WO2004068197A1

WO2004068197A1 - Composite prism, light source unit, and display device

Info

Publication number: WO2004068197A1
Application number: PCT/JP2004/000668
Authority: WO
Inventors: Kuninori Okuhara
Original assignee: Hi-Mec Co., Ltd.
Priority date: 2003-01-27
Filing date: 2004-01-26
Publication date: 2004-08-12
Also published as: JP4520943B2; JPWO2004068197A1

Abstract

A composite prism (1) has a first selective reflection surface (5) on a surface defined by a first corner (101), a third corner (103), a seventh corner (107) and a fifth corner (105). Further, it has a second selective reflection surface (6) on a surface defined by the third corner (103), a fourth corner (104), the fifth corner (105), and a sixth corner (106). The first and second selective reflection surfaces (5, 6) are formed of polarizing separation films. Therefore, the composite prism, unlike an X cube, is capable of effecting composition and decomposition of a plurality of optical paths without arranging the edges of the four prism single bodies in a straight line.

Description

Description Composite prism, light source unit, and display device

The present invention relates to a compound prism, a light source unit, and a display device used for a projection display device or the like. Background art

2. Description of the Related Art In an optical device such as a projection display device (hereinafter, referred to as a projector), conventionally, a plurality of plate-shaped optical elements have been used for the purpose of combining or separating optical paths of a plurality of lights having different wavelengths. I have. For this reason, there is a problem that the optical device cannot be miniaturized. Therefore, a cubic dichroic prism in which four right-angled triangular prisms are joined in an X-shape may be used as a composite prism integrating such functions. Such a dichroic prism is called an X cube because of the shape of the joint.

In this dichroic brake, a selective reflection film capable of selectively reflecting red light and a selective reflection film capable of selectively reflecting blue light are arranged in a cross, and a liquid crystal projector is provided with an optical path combining element. It has been used. At that time, three of the four side surfaces of the dichroic prism are used as the incident end surface, and the other side surface is used as the output end surface (for example, see Japanese Patent Application Laid-Open No. No. 9509).

However, in the X-cube, there is a problem that the productivity is low and the yield is low because each ridge line of the four prisms alone needs to be aligned. In addition, the requirements for angle tolerance are strict at the stage of the prism alone. Therefore, there is a problem that the X cube becomes expensive. In addition, in the case of the X cube, Since each ridge line of the body is aligned, there is a problem in the liquid crystal projector using it that the ridge line appears at the center of the projected image. Therefore, the adhesive must be thinner when joining the prisms to each other, but when the adhesive is thinner, the reliability decreases, such as weakening the heat shock. There is a problem. Furthermore, in the X-cube, the four side surfaces are used as the input end surface and the output end surface, respectively, so there is no space in the side surfaces. Therefore, there is also a problem that the layout of the optical elements constituting the optical path toward the X-cube has a low degree of freedom.

In view of the above problems, the object of the present invention is to eliminate the need to align each ridge line of the four prisms in a straight line unlike the X-cube, thereby improving yield, reducing cost, and improving reliability. It is an object of the present invention to provide a new composite prism capable of improving the image quality, the image quality, and the degree of freedom in design, a light source unit and a display device using the composite prism. Disclosure of the invention

In order to solve the above problems, in the composite prism of the present invention, at least a plurality of bonding surfaces formed by bonding a plurality of translucent members have light having at least predetermined optical characteristics. The first selective reflection surface and the second selective reflection surface that selectively transmit light and reflect the other light are formed in directions parallel to each other or crossing each other without crossing each other. An optical path of at least three lights having different wavelengths can be combined or separated by the first selective reflection surface and the second selective reflection surface.

In the present invention, a first selective reflection surface and a second selective reflection surface are formed on the joining surface of the translucent member, and at least three light beams having different wavelengths are formed by these selective reflection surfaces. Are combined or separated. For this reason, since it is not necessary to combine or separate the optical paths using a single-plate polarization splitting element or the like, it is possible to reduce costs and improve the degree of freedom in design. Also, unlike the X-cube, each ridge of the four prims Since there is no need to align them in a straight line, high yield and high reliability are achieved. Also, the image quality can be improved.

In the present invention, each corner of the rectangular parallelepiped first rectangular plane including a first rectangular plane and a second rectangular plane facing each other is defined as a first corner, a second corner, and a third corner, respectively. And each of the corners corresponding to the first corner, the second corner, the third corner, and the fourth corner in the second rectangular plane is referred to as a fifth corner. When the corner, the sixth corner, the seventh corner, and the eighth corner, the first corner, the third corner, the seventh corner, and the fifth corner are used. The first selective reflection surface is provided on the surface to be configured, and the second selective reflection surface is provided on the surface configured by the third corner, the fourth corner, the fifth corner, and the sixth corner. A reflective surface. In the present invention, for example, each of the first selective reflection surface and the second selective reflection surface is constituted by a polarization splitting surface. Therefore, both the first selective reflection surface and the second selective reflection surface transmit one of the P-polarized light and the S-polarized light within an arbitrary wavelength range, Reflects the other light.

Such a composite prism can be used to configure a display device including a plurality of electro-optical devices such as a liquid crystal light valve that modulates color light emitted from the composite prism.

In another aspect of the present invention, a plurality of parallel light-transmitting members are joined to form an incident surface at an angle of 45 °, and a plurality of mutually parallel joining surfaces are provided. Wherein the first selective reflection surface for selectively reflecting light in a predetermined wavelength band is provided on any of the other bonding surfaces, and the light in a wavelength band different from that of the first selective reflection surface is provided on any of the other joining surfaces. And the second selective reflection surface for selectively reflecting light. In addition, it is possible to join the polarization separation planes in parallel to separate light having a wavelength having any polarization.

In the light source unit using the composite prism according to the present invention, The integrating prism is, as the first selective reflection surface, a first color light dichroic light for selectively reflecting the first color light of the three primary color wavelength bands of red, green and blue. A second color light dichroic mirror that selectively reflects the second color light toward the first color light dichroic mirror as the second selective reflection surface; The dichroic mirror for the second color light is disposed on the opposite side to the dichroic mirror for the first color light, and reflects the third color light toward the dichroic mirror for the second color light. A first color light source unit that emits the first color light toward the first color light dike opening mirror, and a second color light source unit that emits the first color light toward the first color light dike opening mirror. The second color light that emits the second color light toward the color light dichroic mirror A third color light source unit that emits the third color light toward the reflection surface is disposed, the first color light source unit, the second color light source unit, and the third color light source unit. It is preferable that light emission from the color light source unit to the composite prism is switched at a predetermined timing.

In the light source unit using the composite prism according to the present invention, the composite prism serves as the first selective reflection surface as a first color light of a wavelength band of three primary colors of red, green, and blue. A first color light dichroic mirror that selectively reflects light, and selectively directs the second color light to the first color light dichroic mirror as the second selective reflection surface. A first color light source unit that emits the first color light toward the first color light dichroic mirror. A second color light source unit that emits the second color light toward the second color light dichroic mirror is disposed, and the second color light dichroic mirror is arranged to the second color light dichroic mirror. The third color light from the opposite side to the dichroic mirror for color light 1 A third color light source unit for emitting light, wherein light is emitted from the first color light source unit, the second color light source unit, and the third color light source unit to the complex prism at a predetermined timing. Can be switched with preferable.

In the present invention, each of the first color light source unit, the second color light source unit, and the third color light source unit is a light emitting element that emits predetermined color light, The lighting of each of the color light source unit, the second color light source unit, and the third color light source unit is controlled at a predetermined timing.

In the present invention, each of the first color light source unit, the second color light source unit, and the third color light source unit emits light of each color obtained by color-dividing white light. The first color light source unit, the second color light source unit, and the third color light source unit are disposed between the composite prism and the composite prism. A configuration in which shutter means for controlling the shuttering are arranged may be employed.

For example, in a light source unit including two compound prisms according to the present invention, of the two compound prisms, a first compound prism is used as the first selective reflection surface, and red and green are used. A first color light dichroic mirror that selectively reflects the first color light of the three primary wavelength bands of blue; and the second color light as the second selective reflection surface. A second color light dichroic mirror that selectively reflects toward the first color light dichroic mirror; and the first color light dichroic mirror with respect to the second color light dichroic mirror. A third color light reflecting surface disposed on the side opposite to the mirror and reflecting the third color light toward the second color light dichroic mirror; anda second composite prism, The first color light for the first color light of the first compound prism A first color light reflecting surface that reflects toward the dichroic mirror; and a second color light dichroic of the first composite prism that is a second color light as the first selective reflecting surface. A second color light dichroic mirror that selectively reflects toward the tsuk mirror, and a third color light of the first compound prism that applies the third color light as the second selective reflection surface. A third dichroic mirror for color light that selectively reflects toward the reflective surface for light, and further includes a second dichroic mirror for the second composite prism. A white light source that emits white light toward a third color light dichroic mirror of the composite prism, and the second composite prism is provided between the first composite prism and the second composite prism. It is preferable that a shutter means for controlling the timing at which each color light is incident from the prism to the first composite prism is disposed.

The light source cutout to which the present invention is applied is used, for example, in a display device. For example, a display device is configured by arranging a plurality of the complex prisms in a matrix.

Further, the display device may be configured using an electro-optical device that sequentially modulates the color light emitted from the light source unit and sequentially generates a color image corresponding to the color light.

In the present invention, it is preferable that the light source unit includes a polarization conversion unit that aligns the polarization directions of the color lights emitted toward the electro-optical device. With such a configuration, the light use efficiency can be increased, so that the brightness of the display image can be improved.

In this case, a projector or the like can be configured by using a projection optical system that projects images of each color sequentially formed by the electro-optical device. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an explanatory diagram of a compound prism according to Embodiment 1 of the present invention. 2A and 2B are exploded perspective views of a compound prism according to Embodiment 1 of the present invention, and FIG. 2C is an exploded perspective view of a conventional compound prism.

FIG. 3 is an explanatory diagram illustrating a method of manufacturing the composite prism according to Embodiment 1 of the present invention.

FIG. 4 is an explanatory diagram showing the optical characteristics of the selective reflection surface formed on the composite prism according to Embodiment 1 of the present invention.

FIG. 5 is a front view, a left side view, and a plan view of the compound prism according to Embodiment 1 of the present invention. FIG. 6 is an explanatory diagram showing the optical characteristics of the selective reflection surface formed on the composite prism according to the modification of the first embodiment of the present invention.

FIG. 7 is an explanatory diagram of a liquid crystal projector using a compound prism according to a modification of the first embodiment of the present invention.

FIG. 8 is an explanatory diagram of a dichroic mirror array used in the liquid crystal projector shown in FIG.

FIG. 9 is an explanatory diagram of another dichroic mirror array used in the liquid crystal projector shown in FIG.

FIG. 10 is an explanatory diagram of a complex prism according to Embodiment 2 of the present invention.

FIG. 11 is an explanatory diagram showing the optical characteristics of the selective reflection surface formed in the composite prism according to Embodiment 2 of the present invention.

FIG. 12 is an explanatory diagram showing a usage example of the complex prism according to the second embodiment of the present invention.

FIG. 13 is an explanatory diagram illustrating a method of manufacturing a composite prism according to Embodiment 2 of the present invention.

FIG. 14 is an explanatory diagram of a tail lamp using the composite prism according to Embodiment 2 of the present invention.

FIG. 15 is an explanatory diagram of a composite prism according to a first modification of the second embodiment of the present invention.

FIG. 16 is an explanatory diagram of a composite prism according to a second modification of the second embodiment of the present invention.

FIG. 17 is an explanatory diagram showing the optical characteristics of the selective reflection surface used in the composite prism according to Modification 2 of Embodiment 2 of the present invention.

FIG. 18 is an explanatory diagram of a liquid crystal projector using a composite prism according to a first modification of the second embodiment of the present invention.

FIG. 19 is an explanatory diagram of another liquid crystal projector using the compound prism according to the first modification of the second embodiment of the present invention. FIG. 20 is an explanatory diagram of a direct-view type liquid crystal display device using a compound prism according to a first modification of the second embodiment of the present invention.

(Explanation of code)

1, 2, compound prism

5, 7 First selective reflective surface

6, 8 Second selective reflective surface

9 Total reflection surface

3 1 First rectangular plane

3 2 Second rectangular plane

5 1 Red L E D

5 2 Green L E D

5 3 Blue L E D

6 6, 6 7, 6 8 Shutter (Shutter means)

7 3 Polarizing beam splitter

7 4, 89, 17 1 to 17 3 Liquid crystal light valve (electro-optical device) 7 5 Projection optical system

8 0 Light source unit

8 1, 8 2 Polarization separation prism

8 3 Polarization conversion prism (polarization conversion means)

8 5 Polarization separation surface

8 6 Polarizing beam splitter

9 1 LCD panel

1 1 1 White light source

1 1 0 Light source

1 5 0 Dichroic mirror array

2 2 1, 2 2 2, 2 2 3, 2 2 3, 2 2 4, 2 2 5 Translucent member

L G Green light

LR red light BEST MODE FOR CARRYING OUT THE INVENTION

[Embodiment 1]

FIG. 1 is an explanatory diagram of a compound prism according to Embodiment 1 of the present invention. FIGS. 2A and 2B are exploded perspective views of a composite prism according to Embodiment 1 of the present invention, and FIG. 2C is an exploded perspective view of a conventional composite prism. FIG. 3 is an explanatory diagram illustrating a method of manufacturing the composite prism according to Embodiment 1 of the present invention. FIG. 4 is an explanatory diagram showing the optical characteristics of the selective reflection surface formed on the composite prism according to Embodiment 1 of the present invention. FIG. 5 is a front view, a left side view, and a plan view of the compound prism according to Embodiment 1 of the present invention.

In FIG. 1, a composite prism 1 of the present embodiment is a cubic composite prism having a first rectangular plane 31 and a second rectangular plane 32 facing each other, and includes a plurality of translucent members. The following selective reflection surfaces are formed on the plurality of bonding surfaces formed by bonding the two. That is, each corner of the first rectangular plane 31 is referred to as a first corner 101, a second corner 102, a third corner 103, and a fourth corner 104, respectively. Each corner corresponding to the first corner 101, the second corner 102, the third corner 103, and the fourth corner 104 on the second rectangular plane 32 is referred to as a fifth corner. When the corner portion 105, the sixth corner portion 106, the seventh corner portion 107, and the eighth corner portion 108 are set, the first corner portion 101, the third corner portion 103, the A first selective reflection surface 5 is provided on a surface constituted by the seven corners 107 and the fifth corner 105. In addition, a second selective reflection surface 6 is provided on a surface constituted by the third corner 103, the fourth corner 104, the fifth corner 105, and the sixth corner 106. ing. Therefore, the first selective reflection surface 5 and the second selective reflection surface 6 are inclined by 45 ° with respect to the end face of the composite prism 1.

Expressing such a configuration using the XY-Z coordinate axes, the first selective reflection surface 5 has a first corner I 0 1 (x 0, y 0, z 0) and a third corner 10 3 ( xl, yl, z0), the seventh corner 1 07 (xl, yl, zl), the fifth corner 1 105 (x0, y0, z1) formed on a rectangular joint surface, Second selectivity Reflecting surface 6 has third corner 103 (xl, yl, ζθ), fourth corner 104 (x0, yl, ζθ), fifth corner 105 (x0, y0, zl), the sixth corner 106 (xl, y0, zl), and is formed on a rectangular joining surface, and the first selective reflection surface 5 and the It is not orthogonal to the selective reflection surface 6 of 2.

In order to manufacture the composite prism 1 having such a configuration, as shown in FIG. 2A, first, a rod-shaped beam having a triangular cross-section in which a first selective reflection surface 5 made of a multilayer film is formed on an inclined surface. Fabricate the plotter bar 301.

Next, after joining the beam splitter bar 301 via the first selective reflection surface 5, as shown in FIG. 2B, the beam splitter bar 301 is cut at an angle of 45 ° and polished.

Next, as shown in FIG. 2 (B) and FIG. 3 (A), a second selective reflection surface 6 composed of a multilayer film is formed on the polished surface by low-temperature evaporation.

Next, as shown in FIG. 3 (B), after joining again in a par shape, the cut surface is polished. As a result, the composite prism 1 is completed.

In such a composite prism 1, when it is manufactured, the flatness of the first selective reflection surface 5 and the second selective reflection surface 6 is not impaired. In addition, since the first selective reflection surface 5 and the second selective reflection surface 6 are each formed in the same plane, high flatness can be obtained. Furthermore, unlike the X-cup shown in Fig. 3 (C), there is no need to join and join four prisms at each right-angled edge. Therefore, it is not necessary to make the thickness of the adhesive extremely thin, so it shows good results in heat shock tests and has high reliability.

Examples in which various optical elements are configured based on the composite prism 1 of the present embodiment will be described below. First, in this example, both the first selective reflection surface 5 and the second selective reflection surface 6 are configured by a multilayer film, and the first selective reflection surface 5 and the second selective reflection surface 6 are each provided with a selective reflection characteristic as described below.

That is, the first selective reflection surface 5 is provided with the optical characteristics shown in FIG. 4 (A), and the three primary colors red light (light in a wavelength band centered on red) and green light (green light) A surface that transmits P-polarized light and reflects S-polarized light in the visible wavelength band of blue light (light in a wavelength band centered on blue) and blue light (light in a wavelength band centered on blue). The second selective reflection surface 6 has the optical characteristics shown in FIG. 4B, and is a blue reflection surface that transmits red light and green light and reflects blue light. In addition, the second selective reflection surface 6 is configured to transmit P-polarized light and reflect S-polarized light even for blue light.

In the composite prism 1 configured as described above, as shown in FIGS. 1 and 5, when the light LG incident from the rectangular plane 21 is converted into green light polarized in advance into a P wave, this light LG (P) passes through the first selective reflection surface 5 and the second selective reflection surface 6 and travels straight toward the rectangular plane 22. When the light LR incident from the rectangular plane 11 is red light polarized in advance into an S wave, this light LR ′ (S) is converted to a first selective reflection surface with an incident angle of 45 °. After total reflection at 5, the light passes through the second selective reflection surface 6 and goes to the rectangular plane 22.

When the light LB incident from the rectangular plane 32 is assumed to be blue light LB (S) polarized in advance into an S wave, this light LB is incident on the second selective reflection surface 6 at an incident angle of 45 °. After passing through the first selective reflection surface 5, the light is transmitted to the rectangular plane 22.

Therefore, according to the composite prism 1 of the present embodiment, it is possible to combine optical paths of three color lights having different wavelengths.

Conversely, when white light whose polarization direction is adjusted enters from the rectangular plane 22, red light LR is emitted from the rectangular plane 11, and blue light LB is emitted from the rectangular plane 32, Green light LB is emitted from the rectangular surface 21 You. Therefore, it can be said that the optical paths of three or more colored lights having different wavelengths can be separated. At this time, if the polarization direction is adjusted, the combined light of the red light LR and the green light LG is emitted from the rectangular plane 12 and the combined light of the blue light LB and the green light LG is emitted from the rectangular plane 31. You can also.

[Modification of First Embodiment]

FIGS. 6A and 6B show the optical characteristics of the first selective reflection surface 5 and the second selective reflection surface 6 used in the composite prism 1 according to the modification of the first embodiment of the present invention. FIG. 4 is an explanatory diagram showing characteristics. FIG. 7 is an explanatory diagram of a liquid crystal projector using the composite prism. 8 and 9 are explanatory diagrams of a dichroic mirror array used in the liquid crystal projector shown in FIG. As described with reference to FIG. 1, the composite prism 1 of the present example is also a cube-shaped composite prism having a first rectangular plane 31 and a second rectangular plane 32 facing each other, The following selective reflection surfaces are formed on a plurality of bonding surfaces formed by bonding a plurality of translucent members. That is, each corner of the first rectangular plane 31 is referred to as a first corner 101, a second corner 102, a third corner 103, and a fourth corner 104, respectively. In the second rectangular plane 32, each corner corresponding to the first corner 101, the second corner 102, the third corner 103, and the fourth corner 104 is defined. When the fifth corner 105, the sixth corner 106, the seventh corner 107, and the eighth corner 108 are respectively, the first corner 101, the third corner 1 A third selective reflection surface 5 is provided on a surface formed by the third corner portion 107, the seventh corner portion 107, and the fifth corner portion 105. Further, a second selective reflection surface 6 is provided on a surface formed by the third corner 103, the fourth corner 104, the fifth corner 105, and the sixth corner 106. Have. Therefore, the first selective reflection surface 5 and the second selective reflection surface 6 are inclined by 45 ° with respect to the end face of the composite prism 1. Further, the first selective reflection surface 5 and the second selective reflection surface 6 are not orthogonal.

Here, the first selective reflection surface 5 is constituted by a polarization separation film having the optical characteristics shown in FIG. 6A, and the second selective reflection surface 6 It is composed of a polarization separation film having the optical characteristics shown in FIG. 6 (B). As shown in FIG. 7, the liquid crystal projector using the composite prism 1 configured as described above includes a light source unit 110 having a white light source 111 and a reflector 112, and a light source unit 110 having the same. PBS (polarization beam splitter) converter 120 to align white light emitted from 10 into P-polarized light, and light emitted from this PBS converter 120 is converted to blue light LB and red light LR. And a dichroic mirror 130 that separates the light into a mixture of green light and green light LG. For the blue light LB, a total internal reflection mirror 140 that guides the light emitted from the dichroic mirror 130 to the rectangular plane 31 of the composite prism 1 (see FIG. 1) is arranged. The blue light LB is incident on the composite prism 1 as P-polarized light.

On the other hand, for the mixed light of the red light LR and the green light LG, the dichroic mirror array 150, in which the green light LG is selectively S-polarized light, and the total reflection mirror 160, Red light LR emitted from the dichroic mirror array 150 as P-polarized light, and green emitted from the dichroic mirror array 150 as S-polarized light. The light LG enters the compound prism 1 through a common optical path.

Here, as the dichroic mirror array 150, the one shown in FIG. 8 or FIG. 9 can be used. Of these dichroic mirror arrays, the one shown in Fig. 8 has a parallelogram or triangular columnar translucent member 155 having an acute angle of 45 ° in cross section, and is joined at the inclined end face. ing. A dichroic mirror 152 that reflects green light LG and transmits red light LR is formed at the first bonding interface 15 1, and a second bonding interface 15 3 that faces the dichroic mirror 15 2 Total reflection mirrors 15 4 are formed. In addition, an integrated lens array 156 is arranged on the entrance end face of the dichroic mirror 150, and a 1/2 λ plate 157 is arranged on the exit end face from the total reflection mirror 154. Have been.

Therefore, the light emitted from the dichroic mirror 130 shown in FIG. The polarized red light LR and the P-polarized green light LG are guided to the dichroic mirror 152 by the integral lens array 156, and the red light LR passes through the dichroic mirror 152. The light is emitted as P-polarized light. On the other hand, the green light LG is reflected by the dichroic mirror -152, then reflected by the total reflection mirror 154 toward the Ζ2λ plate 157, and is reflected by the S-polarized light. And emitted.

As shown in FIG. 9, the dichroic mirror array 150 has a dichroic mirror 15 which transmits the green light LG and reflects the red light LR at the first bonding interface 151, as shown in FIG. 8 may be formed, and a total reflection mirror 159 may be formed on the second bonding interface 15 3 facing the same. In the dichroic mirror array 150, a λ plate 157 is arranged on the output end face from the dichroic mirror 158. Therefore, the Ρ-polarized red light LR and Ρ-polarized green light LG emitted from the dichroic mirror 130 shown in FIG. 7 are converted by the dichroic mirror (see FIG. 8) into the dichroic mirror. When guided to 158, the green light LG passes through the dichroic mirror 158, is converted into S-polarized light by the 1 / 2λ plate 157, and is emitted. On the other hand, the red light LR is reflected by the dichroic mirror 158, then reflected by the total reflection mirror 159, and emitted as Ρ-polarized light.

In the liquid crystal projector thus configured, a reflective liquid crystal light bulb 17 1 (electro-optical device) for the red light LR and a reflective liquid crystal light ray for the green light LG are provided on a predetermined rectangular plane of the compound prism 1. And a reflective liquid crystal light valve 173 for blue light L Β.

Therefore, when the blue light LB enters the composite prism 1, it passes through the second selective reflection surface 6, reaches the liquid crystal light valve 173 for blue light, and then passes through the liquid crystal light valve 173. Is reflected. In the meantime, the light component modulated by the liquid crystal light valve 173 for each pixel and converted into S-polarized light In other words, the light is reflected by the second selective reflection surface 6 and guided to a projection optical system (not shown).

When the red light LR and the green light LG enter the compound prism 1 as mixed light, only the red light LR passes through the first selective reflection surface 5 and the liquid crystal light valve for red light 17 1 After reaching, it is reflected by this liquid crystal light valve 17 1. In the meantime, the light component which is light-modulated by the liquid crystal light valve 17 1 for each pixel and converted into S-polarized light is reflected by the first selective reflection surface 5 and guided to the projection optical system.

On the other hand, the green light LG is reflected by the first selective reflection surface 5, reaches the liquid crystal light valve 172 for green light, and is reflected by the liquid crystal light valve 172. In the meantime, the light component which is light-modulated for each pixel by the liquid crystal light valve 172 and converted into P-polarized light is transmitted through the first selective reflection surface 5 and guided to the projection optical system.

Then, a predetermined color image is displayed on the screen by each color light emitted from the projection optical system.

Thus, in the liquid crystal projector using the composite prism 1 of the present embodiment, the optical path of the blue light LB and the optical path of the mixed light of the red light LR and the green light LG need only be secured around the polarizing prism 1. The size of the liquid crystal projector can be reduced. In the liquid crystal projector using the composite prism 1 of the present embodiment, when viewed from the polarizing prism 1, the optical path of the blue light LB, the optical path of the mixed light of the red light LR and the green light LG, and the light exiting from the polarizing prism 1. Since the emission paths can be arranged three-dimensionally, the degree of freedom in designing the optical system in the liquid crystal projector is high.

Further, in the composite prism 1 of the present embodiment, unlike the X cup, the ridge lines of each prism are not concentrated at one place, so that it is possible to avoid a situation in which the ridge line of the prism alone is reflected at the center of the projected image.

[Embodiment 2]

FIG. 10 is an explanatory diagram of a composite prism according to Embodiment 2 of the present invention. You. FIG. 11 is an explanatory diagram showing the optical characteristics of the selective reflection surface formed on the composite prism according to Embodiment 2 of the present invention. FIG. 12 is an explanatory diagram showing an example of use of the compound prism according to the second embodiment of the present invention. FIG. 13 is an explanatory diagram illustrating a method of manufacturing a composite prism according to Embodiment 2 of the present invention.

In FIG. 10, the composite prism 2 of the present embodiment is a dichroic mirror module, and has a columnar translucent member 22 1 having a right-angled isosceles triangle having a 45 ° acute angle in cross section. The columnar transparent members 222, 223 each having a parallelogram-shaped section having an acute angle of 45 degrees are joined at the inclined end faces. In addition, one end portion 226 is joined to a columnar dummy translucent member 224 having a right-angled isosceles triangle shape having an acute angle of 45 degrees in cross section, and three joining surfaces 23 are formed. 1, 2 3 2 and 2 3 3 are provided. Among these three bonding interfaces 2 3 1, 2 3 2, and 2 3 3, the first bonding interface 2 3 1 has a first dichroic mirror having the optical characteristics shown in FIG. The first selective reflection surface 7 reflects the red light LR and transmits the green light LG and the blue light LB. In addition, a second selective reflection surface 8 made of a dichroic mirror having the optical characteristics shown in FIG. 11 is formed at the second bonding interface 232, and this second selective reflection surface 8 , Red light LR and green light LG, while transmitting blue light LB. Note that a total reflection surface 9 having the optical characteristics shown in FIG. 11 is formed on the third bonding interface 233 as a mirror for blue light.

In the composite prism 2 configured as described above, the other end 227 serves as an emission end face, and for example, a diffusion lens 241 is arranged as shown in FIG. On the side surface of the composite prism 2, a condenser plate 229 is arranged. In addition, a red LED 51 is arranged toward the first selective reflection surface 7 by the light-collecting plate 2 9, and a green LED 252 is arranged toward the second selective reflection surface 8. Blue LED 5 3 toward reflective surface 9 Are located.

In the module configured as described above, the red light LR emitted from the red LED 51 is reflected by the first selective reflection surface 7 in the composite prism 2 and emitted through the diffusion lens 41. The green light LG emitted from the green LED 52 is reflected by the second selective reflection surface 8 in the complex prism 2 and then transmitted through the first selective reflection surface 7, and then, the diffusion lens 4 Emitted through 1. The blue light LB emitted from the blue LED 53 is reflected by the total reflection surface 9 in the composite prism 2 and then sequentially transmitted through the second selective reflection surface 8 and the first selective reflection surface 7 to be processed. After that, the light is emitted through the diffusion lens 41.

Therefore, according to the composite prism 2 of the present embodiment, it is possible to combine optical paths of three color lights having different wavelengths. In addition, by combining the LEDs 51, 52, and 53 with light, six colors of light can be emitted in addition to white.

When manufacturing the composite prism 2 having such a configuration, as shown in FIG. 13, as shown in FIG. 13, each surface of a plurality of translucent substrates 160 having two parallel substrate surfaces is referred to FIG. 11. After the formation of the first selective reflection surface 7, the second selective reflection surface 8, and the total reflection surface 9 described above, these laminated substrates (light-transmitting substrate 160) are removed. Laminated with a light-transmitting substrate 16 1 via a photo-curable adhesive. At this time, the overlapping position is shifted so that the edge of each substrate is 45 °. Next, after curing the photo-curable adhesive, cut along the cutting line indicated by the dotted line at an angle of 45 ° to the substrate surface of the light-transmitting substrates 16 0 and 16 1. Thereafter, the cut surface is polished, and the composite prism 2 shown in FIG. 10 is manufactured. Therefore, unlike X-Cube, the production efficiency is high and the cost is low.

(Example of using composite prism 2)

FIG. 14 is an explanatory diagram of a tail lamp using the compound prism according to Embodiment 2 of the present invention. For example, as shown in FIG. 14, a large number of composite prisms 2 'can be arranged in a matrix, such as a fly array, to form a display device such as a tail lamp 200 of an automobile. it can. Also, if the composite prism 2 of the present embodiment is used, 600,000 dots (100,000 dots X 600,000 dots), and 100,000 dots (1,200,000 dots) X 830 dot) outdoor display panel. In any of these display devices, if the three types of LEDs 51, 52, and 53 are lit at a predetermined timing, display can be performed in any color. In addition, the resolution is high even at a short distance, and a resolution twice or more that of a conventional display device can be obtained. Furthermore, in addition to black display in one dot, 7 colors can be expressed, so that in addition to brake lights, hazard lights, back lights, key lock warning lights, anti-theft lamps, etc. It can be used as various kinds of pilot lamps, for example, it can be used as a kind of signal lamp. Moreover, since the image design can be selected as an option, a unique lamp can be constructed.

[Modification 1 of Embodiment 2]

The complex prism 2 according to the second embodiment may be configured as, for example, a dichroic mirror array shown in FIG.

FIG. 15 is an explanatory diagram of a composite prism according to a first modification of the second embodiment of the present invention. In the composite prism 2 shown here, the cross-sectional shape is a right-angled isosceles triangle having an acute angle of 45 degrees, and a columnar translucent member 221, and the cross-sectional shape is a parallelogram having an acute angle of 45 degrees. And the columnar translucent member 222 with a cross-sectional shape of an isosceles right triangle with an acute angle of 45 degrees are joined at the inclined end face. Interfaces 2 3 1 and 2 3 2 are provided.

Of these two bonding interfaces, the first bonding interface 2 31 is formed with a first selective reflection surface 7 made of a dichroic mirror having the optical characteristics shown in FIG. 11. The first selective reflection surface 7 reflects the red light LR. While transmitting the green light LG and the blue light LR. Further, a second selective reflection surface 8 made of a dichroic mirror having the optical characteristics shown in FIG. 11 is formed at the second bonding interface 2 32, and the second selective reflection surface 8 While reflecting the red light LR and the green light LG, it transmits the blue light LB.

In the composite prism 2 configured as described above, the other end portion 227 serves as an emission end surface, and for example, a diffusion lens 41 is arranged. On the side of the composite prism 2, a red LED 51 is arranged toward the first selective reflection surface 7, and a green LED 52 is arranged toward the second selective reflection surface 8. . In addition, a blue LED 53 is disposed at the end on the side of the translucent member 25 toward the other end 227.

In the module configured as described above, the red light L R emitted from the red LED 51 is reflected by the first selective reflection surface 7 in the composite prism 2 and emitted through the diffusion lens 41. The green light LG emitted from the green ED 52 is reflected by the second selective reflection surface 8 in the complex prism 2, then passes through the first selective reflection surface 7, and then diffused by the diffusion lens 4. Emitted through 1. The blue light LB emitted from the blue LED 53 sequentially passes through the second selective reflection surface 8 and the first selective reflection surface 7, and then is emitted through the diffusion lens 41.

Therefore, according to the composite prism 2 of the present embodiment, it is possible to combine the optical paths of three color lights having different wavelengths. Such a composite prism 2 also has a tail lamp 200 described with reference to FIG. It can be used as a display device.

[Modification 2 of Embodiment 2]

The composite prism according to the second embodiment may be configured as, for example, a dichroic mirror array for spectrum used in the module shown in FIG.

FIG. 16 shows a composite prism according to Modification 2 of Embodiment 2 of the present invention. FIG. FIG. 17 is an explanatory diagram showing the optical characteristics of the selective reflection surface used in the compound prism according to Modification 2 of Embodiment 2 of the present invention.

In the composite prism 2 ′ shown here, a columnar translucent member 2 21 ′ having a right-angled isosceles triangle having a cross-sectional shape of 45 ° acute angle and a parallel light-transmitting member having a cross-sectional shape of 45 ° acute angle The quadrangular columnar translucent members 22 2 ′ and 22 3 ′ are joined at the inclined end faces. In addition, one end 2 26 ′ is joined to a columnar dummy translucent member 2 24 ′ having a right-angled isosceles triangle having an acute angle of 45 degrees in cross section, and three joining surfaces 2. 3 1 ′, 2 3 2 ′, and 2 3 3 ′.

Of these three bonding interfaces, the first bonding interface 23 1 ′ has a total reflection surface 7 ′ having the optical characteristics shown in FIG. 17 as a mirror for red light. Further, a first selective reflection surface 8 ′ made of a dichroic mirror having the optical characteristics shown in FIG. 17 is formed at the second bonding interface 2 32 ′. 8 'reflects blue light LB and green light LG while transmitting red light LR. In addition, a second selective reflection surface 9 ′ made of a dike opening mirror having the optical characteristics shown in FIG. 17 is formed at the third bonding interface 233 ′, and this second selective reflection surface is formed. 9 'reflects the blue light LR while transmitting the green light LG and the red light LR.

In the composite prism 2 ′ (the second composite prism) configured in this manner, one end 27 ′ is used as an incident end face. For example, a shirt 63, a polarization conversion prism 69, a lens array 61, and a white light source 6 2 is arranged. The composite prism 2 (first composite prism) described with reference to FIG. 10 is disposed on the side of the composite prism 2 ′ via three shirts 66, 67, and 68. The light source unit.

In the light source unit configured as described above, the light emitted from the white light source 62 is incident on the composite prism 2 ′ after the polarization direction is aligned by the polarization conversion prism 69. And the blue light component contained in the white light is While being reflected by the second selective reflection surface 9 ′ of the composite prism 2 ′ and entering the composite prism 2 as blue light LB, the red light component and the green light component are reflected by the second selective reflection surface 9 ′. Through. Next, the blue light LB incident on the composite prism 2 is reflected by the total reflection surface 9 and then sequentially transmitted through the second selective reflection surface 8 and the first selective reflection surface 7. The light is emitted through the diffusion lens 4 1.

Further, the red light component and the green light component transmitted through the second selective reflection surface 9 ′ reach the first selective reflection surface 8 ′, and the green light component contained therein passes through the second selective reflection surface 8 ′ of the composite prism 2 ′. The red light component is reflected by the first selective reflection surface 8 ′ and is incident on the compound prism 2 as green light LG as the green light LG, while being transmitted through the first selective reflection surface 8 ′. Then, the green light LG incident on the composite prism 2 is reflected by the second selective reflection surface 8, passes through the first selective reflection surface 7, and then emerges through the diffusion lens 41. Is done.

The red light component transmitted through the first selective reflection surface 8 ′ is reflected by the total reflection surface 7 ′ and enters the composite prism 2 as red light LR. Then, the red light LG that has entered the composite prism 2 is reflected by the first selective reflection surface 7, and then emitted through the diffusion lens 41.

As described above, according to the composite prism 2 ′ of the present embodiment, the optical paths of three color lights having different wavelengths can be separated.

By opening and closing the three shutters 66, 67, 68 at a predetermined timing, an arbitrary color can be emitted from the composite prism 2. Therefore, even if a color wheel is not used, it can be used as a light source unit of a field sequential type liquid crystal projector, and such a light source unit has little light absorption in an optical path. Therefore, a high-luminance color image can be displayed.

Further, when constructing an outdoor display panel requiring high luminance, a high-pressure mercury lamp, a halogen lamp, or the like can be used as a light source.

Further, in this example, the white light is converted by the polarization conversion prism 69 (polarization conversion means). Since the polarization direction is adjusted to P-polarized light or S-polarized light, a liquid crystal panel can be used as the shutter 66, 67, 68 (shutter means). If such a liquid crystal panel is used as the shutter 66, 67, 68, it is easy to achieve synchronization.

[Usage Example 1 of Liquid Crystal Projector of Second Embodiment]

The compound prisms 2 and 2 ′ according to the second embodiment and the modifications thereof can be mounted on a liquid crystal projector as described below. FIG. 18 is an explanatory diagram of a liquid crystal projector using a compound prism according to a first modification of the second embodiment of the present invention. The liquid crystal projector shown in FIG. 18 uses the complex prism 2 according to the modification of the second embodiment as a light source, and a polarizing plate 71 is disposed on the emission side of the complex prism 2. A polarization beam splitter 73 having a polarization separation surface 72 is provided. Further, a reflective liquid crystal light valve 74 is arranged to face the end face of the polarizing beam splitter 73, and a projection optical system 75 is arranged on the opposite end face.

In the liquid crystal projector configured in this manner, red light LR, green light LG, and blue light LB are sequentially emitted from the composite prism 2, and only the P-polarized light is emitted by the polarizing plate 71, for example, into the polarizing beam splitter 7. Light is incident on 3. Then, the light incident on the polarization beam splitter 73 is reflected by the polarization separation surface 72 toward the liquid crystal light valve 74, modulated by the liquid crystal light valve 74, and then again polarized light separation surface 72. Head for. At this time, the S-polarized light passes through the polarization splitting surface 72 and is enlarged and projected from the projection optical system 75.

In the meantime, in accordance with the timing at which the LEDs 51, 52, and 53 of each color are sequentially turned on, each pixel is driven by the liquid crystal light valve 74, and an image corresponding to the color light is sequentially formed. Therefore, a new type of field-sequential type liquid crystal projector can be constructed, and according to this liquid crystal projector, a color image can be enlarged and projected from the projection optical system 75. Can be.

[Example 2 of application to liquid crystal projector of Embodiment 2]

FIG. 19 is an explanatory diagram of another liquid crystal projector using the compound prism according to the first modification of the second embodiment of the present invention.

The liquid crystal projector shown in FIG. 19 includes a composite prism 2 according to a modification of the second embodiment and a polarization conversion prism 8 3 (polarization conversion means) including two polarization separation prisms 8 1 and 8 2. A plurality of light source units 80 are arranged. Here, in the polarization conversion prism 83, a half-plate plate 88 is disposed between the polarization separation prisms 81 and 82. In addition, a polarizing beam splitter 86 having a polarization splitting surface 85 is disposed adjacent to the plurality of light source units 80, and a reflective liquid crystal light valve 89 is disposed on the opposite side. Have been. FIG. 19 shows a state where the red light LR is emitted.

In the liquid crystal projector configured as described above, the red light LR, the green light LG, and the blue light LB are sequentially emitted from the composite prism 2 to the first polarization separation prism 81 of the polarization conversion prism 83. Then, of the color light emitted from the complex prism 2, for example, the P-polarized light component passes through the polarization splitting surface of the first polarization splitting prism 81, and then becomes the polarization splitting surface of the polarization beam splitter 86. After passing through 85, it goes to the liquid crystal light valve 89. Then, after being modulated by the liquid crystal light valve 74, the light returns to the polarization splitting surface 72 again. At this time, the S-polarized light is reflected by the polarization splitting surface 85 and is enlarged and projected from a projection optical system (not shown).

The S-polarized light component of the color light emitted from the composite prism 2 is reflected by the polarization splitting surface of the first polarization splitting prism 81, and the P-polarized light is reflected by the 1Z2 plate 88. After being converted into the light, the light enters the second polarization splitting prism 82. Then, after being reflected by the polarization splitting surface of the second polarization splitting prism 82 and entering the polarization beam splitter 86, the light passes through the polarization splitting surface 85 and travels to the liquid crystal light valve 89. And liquid crystal light pulp After being modulated by 8 9, it goes to the polarization splitting surface 85 again. At this time, the S-polarized light is reflected by the polarization splitting surface 85 and is enlarged and projected from a projection optical system (not shown).

During that time, each pixel is driven by the liquid crystal light valve 89 in accordance with the timing at which the LEDs 51, 52, 53 of each color are sequentially turned on, and an image corresponding to the color light is sequentially formed. Therefore, a color image is enlarged and projected from the projection optical system.

This configuration has the advantage that the efficiency of use of the light emitted from the LEDs 51, 52, and 53 is higher than that of a conventional field-sequential liquid crystal projector using color filters. is there.

[Example of application to direct-view display device of Embodiment 2]

FIG. 20 is an explanatory diagram of a direct-view type liquid crystal display device using a compound prism according to a first modification of the second embodiment of the present invention.

The liquid crystal display device shown in FIG. 20 is a direct-view display device using a transmissive or transflective liquid crystal panel 91. As the liquid crystal panel 91, for example, an active matrix type liquid crystal panel using TFT as a pixel switching element can be used.

In such a display device, a polarizing plate 92 is disposed on the display surface side, and an optical sheet 96 such as a diffusion plate and a light guide plate 93 are disposed on the back surface side by side. Further, a plurality of light source units 80 described with reference to FIG. 19 are arranged at the side end of the light guide plate 93, and this light source unit 80 is a modification of the second embodiment. It has a compound prism 2 according to the example and a polarization conversion prism 83, and in the polarization conversion prism 83, a 2λ plate is arranged between two polarization separation prisms.

In the display device configured in this way, similarly to the liquid crystal projector shown in FIG. 19, the red light LR, the green light LG, and the blue light LB are sequentially emitted from the composite prism 2 and passed through the polarization conversion prism 83. Light enters the light guide plate 93. Then, the light incident on the light guide plate 93 is reflected inside the light guide plate 93. The light is incident on the liquid crystal panel 91 repeatedly. Then, after being modulated by the liquid crystal panel 91, the light is emitted and a color image is displayed. Meanwhile, in the liquid crystal panel 91, each pixel is driven according to the timing when the LED of each color is sequentially turned on, and an image corresponding to the color light is sequentially formed. Therefore, these images are combined and a color image is displayed. The greatest feature of the display device configured in this way is that a color image is displayed without using a color filter. Therefore, there is no decrease in light use efficiency due to the color filter. In addition, in the display device of this example, the light sources of the three primary colors emitted from the red LED 51, the green LED 52, and the blue LED 53 are converted into polarized light before entering the light guide plate 93. As a result, the illuminance of the light source can be maintained as it is and emitted to the liquid crystal panel 91. As a result, it is possible to obtain about three times the brightness of the current level, so that users can see clear images even when they need to view images outdoors, such as with mobile phones and mobile phones.

[Other embodiments]

In the above embodiment, an example in which a liquid crystal light valve is used as a light valve of the projector has been described. The composite prism according to the present invention may be used for a projector that uses.

Further, in the above embodiment, the example in which the composite prism according to the present invention is used for the projector and the direct-view display device has been described. However, the composite prism according to the present invention is used for other display devices or other optical devices. It is good. Industrial applicability

According to the present invention, unlike the X-cube, each ridge line of the four prisms does not have to be aligned, so that the yield, cost, and reliability can be improved. For optical path synthesis or optical path separation A compound prism can be provided. Further, by using the composite prism according to the present invention, it is possible to improve image quality and design freedom in various display devices.

Claims

The scope of the claims

1. At least a plurality of joining surfaces formed by joining a plurality of translucent members selectively transmit light having at least predetermined optical characteristics and reflect other light. The selective reflection surface and the second selective reflection surface are formed so as to be parallel or non-perpendicular to each other,

A composite prism, wherein at least three light paths having different wavelengths can be combined or separated by the first selective reflection surface and the second selective reflection surface.

2. In Claim 1, the corners of the first rectangular plane having a rectangular parallelepiped shape composed of a first rectangular plane and a second rectangular plane opposed to each other are referred to as a first corner and a second corner, respectively. A third corner and a fourth corner, and each corner corresponding to the first corner, the second corner, the third corner and the fourth corner on the second rectangular plane. When they are the fifth corner, the sixth corner, the seventh corner, and the eighth corner, respectively,

The first selective reflection surface is provided on a surface formed by the first corner, the third corner, the seventh corner, and the fifth corner,

A composite prism comprising the second selective reflection surface on a surface formed by the third corner, the fourth corner, the fifth corner, and the sixth corner. .

3. The composite prism according to claim 2, wherein each of the first selective reflection surface and the second selective reflection surface is constituted by a polarization splitting surface.

4. The device according to claim 2 or 3, further comprising a plurality of electro-optical devices for modulating the color light emitted from the compound prism. A display device characterized by the following.

5. The method according to claim 1, further comprising: a plurality of parallel joining surfaces, wherein the plurality of columnar light-transmitting members are joined to form an angle of 45 ° on an incident surface,

The first selective reflection surface selectively reflecting light in a predetermined wavelength band on any of the plurality of bonding surfaces;

A composite prism comprising, on any one of the other joining surfaces, the second selective reflection surface that selectively reflects light in a wavelength band different from that of the first selective reflection surface.

6. A light source unit provided with a compound prism as defined in claim 5, wherein

The composite prism is a first dichroic light for the first color light that selectively reflects the first color light of the three primary color wavelength bands of red, green and blue as the first selective reflection surface. A second color light dichroic mirror that selectively reflects the second color light toward the first color light dichroic mirror as the second selective reflection surface; The third color light dichroic mirror is disposed on the opposite side of the second color light dichroic mirror with respect to the second color light dichroic mirror, and the third color light is transmitted to the second color light dichroic mirror. A third color light reflecting surface that reflects toward

A first color light source unit that emits the first color light toward the first color light dichroic mirror is arranged;

A second color light source unit that emits the second color light toward the second color light dichroic mirror;

A third color light source unit that emits the third color light toward the reflection surface is disposed;

The first color light source unit, the second color light source unit, and the third color light A light source unit, wherein light emission from a source to the compound prism is switched at a predetermined timing.

7. A light source unit having a composite prism as defined in claim 5, wherein

The compound prism is a first dichroic light for a first color light, which selectively reflects a first color light of a wavelength band of three primary colors of red, green, and blue as the first selective reflection surface. And a second color light dichroic mirror that selectively reflects the second color light toward the first color light dichroic mirror as the second selective reflection surface,

A third color light source unit that emits third color light from a side opposite to the first color light dichroic mirror with respect to the second color light dichroic mirror;

A light source unit, wherein light emission from the first color light source unit, the second color light source unit, and the third color light source unit to the composite prism is switched at a predetermined timing.

8. The light-emitting element according to claim 6, wherein the first color light source, the second color light source, and the third color light source each emit a predetermined color light. And

The light source unit, wherein lighting of the first color light source unit, the second color light source unit, and the third color light source unit is controlled at a predetermined timing.

9. The method according to claim 6, wherein the first color light source, the second color light source, and the third color light source are each obtained by color-dividing white light. Emitted light of each color,

Between the first color light source unit, the second color light source unit, the third color light source unit, and the composite prism, the timing at which each color light is incident on the composite prism A light source unit, comprising shutter means for controlling the lighting.

10. A light source unit comprising two composite prisms as defined in claim 5, wherein

Of the two composite prisms, the first composite prism selectively serves as the first selective reflection surface, the first color light of the three primary color wavelength bands of red, green, and blue. A first color light dichroic mirror that reflects light to the first color light dichroic mirror as the second selective reflection surface, and selectively reflects the second color light toward the first color light dichroic mirror. A second dichroic mirror for color light, and a dichroic mirror for second color light, the dichroic mirror for first color light being disposed on a side opposite to the dichroic mirror for first color light, and receiving a third color light. A third color light reflecting surface that reflects toward the second color light dichroic mirror;

The second composite prism includes a first color light reflecting surface that reflects the first color light toward the first color light dichroic mirror of the first composite prism, and the first selection. A second color light dichroic mirror for selectively reflecting the second color light as a reflective surface toward the second color light dichroic mirror of the first composite prism; A third color light dichroic mirror for selectively reflecting the third color light toward the third color light reflection surface of the first compound prism as a second selective reflection surface; .,

Further, the second composite prism is provided with respect to the second composite prism. A white light source that emits white light toward the third color light dichroic mirror of

A shutter means for controlling a timing at which each color light is incident from the second compound prism to the first compound prism, between the first compound prism and the second compound prism. The light source unit, wherein the light source unit is disposed.

11. The method according to claim 9 or 10, further comprising: a polarization conversion unit that aligns a polarization direction of the white light,

A light source unit, wherein a liquid crystal panel is used as the shirt unit.

12. A display device comprising the light source unit defined in any one of claims 5 to 11.

13. The display device according to claim 12, wherein a plurality of the compound prisms are arranged in a matrix form.

14. An electro-optical device according to claim 12, further comprising: an electro-optical device that sequentially modulates the color light emitted from the light source unit and sequentially generates a color image corresponding to the color light. Characteristic display device.

15. The display device according to claim 14, wherein the light source unit includes a polarization conversion unit that aligns a polarization direction of color light emitted toward the electro-optical device.

16. The projection optical system according to claim 14 or 15, further comprising a projection optical system configured to project images of respective colors sequentially formed by the electro-optical device. A projection type display device characterized by the above-mentioned.