Condensing lens 105a: Incident surface 105b: Exit surface 106: Refractive lens 110: Mirror 120: Heat dissipation unit 125: Heat pipes 201, 202, 203: Light source device 211: Laser light source 221: Coupling lens 222: 1/2 wavelength plate 223: Polarized Separation element 241: Dichroic mirror 241A: Region 261: Phosphorant unit (static phosphor unit)
261a: Reflective member 261b: Fluorescent material

Claims (31)

An excitation light source that emits the first colored light,
An optical member having a reflecting surface that reflects the first colored light,
A wavelength conversion member in which the first color light reflected by the optical member is incident, and at least a part of the first color light is converted into a second color light having a wavelength different from that of the first color light and emitted. With a wavelength conversion unit
A condensing element that condenses the first color light emitted from the wavelength conversion unit is provided.
Point P, the center of the first colored light on the reflective surface of the optical member,
The luminous flux collected by the condensing element is Q,
The center of the light beam emitted by the excitation light source and the optical path leading to the point P are LO.
Assuming that the optical path from the point P to the condensing element is L1,
The point P and the luminous flux Q do not intersect,
A light source device in which a straight line including the optical path L0 intersects a plane formed by the optical path L1 and the luminous flux Q at approximately 90 degrees. The light source device according to claim 1, wherein the excitation light incident on the wavelength conversion member of the wavelength conversion unit is incident on P-polarized light. The light source device according to claim 2, wherein the excitation light incident on the optical member is incident with S-polarized light. The wavelength conversion unit has a first region that reflects or diffusely reflects the first color light reflected by the optical member, and the first color light that is provided with the wavelength conversion member and reflected by the optical member. It has a region for converting and emitting the second color light, and when the first color light is incident, the first color light and the second color light are sequentially switched to enter the incident surface of the first color light. The light source device according to any one of claims 1 to 3, which emits light to the side. The wavelength conversion unit is provided with the wavelength conversion member in a region where the first color light reflected by the optical member is incident, and the wavelength conversion member uses a part of the incident first color light to be the first. When the first color light is converted into the second color light and a part of the first color light reflected by the optical member is reflected and the first color light is incident, the first color light and the second color light are combined. The light source device according to any one of claims 1 to 4, wherein the first colored light is emitted to the incident surface side. An optical mixing element that mixes the first color light and / or the second color light emitted from the wavelength conversion unit, and the first color light and / or the second color light emitted from the wavelength conversion unit. The light source device according to any one of claims 1 to 5, further comprising a light guide means for guiding the light source to the optical mixing element. When the center of the projected image of the first color light projected on the wavelength conversion unit is the point R,
The light source device according to claim 6, wherein the optical mixing element is located on the perpendicular line of the point R on the emission surface of the wavelength conversion unit. The first color light reflected by the optical member is focused on the optical path between the optical member and the wavelength conversion unit, and the second color light emitted from the wavelength conversion unit is substantially parallelized. Further has a second light collecting element
A straight line L1 is defined as a straight line connecting the center of the projected image on the incident surface of the second condensing element and the point P projected by the first colored light incident on the condensing element after being reflected by the reflecting surface. ,
When the intersection of the incident surface of the first colored light and the straight line L1 which is condensed by the second condensing element and is incident on the wavelength conversion unit is defined as a point S,
The light source device according to any one of claims 1 to 7, wherein the positions of the point R and the point S are different. The light source device according to claim 8, wherein a mirror is provided between the excitation light source and the optical member, and the bending direction of the mirror is different from the direction reflected by the optical member. The light source device according to claim 9, wherein the surface of the mirror that reflects the excitation light is a diffuse reflection surface. The light source device according to claim 10, wherein the straight line L1 and the incident surface of the first colored light incident on the wavelength conversion unit perpendicularly intersect. The optical mixing element is a rod integrator.
The light source device according to claim 6, further comprising a refracting optical element that guides the first color light and / or the second color light emitted from the wavelength conversion unit to an incident opening of the lot integrator. The projected image center of the first colored light projected on the incident opening of the rod integrator, the projected image center of the second colored light projected on the incident opening of the rod integrator, and the refraction optical element. 12. The light source device according to claim 12, wherein the optical axes of the above intersect at one point. When the straight line L2 is defined as a straight line connecting the point R and the center of the projected image on the incident opening of the rod integrator projected by the first colored light.
The light source device according to claim 12 or 13, wherein the surface including the straight line L1 and the straight line L2 and the short side of the incident opening of the rod integrator are arranged substantially in parallel. _{Let θ 1 be} the incident angle of the first colored light ray incident on the incident opening of the rod integrator at the largest angle, and the second incident on the rod integrator at the largest angle. When the incident angle of the ray of colored light of is θ ₂ ,
The light source device according to any one of claims 12 to 14, wherein θ ₁ is _{smaller than θ 2. Let θ 1 be} the incident angle of the first colored light ray incident on the incident opening of the rod integrator at the largest angle, and the second incident on the rod integrator at the largest angle. When the incident angle of the ray of colored light of is θ ₂ ,
The light source device according to any one of claims 12 to 14, wherein θ ₁ and θ _{2 are the same.} The light source device according to any one of claims 12 to 16, wherein the rod integrator has an incident opening smaller than an exit opening. The rod integrator is composed of a glass rod integrator.
When the total reflection condition of the glass rod integrator is θ _glass ,
The light source device according to any one of claims 12 to 17, wherein the θ _{glass is larger than the θ1 and the θ2.} The excitation light source has a plurality of laser diodes arranged in an array.
The projection range on the incident opening of the rod integrator projected by the first colored light emitted from the laser diode is elliptical.
The light source device according to any one of claims 12 to 18, wherein the long axis of the elliptical shape is substantially parallel to the long side or the short side of the incident opening of the rod integrator. The light source device according to claim 19, wherein a plurality of laser diodes provided in the light source unit are arranged on the same substrate. The excitation light source is composed of a plurality of laser diodes arranged in rows and columns, and a light source unit provided with a coupling lens on the emission surface side of the laser diodes.
In the divergence angle of the first colored light emitted from the laser diode, the divergence angle in the larger direction in the row direction or the column direction is set to θ.
Let p be the pitch of the adjacent laser diodes.
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 is the following formula 1 ≦ p / Ltan θ ≦ 4
The light source device according to any one of claims 1 to 20. The light source device according to any one of claims 1 to 21, wherein the optical member has an optical property of transmitting the first colored light and the second colored light, and the luminous flux Q intersects with the optical member. The light source device according to any one of claims 1 to 22, wherein the optical member has an optical property of transmitting the first colored light and the second colored light, and the luminous flux Q does not intersect with the optical member. .. The light source device according to claim 22 or 23, wherein the reflecting surface has an optical property of reflecting the first colored light while transmitting the second colored light. The wavelength conversion unit includes a disk member in which a circular substrate is divided into a first region and a region for emitting second colored light in the circumferential direction, and the disk member passing through the center of the disk member. The light source device according to any one of claims 2 and 4 to 24, further comprising a drive unit that rotationally drives a straight line perpendicular to a plane as a rotation axis. The light source device according to claim 25, wherein the surface vertices of all the lenses of the light source device are contained in a cylinder formed by a disk of a phosphor wheel. A large-diameter element having a positive power and a parallelizing element having a negative power are arranged on the optical path between the excitation light source and the optical member according to the traveling direction of the first colored light.
Any of claims 1 to 26, wherein the first colored light emitted from the excitation light source is focused by the large-diameter element and is made substantially parallel light by the parallelizing element, and is incident on the optical member. The light source device according to. The light source device according to any one of claims 1 to 27,
An illumination optical system that guides the light emitted from the light source device to the image display element, and
An image projection device including a projection optical system that projects an image generated by the image display element using light guided by the illumination optical system. 28. The image projection apparatus according to claim 28.
An image projection device in which the optical axis shared by a large number of lenses forming the projection optical system and the emission direction of the first colored light emitted from the excitation light source are not in the same plane. The projection optical device according to claim 29, wherein the optical axis shared by a large number of lenses forming the projection optical system and the emission direction of the first color light emitted from the excitation light source are perpendicular to each other. A light source optical system having an excitation light source that emits first colored light.
An optical member having a reflecting surface that reflects the first colored light emitted from the excitation light source, and
A wavelength conversion member in which the first color light reflected by the optical member is incident, and at least a part of the first color light is converted into a second color light having a wavelength different from that of the first color light and emitted. With a wavelength conversion unit
Point P, the center of the first colored light on the reflective surface of the optical member,
The luminous flux collected by the condensing element of the first color light emitted from the wavelength conversion unit is Q,
LO, the optical path leading to the point P and the substantially center of the light flux emitted from the excitation light source.
Assuming that the optical path from the point P to the condensing element is L1,
The point P and the luminous flux Q do not intersect,
The straight line including the optical path L0 is a light source optical system that intersects the plane formed by the optical path L1 and the luminous flux Q at approximately 90 degrees.

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