JP7086518B2 - Light source optical system and projection type display device using this - Google Patents

Description

The present invention relates to a light source optical system and a projection type display device using the same.

In recent years, projectors have been developed in which a phosphor is irradiated with a luminous flux emitted from a high-power laser diode (hereinafter, LD) as excitation light, and wavelength-converted fluorescent light is used as a light source. In such a projector, it is possible to increase the brightness of the projector by increasing the number of LDs or increasing the output.

However, if the intensity of the incident light on the phosphor is increased, the light density of the focused spot on the phosphor surface becomes too high, and the light conversion efficiency may decrease.

The technique described in Patent Document 1 is known as a technique for solving such a problem. Patent Document 1 discloses a configuration in which two fly-eye lenses are provided after an optical system that compresses a light flux from a plurality of LDs to make the light density of a focused spot formed on the phosphor uniform. There is.

Japanese Unexamined Patent Publication No. 2012-118110

As a problem not presented in the above-mentioned Patent Document 1, there is an influence of variation that each LD itself has. Specifically, the parallelism of the output light of the LD may vary depending on the object. Therefore, the light source image formed in the vicinity of the second fly-eye lens in the configuration described in the above-mentioned Patent Document 1 protrudes from the predetermined lens cell of the second fly-eye lens and enters the adjacent lens cell. In some cases. As a result, the amount of light that is dispelled by the optical element in the subsequent stage increases, and the light utilization efficiency may decrease.

Further, if the lens cell is made too large with respect to the light source image in order to prevent it from protruding into the adjacent lens cell, the optical system becomes large, which is not preferable.

Therefore, an object of the present invention is to provide a light source optical system capable of suppressing a decrease in light utilization efficiency and an increase in size, and a projection type display device using the same.

In order to achieve the above object, the light source optical system of the present invention is used.
A light source optical system that guides the luminous flux from a light source to a wavelength conversion element.
The surface on the light source side is a first lens surface array having a plurality of first lens surfaces, and the surface on the side of the wavelength conversion element is provided with a plurality of second lens surfaces, and the first lens surface array is provided. A lens array , which is a second lens surface array that guides the luminous flux from the wavelength conversion element to the wavelength conversion element.
It is provided with a light guide element that guides the light flux from the second lens surface array in the direction of the wavelength conversion element and guides the light flux from the wavelength conversion element in a direction different from that of the light source.
When the lateral direction of the second lens surface is the first direction and the longitudinal direction of the second lens surface is the second direction, the first lens surface and the first lens surface array are used. The width of the light source image formed between the light source image and the light source image in the second direction is wider than the width of the light source image in the first direction.

According to the present invention, it is possible to provide a light source optical system capable of suppressing a decrease in light utilization efficiency and an increase in size, and a projection type display device using the same.

Schematic diagram of the configuration of the light source device shown in the first embodiment of the present invention. Schematic diagram of laser diode An explanatory diagram of the relationship between the second flyeye lens used in the first embodiment of the present invention and the light source image. Explanatory drawing of fly eye lens used in 1st Example of this invention Explanatory drawing of fly eye lens used in 2nd Example of this invention Explanatory drawing of relationship between the second flyeye lens used in the second embodiment of the present invention and the light source image. Explanatory drawing of fly eye lens used in 3rd Example of this invention Explanatory drawing of relationship between 2nd flyeye lens used in 3rd Example of this invention and light source image Schematic diagram of the configuration of the light source device shown in the fourth embodiment of the present invention. Schematic diagram of the configuration of the light source device shown in the fifth embodiment of the present invention. Configuration explanatory view of the projector which can mount the light source apparatus shown in each embodiment of this invention A modified example of the flyeye lens used in each embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be exemplified with reference to the drawings. However, the relative arrangement of the components described in this embodiment should be appropriately changed depending on the configuration of the apparatus to which the present invention is applied and various conditions. That is, the present invention is not limited to the embodiments described later, and various modifications and changes can be made within the scope of the gist thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First Example]
(Structure of light source optical system and light source device)
FIG. 1 is a diagram showing a configuration of a light source device as a first embodiment of the present invention. In FIG. 1, the lateral direction of the second fly-eye lens 62 is the x-axis direction (first direction), the longitudinal direction is the y-axis direction (second direction), and the second fly-eye lens 62 is orthogonal to the x-axis direction and the y-axis direction. The direction is the z-axis direction.

The light source optical system shown in this embodiment includes a light guide optical system having a parabolic mirror array 3, a flat mirror 4, and a concave lens 5. Further, the light source optical system includes a first fly-eye lens 61 as a first lens surface array, a second fly-eye lens 62 as a second lens surface array, and a dichroic mirror 7 as a light guide element. It includes a condenser lens unit 8 as an optical optical system.

The light source device shown in this embodiment includes a light source 1, a collimator lens 2, and a phosphor 9 in addition to the above-mentioned light source optical system, and the condensing lens unit 8 collects the fluorescent light reflected by the phosphor 9. It is configured to be taken in and converted into parallel light to lead to an illumination optical system (not shown).

(Optical path from light source 1 to illumination optical system)
The light source 1 is an LD that emits blue light. The luminous flux emitted from the light source 1 is a divergent luminous flux, and the same number of collimator lenses 2 as the light source 1 are provided in the traveling direction of the luminous flux from the light source 1. Since the collimator lens 2 has a positive power, the divergent luminous flux from the light source 1 becomes a parallel luminous flux by the collimator lens 2.

Here, the detailed configuration of the light source 1 will be described with reference to FIG. FIG. 2 is a schematic diagram showing the configuration of the LD used as the light source 1 in this embodiment. FIG. 2A is a diagram depicting the internal structure of the same xz cross section as in FIG.

The LD includes an optical semiconductor having a double heterostructure inside the package 11. This optical semiconductor has a structure in which a plurality of clad layers 12 sandwich the active layer 13, and atoms are activated by applying an electric field to perform stimulated emission, and light in a resonance state in the active layer 13 is emitted. , It is radiated from the cleavage plane on the side that is a half mirror. Reference numeral 14 is a cleavage plane on the side where light is emitted, and the light emission distribution (light emitting surface) 14A as a light source has a shape along the cleavage plane 14.

FIG. 2B is a schematic diagram of the yz cross section of the light source 1, and FIG. 2C is a schematic diagram of the xy cross section of the light source 1. 2 (b) and 2 (c) show that the light emission distribution of the light source is elongated in the y direction along the cleavage plane 14 as described above.

In this embodiment, the light source 1 is arranged so that the longitudinal direction of the light emission distribution of the light source is parallel to the y-axis direction. By arranging in this way, the polarization direction of the light flux from the light source 1 becomes parallel to the y-axis direction, and the direction becomes the direction of S polarization with respect to the reflection surface such as the parabolic mirror array 3 and the plane mirror 4. In general, S-polarization has a higher reflectance than P-polarization. Therefore, in a system that repeats reflection in a certain cross section such as the light source optical system shown in this embodiment, the emission distribution of the light source 1 may be parallel to the y-axis direction. preferable.

In other words, the plane parallel to the optical axis of the collimator lens 2 as a positive lens and the normal of the reflection plane that reflects the light beam from the collimator lens 2 is used as a reference plane. At this time, the radiation angle of the light source 1 on the reference plane is smaller than the radiation angle of the light source 1 on the plane including the optical axis of the collimator lens 2 and orthogonal to the reference plane. The radiation angle referred to here is a divergence angle that is 50% of the maximum intensity of the intensity distribution of the luminous flux from the light source 1.

After ejecting the collimator lens 2, the plurality of luminous fluxes travel in the z-axis direction and then head toward the planar mirror 4 while reducing the distance between them by the parabolic mirror array 3. The luminous flux reflected by the plane mirror 4 is incident on the concave lens 5. Since the concave lens 5 shares the focal position with the focal point of the parabolic mirror array 3, the concave lens 5 emits a light flux as a parallel light flux.

The parallel light flux emitted from the concave lens 5 is incident on the first flyeye lens 61 and is divided into a plurality of light fluxes. The divided light beam emitted from the second fly-eye lens 62 is reflected by the dichroic mirror 7 and directed toward the condenser lens unit 8. The dichroic mirror 7 has a minimum size necessary to reflect the light flux from the second fly-eye lens 62, and the blue light from the light source 1 is reflected on the surface thereof, but the wavelength of the fluorescent light described later is It is coated with a dielectric multilayer film (dichroic film) that has the property of transmitting.

The divided light beam reflected by the dichroic mirror 7 is focused and superimposed on the phosphor 9 by the condenser lens unit 8 having a positive power. As a result, a light-collecting spot is formed on the phosphor 9. Since the light-collecting spots formed on the phosphor 9 are conjugate to each lens cell of the first fly-eye lens 61, they have a rectangular and uniform distribution.

A part of the light flux incident on the phosphor 9 is converted into fluorescent light mainly having red and green spectra and reflected, and a part of the light beam is reflected as blue light without being converted. That is, the phosphor 9 is a wavelength conversion element that converts a part of the wavelength of the luminous flux from the light source. The reflected white light beam composed of the three primary colors of red, green, and blue is converted into parallel light again by the condenser lens unit 8 and heads toward the illumination optical system.

With the above configuration and optical path, a white luminous flux can be guided to the illumination optical system.

(Reason for reduced light utilization efficiency)
As described above, the parallel light flux from the concave lens 5 is divided into a plurality of light fluxes by the plurality of first lens cells (first lens surface) 61A included in the first flyeye lens 61. Then, the plurality of luminous fluxes are guided to the corresponding lens cell among the plurality of second lens cells (second lens surface) 62A included in the second flyeye lens 62. As a result, a light source image 14'of the light source 1 is formed in each lens cell of the second fly eye 62. More specifically, in the optical axis direction view of the second lens cell 62A, the light source image 14'is formed inside the second lens cell 62A. Further, the width of the light source image 14'in the first direction is narrower than the width of the second lens cell 62A in the first direction, and the width of the light source image 14'in the second direction is that of the second lens cell 62A. It is narrower than the width in the second direction.

When this light source image is incident on a lens cell different from the corresponding lens cell, the focused spot formed on the phosphor 9 becomes larger by the amount of the luminous flux incident on the lens cell different from the corresponding lens cell. .. Increasing the light-collecting spot on the phosphor 9 is equivalent to increasing the emission point of the light source for the third fly-eye lens 18a and the fourth fly-eye lens 18b in the illumination optical system 200 described later.

The luminous flux having a large light-collecting spot on the phosphor 9 may protrude from the corresponding lens cell among the plurality of lens cells included in the fourth fly-eye lens 18b and enter a lens cell different from the corresponding lens cell. be. As a result, a part of the light flux from the fourth fly-eye lens 18b may be dispelled by the optical element in the subsequent stage or may be guided to the outside of the liquid crystal panel 25 described later. That is, the luminous flux that is not effectively used increases in this way, and the light utilization efficiency decreases.

(Relationship between the light source image and the second lens cell)
Therefore, in each embodiment of the present invention, the second lens cell is shaped so that the longitudinal direction of the second lens cell and the longitudinal direction of the light source image coincide with each other. In other words, the lateral direction of the second lens cell is the first direction, and the longitudinal direction of the second lens cell is the second direction. At this time, the width of the light source image formed between the first flyeye lens 61 and the phosphor 9 by the first lens cell in the second direction is wider than the width of the light source image in the first direction.

Specifically, as shown in FIG. 3B, the longitudinal direction of the second lens cell 62A is the y-axis direction, and the longitudinal direction of the light source image 14'is also the y-axis direction. With such a configuration, it is possible to suppress the above-mentioned decrease in light utilization efficiency. Further, as shown in FIG. 3A, the size of the second fly-eye lens 62 is suppressed by making the second lens cell 62A square and having a shape sufficiently large with respect to the light source image 14'. Is possible.

(Structure of the first fly-eye lens 61 and the second fly-eye lens 62)
Next, the detailed configuration of the first fly-eye lens 61 and the second fly-eye lens 62 in this embodiment will be described with reference to FIG.

FIG. 4 is an enlarged view of the first and second flyeye lenses 61 and 62 in this embodiment. FIG. 4A illustrates the same xx cross section as in FIG. 1, the yz cross section is shown in FIG. 4B, and the xy cross section is shown in FIG. 4C.

As shown in FIG. 4, in this embodiment, the luminous flux is compressed in the x-axis direction, but the luminous flux is not compressed in the y-axis direction. In other words, the width of the second fly-eye lens 62 in the first direction is narrower than the width of the first fly-eye lens 61 in the first direction. Then, the width of the second fly-eye lens 62 and the width of the first fly-eye lens 61 are equal in the second direction.

The reason for such a configuration is as follows. As described above, the dichroic mirror 7 has a property of reflecting the blue light from the light source 1 and guiding it to the phosphor 9, and the phosphor 9 emits a part of the blue light from the light source 1 through the dichroic mirror 7. It converts to fluorescent light including green light and red light and emits fluorescent light and non-converted light. The unconverted light incident on the dichroic mirror 7 is not guided to the illumination optical system in the subsequent stage and returns to the light source 1 side. That is, the larger the dichroic mirror 7, the lower the light utilization efficiency.

Therefore, in this embodiment, as described above, the luminous flux is compressed in the x direction so that the width of the second fly-eye lens 62 in the first direction is larger than the width of the first fly-eye lens 61 in the first direction. I'm making it smaller. This makes it possible to reduce the width of the dichroic mirror 7 in accordance with the width of the second flyeye lens 62 as compared with the case where the light flux is not compressed in the x direction.

That is, the width of the dichroic mirror 7 and the width of the second flyeye lens 62 are substantially equal in the x-axis direction. In other words, consider a direction orthogonal to the optical axis of the second fly-eye lens 62 on a plane (first cross section) parallel to the normal of the dichroic mirror 7 and the optical axis of the condenser lens unit 8. The width Wd of the dichroic mirror 7 in this direction and the width Wf2 of the second flyeye lens 62 satisfy a relationship of at least 0.8 <Wd / Wf2 <1.2, and more preferably 0.9 <Wd. The relationship of / Wf2 <1.1 is satisfied. Then, in the first cross section, the width Wf2 of the second flyeye lens 62 in the first direction is narrower than the width Wf1 of the first flyeye lens 61 in the first direction.

In this way, by compressing the luminous flux in the first cross section, the width of the dichroic mirror 7 in the first cross section in the x-axis direction can be reduced, and the light source optical system can suppress the decrease in light utilization efficiency. Can be made smaller. If the width of the dichroic mirror 7 in the y-axis direction is reduced on the plane (yz cross section) orthogonal to the optical axis of the condenser lens unit 8, the unconverted light from the phosphor 9 guided to the illumination optical system increases. It is possible to suppress the decrease in light utilization efficiency due to the above.

However, in this case, the distance between the dichroic mirror 7 and the condenser lens unit 8 cannot be shortened. Further, even if the width of the dichroic mirror 7 in the y-axis direction can be reduced, the diameter of the condenser lens unit 8 does not change, so that the light source optical system cannot be sufficiently reduced. Therefore, as described above, it is preferable to reduce the width of the dichroic mirror 7 in the x-axis direction shown in FIG.

The width Wd of the above-mentioned dichroic mirror 7 may be defined as follows. That is, when the dichroic mirror 7 has a configuration in which a dichroic film is applied to a part of a transparent substrate, the width of the region to which the dichroic film is applied may be defined as Wd.

Further, as shown in FIG. 4A, the luminous flux compression in this embodiment is realized by the eccentricity of a part of the plurality of first lens cells and a part of the plurality of second lens cells. Specifically, a plurality of lens cells whose positions in the y-axis direction do not change from those of the lens cells 61C and 62C at the center of both fly-eye lenses in the z-axis direction view in FIG. 4A, and the positions in the x-axis direction. Does not change Lens cells other than multiple lens cells are eccentric. The eccentricity referred to here means that the optical axis of the lens cell is eccentric with respect to the center of gravity of the lens cell in the optical axis direction view of the lens cell.

When the luminous flux is compressed by the eccentricity, the light source image formed on the second flyeye lens 62 does not become large. However, if the amount of eccentricity is too large, in the case of a spherical lens, the inclination becomes steep, and the lens shape may not be maintained or molding may be difficult. In this case, the degree of inclination can be relaxed by changing the radius of curvature for each lens cell. The change in the radius of curvature does not necessarily have to be rotationally symmetric. That is, it is only necessary to loosen the radius of curvature for a cross section having a large amount of eccentricity, and it is possible to obtain a so-called toric surface shape.

As described above, the shapes of the first lens cell 61A and the second lens cell 62A can be appropriately changed. The radius of curvature of at least one of the first lens cell 61A and the second lens cell 62A may be different from the radius of curvature of the other lens cells, and as described above, at least one lens cell may be a toric lens. ..

Further, it is preferable that the luminous flux compression rate satisfies the following conditions.

The width of the first lens cell 61A shown in FIG. 4C in the x-axis direction (first direction) is x1, and the width in the y-axis direction (second direction) is y1. Further, the width of the second lens cell 62A in the x-axis direction is x2, and the width in the y-axis direction is y2.

At this time, the light source optical system is
0.2 <x2 / x1 <0.8
It is preferable to be at least satisfied. More preferably, 0.3 <x2 / x1 <0.7 is satisfied, and more preferably 0.4 <x2 / x1 <0.6 is satisfied.

If the value deviates from the lower limit of the above conditional expression, the compression rate is too high and the amount of eccentricity of the first lens cell 61A increases, and as a result, the aberration also increases, which is not preferable. On the other hand, if it deviates from the upper limit value, the compression rate is too low and the dichroic mirror 7 cannot be made sufficiently small, and the above-mentioned decrease in light utilization efficiency cannot be sufficiently suppressed, which is not preferable.

Considering the compression rate in the y-axis direction, the preferable range of the compression rate can also be expressed as follows. That is, the light source optical system is
0.1 <(x2 / y2) / (x1 / y1) <0.8
It is preferable to be at least satisfied. More preferably, 0.2 <(x2 / y2) / (x1 / y1) <0.7 is satisfied, and more preferably 0.3 ≦ (x2 / y2) / (x1 / y1) ≦ 0.6 is satisfied. Then it is good.

In this embodiment, x2 / x1 = 0.5 and y2 / y1 = 1.0, so that
(X2 / y2) / (x1 / y1) = 0.5
It has become.

[Second Example]
FIG. 5 is a diagram showing the shapes of the xy cross sections of the first flyeye lens 61 and the second flyeye lens 62 in the light source optical system as the second embodiment of the present invention. The configurations other than the first fly-eye lens 61 and the second fly-eye lens 62 are the same as those in the first embodiment described above, and thus the description thereof will be omitted.

In this embodiment, the first fly-eye lens 61 compresses the luminous flux in the x direction, which is the same as the first embodiment described above, but the first fly-eye lens 61 expands the luminous flux width in the y direction. 1 Different from the embodiment. In other words, the width of the second fly-eye lens 62 in the second direction is wider than the width of the first fly-eye lens 61 in the second direction. As a result, the relationship between the second lens cell 62A and the light source image 14'is shown in FIG.

As shown in FIG. 6, since the luminous flux width is expanded in the y direction in this embodiment, the decrease in light utilization efficiency due to the variation in LD is further suppressed in the y direction as compared with the first embodiment described above. It becomes possible to do.

Further, in the x direction, the aspect ratio of the light source image 14'and the aspect ratio of the second lens cell 62A are made substantially the same by further compressing the luminous flux width as compared with the first embodiment described above. As a result, even if the position of the light source image 14'is moved due to the variation in LD, the sensitivity characteristics are the same in the x direction and the y direction. Further, the area of the entire second fly-eye lens 62 is the same as that of the first embodiment described above, thereby suppressing the increase in size.

In this embodiment, it should be noted that
(X2 / y2) / (x1 / y1) = 0.3
It has become.

[Third Example]
FIG. 7 is a diagram showing the shapes of the xy cross sections of the first flyeye lens 61 and the second flyeye lens 62 in the light source optical system as the third embodiment of the present invention. The configurations other than the first fly-eye lens 61 and the second fly-eye lens 62 are the same as those in the first embodiment described above, and thus the description thereof will be omitted.

In this embodiment, unlike the first embodiment described above, the first flyeye lens 61 does not compress the luminous flux in the x direction, but instead expands the luminous flux width in the y direction. As a result, the relationship between the second lens cell 62A and the light source image 14'is shown in FIG.

As shown in FIG. 8, the size of the entire second fly-eye lens 62 is larger than that of the first embodiment described above, but the second lens cell 62A with respect to the light source image 14'. It is possible to secure a larger amount of margin. Therefore, as compared with the first embodiment described above, the present embodiment can further suppress the decrease in the light utilization efficiency due to the variation in LD. As a result, it is not necessary to intentionally increase the size of the optical element in order to prevent the light from being eclipsed in the subsequent optical system, and as a result, it is possible to suppress the increase in size of the optical system.

In this embodiment, it should be noted that
(X2 / y2) / (x1 / y1) = 0.5
It has become.

[Fourth Example]
FIG. 9 is a diagram showing the configuration of the light source optical system shown in the fourth embodiment of the present invention.

The difference from the first embodiment described above is that the concave lens 5 is omitted, and the convergent luminous flux is incident on the first flyeye lens 61 instead of the parallel luminous flux.

The point that the first fly-eye lens 61 guides the light to the second fly-eye lens 62 while compressing the light flux in the x direction is the same as that of the first embodiment described above, but in this embodiment, the convergent light flux is It is incident on the first fly-eye lens 61. Therefore, the amount of eccentricity of each lens cell of the first flyeye lens 61 can be reduced as compared with the case where a parallel light flux is incident, and the lens can be made easier to mold.

That is, the eccentricity of the predetermined lens cell among the plurality of first lens cells 61A is smaller than the eccentricity of the predetermined lens cell among the plurality of second lens cells 62A. The amount of eccentricity referred to here is the distance between the center of gravity of each lens cell and the optical axis of each lens cell in the optical axis direction view of each lens cell.

Further, since the concave lens 5 is not required, it is possible to realize a smaller light source optical system and light source device.

[Fifth Example]
FIG. 10 is a schematic view of a light source optical system and a light source device as a fifth embodiment of the present invention.

This configuration is an example in which two light source devices 100 shown in the first embodiment are used to increase the brightness, and the light flux from the light source device 13 is combined with a plurality of lenses 15, a synthetic prism 16, and a lens 17. After synthesizing with an optical system, it is led to an illumination optical system (not shown).

At this time, by setting the direction of compression of the luminous flux performed by the first flyeye lens 61 to the x-axis direction, it is possible to suppress the increase in size in the x-axis direction that occurs when a plurality of light source devices 100 are arranged. Become. In other words, the width of the second fly-eye lens 62 in the x-axis direction on the normal of the dichroic mirror 7 and the plane parallel to the optical axis of the condenser lens unit 8 is the x-axis direction of the first fly-eye lens 61. Narrower than the width of.

[Sixth Example]
FIG. 11 is a diagram showing a configuration of a projector (projection type display device) equipped with the light source optical system and the light source device shown in each of the above-described embodiments.

Reference numeral 100 is the light source device shown in the first embodiment described above, and of course, the light source device shown in the examples other than the first embodiment may be used.

Reference numeral 200 is an illumination optical system for illuminating the liquid crystal panel 25 (light modulation element) described later using the light flux from the light source device 100. The illumination optical system 200 includes a third fly-eye lens 18a, a fourth fly-eye lens 18b, a polarization conversion element 19, and a condenser lens 20.

The luminous flux from the light source device 100 is divided into a plurality of luminous fluxes by the third flyeye lens 18a, and a light source image is formed between the fourth flyeye lens 18b and the polarization conversion element 19. The polarization conversion element 19 is configured to align the polarization directions of the incident light flux in a predetermined direction, and the light flux from the polarization conversion element 19 is guided to the color separation / synthesis unit 300 by the condenser lens 20.

The color separation / synthesizing unit 300 includes a polarizing plate 21, a dichroic mirror 22, a wavelength-selective retardation plate 23, a red liquid crystal panel 25r, a green liquid crystal panel 25g, and a blue liquid crystal panel 25b. 25g and 25b are collectively referred to as a liquid crystal panel 25. Further, it includes a red λ / 4 plate 24r, a green λ / 4 plate 24g, a blue λ / 4 plate 24b, a first polarization beam splitter 26a, a second polarization beam splitter 26b, and a synthetic prism 27. The red λ / 4 plate 24r, the green λ / 4 plate 24g, and the blue λ / 4 plate 24b are collectively referred to as the λ / 4 plate 24. Further, the portion of the color separation / compositing unit 300 excluding the liquid crystal panel 25 is used as the color separation / compositing system.

The polarizing plate 21 is a polarizing plate that transmits only light in the polarization direction arranged by the polarization conversion element 19, and blue light and red light among the light from the polarizing plate 21 by the dichroic mirror 22 are the second polarizing beam splitter 26b. Is guided in the direction of. On the other hand, the green light is directed in the direction of the first polarization beam splitter 26a.

The first polarizing beam splitter 26a and the second polarizing beam splitter 26b are configured to guide the light from the dichroic mirror 22 to the liquid crystal panel 25 and the light from the liquid crystal panel 25 to the synthesis prism 27 according to the polarization direction. It has been done. Further, the λ / 4 plate 24 has an effect of enhancing the light detection effect by giving a phase difference of λ / 2 in the round trip due to reflection by the liquid crystal panel 25.

The synthetic prism 27 synthesizes blue light and red light from the second polarizing beam splitter 26a and green light from the second polarizing beam splitter 26b and guides them to the projection optical system 28.

With such a configuration, the projector shown in FIG. 11 can project a color image onto a projected surface such as a screen.

In addition, a configuration having a plurality of light source devices 100 shown in FIG. 10 may be provided instead of the light source device 100 at the position in FIG. 11 where the light source device 100 is provided. In this case, the parallel light flux from the lens 17 shown in FIG. 10 may be incident on the illumination optical system 200.

Although the preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these examples, and various modifications and modifications can be made within the scope of the gist thereof.

(Other embodiments)
In each of the above embodiments, the first fly-eye lens 61 and the second fly-eye lens 62 were separate optical elements. In other words, the light source optical system includes a first fly-eye lens 61 as a first lens array including a first lens surface array and a second lens including a second lens surface array in order from the light source 1 side. It was equipped with a second fly-eye lens 62 as an array.

However, each embodiment of the present invention is not limited to the above configuration, and may have a configuration in which the first and second flyeye lenses are formed on both sides of one element as shown in FIG. In other words, the microlens array 60 whose surface on the light source 1 side is the first lens surface array 61S and the surface on the phosphor 9 side is the second lens surface array 62S is between the light source 1 and the phosphor 9. It may be configured to prepare for. As shown in FIG. 12, it is preferable to integrally mold the lens cell because the relative displacement of the double-sided lens cell can be minimized.

Further, although not described in detail in each of the above-described embodiments, the light source 1 and the collimator lens 2 may be held by separate holding members or may be held by the same holding member. For example, an LD bank in which eight light sources 1 and eight collimator lenses 2 are integrated may be used.

Further, instead of the planar mirror 4 shown in each of the above-described embodiments, a prism may be used to guide the light flux from the parabolic mirror array 3 to the concave lens 5.

Further, in each of the above-described embodiments, the configuration in which the light source image is formed on the second fly-eye lens 62 by the first fly-eye lens 61 is illustrated, but the light source image is in the vicinity of the second fly-eye lens 62. It should be formed. In other words, the light source image may be formed between the second fly-eye lens 62 and the phosphor 9, or between the second fly-eye lens 62 and the dichroic mirror 7.

The width of the light source image in each of the above-described embodiments may be defined as follows. That is, the width of the region up to a predetermined ratio of the maximum intensity in the intensity distribution in each region in which each light source image is formed may be the width of the light source image. For example, the full width at half maximum in the above-mentioned intensity distribution may be the width of the light source image. It may be a width. This definition may be applied to both the long-side and short-side widths of the light source image.

1 Light source 9 Fluorescent material (wavelength conversion element)
14'Light source image 61 First fly-eye lens (first lens surface array)
61A 1st lens cell (1st lens surface)
62 Second fly-eye lens (second lens surface array)
62A Second lens cell (second lens surface)

Claims (17)

A light source optical system that guides the luminous flux from a light source to a wavelength conversion element.
The surface on the light source side is a first lens surface array having a plurality of first lens surfaces, and the surface on the side of the wavelength conversion element is provided with a plurality of second lens surfaces, and the first lens surface array is provided. A lens array, which is a second lens surface array that guides the luminous flux from the wavelength conversion element to the wavelength conversion element.
A light guide element that guides the light flux from the second lens surface array in the direction of the wavelength conversion element and guides the light flux from the wavelength conversion element in a direction different from that of the light source is provided.
When the lateral direction of the second lens surface is the first direction and the longitudinal direction of the second lens surface is the second direction, the first lens surface and the first lens surface array are used. A light source optical system characterized in that the width of the light source image formed between the wavelength conversion element and the light source image in the second direction is wider than the width of the light source image in the first direction. In the optical axis direction view of the second lens surface, the light source image is formed inside the second lens surface.
The width of the light source image in the first direction is narrower than the width of the second lens surface in the first direction, and the width of the light source image in the second direction is the width of the second lens surface. The light source optical system according to claim 1, wherein the width is narrower than the width in the second direction. The light source according to claim 1 or 2, wherein the width of the second lens surface array in the first direction is narrower than the width of the first lens surface array in the first direction. Optical system. When the width of the first lens surface in the first direction is x1 and the width of the second lens surface in the first direction is x2,
0.2 <x2 / x1 <0.8
The light source optical system according to claim 3, wherein the light source optical system is characterized in that. One of claims 1 to 4, wherein the width of the second lens surface array in the second direction is wider than the width of the first lens surface array in the second direction. The light source optical system according to the section. The width of the first lens surface in the first direction is x1, and the width of the first lens surface in the second direction is y1.
When the width of the second lens surface in the first direction is x2 and the width of the second lens surface in the second direction is y2.
0.1 <(x2 / y2) / (x1 / y1) <0.8
The light source optical system according to any one of claims 1 to 5, wherein the light source optical system is characterized in that. The invention according to any one of claims 1 to 6, wherein the optical axis of at least one of the plurality of first lens surfaces is eccentric with respect to the center of gravity of the first lens surface. Light source optical system. The invention according to any one of claims 1 to 7, wherein the optical axis of at least one of the plurality of second lens surfaces is eccentric with respect to the center of gravity of the second lens surface. Light source optical system. The light beam incident on the first lens surface array from the light source is a convergent light beam, and the amount of eccentricity of a predetermined lens surface among the plurality of first lens surfaces is among the plurality of second lens surfaces. The light source optical system according to claim 7 or 8, wherein the amount of eccentricity of the lens surface corresponding to the predetermined lens surface is smaller than that of the lens surface. The light source optical system according to any one of claims 1 to 8, wherein at least one of the plurality of first lens surfaces and the plurality of second lens surfaces is a toric lens. Further provided with a condensing optical system that guides the light flux from the light guide element to the wavelength conversion element and has positive power.
When the plane parallel to the normal of the light guide element and the optical axis of the condensing optical system is defined as the first cross section,
The first cross section is characterized in that the width of the second lens surface array in the first direction is narrower than the width of the first lens surface array in the first direction. The light source optical system according to any one of 1 to 10. The eleventh aspect of claim 11, wherein in the first cross section, the width of the light guide element in a direction orthogonal to the optical axis of the condensing optical system is smaller than the diameter of the condensing optical system. Light source optical system. A light source optical system that guides the luminous flux from a light source to a wavelength conversion element.
A first lens plane array with a plurality of first lens planes,
A second lens surface array having a plurality of second lens surfaces and guiding a luminous flux from the first lens surface array to the wavelength conversion element.
A light guide element that guides the light flux from the second lens surface array in the direction of the wavelength conversion element and guides the light flux from the wavelength conversion element in a direction different from that of the light source is provided.
When the lateral direction of the second lens surface is the first direction and the longitudinal direction of the second lens surface is the second direction, the first lens surface and the first lens surface array are used. The width of the light source image formed between the light source image and the light source image in the second direction is wider than the width of the light source image in the first direction.
A light source optical system characterized in that the width of the second lens surface array in the second direction is wider than the width of the first lens surface array in the second direction. A light source optical system that guides the luminous flux from a light source to a wavelength conversion element.
A first lens plane array with a plurality of first lens planes,
A second lens surface array having a plurality of second lens surfaces and guiding a luminous flux from the first lens surface array to the wavelength conversion element.
A light guide element that guides the light flux from the second lens surface array in the direction of the wavelength conversion element and guides the light flux from the wavelength conversion element in a direction different from that of the light source is provided.
When the lateral direction of the second lens surface is the first direction and the longitudinal direction of the second lens surface is the second direction, the first lens surface and the first lens surface array are used. The width of the light source image formed between the light source image and the light source image in the second direction is wider than the width of the light source image in the first direction.
A light source optical system characterized in that at least one of the plurality of second lens surfaces is eccentric with respect to the center of gravity of the second lens surface. A light source optical system that guides the luminous flux from a light source to a wavelength conversion element.
A first lens plane array with a plurality of first lens planes,
A second lens surface array having a plurality of second lens surfaces and guiding a luminous flux from the first lens surface array to the wavelength conversion element.
A light guide element that guides the light flux from the second lens surface array in the direction of the wavelength conversion element and guides the light flux from the wavelength conversion element in a direction different from that of the light source is provided.
When the lateral direction of the second lens surface is the first direction and the longitudinal direction of the second lens surface is the second direction, the first lens surface and the first lens surface array are used. The width of the light source image formed between the light source image and the light source image in the second direction is wider than the width of the light source image in the first direction.
A light source optical system, characterized in that at least one of the plurality of first lens surfaces and the plurality of second lens surfaces is a toric lens. A light source optical system that guides the luminous flux from a light source to a wavelength conversion element.
A first lens plane array with a plurality of first lens planes,
A second lens surface array having a plurality of second lens surfaces and guiding a luminous flux from the first lens surface array to the wavelength conversion element.
A light guide element that guides the light flux from the second lens surface array toward the wavelength conversion element and guides the light flux from the wavelength conversion element in a direction different from that of the light source.
It is provided with a condensing optical system that guides the light flux from the light guide element to the wavelength conversion element and has positive power.
When the lateral direction of the second lens surface is the first direction and the longitudinal direction of the second lens surface is the second direction, the first lens surface and the first lens surface array are used. The width of the light source image formed between the light source image and the light source image in the second direction is wider than the width of the light source image in the first direction.
When the plane parallel to the normal of the light guide element and the optical axis of the condensing optical system is the first cross section, the first direction of the second lens plane array in the first cross section. The width of the light source optical system is narrower than the width of the first lens surface array in the first direction. With the light source
A positive lens provided in the traveling direction of the luminous flux from the light source, and
With the wavelength conversion element
The light source optical system according to any one of claims 1 to 16.
Light modulation elements and
An illumination optical system that illuminates the light modulation element using a luminous flux from the light source optical system, and
A projection type display device comprising: a color separation synthesis system for guiding a light flux from the light source optical system to the light modulation element and a color separation synthesis system for guiding the light flux from the light modulation element to the projection optical system.

Images