JP7338409B2 - Light source device, image projection device and light source optical system - Google Patents

Description

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

2. Description of the Related Art Today, projectors (image projection apparatuses) that enlarge and project various images are widely used.
The projector uses a digital micromirror device (DMD
) or a liquid crystal display element, and the emitted light from the spatial light modulation element modulated by a video signal is displayed on a screen as a color image.

Conventionally, high-intensity super-high-pressure mercury lamps and the like have been mainly used for projectors, but because of their short life, frequent maintenance was required. Therefore, in recent years, the number of projectors using a laser light source, an LED (Light Emitting Diode) light source, or the like instead of an ultra-high pressure mercury lamp is increasing. This is because laser light sources and LED light sources have a longer life than ultra-high pressure mercury lamps, and also have good color reproducibility due to their monochromaticity.

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

Since several tens of [W] of excitation light are condensed and irradiated onto the phosphor, the efficiency is lowered and the aging occurs due to burnout or temperature rise. Therefore, by forming a phosphor layer on the disk and rotating the disk, the irradiation position of the excitation light is prevented from concentrating on one point. This disk is called a phosphor wheel. In the phosphor wheel, the phosphor is formed in a fan shape or an annular shape along the outer circumference of the disk.

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

Furthermore, as a light source device using a DMD and a phosphor wheel as described above, a device has been proposed in which a part of the phosphor wheel is used as a reflector in order to reduce the size of the entire device (see, for example, Patent Document 2). ). In the technique described in Patent Document 2, the excitation light is reflected by the phosphor wheel in the same direction as the fluorescent light, and the reflected excitation light does not return to the excitation light source. A polarization separation element is used to separate the optical paths. As a result, the excitation light and the fluorescence light are combined on the same optical path, and are irradiated onto the DMD.

Japanese Patent No. 4711156 Japanese Patent No. 5817109

However, in Patent Literature 1 described above, since the optical path of the pumping light is detoured, the overall size of the apparatus is increased. On the other hand, in Patent Document 2 described above, the use of the retardation plate and the polarization splitting element increases the cost. Further, the optical path of the excitation light directed toward 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 separation element. As a result, the density of condensed light on these optical elements increases, causing breakage or the like, which may lead to a decrease in reliability.

SUMMARY OF THE INVENTION The present invention was completed based on the awareness of the above problems, and an object of the present invention is to provide a light source device that can be reduced in size and cost.

A light source device of the present invention comprises an excitation light source that emits a first color light, an optical member that has a reflecting surface that reflects the first color light emitted from the excitation light source, and the first color light reflected by the optical member. a wavelength conversion unit having a wavelength conversion member for converting at least part of the first color light into second color light having a wavelength different from that of the first color light and emitting the second color light; and the optical member. and the wavelength conversion unit, collects the first color light reflected by the optical member, and emits the first color light and the second color light emitted from the wavelength conversion unit. , wherein the center of the first color light on the reflecting surface of the optical member is defined as a point P, and the first color light is condensed and projected onto the wavelength conversion unit. Let R be the center of the image, let Q be the luminous flux of the first color light emitted from the wavelength conversion unit and condensed by the condensing element, and reach approximately the center of the luminous flux emitted from the excitation light source and the point P. The optical path is LO, the straight line (optical path) from the point P to the condensing element is L1, the optical path from the condensing element to the point R is L12, and the optical path from the point R to the condensing element is Q1. , the point P and the light flux Q do not intersect, and the plane PL1 including the optical paths L0 and L1 and the plane PL2 including the optical paths L12 and Q1 are not parallel. .

According to the present invention, it is possible to provide a light source device that can be reduced in size and cost.

It is a schematic diagram for demonstrating the outline|summary of a light source device. It is a schematic diagram for demonstrating the outline|summary of a light source device. It is a schematic diagram for demonstrating the outline|summary of a light source device. It is a schematic diagram for demonstrating the outline|summary of a light source device. It is a schematic diagram for demonstrating the outline|summary of a light source device. It is a schematic diagram for demonstrating the outline|summary of a light source device. It is a schematic diagram for demonstrating the optical characteristic of the rod integrator which a light source device has. It is a schematic diagram for demonstrating the structure of the rod integrator which a light source device has. 1 is a schematic configuration diagram showing a projector device 1 including a light source device according to a first embodiment; FIG. 1 is a schematic configuration diagram showing a light source device according to a first embodiment; FIG. FIG. 3 is an explanatory diagram of a main part of a light source unit included in the light source device according to the first embodiment; It is a figure which shows an example of a structure of the dichroic mirror which the light source device which concerns on 1st Embodiment has. 4 is an explanatory diagram of the configuration of a phosphor unit included in the light source device according to the first embodiment; FIG. 3 is an explanatory diagram of a schematic configuration of a color wheel included in the light source device according to the first embodiment; FIG. FIG. 4 is a view of the entrance opening of the light tunnel of the light source device according to the first embodiment, viewed from the light incident direction; It is a schematic block diagram which shows the light source device which concerns on 2nd Embodiment. It is a figure which shows an example of a structure of the dichroic mirror which the light source device which concerns on 2nd Embodiment has. It is a schematic block diagram which shows the light source device which concerns on 3rd Embodiment. It is a schematic block diagram which shows the light source device which concerns on 4th Embodiment. FIG. 11 is a schematic diagram illustrating the configuration of a phosphor unit included in a light source device according to a fourth embodiment; FIG. 2 is an explanatory diagram for explaining the first embodiment; FIG. FIG. 10 is an explanatory diagram for explaining Example body 2; FIG. 11 is an explanatory diagram for explaining the third embodiment; FIG. 11 is an explanatory diagram for explaining a fourth embodiment; FIG. 11 is an explanatory diagram for explaining a fourth embodiment; FIG. 11 is an explanatory diagram for explaining a fourth embodiment;

Conventionally, as a light source device using a digital micromirror device (DMD) and a phosphor wheel, there is known one in which a part of the phosphor wheel is used as a reflector in order to downsize the entire device. In this light source device, the excitation light is reflected by the phosphor wheel in the same direction as the fluorescence light, and a retardation plate (1/4 wavelength plate) and a polarization separator are placed on the optical path so that the reflected excitation light does not return to the excitation light source. Place the elements.

In a light source device having such a configuration, a retardation plate (quarter-wave plate) and a polarization separation element are arranged on the optical path of excitation light, which not only restricts the miniaturization of the device, Cost will be higher. Further, the optical path of the excitation light directed toward 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 separation element.
As a result, the density of condensed light on these optical elements increases, causing breakage or the like, which may lead to a decrease in reliability.

The present inventors paid attention to the fact that such a structure inside the light source device is a factor that hinders the miniaturization and cost reduction of the device main body, and that it is a factor that lowers the reliability. Further, in the light source device, the optical path of the excitation light directed toward the phosphor wheel and the optical path of the excitation light reflected from the phosphor wheel are formed so as not to overlap, thereby reducing the size and cost of the device body. In addition, the inventors have found that it contributes to the improvement of reliability and arrived at the present invention.

That is, the present invention includes a light source that emits excitation light, an optical member that has a reflecting surface that reflects the excitation light emitted from the light source, and the excitation light reflected by the optical member enters, and at least part of the excitation light a second color light having a wavelength different from that of the excitation light, and is provided on an optical path between the optical member and the wavelength conversion unit, and is reflected by the optical member. and a condensing element condensing the excitation light emitted from the wavelength conversion unit and the fluorescence emitted from the wavelength conversion unit. Let R be the projection image center of the excitation light condensed and projected upward, let Q be the luminous flux of the first color light emitted from the wavelength conversion unit and condensed by the condensing element, from the excitation light source The optical path extending from the approximate center of the emitted ray bundle to the point P is LO, the straight line (optical path) from the point P to the condensing element is L1, the optical path from the condensing element to the point R is L12, and the point R , the light beam Q does not intersect with the point P, the plane PL1 including the optical paths L0 and L1, and the optical path L12 and the optical path Q1 are included. The gist is that it should not be parallel to the plane PL2.

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 prevented from passing through the same location on the optical member. Since this can be prevented, it is possible to suppress damage to the optical member due to an increase in the density of condensed light, thereby improving reliability. In addition, since there is no need to prepare a special optical element such as a retardation plate or a polarization separation element to separate the optical path of the excitation light emitted from the wavelength conversion unit, the number of parts can be reduced, and the manufacturing cost can be reduced. Together with this, the device can be miniaturized.
Also, a plane including the optical path of the excitation light incident on the optical member and the optical path of the excitation light reflected by the optical member and directed to the condensing element (optical paths before and after the optical member), and between the condensing element and the wavelength conversion unit Since the plane including the optical path of the excitation light (the optical path before and after the wavelength conversion unit) is not parallel, the size of the device can be reduced.

The outline of the light source device will be described below with reference to FIG.
FIG. 1 is a schematic diagram for explaining the outline of the light source device 100. As shown in FIG. FIG. 1A is an explanatory diagram of the components of the light source device 100, and FIG. 1B is an explanatory diagram of excitation light projected onto the reflection surface 102a of the dichroic mirror 102 of the light source device 100. FIG. In FIG. 1B, the reflecting surface 102a is shown from the traveling direction of the excitation light from the light source 101. FIG.

As shown in FIG. 1, the light source device 100 includes a light source (excitation light source) 101, a dichroic mirror 102 that constitutes an example of an optical member, a phosphor unit 103 that constitutes an example of a wavelength conversion unit, and an example of a light mixing element. It includes a rod integrator 104 that

Note that the configuration of the light source device 100 is not limited to the configuration shown in FIG. 1, and can be changed as appropriate. For example, the light source device 100 may include only the light source 101, the dichroic mirror 102 and the phosphor unit 103. Of the light source device 100 having the light source 101, the dichroic mirror 102, and the phosphor unit 103, the components other than the light source 101 constitute a "light source optical system."

The light source 101 emits excitation light (first color light). The dichroic mirror 102 has a reflecting surface 102 a that reflects the excitation light emitted from the light source 101 and guides it to the phosphor unit 103 . Regarding the portion other than the reflecting surface 102a in the dichroic mirror 102,
It may have an optical characteristic of transmitting excitation light emitted from the light source 101 and fluorescent light emitted from the phosphor unit 103, which will be described later.

The phosphor unit 103 has a first region that reflects (or diffusely reflects) the excitation light, and converts at least part of the excitation light into fluorescent light (second color light) having a wavelength different from that of the excitation light and emits it. and a second region. When the excitation light is incident on the phosphor unit 103, the excitation light and the fluorescence light are sequentially switched to the excitation light incident surface side (upper side shown in FIG. 1) and emitted. The rod integrator 104 is provided so that the excitation light and fluorescence light emitted from the phosphor unit 103 are incident thereon, mixes (homogenizes) the incident excitation light and fluorescence light, and emits them to the outside of the light source device 100 . .

FIG. 1 shows the case where the first region of phosphor unit 103 is arranged on the optical path of the excitation light emitted from light source 101 . The excitation light emitted from the light source 101 is reflected by the reflecting surface 102 a of the dichroic mirror 102 toward the phosphor unit 103 . The excitation light reflected by the reflective surface 102 a is reflected by the first region of the phosphor unit 103 toward the incident surface of the excitation light. 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 manner, the center of the excitation light on the reflecting surface 102a of the dichroic mirror 102 is defined as a point P, and the luminous flux of the excitation light emitted from the phosphor unit 103 is defined as a 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 the point P and the light beam Q do not intersect.

Here, the center point P of the excitation light on the reflecting surface 102a (projected image center of the excitation light to be projected) is defined as follows.
(1) When the light intensity distribution of the projection range of the excitation light projected onto the reflection surface 102a is line-symmetrical or point-symmetrical, the center of the minimum circumscribed circle of the projection range of the excitation light is defined as the projection image center.
(2) When the light intensity distribution of the projection range of the excitation light projected onto the reflecting surface 102a is not linearly symmetrical or point-symmetrical (i.e., other than (1) above), as shown in FIG. When the total energy of the excitation light projected onto the surface 102a is A, the projection range is cut out by a circle of arbitrary radius r, and the total energy of the light contained in the circle is B, B/A is 93. % or more (B/A≧93%), and the center of the circle having the radius r′ at which the energy density in the circle is maximum is defined as the projection image center.

It should be noted that the projection range of the excitation light indicates a range having energy equal to or higher than 1/e ² of the maximum energy in the energy distribution of the excitation light projected onto the reflecting surface 102a. Also, the energy density is obtained by dividing the "energy contained in the circle" by the "area of the circle". That is, the energy density is obtained by the following formula.
Energy density = (energy contained in circle) / (area of circle)
Note that the projection image center (point P) of the excitation light defined in this way is
Assume that the determination is made with all the light sources 101 provided inside turned on.

Further, the luminous flux (luminous flux Q) of the excitation light emitted from the phosphor unit 103 is 1/e ² of the maximum energy in the energy distribution of the excitation light on the plane perpendicular to the propagation direction of the excitation light.
A bundle of light rays passing through a range with energy equal to or greater than

According to the light source device 100 according to the present invention, the luminous flux Q of the excitation light emitted from the phosphor unit 103 is centered on the reflecting surface 102a of the excitation light emitted from the light source 101 (the center of the projection image of the excitation light). Since the excitation light does not intersect, it is possible to prevent the excitation light from passing through the same point on the dichroic mirror 102.
2 can be prevented from being damaged. In addition, since there is no need to prepare a special optical element such as a retardation plate or a polarization separation element to separate the optical path of the excitation light emitted from the phosphor unit 103, the number of parts can be reduced, and the manufacturing cost can be reduced. At the same time, the size of the device can be reduced.

Note that the light source device 100 shown in FIG. 1 describes a case where the phosphor unit 103 sequentially switches between excitation light and fluorescence light and emits the light. That is, the case where excitation light and fluorescence light are emitted in a time-division manner is described. However, the configuration of the phosphor unit 103 is not limited to this, and may be configured to emit excitation light and fluorescence light at the same time.

For example, instead of the above-described first and second regions, the phosphor unit 103 has a region that reflects part of the excitation light and converts the other part of the excitation light into fluorescent light different from the excitation light (the second region). 3). For example, excitation light is reflected and fluorescent light is converted by a wavelength conversion member provided in this region. Such a phosphor unit 103 is sometimes called a static phosphor unit. When the excitation light is incident on the stationary phosphor unit 103, the excitation light and the fluorescent light are combined and emitted to the excitation light incident surface side (upper side shown in FIG. 1). Even when such a phosphor unit 103 is provided, the same effect as in the case of using the time-division phosphor unit 103 can be obtained.

Further, the light source device 100 shown in FIG. 1 may be provided with light guide means for guiding one or both of the excitation light and the fluorescence light emitted from the phosphor unit 103 to the rod integrator 104 . For example, the light guide means is composed of a condensing lens or a refractive lens, and is arranged on the optical path between the phosphor unit 103 and the rod integrator 104 . By providing the light guiding means in this way, 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 improved. .

Furthermore, in the light source device 100, the position of the rod integrator 104 can be changed as appropriate from the viewpoint of improving the utilization efficiency of the excitation light and/or fluorescence light incident on the rod integrator 104. FIG.
FIG. 2 is a schematic diagram for explaining the outline of the light source device 100 according to the present invention. In FIG. 2, the same reference numerals are given to the same components as in FIG. 1, and the description thereof will be omitted. Note that FIG. 2 shows the case where the reflecting surface 102a is formed on the surface of the dichroic mirror 102. As shown in FIG. The same applies to the drawings shown below.

As shown in FIG. 2, consider the case where the projection image center of the excitation light projected onto the phosphor unit 103 from the dichroic mirror 102 is defined as a point R. FIG. In this case, rod integrator 104 is preferably arranged on the perpendicular to point R on exit surface 103 a of phosphor unit 103 . By arranging the rod integrator 104 in this way, when the fluorescent light is emitted perpendicularly to the emission surface 103a of the phosphor unit 103, the fluorescent light can be efficiently incident on the rod integrator 104. Utilization efficiency can be improved.

Further, in the light source device 100, it is arranged on the optical path between the dichroic mirror 102 and the phosphor unit 103, and collects the excitation light reflected by the dichroic mirror 102, and collects the fluorescence light emitted from the phosphor unit 103. A substantially collimating condensing element may be provided. For example, the condensing element is composed of a condensing lens.
FIG. 3 is a schematic diagram for explaining the outline of the light source device 100 according to the present invention.
In FIG. 3, the same reference numerals are given to the same components as in FIG. 1, and the description thereof will be omitted.

The light source device 100 shown in FIG. 3 has 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 and substantially parallelizes the fluorescence light emitted from the phosphor unit 103 .

Here, after being reflected by the reflecting surface 102a of the dichroic mirror 102, the condenser lens 10
5, the projected image center on the incident surface 105a of the condenser lens 105, which is projected by the excitation light incident on 5;
A straight line connecting the point P on the reflecting surface 102a described above is a straight line L1. A point S is the intersection of the incident surface 103b of the excitation light that is condensed by the condensing lens 105 and enters the phosphor unit 103 and the straight line L1. In the light source device 100, the point S described above and the point R, which is the center of the projection image of the excitation light projected onto the phosphor unit 103, are arranged at different positions. By providing the condensing lens 105 in this way, the excitation light and the fluorescence light that diverge after being emitted from the phosphor unit 103 are collimated. Therefore, light utilization efficiency can be improved.

In the light source device 100 shown in FIG. 3, the straight line L1 described above preferably intersects the incident surface 103b of the phosphor unit 103 perpendicularly. In this way, the straight line L1 is the phosphor unit 10
3, the distance between the dichroic mirror 102 and the phosphor unit 103 can be shortened, and the overall size of the light source device 100 can be reduced.

When light passes through a thick optical element, the incident surface and the exit surface of the optical element are the incident surface and the exit surface, respectively.
For example, as shown in FIG. 3, in the condensing lens 105, the surface of the condensing lens 105 that is reflected and incident on the reflecting surface 102a of the dichroic mirror 102 becomes an incident surface 105a. A surface from which light is emitted toward the body unit 103 is an output surface 105b.

Furthermore, in the light source device 100, the excitation light and/or the fluorescence light arranged in the optical path between the condenser lens 105 and the rod integrator 104 and collimated by the condenser element (condenser lens 105) is condensed. A refractive optical element leading to the rod integrator 104 may be provided. For example, a refractive optical element consists of a refractive lens.
FIG. 4 is a schematic diagram for explaining the outline of the light source device 100. As shown in FIG. In FIG. 4, the same reference numerals are assigned to the same components as in FIG. 3, and the description thereof will be omitted.

The light source device 100 shown in FIG. 4 includes a refractive lens 106 as a refractive optical element on the optical path between the condenser lens 105 and the rod integrator 104 . The refracting lens 106 collects (refracts) the excitation light and/or fluorescence light collimated by the condensing element (condensing lens 105 ) and guides it to the incident opening 104 a of the rod integrator 104 . By providing the refracting lens 106 in this way, the excitation light and/or the fluorescence light collimated by the condenser lens 105 can be efficiently made incident on the rod integrator 104, thereby improving the light utilization efficiency.

Further, in the light source device 100 shown in FIG. 4, it is preferable to select the arrangement of the rod integrators 104 from the viewpoint of homogenization (uniformity) of excitation light and/or fluorescence light incident on the rod integrators 104 . More specifically, when the rod integrator 104 has a rectangular inner peripheral cross section, it is preferable that the rod integrator 104 be arranged such that the excitation light or the like incident on the rod integrator 104 is incident on the inner side surface corresponding to the long side. .

Furthermore, in the light source device 100 shown in FIG. 4, the reflecting surface 1 of the dichroic mirror 102
It is preferable to select the arrangement of the light source 101 from the viewpoint of suppressing the vignetting of the excitation light in 02a. More specifically, when the light emitting surface of the light source 101 has a rectangular shape, it is preferable to arrange so that the width of the excitation light is narrow.

FIG. 5 is a schematic diagram for explaining the outline of the light source device 100 according to the present invention. In FIG. 5, the same reference numerals are assigned to the same components as in FIG. 4, and the description thereof will be omitted. 5A is an explanatory diagram of the components of the light source device 100, FIG. 5B is an explanatory diagram of the incident aperture 104a of the rod integrator 104 of the light source device 100, and FIG. is an explanatory diagram of . 5B shows the incident aperture 104a of the rod integrator 104 from the phosphor unit 103 side. 5C shows the light emitting surface of the light source 101 from the dichroic mirror 102 side.

In the light source device 100 shown in FIG. 5A, a point T is the projection image center on the incident aperture 104a of the rod integrator 104 projected by the excitation light and/or fluorescence light condensed (refracted) by the refracting lens 106 . A straight line connecting this point T and a point R, which is the center of the projection image of the excitation light projected onto the phosphor unit 103, is a straight line L2.
On the other hand, as shown in FIG. 5B, the entrance opening 104a of the rod integrator 104 has a rectangular shape with a long side _LE1 and a short side _SE1 .
Also, as shown in FIG. 5C, the light emitting surface 101a of the light source 101 is assumed to have a rectangular shape having a long side _LE2 and a short side _SE2 .

In the light source device 100, it is preferable that the plane including the straight lines L1 and L2 (that is, the plane including the paper surface shown in FIG. 5A) and the short side _SE1 of the incident aperture 104a of the rod integrator 104 are substantially parallel. . That is, it is preferable to dispose rod integrator 104 so that short side _SE1 of rod integrator 104 shown in FIG. 5B is parallel to the paper surface shown in FIG. 5A. By arranging the rod integrator 104 in this way, the excitation light or the like can be made to enter the inner side surface corresponding to the long side _LE1 of the entrance opening 104a of the rod integrator 104. Therefore, the excitation light inside the rod integrator 104 can be As the number of reflections of light or the like increases, the excitation light or the like can be made 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 plane including the straight lines L1 and L2 (that is, the plane including the paper surface shown in FIG. 5A) and the short side _SE2 of the light emitting surface 101a of the light source 101 are substantially parallel. . That is, it is preferable to dispose the light source 101 so that the short side _SE2 of the light emitting surface 101a shown in FIG. 5C is parallel to the plane of the paper shown in FIG. 5A. By arranging the light source 101 in this way, the width of the light beam extending in the extending direction of the plane including the straight lines L1 and L2 can be narrowed, so that the eclipse on the reflecting surface 102a of the dichroic mirror 102 can be suppressed, and the light utilization efficiency can be improved. can be suppressed. In addition, the light reflected by the phosphor unit 103 can be prevented from interfering with the dichroic mirror 102, and a decrease in light utilization efficiency can be suppressed.

Furthermore, in the light source device 100 , the arrangement of the rod integrator 104 is preferably selected in relation to the refracting lens 106 . For example, in the light source device 100, the projection image center of the excitation light projected onto the entrance opening 104a of the rod integrator 104, the projection image center of the fluorescence light projected onto the entrance opening 104a of the rod integrator 104, and the refraction It is preferable that the optical axis of the lens 106 intersects at one point.

FIG. 6 is a schematic diagram for explaining the outline of the light source device 100 configured as described above.
In FIG. 6 , the same reference numerals are given to the configurations common to those in FIG. 5A , and the description thereof will be omitted. 6A shows the optical path of the excitation light in the light source device 100, and FIG. 6B shows the optical path of the fluorescence light in the light source device 100. As shown in FIG. For convenience of explanation, FIG. 6 shows a pair of condensing lenses 105 ₁ and 105 ₂ arranged along the light propagation direction.

In the light source device 100 shown in FIG. 6, the projection image center on the entrance opening 104a of the rod integrator in the excitation light condensed by the refraction lens 106 and the incidence of the rod integrator 104 in the fluorescence light condensed by the refraction lens 106 are shown. The projection image center on the opening 104a is assumed to be the point T described above.
Further, the refracting lens 106 is arranged so that its optical axis LA passes through the point T. As shown in FIG. Therefore, the projection image center of the excitation light projected onto the incident aperture 104a of the rod integrator 104, the projection image center of the fluorescent light projected onto the incident aperture 104a of the rod integrator 104, and the light of the refractive lens 106 It intersects with the axis LA at one point. As a result, the excitation light and the fluorescence light can be made incident near the center of the entrance opening 104a of the rod integrator 104, so that the eclipse of light due to the entrance opening 104a of the rod integrator 104 can be suppressed, and the light utilization efficiency is improved. can do. Further, even when the optical elements in the light source device 100 are misaligned due to the tolerance of the parts, it is possible to suppress the deterioration of the light utilization efficiency.

Furthermore, in the light source device 100, the arrangement of the refracting lens 106 is preferably selected from the viewpoint of setting the angles of the excitation light and the fluorescence light incident on the entrance opening 104a of the rod integrator 104 within a certain range. The angle of the ray with respect to the entrance opening 104a is the angle formed by the normal line of the plane parallel to the entrance opening 104a and the ray. For example, in the light source device 100, the incident angle of the excitation light ray incident on the incident aperture 104a at the largest angle is greater than the incident angle of the fluorescent light ray incident on the incident aperture 104a at the largest angle. is preferably set small.

As shown in FIG. 6, the angle of incidence of the excitation light ray incident on the incident aperture 104a at the largest angle is _θ1 , and the fluorescence light ray incident on the incident aperture 104a at the largest angle is the angle θ ₂ . In the light source device 100, it is preferable to set the angle _θ1 smaller than the angle _θ2 . By making the incident angle θ ₁ of the excitation light smaller than the incident angle θ ₂ of the fluorescence light in this way, it is possible to suppress the vignetting of light in the optical system arranged in the rear stage of the light source device 100, and to improve the light utilization efficiency. can be done.

In addition, in the light source device 100 according to the present invention, the incident angle _θ1 of the excitation light and the incident angle _θ2 of the fluorescent light may be set to the same angle. By making the incident angle θ ₁ of these excitation lights the same as the incident angle θ ₂ of the fluorescent light, the light distributions of the excitation light and the fluorescent light projected on the DMD or the screen can be made substantially the same. It is possible to suppress the occurrence of color unevenness in the excitation light or the like.

Furthermore, in the light source device 100 according to the present invention, it is preferable to select the optical characteristics of the rod integrator 104 based on the relationship between the incident angle θ ₁ of the excitation light and the incident angle θ ₂ of the fluorescent light described above. For example, in the light source device 100, the rod integrator 104 is composed of a glass rod integrator, and the total reflection condition of the glass rod integrator is set larger than the incident angle _θ1 of the excitation light and the incident angle _θ2 of the second color light. is preferred.

FIG. 7 is a schematic diagram for explaining the optical characteristics of the rod integrator 104 included in the light source device 100. FIG. In the light source device 100 shown in FIG. 7, the rod integrator 104 is composed of a glass rod integrator. It is also assumed that the total reflection condition in rod integrator 104 is angle θ _glass . In this case, the angle θ _glass is set larger than the incident angle θ ₁ of the excitation light and the incident angle θ ₂ of the fluorescence light. As a result, it is possible to prevent the loss of the excitation light or the like inside the rod integrator 104, so that the light utilization efficiency can be improved.

In the light source device 100, the rod integrator 104, which constitutes the light mixing element, preferably has a tapered shape in which the entrance opening 104a is smaller than the exit opening 104b, as shown in FIG. By making the rod integrator 104 tapered in this way, the angle of emission of the light emitted from the rod integrator 104 can be reduced. Utilization efficiency can be improved.

A number of embodiments are described below. It should be noted that the multiple embodiments shown below are examples of the light source optical system, the light source device, and the image projection device according to the present invention, and can be modified as appropriate. Moreover, it is also possible to combine each embodiment suitably.

(First embodiment)
FIG. 9 shows a projector device (image projection device) including the light source device 20 according to the first embodiment.
1 is a schematic block diagram showing 1. FIG. 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 (image display element) 40, and a projection optical system 5.
0 and a cooling device 60 .

The housing 10 includes a light source device 20, an illumination optical system 30, an image forming element 40, and a projection optical system 5.
0 and the cooling device 60 are accommodated. The light source device 20 emits light including wavelengths corresponding to R (red), G (green), and B (blue), for example. Note that the internal configuration of the light source device 20 will be described later in detail.

The illumination optical system 30 substantially uniformly illuminates the image forming element 40 with uniform light from a light tunnel 29 of the light source device 20, which will be 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 (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. image forming element 4
0 drives the minute mirror surface in synchronization with the light (blue light, green light, red light, yellow light) emitted from the illumination optical system 30 to generate a color image.

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

FIG. 10 is a schematic configuration diagram showing the light source device 20 according to the first embodiment. 10A shows the optical path of blue laser light in light source device 20, and FIG. 10B shows the optical path of fluorescent light in light source device 20. As shown in FIG.

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 which is an example of an optical member, which are arranged in order in the light propagation direction. 24, a second optical system 25, a phosphor unit 26 that is an example of a wavelength conversion unit, a refractive optical system 27, a color wheel 28, and a light tunnel 29 that is an example of a light mixing element.

10, the color wheel 28 (see FIG. 9) is omitted for convenience of explanation. In this embodiment, the color wheel 28 is described as a constituent element of the light source device 20 . However, the configuration of the light source device 20 is not limited to this, and may be configured without the color wheel 28 .

As for 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 (blue laser light) with an emission intensity centered at 455 [nm]. Below, blue laser light is simply referred to as blue light. Laser light source 2
The blue light emitted from 1 is linearly polarized light with a constant polarization direction, and is also used as excitation light for exciting the phosphors of the phosphor unit 26, which will be described later.

The light emitted from the laser light source 21 is not limited to light in the blue wavelength band as long as the light has a wavelength that can excite a phosphor, which will be described later. Moreover, although the laser light source 21 has a plurality of light sources, it is not limited to this, and may be configured with a single light source. Also, the laser light source 21 can be configured as a plurality of light sources arranged in an array on a substrate, but the configuration is not limited to this, and other arrangement configurations may be used.

The coupling lens 22 receives the blue light emitted from the laser light source 21 and converts it into parallel light (
collimated light). In the following description, parallel light is not limited to completely collimated light, but includes substantially parallel light. The number of coupling lenses 22 may correspond to the number of light sources of the laser light source 21 and can be increased or decreased according to the increase or decrease of the number of light sources of the laser light source 21 .

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

FIG. 11 is an explanatory diagram of a main part of a 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 facing the laser diode 21A. In the light source unit, among the divergence angles of the blue light (excitation light) emitted from each laser diode 21A, the larger divergence angle in the row direction or the column direction is θ, the pitch between adjacent laser diodes 21A is P, Assuming that the distance from the light emitting point of the laser diode 21A to the coupling lens 22 is L, the arrangement interval (P/L tan θ) of each laser diode 21A is set so as to satisfy (Equation 1) shown below.
1 ≤ P/L tan θ ≤ 4 (Equation 1)

Also, most preferably, the arrangement intervals of the laser diodes 21A are set so as to satisfy the following (formula 2).
P/L tan θ = 2 (Formula 2)
By satisfying (Equation 2), the light from each laser diode 21A can be made incident only on the corresponding coupling lens 22 while reducing the light emitting surface of the laser light source 21. It is possible to prevent the incident light and suppress the decrease in light utilization efficiency.

It is preferable that the plurality of laser diodes 21A included in the light source unit be arranged on the same substrate. By arranging a plurality of laser diodes 21A on the same substrate, the area of the light emitted from the light source unit can be reduced, so that the eclipse of light in various optical elements on the optical path can be suppressed, and the light utilization efficiency can be improved. be able to.

As shown in FIG. 10, the first optical system 23 has positive power as a whole, and includes a large aperture lens 23a and a negative lens in order from the laser light source 21 side toward the phosphor unit 26 side. 23b. The large-aperture lens 23a constitutes an example of a large-aperture element, and is composed of a lens that has positive power and converges and synthesizes the parallel light emitted from the coupling lens 22. FIG. The negative lens 23b constitutes an example of a collimating element, and is composed of a lens that converts the blue light condensed by the large-aperture lens 23a into parallel light. The first optical system 23 reduces the diameter of the blue light (excitation light) incident from the coupling lens 22 as substantially parallel light and guides it to the dichroic mirror 24 .

The dichroic mirror 24 is arranged to be inclined with respect to the propagation direction of the blue light emitted from the first optical system 23 . More specifically, it is arranged with the front end inclined downward along the propagation direction of the blue light emitted from the first optical system 23 . The dichroic mirror 24 has an optical characteristic of reflecting the blue light collimated by the first optical system 23 and transmitting the fluorescent light (second color light) converted by the phosphor unit 26 . there is For example, the dichroic mirror 24 is coated with the optical properties described above.

FIG. 12 is a diagram showing an example of the configuration of the dichroic mirror 24 included in the light source device 20 according to the first embodiment. 12 shows the dichroic mirror 24 from the incident direction of the blue light emitted from the first optical system 23 side. As shown in FIG. 12, 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 the first region 24A and the second region 24B, respectively.
shall be called

The first region 24A reflects blue light emitted from the first optical system 23 (negative lens 23b), while transmitting fluorescent light converted from blue light by the phosphor of the phosphor unit 26, which will be described later. It has optical properties. This first area 24A constitutes the reflecting surface 102a shown in FIG. The second region 24B has optical properties of transmitting these blue light and fluorescent light.

The first area 24A is arranged on the optical axis of the first optical system 23, while the second optical system 25
is located on the optical axis of the first optical system 23 (negative lens 23
b) is displaced to the side. On the other hand, the second region 24B is not arranged on the optical axis of the second optical system 25, and is shifted to a position opposite to the first optical system 23 with respect to the optical axis of the second optical system 25. are placed.

The second optical system 25 has positive power as a whole, and has a positive lens 25A and a positive lens 25B in order from the laser light source 21 side toward the phosphor unit 26 side. The second optical system 25 collects the blue light reflected by the dichroic mirror 24 and guides it to the phosphor unit 26 . Also, the second optical system 25 collimates the fluorescent light emitted from the phosphor unit 26 . In addition, 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 the blue light emitted from the second optical system 25, and a function of converting the blue light into fluorescent light in a wavelength range different from that of the blue light by means of the phosphor by using the blue light as excitation light. It is a unit that switches between The fluorescent light converted by the phosphor unit 26 is, for example,
It is light in a yellow wavelength region with a center of emission intensity of 550 [nm].

FIG. 13 is an explanatory diagram of the configuration of the phosphor unit 26 included in the light source device 20 according to the first embodiment. 13A shows the phosphor unit 26 from the direction of incidence of blue light, and FIG. 13B shows the phosphor unit 26 from the direction orthogonal to the direction of incidence of blue light. Note that the configuration of the phosphor unit 26 shown in FIG. 13 is an example, and the configuration is not limited to this and can be changed as appropriate.

As shown in FIG. 13, the phosphor unit 26 includes a disc member (substrate) 26A and a disc member 2
6A and a drive motor (driving section) 26C that rotates about a straight line that passes through the center of the disk member 26A and is perpendicular to the plane of the disk member 26A as a rotation axis 26B. The disk member 26A can be, for example, a transparent substrate or a metal substrate (such as an aluminum substrate), but is not limited to this.

Most of the circumferential direction (270
) is defined by the fluorescence region 26D, and a small portion in the circumferential direction (angle range smaller than 90° in the first embodiment) is defined by the excitation light reflection region 26E. The excitation light reflecting region 26E constitutes an example of a first region that reflects (or diffusely reflects) the excitation light reflected by the dichroic mirror 24. FIG. The fluorescent region 26D constitutes an example of a region that converts the excitation light reflected by the dichroic mirror 24 and emits fluorescent light. The phosphor region 26D includes a reflective coat 26D1 and a phosphor layer 26 in order from the lower layer side to the upper layer side.
D2 and an antireflection coat (AR coat) 26D3 are laminated.

The reflective coat 26D1 has a property of reflecting light in the wavelength range of fluorescent light (emission light) from the phosphor layer 26D2. When the disk member 26A is made of a metal substrate with high reflectance,
It is also possible to omit the reflective coat 26D1. In other words, it is possible to give the disk member 26A the function of the reflective coat 26D1.

As the phosphor layer 26D2, for example, a phosphor material dispersed in an organic/inorganic binder, a phosphor material crystal directly formed, or a rare earth phosphor such as a Ce:YAG system can be used. . The phosphor layer 26D2 constitutes an example of a wavelength conversion member that converts at least part of the excitation light into fluorescence light having a wavelength different from that of the excitation light and emits the fluorescent light. Phosphor layer 26D2
For example, yellow, blue, green, and red wavelength bands can be used for the wavelength band of the fluorescent light (emission light) from The case of use will be exemplified and explained. Further, although phosphor is used as the wavelength conversion element in this embodiment, phosphor, nonlinear optical crystal, or the like may be used.

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

A reflective coat (reflecting surface) 26E1 having a property of reflecting light in the wavelength region of blue light guided from the second optical system 25 is laminated on the excitation light reflecting region 26E. If the disk member 26A is made of a highly reflective metal substrate, the reflective coat 26E1 can be omitted. In other words, it is possible to give the disk member 26A the function of the reflective coat 26E1.

By rotationally driving the disk member 26A by the drive motor 26C, the position of the blue light irradiation on the phosphor unit 26 moves with time. As a result, phosphor unit 2
6 is converted into fluorescent light (second colored light) having a wavelength different from that of the blue light (first colored light) in the fluorescent region (wavelength conversion region) 26D. emitted. On the other hand, the other part of the blue light incident on the phosphor unit 26 is reflected by the excitation light reflecting region 26E and emitted as blue light.

The number and range of the fluorescent regions 26D and the excitation light reflecting regions 26E have a degree of freedom, and various design changes are possible. For example, each two fluorescence regions and excitation light reflection regions are arranged at 90° in the circumferential direction.
You may arrange|position alternately so that it may become a space|interval.

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

FIG. 14 is an explanatory diagram of a schematic configuration of the color wheel 28 included in the light source device 20 according to the first embodiment. 14A shows the color wheel 28 from the direction of incidence of blue light and fluorescent light, and FIG. 14B shows the color wheel 28 from the direction orthogonal to the direction of incidence of blue light and fluorescent light. As shown in FIG. 14, the color wheel 28 has an annular member 28A and a drive motor (driving section) 28C that rotates the annular member 28A around a rotation shaft 28B.

The annular member 28A is defined in a plurality of regions along the circumferential direction. The toroidal member 28A includes a circumferentially partitioned diffusion region 28D and filter regions 28R, 28G and 28G.
8Y. Diffusion region 28D is a region for transmitting and diffusing the blue light emitted from phosphor unit 26 . The filter region 28R is a region that transmits light including the wavelength region of the red component in the fluorescent light emitted from the phosphor unit 26. As shown in FIG. Similarly, the filter regions 28G and 28Y are regions that transmit light including the wavelength regions of the green component and the yellow component among the fluorescent light emitted from the phosphor unit 26, respectively.

In the above description, it is assumed that the color wheel 28 has areas through which the red, green, and yellow components of the fluorescent light are respectively transmitted. However, the configuration of the color wheel 28 is not limited to this.
It may have regions that transmit red component light and green component light, respectively.

Also, the area ratio of each region in the color wheel 28 is based on the design specifications of the projector device 1 . However, for example, since blue light emitted from the phosphor unit 26 is transmitted through the diffusion region 28D in the color wheel 28, 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 , and the ratio of the area of the diffusion region 28D to the total area of the color wheel 28. FIG.

The annular member 28A rotates in the circumferential direction by rotationally driving the drive motor 28C. By rotating the annular member 28A in the circumferential direction, the blue light emitted from the phosphor unit 26 enters the diffusion region 28D, and the fluorescent light emitted from the phosphor unit 26 passes through the filter regions 28R, 28G and . 28Y sequentially. Phosphor unit 26
Light (blue light and fluorescent light) emitted from the LED passes through the color wheel 28, whereby blue light, green light, red light, and yellow light are emitted sequentially. Light transmitted through each area of the color wheel 28 enters a light tunnel 29 .

The light tunnel 29 is an optical element in which four mirrors are formed inside a square prism, and the light that enters from one end of the square prism is reflected multiple times by the internal mirrors to make the light distribution uniform. It is an element (light homogenizing element). The light tunnel 29 is arranged so that light (blue light and fluorescent light) condensed by the refractive optical system 27 is incident. Although the light tunnel 29 is shown as an example of the light mixing element in the first embodiment, it is not limited to this, and a rod integrator, fly-eye lens, or the like can also be used.

FIG. 15 is a view of the entrance opening 29A of the light tunnel 29 of the light source device 20 according to the first embodiment, viewed from the light incident direction. FIG. 15 shows the projected range of blue light on the entrance opening 29A of the light tunnel 29. In FIG. The light tunnel 29 is arranged slightly inclined as shown in FIG. The tilt angle of the light tunnel 29 changes depending on the performance required of the light source device 20 .

In the light source unit of the light source device 20 according to the first embodiment, as described above, the laser light sources 21 (laser diodes 21A) are arranged in an array. As shown in FIG. 15B, a light tunnel 29 projected by blue light or the like emitted from the laser diode 21A
The projection range on the entrance aperture 29A of is configured in an elliptical shape (see FIGS. 15A and 15B).
For example, as shown in FIG. 15A, the projection range of blue light or the like on the incident aperture 29A is such that the long axis of the elliptical shape is arranged substantially parallel to the short sides of the incident aperture 29A. By setting the projection range of the blue light or the like on the incident aperture 29</b>A in this way, vignetting of the blue light or the like due to the light tunnel 29 can be suppressed. In addition, as shown in FIG. 15B, the projection range of the blue light or the like on the entrance opening 29A may be arranged such that the long axis of the elliptical shape is substantially parallel to the long sides of the entrance opening 29A.
The elliptical shape here means a shape in which there is a difference between the full width at half maximum (FWHM) of the intensity distribution in the vertical direction of the projection range and the full width at half maximum (FWHM) of the intensity distribution in the horizontal direction. In other words, it is a shape that does not have an isotropic intensity distribution.

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

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-aperture lens 23a of the first optical system 23, and then converted into parallel light by the negative lens 23b. Blue light emitted from the negative lens 23b passes through the first region 24 of the dichroic mirror 24.
It is reflected at A and goes 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 projection image of the excitation light described above is formed in the first region 24A.

As described above, the first area 24A of the dichroic mirror 24 is the second optical system 25.
is shifted toward the first optical system 23 with respect to the optical axis of . Therefore, the blue light path is
The light enters a part of the second optical system 25 (more specifically, the positive lens 25A) on the side of the first optical system 23 . The blue light advances toward the optical axis of the second optical system 25 at an angle, and is emitted from the second optical system 25 (more specifically, the positive lens 25B). Blue light emitted from the second optical system 25 enters the phosphor unit 26 .

Here, it is assumed that the blue light incident on the phosphor unit 26 is incident on the excitation light reflection region 26E. The blue light incident on the excitation light reflecting region 26E is specularly reflected. Excitation light reflection area 2
The blue light specularly reflected by 6E enters a part of the second optical system 25 (more specifically, the positive lens 25B) on the side opposite to the first optical system 23 . 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 (more specifically, the positive lens 25A).

Blue light emitted from the second optical system 25 (more specifically, the positive lens 25A) passes through the second region 24B of the dichroic mirror 24. As shown in FIG. A luminous flux of blue light specularly reflected from the phosphor unit 26 or a luminous flux of blue light emitted from the second optical system 25 and transmitted through the second region 24B of the dichroic mirror 24 is the phosphor unit 103 described above. constitutes a luminous flux Q of excitation light emitted from . As mentioned above, the second region 24 of the dichroic mirror 24
B has the optical property of transmitting excitation light (and fluorescence light). Therefore, even when the blue light beam (the light beam Q) intersects the dichroic mirror 24, it is possible to suppress a decrease in light utilization efficiency.

The blue light that has passed through the second region 24B of the dichroic mirror 24 enters the refractive optical system 27 . The blue light advances toward the optical axis of the refractive optical system 27 at an angle and enters the light tunnel 29 via the color wheel 28 . light tunnel 29
After being reflected multiple times inside the light source device 20 and made uniform, the light enters the illumination optical system 30 arranged outside the light source device 20 .

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

Until the blue light emitted from the laser light source 21 is guided to the phosphor unit 26, the fluorescence optical path is the same as the blue light optical path described above. Here, it is assumed that the blue light incident on the phosphor unit 26 is incident on the fluorescent region 26D. The blue light incident on the fluorescent region 26D acts as excitation light for the fluorescent material, is wavelength-converted by the fluorescent material, becomes fluorescent light including, for example, a yellow wavelength range, and acts on the reflective coat 26D1 and the fluorescent material layer 26D2. is Lambertian reflected by

The fluorescent light Lambertianly reflected by the fluorescent region 26D is converted into parallel light by the second optical system 25. FIG. The fluorescent light emitted from the second optical system 25 is reflected by the dichroic mirror 24
and enter the refractive optical system 27 . The fluorescent light advances toward the optical axis of the refractive optical system 27 at an angle and enters the light tunnel 29 via the color wheel 28 . After being reflected multiple times inside the light tunnel 29 and homogenized, the light 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 made different before and after the reflection of the phosphor unit 26 . More specifically, the point (point P shown in FIG. 1) at the center of the projection image of the blue light projected onto the first region 24A of the dichroic mirror 24 from the laser light source 21 and the blue light reflected from the phosphor unit 26 The blue light optical path is formed so that the light flux (the light flux Q shown in FIG. 1) does not intersect. As a result, the luminous flux of blue light emitted from the phosphor unit 26 does not cross the center of the projected image of the blue light emitted from the laser light source 21, so that the blue light does not pass through the same point on the dichroic mirror 24. can be prevented, it is possible to prevent the dichroic mirror 24 from being damaged due to an increase in the density of condensed light, and to improve the reliability.

In addition, since it is not necessary to prepare a special optical element such as a retardation plate or a polarization separation element (polarization beam splitter) in order to separate the optical path of the blue light emitted from the phosphor unit 26,
The number of parts can be reduced, the manufacturing cost can be reduced, and the size of the light source device 20 can be reduced. Furthermore, since optical components for manipulating polarized light, such as retardation plates and polarization splitting elements, are not used, it is possible to suppress deterioration in light utilization efficiency due to the reflectance, transmittance, and absorptivity of optical components.

Furthermore, in the light source device 20 according to the first embodiment, the blue light emitted from the laser light source 21 is linearly polarized light having a constant polarization direction. Further, the light source units having a plurality of laser light sources 21 are arranged so that the directions of linearly polarized light are all the same. Therefore, the directions of linearly polarized 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 shown in FIG. 15, if the light source unit is tilted according to the tilt of the light tunnel 29, the direction of the linearly polarized light changes. In such a situation where the direction of linearly polarized light changes, in the case of a configuration in which polarized light is manipulated by a polarization separation element or the like, the light utilization efficiency may decrease when passing through the polarization separation element. Since the light source device 20 according to the first embodiment does not employ a configuration for manipulating polarized light, it is possible to prevent the light utilization efficiency from deteriorating due to the inclination of the laser light source 21 .

(Second embodiment)
A light source device 201 according to the second embodiment differs from the light source device 20 according to the first embodiment in the configuration of the dichroic mirror. The configuration of the light source device 201 according to the second embodiment will be described below, focusing on differences from the light source device 20 according to the first embodiment. FIG. 16 shows the second
1 is a schematic configuration diagram showing a light source device 201 according to an 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. As shown in FIG. In addition, in FIG. 16, regarding the configuration common to FIG. 10,
The same reference numerals are given and the description is omitted. Also, in FIG. 16B, part of the optical path of the fluorescent light is omitted for convenience of explanation.

As shown in FIG. 16, the light source device 201 differs from the light source device 20 according to the first embodiment only in that it includes a dichroic mirror 241 . The dichroic mirror 241 is tilted like the dichroic mirror 24, while the dichroic mirror 2
It has a length less than 4. Since the dimension of the dichroic mirror 24 is configured to be short, the light source device 20 can be miniaturized. The dichroic mirror 241 has the same optical characteristics as part of the dichroic mirror 24 (first region 24A).

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

The region 241A, like the first region 24A, reflects blue light emitted from the first optical system 23 (negative lens 23b) and converts the blue light into fluorescent light by the phosphor of the phosphor unit 26. It has optical properties of transmitting Also, the region 241A is arranged at the same position as the first region 24A. In other words, the area 241A 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 located in the first position relative to the optical axis of the second optical system 25. is arranged at a position shifted toward the optical system 23 side.

The blue light path and fluorescence light 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 emitted to the second optical system 25 in the same manner as in the first embodiment. Similar to the blue light path. In the light source device 201 according to the second embodiment, unlike the first embodiment, blue light emitted from the second optical system 25 does not pass through the dichroic mirror 241 . The blue light flux (luminous flux Q) emitted from the phosphor unit 103 does not cross the dichroic mirror 24 . On the other hand, the fluorescence optical path is the same as in the first embodiment, as shown in FIG. 16B.

In the light source device 201 according to the second embodiment, the optical path of the blue light emitted from the laser light source 21 is different before and after the reflection of the phosphor unit 26. As with the light source device 20, it is highly reliable and can be made smaller and less expensive.

In particular, in the light source device 201, the width of the dichroic mirror 241 is greater than the width of the second optical system 25.
can be reduced, the size of the light source device 201 can be reduced. Furthermore, since the optical path of the 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)
A light source device 202 according to the third embodiment includes a light source unit (hereinafter referred to as a “first light source unit” as appropriate) consisting of a laser light source 21 and a coupling lens 22, and in addition to the laser light source 21
1 and a coupling lens 221 (hereinafter referred to as a “second light source unit”), and polarization optics for synthesizing the excitation light from the second light source unit with the excitation light from the first light source unit. It differs from the light source device 201 according to the second embodiment in that it has components.

The configuration of the light source device 202 according to the third embodiment will be described below, focusing on differences from the light source device 201 according to the second embodiment. FIG. 18 is a schematic configuration diagram showing a light source device 202 according to the third embodiment. 18A shows the optical path of blue laser light in the light source device 202 according to the third embodiment, and FIG. 18B shows the optical path of fluorescent light in the light source device 202 according to the third embodiment. In addition, in FIG. 18, the same reference numerals are given to the same configurations as in FIG. 16, and the description thereof will be omitted. Also, in FIG. 18B, 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 has a laser light source 211 and a coupling lens 221 that constitute a second light source unit. The second light source unit is arranged such 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 a configuration similar to that of the laser light source 21 . That is, the laser light source 211 has an array of light sources (laser diodes) that emit a plurality of laser beams, and emits, for example, blue light with an emission intensity centered at 455 [nm]. Here, both the laser light sources 21 and 211 are configured to emit P-polarized light. Like the coupling lens 22, the coupling lens 221 is a lens that receives the blue light emitted from the laser light source 211 and converts it into parallel light (collimated light).

The light source device 202 has a half-wave plate 222 and a polarization separation element 223 that constitute polarization optical components. A half-wave plate 222 is arranged to face the plurality of coupling lenses 221 . The half-wave plate 222 converts the P-polarized component of the blue light emitted from the laser light source 211 into an S-polarized 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 separation element 223 has an optical characteristic of reflecting the S-polarized component of blue light and transmitting the P-polarized component of blue light.

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

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

In the light source device 202 according to the third embodiment, the optical path of the blue light emitted from the laser light source 21 is different before and after the reflection of the phosphor unit 26. As with the light source device 201, it is highly reliable and can be made smaller and less expensive. In particular, since the light source device 202 combines the excitation light from the first light source unit with the excitation light from the second light source unit, the luminance of the excitation light can be increased and the light utilization efficiency can be improved. In addition, since the polarization is manipulated by the half-wave plate 222 and the polarization separation element 223 that constitute the polarization optical component, the separation and combination of the optical paths can be performed regardless of the presence or absence of the mixture of the polarized components of the light emitted from the light source. can be realized.

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

FIG. 19 is a schematic configuration diagram showing a light source device 203 according to the fourth embodiment. 19A shows the optical path of blue laser light in the light source device 203, and FIG. 19B shows the optical path of fluorescent light in the light source device 203. As shown in FIG. In addition, in FIG. 19, the same reference numerals are given to the same configurations as in FIG. 16, and the description thereof will be omitted. Also, in FIG. 19B, part of the optical path of the fluorescent light is omitted for convenience of explanation.

In the light source device 203 according to the fourth embodiment, instead of the rotationally driven phosphor unit 26, a non-rotationally driven phosphor unit (hereinafter referred to as a "static phosphor unit" as appropriate) is provided.
261. The stationary phosphor unit 261 reflects part of the blue light (excitation light) emitted from the laser light source 21 as it is, while converting the other part of the blue light into fluorescent light and emits (
release).

FIG. 20 is a schematic diagram for explaining the configuration of the static phosphor unit 261 included in the light source device 203 according to the fourth embodiment. In FIG. 20, the static phosphor unit 261 is shown from a direction orthogonal to the incident direction of blue light. As shown in FIG. 20, stationary phosphor unit 261
is configured by stacking a phosphor 261b as a wavelength converting member on a reflecting member 261a that reflects excitation light. For example, the reflecting member 261a and the phosphor 261b have a rectangular shape in plan view. The phosphor 261b is applied on the reflecting member 261a.

The phosphor 261b converts, for example, 80% of the incident blue light (excitation light) into fluorescent light. When blue light enters stationary phosphor unit 261, 80% of the blue light acts as excitation light for phosphor 261b and is wavelength-converted by phosphor 261b.
As a result, for example, the emitted light becomes fluorescent light including a yellow wavelength region with a center of emission intensity of 550 [nm], and is Lambertian reflected by the action of the phosphor 261b and the reflecting member 261a.

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

The blue light path and fluorescent light path in the light source device 203 having such a configuration will be described with reference to FIGS. 19A and 19B. As shown in FIGS. 19A and 19B, the blue light path and fluorescence light path in light source device 203 are the same as in the second embodiment, except for wavelength conversion and reflection in stationary 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 before and after the reflection of the stationary phosphor unit 261. As with the light source device 201, it is highly reliable, and can be downsized and reduced in cost. In particular, in the light source device 203, the static phosphor unit 261
Since blue light and fluorescent light are emitted at the same time, there is no need to rotationally drive the phosphor unit, and the manufacturing cost of the device can be reduced. In addition, since a motor for rotational driving can be omitted, it is possible to reduce noise and prevent deterioration in reliability due to the life of the motor.

Four embodiments of the present invention, ie, Embodiments 1 to 4, will be described below.
Embodiments 1 to 4 are configurations in which the optical paths of the excitation light and fluorescence light in the first to fourth embodiments described above are configured three-dimensionally.
As described above, in FIG. 5A, the plane including the straight lines L1 and L2 (that is, the plane including the paper surface shown in FIG. 5A) and the short side _SE1 of the incident aperture 104a of the rod integrator 104 are substantially parallel. Although it is preferable that there is one, they do not necessarily have to be parallel.
That is, the rod integrator 104 may be slightly rotated around the straight line L2 as the central axis.

(Embodiment 1)
The light source device of Embodiment 1 shown in FIG. 21 has a form in which the long side of the incident aperture of the rod integrator 104 is parallel to the plane containing the straight lines L1 and L2.
As described above, the present invention includes a plane including the optical path of the excitation light incident on the optical member and the optical path of the excitation light reflected by the optical member and directed to the condensing element (optical paths before and after the optical member), and the condensing element. One of the characteristics is that the planes including the optical path of the excitation light between the wavelength conversion units (optical paths before and after the wavelength conversion unit) are not parallel.

The configuration shown in FIG. 21A is similar to the configuration in FIG. 5A. In FIG. 5, it is assumed that the plane including the straight line L1 and the straight line L2 is "inside the plane including the plane of the paper". That is, the straight line L2 intersects the extension of the straight line L1." However, in Embodiment 1 described here, the extension of the straight line L1 and the straight line L2 do not intersect.

Reference numerals in FIG. 21A will be explained.
L0 is an optical path (straight line) starting from the substantially central portion of the bundle of rays emitted from the light source 101 and reaching the point P. FIG.
L1 is an optical path (straight line) that connects the projected image center on the entrance surface 105a of the condenser lens 105 and the point P on the reflection surface 102a, which is projected by the excitation light incident on the condenser lens 105.
L12 is an optical path (straight line) along which a ray of light passing through the approximate center point of the ray bundle forming the projected image on the entrance surface 105a emerges from the exit surface 105b of the condenser lens 105 and travels toward the reflection point R.
Q is the luminous flux of excitation light emitted from the phosphor unit 103 .
Q1 is an optical path that is reflected at the reflection point R and directed to the condenser lens 105 .
Q2 is an optical path that is refracted by the condensing lens 106 and directed to a point T that is incident on the rod integrator 104 .
The optical paths Q1 and Q2 are optical paths represented by the central ray of the luminous flux, and are also referred to as rays Q1 and Q2. Also, the luminous flux Q is also referred to as a ray Q, with its central ray as a representative ray, representing this representative ray. Also, Q, Q1, and Q2 are regarded as light fluxes including light rays Q, Q1, and Q2, and are also referred to as light flux Q, light flux Q1, and light flux Q2.
U is the virtual intersection of the light rays L1 and L2.
V is the virtual intersection point of the ray Q1 and the ray Q;
W is the virtual intersection point of the ray Q and the ray Q2.

In order to clarify the three-dimensional positional relationship, the direction of incidence on the reflecting surface 102a is defined as the Z-axis, and right-handed XYZ coordinate axes are defined as shown in the figure.
21A is a view of the YZ plane viewed from the - side of the X axis, and FIG. 21B is a view of the state of FIG. 21A viewed from the side of the rod integrator 104. It is the figure seen from.

As shown in FIGS. 21A and 21B, the light beam emitted from the light source 101 is directed to the dichroic mirror 102 either directly or after being folded back (directly in the figure), and the light beam incident on the dichroic mirror 102 travels along the straight line L0. The straight line L0 itself may be regarded as a ray.
The light emitted from the light source 101 is treated as "a bundle of light rays that proceed discretely or with a constant width", and this "optical path approximately at the center of the bundle of light rays" is defined as a straight line L0.
The light source is composed of a single light emitting part or a plurality of light emitting parts arranged in an array on a certain surface. becomes L0.
The straight line L0 is not limited to being the center of the light-emitting portion or the light-emitting portion group, but rather the optical path at the approximate center of the bundle of rays.
A light ray traveling along the straight line L0 is reflected at the point P, enters the condensing lens 105, and travels to the point R due to the refraction action of the condensing lens 105. FIG. At this time, the point R on the phosphor unit 103 is a reflection area, specularly reflected at the point R, and the specularly reflected ray Q1 travels toward the condensing lens 105 again. The luminous flux Q1 is refracted into the luminous flux Q by the refraction action of the condensing lens. The luminous flux Q is refracted by the condensing action of the condensing lens 106 and travels to the point T as a luminous flux Q2.

Originally, a light ray passing through the condensing lens 105 is refracted at the boundary of the lens and directed to the condensing point R, but in the drawing, it is depicted as if it is refracted at a point U inside the lens. This is for the purpose of simplifying the explanation in order to correctly convey the features of the present invention, and in reality, the light is refracted when passing through the lens interfaces (105a and 105b in FIG. 3).
The same applies to the inflection point V where the ray Q1 reflected at the point R is refracted to become the ray Q. The same is true for the inflection point W where the ray Q is refracted at the inflection point W by the refraction action of the condensing lens 106 and becomes the ray Q2. is.

In the light source device of the present invention, as shown in FIG. 21B, the plane PL1 including the straight lines L0 and L1 and the plane PL2 including the straight line L12 and the light flux (light beam) Q1 are not in a parallel relationship (non-parallel to each other). There is.)” is characterized.
Further, "a straight line (an extension of the straight line L1) including light rays traveling straight along the straight line L1 does not intersect with a straight line L2 (perpendicular to the point R) due to the refractive power of the condenser lens 105".
In the light source device of Embodiment 1, the long side of the incident aperture of rod integrator 104 is parallel to plane PL1.

(Embodiment 2)
The light source device of Embodiment 2 shown in FIG. 22 is a modification of Embodiment 1 described above, and the long side of the incident aperture of rod integrator 104 is slightly rotated clockwise with respect to plane PL1. A point is different from the first embodiment, and other points are the same as the first embodiment.
(Embodiment 3)
The light source device of Embodiment 3 shown in FIG. 23 is also a modification of Embodiment 1 described above, and the long side of the incident aperture of rod integrator 104 is slightly rotated counterclockwise with respect to plane PL. The second embodiment is different from the first embodiment in that the second embodiment is identical to the first embodiment.

In both Embodiments 2 and 3, as is clear from FIGS. most of the incident light enters the long side of the rod integrator.
In the light source devices of Embodiments 1 to 3, the light source unit and the phosphor unit are arranged so that when the rotation center axis of the phosphor unit 103 is determined, the rotation center axis and the light beam L0 do not intersect. It can be said that it is characteristic that there is
Here, although the light emitted from the light source 101 is treated as a bundle of light beams with a constant width or discrete progress, the optical path at the approximate center of the bundle of light beams is defined as the straight line L0. Since the bundle of rays has a constant width (thickness), the off-center edge may intersect the central axis of rotation. The gist of the present invention is that the light emitted from the light source 101 has a constant width, or the optical paths (straight lines) along the substantially central ray (optical path) of the bundle of rays that proceed discretely are L0, L1, and the like.

Note that FIGS. 21B, 22, and 23 exaggerate how the central axis of rotation and the light ray L0 do not intersect.
With such a configuration, the excitation light or the like can be incident so as to hit the inner side surface corresponding to the long side of the entrance opening 104 a of the rod integrator 104 , so that the number of reflections of the excitation light or the like inside the rod integrator 104 can be increased. Accordingly, the excitation light and the like can be made uniform, and the occurrence of color unevenness in the excitation light and the like can be suppressed.
Further, in Embodiments 2 and 3, when the straight line connecting the point R and the center of the projection image on the incident aperture of the rod integrator on which the first color light is projected is the straight line L2, the straight line L1 and the straight line L2 are The plane including the rod integrator and the direction of the short side of the incident aperture of the rod integrator are kept from being parallel to each other. That is, the lot integrator 104 is rotated around the straight line L2.
With such a configuration, it becomes possible to increase the number of times of reflection on the internal reflection surface, and a large effect of uniformity is obtained.

In particular, in the embodiment of FIG. 22, many rays of excitation light reaching the lot integrator 104 tend to hit the internal reflection regions located on the long side of the rod integrator 104 . In other words, it can be seen that when the luminous flux width of the excitation light beam is increased, the second embodiment shown in FIG. 22 "has a wider internal reflection area located on the long side" than the third embodiment shown in FIG. Therefore, Embodiment 2 of FIG. 22 is more preferred.
On the other hand, if the layout is such that the plane PL1 and the plane PL2 are parallel, the light will be incident from the short side of the lot integrator, making uniformity difficult.
Therefore, the plane PL1 and the plane PL2 are not parallel, and are desirably larger than 45 degrees and smaller than 135 degrees, that is, by making them "a positional relationship of approximately 90 degrees", the plane PL1 and the "long side direction of the lot integrator 104 are aligned, the incident direction of the excitation light is deflected by "approximately 90 degrees" without changing the arrangement of the rod integrator 104, and many light rays are directed to the internal reflection area located on the long side of the rod integrator 104. can lead. Therefore, it is effective for uniformity.
Even if the angle between the plane PL1 and the plane PL2 is slightly angled (that is, they are not parallel), the optical path can be bent in the direction forming the angle, which is effective in miniaturizing the apparatus.
Further, in order to further reduce the volume of the apparatus, a greater effect can be obtained by appropriately setting the angle formed by the planes PL1 and PL2. is set to "approximately 90 degrees (at least in the range of greater than 45 degrees and less than 135 degrees)" as described above, the optical path can be bent more cubic, and the optical system can be made compact.

Still another embodiment will be described as a fourth embodiment.
24, 25, and 26 are explanatory diagrams of the fourth embodiment.
FIG. 24 is viewed from the same direction as FIG. 21A, the first embodiment described above.
In FIG. 24, a light ray emitted from a light source (same as the light source 101 in FIG. 21A), which is not shown, travels in the + direction of the X axis, which is the depth direction of the paper, and passes through lenses LN1 and LN2. , is folded back in the Z direction by the folding mirror BM and directed toward the reflecting surface 102a (see FIG. 1A) of the mirror DM. The light beam after being folded by the folding mirror BM corresponds to the optical path L0 shown in FIGS. 21A, 21B, 22, and 23, and has the same general function.
21 to 23 corresponds to the mirror DM in FIGS. 24, 25 and 26. In FIG.

The light beam folded back by the mirror BM becomes a light beam L1 traveling in the Z direction, that is, from right to left on the drawing (left-right opposite to FIG. 21B).
Next, the light is folded downward in the plane of the drawing by the mirror DM, follows the optical path L1, is collected by the condensing lenses LN3 and LN4, and is condensed at the point R on the phosphor unit PW through the optical path L12. In the reflection area on PW, the condensed light source light is reflected and becomes high-speed Q and is again condensed by lenses LN4 and LN3 without interference with mirror DM (passing in front of the paper, in the depth direction of the paper). (because the position of ) is different), it passes near the mirror DM and goes to the lens LN5.
The light source light (excitation light) condensed by the lens LN5 reaches the rod integrator LT. Here, the rod integrator LT is arranged such that the direction parallel to the YZ plane (paper surface) is along the long side of the incident surface. Actually, it may be slightly rotated around the perpendicular line of the point R, so it is written as along the long side. Also, it is along the direction perpendicular to the plane of the paper. At this time, a light beam (excitation light) incident on the rod integrator LT becomes a light beam incident on the rod integrator LT from the depth direction with respect to the plane of FIG. 24 . That is, many rays are incident on the long sides of the rod integrator LT.

FIG. 25 is a diagram of FIG. 24 rotated 90 degrees around the Y-axis.
The light beams reflected by the mirror DM and directed downward are reflected by the reflecting surface of the phosphor unit PW and directed upward. Head to the rod integrator LT via the wheel CW.
Here, the rod integrator LT is arranged such that the direction parallel to the XY plane (paper surface) is along the short side, and the light beam (excitation light) incident on the rod integrator LT is directed parallel to the paper surface in FIG. to the rod integrator LT. That is, many rays are incident on the long sides of the rod integrator LT.

FIG. 26 is a view of the phosphor unit viewed from the rod integrator side, which corresponds to the direction shown in FIG.
Further, as shown in FIGS. 24 and 25, the plane PL1 and the plane PL2 are set at approximately 90 degrees. Approximately 90 degrees is a range larger than 45 degrees and smaller than 135 degrees. By adopting such a configuration, it is possible to separate the light beam L1 from the optical path including the light beam Q of the excitation light emitted from the phosphor unit PW. Also, it becomes easier to separate the light flux Q from the mirror DM.
Even if the plane PL1 is along the long side of the rod integrator LT, the incident direction of the excitation light is rotated by approximately 90 degrees when viewed from the incident position of the lot integrator LT. , the excitation light can be incident.

The above configuration eliminates the need for the PBS and wavelength plate that were required in the prior art, simplifies the configuration, and bends the optical path three-dimensionally. It is now possible to switch to
Specifically, the excitation light can be made to enter the inner surface corresponding to the long side LE ₁ (see FIG. 5B) of the entrance opening 104 a of the rod integrator 104 . As a result, the excitation light and the like can be made uniform as the number of reflections of the excitation light and the like inside the rod integrator 104 increases, and the occurrence of color unevenness in the excitation light and the like can be suppressed.

Although the preferred embodiments of the present invention have been shown in each of the above-described embodiments, the present invention is not limited to the contents thereof. In particular, the specific shape and numerical values of each part exemplified in each embodiment are merely examples of specific implementations performed when carrying out the present invention, and the technical scope of the present invention may not be construed as being limited by these. It should not exist. As described above, the present invention is not limited to the contents described in the present embodiment, and can be modified as appropriate without departing from the scope of the invention.

1: projector device 10: housing 20: light source device 21: laser light source 21A: laser diode 22: coupling lens 23: first optical system 23a: large aperture lens 23b: negative lens 24: dichroic mirror 24A: area (second 1 area)
24B: area (first area)
25: Second optical system 25A, 25B: Positive lens 26: Phosphor unit 27: Refractive optical system 28: Color wheel 29: Light tunnel 29A: Entrance aperture 30: Illumination optical system 40: Image forming element 50: Projection optics System 60: cooling device 100: light source device 101: light source 101a: light emitting surface 102: dichroic mirror 102a: reflecting surface 103: phosphor unit 103a: exit surface 103b: entrance surface 104: rod integrator 104a: entrance opening 104b: exit opening Part 105: condenser lens 105a: entrance surface 105b: exit surface 106: refracting lenses 201, 202, 203: light source device 211: laser light source 221: coupling lens 222: half-wave plate 223: polarization separating element 241: dichroic Mirror 241A: Area 261: Phosphor unit (static phosphor unit)
261a: Reflective member 261b: Phosphor

Claims (28)

A light source device,
an excitation light source that emits a first color light;
an optical member having a reflecting surface that reflects the first color light emitted from the excitation light source;
a wavelength conversion member that receives the first colored light reflected by the optical member, converts at least part of the first colored light into second colored light having a wavelength different from that of the first colored light, and emits the second colored light; a wavelength conversion unit having
provided on an optical path between the optical member and the wavelength conversion unit, condenses the first color light reflected by the optical member, and emits the first color light and the first color light emitted from the wavelength conversion unit; Equipped with a condensing element for condensing two colored lights,
Let the center of the first color light on the reflecting surface of the optical member be a point P,
A projection image center of the first color light condensed and projected onto the wavelength conversion unit is defined as a point R,
Let Q be the luminous flux of the first color light emitted from the wavelength conversion unit and condensed by the condensing element,
The optical path from the approximate center of the ray bundle emitted from the excitation light source to the point P is LO,
A straight line (optical path) from the point P to the condensing element is L1,
L12 is the optical path from the condensing element to the point R,
When the optical path from the point R to the condensing element is Q1,
A light source device characterized in that the point P and the light flux Q do not intersect, and a plane PL1 including the optical paths L0 and L1 and a plane PL2 including the optical paths L12 and Q1 are not parallel. 2. A straight line including the optical path L0 does not intersect a perpendicular line including the point R with respect to the surface of the wavelength conversion unit on which the first color light is condensed and projected onto the wavelength conversion unit. 2. The light source device according to 1. 3. The light source device according to claim 1, wherein the angle between the plane PL1 and the plane PL2 is approximately 90 degrees. The wavelength conversion unit includes a first region that reflects or diffusely reflects the first color light reflected by the optical member, and the wavelength conversion member provided with the first color light reflected by the optical member. and a region that converts and emits the second color light,
When the first colored light is incident, the first colored light and the second colored light are sequentially switched to the incident surface side of the first colored light and emitted. The light source device according to any one of items. 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 converts part of the incident first color light into the first color light. converting into two colored lights and reflecting a part of the first colored lights reflected by the optical member;
4. The apparatus according to any one of claims 1 to 3, wherein when the first colored light is incident, the first colored light and the second colored light are collectively emitted to the incident surface side of the first colored light. 1. The light source device according to 1. a light mixing element for mixing the first colored light and/or the second colored light emitted from the wavelength conversion unit;
6. The apparatus according to any one of claims 1 to 5, further comprising light guiding means for guiding the first colored light and/or the second colored light emitted from the wavelength conversion unit to the light mixing element. 1. The light source device according to 1. When the projection image center of the first color light projected onto the wavelength conversion unit is a point R, the light mixing element is arranged on a perpendicular line to the point R on the emission surface of the wavelength conversion unit. 7. The light source device according to claim 6, characterized in that: A straight line 1 is a straight line connecting the center of the projection image on the incident surface of the light collecting element projected by the first color light incident on the light collecting element after being reflected by the reflecting surface and the point P,
When the point S is the intersection of the straight line 1 and the plane of incidence of the first color light condensed by the condensing element and incident on the wavelength conversion unit,
8. The light source device according to claim 1, wherein positions of said point R and said point S are different. 9. The light source device according to claim 8, wherein the straight line 1 and the plane of incidence of the first color light incident on the wavelength conversion unit perpendicularly intersect. The light mixing element is a rod integrator,
7. A light source device according to claim 6, wherein said light guiding means is a refractive optical element. A projection image center of the first color light projected onto the entrance aperture of the rod integrator, a projection image center of the second color light projected onto the entrance aperture of the rod integrator, and the refractive optical element. 11. The light source device according to claim 10, wherein the optical axis of . a plane including the optical path L1 and the straight line 2, where a straight line connecting the point R and the center of the projection image on the incident aperture of the rod integrator projected by the first color light is a straight line 2; 12. The light source device according to claim 11, wherein the rod integrator is arranged so as not to be parallel to the short side of the entrance opening of the rod integrator. a plane including the optical path L1 and the straight line 2, where a straight line connecting the point R and the center of the projection image on the incident aperture of the rod integrator projected by the first color light is a straight line 2; 13. The light source device according to any one of claims 10 to 12, wherein the short sides of the light emitting surface of the excitation light source are arranged substantially parallel to each other. Let θ1 be the incident angle of the ray of the first color light incident on the incident aperture of the rod integrator at the largest angle, and the second color light incident on the incident aperture of the rod integrator at the largest angle. 14. The light source device according to claim 10, wherein .theta.1 is smaller than .theta.2, where .theta.2 is the incident angle of the colored light. Let θ1 be the incident angle of the ray of the first color light incident on the incident aperture of the rod integrator at the largest angle, and the second color light incident on the incident aperture of the rod integrator at the largest angle. 15. The light source device according to claim 10, wherein .theta.1 and .theta.2 are the same, where .theta.2 is the incident angle of the colored light. 16. The light source device according to any one of claims 10 to 15, wherein the rod integrator has an entrance opening smaller than an exit opening. The rod integrator is composed of a glass rod integrator,
Let θ1 be the incident angle of the ray of the first color light incident on the incident aperture of the rod integrator at the largest angle, and the second color light incident on the incident aperture of the rod integrator at the largest angle. When the incident angle of the colored light rays is θ2 and the total reflection condition of the glass rod integrator is θ _glass ,
17. The light source device according to claim 10, wherein the [theta] _glass is set larger than the [theta]1 and the [theta]2. The excitation light source includes a plurality of laser diodes arranged in an array,
a projection range on an entrance opening of the rod integrator projected by the first color light emitted from the laser diode is elliptical;
18. The light source device according to any one of claims 10 to 17, wherein the long axis of the elliptical shape is arranged substantially parallel to the long side or short side of the entrance opening of the rod integrator. 19. The light source device of claim 18, wherein the plurality of laser diodes 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 diode,
Let θ be the divergence angle of the first color light emitted from the laser diode in the larger direction of the row direction or the column direction,
Let p be the pitch of the adjacent laser diodes,
20. The method according to any one of claims 1 to 19, wherein the arrangement interval of the laser diodes satisfies the following formula, where L is the distance from the light emitting point of the laser diode to the coupling lens. light source device.
1 ≤ p/L tan θ ≤ 4 The optical member has a transmissive region having an optical property of transmitting the first colored light and the second colored light in a region other than the reflecting surface , and the light beam Q intersects with the optical member. The light source device according to any one of claims 1 to 20. The optical member has a transmissive region having an optical characteristic of transmitting the first colored light and the second colored light in a region other than the reflecting surface , and the light flux Q does not intersect with the optical member. The light source device according to any one of claims 1 to 20. 23. The light source device according to claim 21, wherein the reflecting surface has an optical characteristic of reflecting the first colored light and transmitting the second colored light. In the wavelength conversion unit, a circular substrate is divided in the circumferential direction into a first region for reflecting or diffuse reflection of the first color light reflected by the optical member and a region for emitting the second color light. and a driving portion that rotates about a straight line that passes through the center of the disk member and is perpendicular to the plane of the disk member as a rotation axis. 24. The light source device according to any one of 23. 25. The light source unit and the phosphor unit according to claim 24, wherein the light source unit and the phosphor unit are arranged so that when the rotation center axis of the wavelength conversion unit is determined, the rotation center axis and the light beam L0 do not intersect. Light source device. A large-diameter element having a positive power along the traveling direction of the first color light and a collimating element having a negative power are arranged on an optical path between the excitation light source and the optical member,
2. The first color light emitted from the excitation light source is condensed by the large-diameter element, converted into substantially parallel light by the collimating element, and incident on the optical member. 26. A light source device according to any one of claims 25 to 25. a light source device according to any one of claims 1 to 26;
an illumination optical system for guiding light emitted from the light source device to an image display element;
and a projection optical system for projecting an image generated by the image display element using the light guided by the illumination optical system. A light source optical system ,
an excitation light source that emits a first color light;
an optical member having a reflecting surface that reflects the first color light emitted from the excitation light source;
a wavelength conversion member that receives the first colored light reflected by the optical member, converts at least part of the first colored light into second colored light having a wavelength different from that of the first colored light, and emits the second colored light; a wavelength conversion unit having
provided on an optical path between the optical member and the wavelength conversion unit, condenses the first color light reflected by the optical member, and emits the first color light and the first color light emitted from the wavelength conversion unit; Equipped with a condensing element for condensing two colored lights,
Let the center of the first color light on the reflecting surface of the optical member be a point P,
A projection image center of the first color light condensed and projected onto the wavelength conversion unit is defined as a point R,
Let Q be the luminous flux of the first color light emitted from the wavelength conversion unit and condensed by the condensing element,
The optical path from the approximate center of the ray bundle emitted from the excitation light source to the point P is LO,
A straight line (optical path) from the point P to the condensing element is L1,
L12 is the optical path from the condensing element to the point R,
When the optical path from the point R to the condensing element is Q1,
that the point P and the luminous flux Q do not intersect;
A light source optical system, wherein a plane PL1 including the optical paths L0 and L1 and a plane PL2 including the optical paths L12 and Q1 are not parallel.

Images