JP2007093970A - Projection type image display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projection type image display apparatus capable of increasing the light quantity of desired color image light. <P>SOLUTION: In one projection system, red light emitted from an illuminating apparatus 51R is transmitted through a liquid crystal panel 1R, then, the red image light is generated, green light emitted from an illuminating apparatus 51G-1 is transmitted through a first liquid crystal display panel for green 1G-1, then, the first green image light is generated. Similarly, in the other projection system, blue light emitted from an illuminating apparatus 51B is transmitted through a liquid crystal display panel for green 1B, then, the blue image light is generated, and green light emitted from an illuminating apparatus 51G-2 is transmitted through a second liquid crystal panel for green 1G-2, then, the second green image light is generated. The red image light and the first green image light are synthesized by one dichroic prism 2RG, and projected through one projection lens 3. Similarly, the blue image light and the second green image light are synthesized by the other dichroic prism 2BG and projected through the other projection lens 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a projection display apparatus such as a liquid crystal projector.

Conventionally, a cross dichroic prism has been known as an optical element that combines light utilizing the difference in wavelength of light. Further, there is known a projection display apparatus that synthesizes and projects image lights of respective colors (see Patent Document 1, Patent Document 2, and Patent Document 3).
Japanese Patent No. 2867590 Japanese Patent No. 2990376 Japanese Patent No. 3180498

  As a projection display apparatus using the cross dichroic prism, a configuration shown in FIG. 14 can be considered. In this projection display apparatus, the liquid crystal display panel 1R receives red light to generate red image light, the liquid crystal display panel 1G receives green light to generate green image light, and the liquid crystal display panel 1B has blue light. Receiving blue light. Each color image light is combined by the cross dichroic prism 2 to become color image light. This color image light is projected by the projection lens 3 (the other components will be described in detail in the embodiment of the present invention).

  By the way, in a projection display apparatus using a solid-state light source such as an LED, there are cases where the amount of specific color light such as green light is small or the utilization efficiency is low (this will be further described in the embodiment).

  As a configuration that can increase the amount of green light, a projection display apparatus shown in FIG. 15 is conceivable. In this configuration, instead of the rod integrator 12, a rod integrator 120 with a tapered inclination angle reduced or a rectangular parallelepiped shape is provided, and two green LEDs 11 are arranged on the light incident surface of the rod integrator 120. . However, in such a configuration, even if the amount of incident green light is twice that of the configuration in FIG. 14, the taper angle of the rod integrator 120 is reduced by the amount of increase in the light incident surface of the rod integrator 120. Since the effect of reducing the dispersion angle is reduced, the effective light (light having a dispersion angle within a range that can be used by the projection lens 3) incident on the video display panel 1G is less than twice.

  In view of the above circumstances, an object of the present invention is to provide a projection display apparatus that can increase the amount of desired color image light.

  In order to solve the above-described problem, the projection display apparatus of the present invention includes a first image light generation unit that generates image light of the first color and a second image light generation that generates image light of the second color. Means, a third image light generating means for generating two third color image lights using two light valves, one of the first color image light and the third color image light; First dichroic combining means for combining light using wavelength selectivity of light, first projection means for projecting composite image light emitted from the first dichroic combining means, the image light of the second color, and the Second dichroic combining means for combining the other one of the third color image lights using wavelength selectivity of light, and second for projecting the combined image light emitted from the second dichroic combining means. Projection means (hereinafter referred to as this section). First configuration Te that).

  With the above configuration, it is sufficient that the first dichroic combining unit and the second dichroic combining unit synthesize two colors of image light, respectively, and the specific color light generated when the cross dichroic prism is used in both side wavelength bands. It is possible to suppress a decrease in light use efficiency of specific color light due to reflection (cut).

  In the projection display apparatus having the first configuration, the third image light generating unit may include two independent illumination systems that respectively irradiate each light valve with the third color light. In this configuration, each dichroic combining unit may be configured to reflect the third color light.

  In the projection display apparatus having the first configuration, the third image light generation unit divides the light emitted from the illumination system by irradiating a third color light, and divides each light into the two lights. And a spectroscopic unit that leads to each of the light valves (hereinafter, referred to as a second configuration in this section).

  In the projection display apparatus having the second configuration, the spectroscopic unit includes two polarization beam splitters or one polarization beam splitter and a reflection member. In such a configuration, a phase difference plate may be provided so as to align the polarization direction of the light emitted from the spectroscopic means.

  Alternatively, in the projection display apparatus of the second configuration, the spectroscopic means may be configured to include a half mirror.

  In the projection display apparatus having these configurations, each color image light emitted from each image light generating means may be configured to have the same polarization direction.

  The projection display apparatus of the present invention also includes a first image light generating means for generating a first color image light that is a predetermined polarized light, and a second image light that generates a second color image light that is a predetermined polarized light. Image light generating means, third image light generating means for generating two pieces of third color image light as predetermined polarized light using two light valves, the first color image light and the third color First polarized light combining means for combining one of the image lights using the polarization dependence of light, first projection means for projecting the combined image light emitted from the first polarized light combining means, Second polarized light combining means for combining the second color image light and the other one of the third color image light using the polarization dependence of the light, and the second polarized light combining means. Second projecting means for projecting composite image light (hereinafter referred to as the first in this section). Configuration that).

  If it is said structure, the specific color light cut which arises with a dichroic prism will not arise, and the light quantity of the 3rd color image light can be increased.

  In the projection display apparatus having the third configuration, the third image light generation unit may include two independent illumination systems that respectively irradiate each light valve with the third color light.

  Alternatively, in the projection-type image display device having the third configuration, the third image light generation unit divides the light emitted from the illumination system with one illumination system that emits the third color light, And a spectroscopic unit that leads to the two light valves (hereinafter referred to as a fourth configuration in this section).

  In the projection display apparatus having the fourth configuration, the spectroscopic unit may include two polarization beam splitters or one polarization beam splitter and a reflection member. In such a configuration, a phase difference plate may be provided so as to align the polarization direction of the light emitted from the spectroscopic means.

  Alternatively, in the projection display apparatus of the fourth configuration, the spectroscopic means may be configured to include a half mirror.

  In the third configuration or a configuration subordinate thereto, each polarized light combining unit is configured so that the polarization directions of the two color image lights emitted from the first polarized light combining unit and the second polarized light combining unit are the same. A narrow band phase difference plate may be provided on the light emitting side.

  The projection display apparatus according to the present invention also includes a first video light generating means for generating a first color video light, a second video light generating means for generating a second color video light, and a third color light. Third image light generating means for generating two image lights using two light valves, and first combining means for combining the first color image light and one of the third color image lights And a first projection means for projecting the composite image light emitted from the first composition means, and a second composition means for combining the second color image light and the other one of the third color image lights. And a second projecting unit that projects the synthesized video light emitted from the second synthesizing unit (hereinafter referred to as a fifth configuration in this section). The first synthesizing means and the second synthesizing means are not limited to those that synthesize light according to the wavelength selectivity of light or the polarization dependence of light. The first combining unit may combine light based on the wavelength selectivity of the light, and the second combining unit may combine light based on the polarization dependence of the light. Conversely, the first combining unit may combine light based on the polarization dependence of light, and the second combining unit may combine light based on the wavelength selectivity of light.

  In the projection display apparatus having the fifth configuration, the third image light generation unit may include two independent illumination systems that respectively irradiate each light valve with the third color light. Further, in the projection display apparatus having the fifth configuration, the third image light generating means splits each light by splitting light emitted from the illumination system and one illumination system that emits the third color light. Spectroscopic means for guiding the light valves to the two light valves, respectively.

  In these configurations, the third video light generating means for generating two third color video lights may generate two third color video lights having a relationship of interpolating between pixels. In the projection display apparatus having these configurations, the third color may be green.

  According to the present invention, there is an effect that the amount of desired color image light can be increased.

  Hereinafter, a projection display apparatus according to an embodiment of the present invention will be described with reference to FIGS. In order to avoid redundancy due to duplication of explanation, the same components as those in the projection display apparatus shown in FIG. 14 are denoted by the same reference numerals.

  FIG. 1 is a view showing an optical system of a projection display apparatus according to this embodiment. This projection display apparatus has two projection systems. One projection system includes two illumination devices 51R and 51G-1, a liquid crystal display panel 1R, a liquid crystal display panel 1G-1, a dichroic prism (may be a dichroic mirror) 2RG, and a projection lens 3. Another projection system includes two illumination devices 51B and 51G-2, a liquid crystal display panel 1B, a liquid crystal display panel 1G-2, a dichroic prism (may be a dichroic mirror) 2BG, and a projection lens 3.

  Each illuminating device 51 includes an LED (light emitting diode) 11, a tapered rod integrator 12, a polarization conversion device 13, and a rectangular parallelepiped rod integrator 15.

  The LED 11 includes an LED chip 11a and a heat sink (heat radiating plate) 11b. The LED chip 11a in the illumination device 51R emits red light, and the LED chip 11a in the illumination device 51G-1 and the illumination device 51G-2 emits green light (not necessarily in the same wavelength band), and the illumination device 51B. The LED chip 11a emits blue light.

  The tapered rod integrator 12 has a tapered shape in which the light exit surface is larger than the light incident surface, and reduces the dispersion angle distribution existing in the light emitted from the LED chip 11a. And an effect of making the illuminance distribution non-uniformity existing in the light emitted from the LED chip 11a uniform (light integration effect). The tapered rod integrator 12 is made of a transparent member (transparent glass or the like) or a hollow member whose inner surface is a mirror.

  The polarization conversion device 13 has a V-shaped dielectric multilayer film (polarization separation film) at a position facing the light exit surface of the rod integrator 12. S-polarized light reflected by one surface of the V-shaped dielectric multilayer film is reflected by the adjacent reflective surface (or dielectric multilayer film), and similarly, the V-shaped dielectric multilayer film The S-polarized light reflected by the other surface is reflected by the adjacent reflecting surface (or dielectric multilayer film). The P-polarized light transmitted through the dielectric multilayer film is converted into S-polarized light by a phase difference plate (1 / 2λ plate). Of course, the light can be aligned with P-polarized light.

  The rectangular parallelepiped rod integrator 15 is made of a transparent member (transparent glass or the like) or a hollow member whose inner surface is a mirror, and makes light illuminance distribution uniform on the light emitting end surface by reflecting light on the inner surface. The light emitting end face of the rod integrator 15 is, for example, rectangular.

  In one projection system, red image light is generated by the red light emitted from the illumination device 51R passing through the red liquid crystal display panel 1R, and the green light emitted from the illumination device 51G-1 is for green. The first green image light is generated by passing through the first liquid crystal display panel 1G-1. Similarly, in another projection system, the blue light emitted from the illuminating device 51B passes through the blue liquid crystal display panel 1B to generate blue image light, and the green light emitted from the illuminating device 51G-2. The second green image light is generated by transmitting the light through the second liquid crystal display panel 1G-2 for green (hereinafter, when the specific liquid crystal display panel is not indicated, the symbol “1” is simply used). May be used). Then, the red video light and the first green video light are combined by one dichroic prism 2RG and projected by one projection lens 3. Similarly, the blue image light and the second green image light are combined by the other dichroic prism 2BG and projected by the other projection lens 3. Both projection lenses 3 may be movably arranged so that their optical axes can be adjusted. Further, the optical axes of both projection lenses 3 are parallel to each other, and each liquid crystal display panel 1 is arranged so that its center is somewhat shifted with respect to the optical axis of each projection lens 3, thereby allowing a predetermined distance from the projection lens 3. Each image light may be projected onto a screen (in particular, a transmissive screen for a rear projector).

  The dichroic prism 2RG reflects green light and transmits red light. The dichroic prism 2BG reflects green light and transmits blue light. That is, the green image light is reflected. Here, for the cross dichroic prism 2 shown in FIG. 14 and FIG. 15, the characteristic of the first dichroic region (reflecting characteristic with respect to wavelength) is the characteristic of reflecting light in the red wavelength band as shown in the upper part of FIG. The characteristic (reflection characteristic with respect to wavelength) of the second dichroic region is a characteristic of reflecting light in the blue wavelength band as shown in the lower part of FIG. For this reason, as shown in FIG. 7, a part of the wavelength on both sides of the green light in the intermediate wavelength band is reflected (cut), and the light use efficiency of the green light is lowered.

  On the other hand, if the dichroic prism 2RG and the dichroic prism 2BG are used, the above-described action of partial reflection (cut) of both wavelengths of the green light does not occur, so that the light utilization efficiency of the green light is improved. In addition, the light emitted from each green LED is reduced in dispersion angle by the tapered rod integrator 12 in each of the two lighting devices 51G-1 and 51G-2, so that the amount of light also increases. That is, instead of disposing two LEDs on the light incident side of one rod integrator, the tapered rod integrator 12 can be applied to each green LED. Thus, in the projection display apparatus shown in FIG. 15, effective light incident on the display panel 1G in comparison with the projection display apparatus shown in FIG. 14 (dispersion within a range that can be used by the projection lens 3). In contrast to the projection type video display device shown in FIG. 14, the light incident on the video display panel 1G is effective compared to the projection type video display device shown in FIG. The light is almost doubled. FIG. 13 shows the relationship between the angle component and the light amount (at each dispersion angle) in the projection video display apparatus having the configuration of FIG. 1, the projection video display apparatus having the configuration of FIG. 14, and the projection video display apparatus having the configuration of FIG. The graph (simulation result) which showed the integrated value of the light quantity is shown. Note that application of the rod integrator 120 having a rectangular parallelepiped shape or a small taper angle and a plurality of green LEDs shown in FIG. 15 to the lighting devices 51G-1 and 51G-2 is not excluded.

  Both panels are arranged so that the pixel positional relationship between the first liquid crystal display panel 1G-1 and the second liquid crystal display panel 1G-2 is interpolated with each other, and an image that matches the pixel relationship is provided. You may make it supply a signal to each liquid crystal display panel 1G-1 and 1G-2. According to this, the resolution about a green image can be raised. Further, the LEDs 11 in the two lighting devices 51G-1 and 51G-2 may be alternately lighted in a time division manner. A configuration without the polarization conversion device 13 may also be employed. These modifications can also be applied to the projection type video display apparatus having other configurations described below.

  FIG. 2 is an explanatory view showing another example of the projection display apparatus of the present invention. The illumination device 51R and the illumination device 51B are disposed to face each other with the dichroic prism 2GR and the dichroic prism 2GB interposed therebetween.

  Red light from the illumination device 51R (red video light that has passed through the liquid crystal display panel 1R) is incident on one light incident surface of the dichroic prism 2GR, and blue light (from the illumination device 51B is incident on one light incident surface of the dichroic prism 2GB. Blue image light that has passed through the liquid crystal display panel 1B enters. A liquid crystal display panel 1G-1 is disposed on the other light incident surface of the dichroic prism 2GR, and a liquid crystal display panel 1G-2 is disposed on the other light incident surface of the dichroic prism 2GB. Has been.

  The illuminating device 51G-3 includes one LED 11 that emits green light, a tapered rod integrator 12A, a rectangular parallelepiped rod integrator 15, and a polarization conversion device 16. The polarization conversion device 16 aligns light incident from the side surface via the rod integrator 15 with, for example, S-polarized light. The polarization conversion device 16 has a structure in which two polarization beam splitters are arranged, or one polarization beam splitter and a reflection member that reflects light transmitted through the polarization beam splitter. And it arrange | positions to S polarization | polarized-light light by providing the phase difference plate (1/2 (lambda) plate) 16a in the light emission side of the polarizing beam splitter or reflection member located in a back | latter stage side. A structure in which the retardation plate is disposed between two polarizing beam splitters or between one polarizing beam splitter and a reflecting member may be employed.

  The two polarization beam splitters or one polarization beam splitter and the reflecting member in the polarization conversion device 16 have substantially the same size as the dichroic prisms 2GR and 2GB. The S-polarized light emitted from the polarization converter 16 becomes green image light through the two liquid crystal display panels 1G-1 and 1G-2, and these green image lights are incident on the dichroic prisms 2GR and 2GB, respectively. . The dichroic prism 2GR reflects red image light, transmits green image light, and guides each color image light to the projection lens 3. The dichroic prism 2GB reflects blue image light, transmits green image light, and guides each color image light to the projection lens 3.

  With the above configuration, even if one side wavelength of green light is partially reflected (cut) in the dichroic prism 2GR and the dichroic prism 2GB, a part of both side wavelengths as shown in FIG. The light utilization efficiency of green light is improved as compared with the structure using the cross dichroic prism 2 because only half of the light is reflected (cut). In addition, since the shape of the optical element constituting the polarization conversion device 16 is larger than that of the polarization conversion device 13, the use efficiency of green light can be improved by using the polarization conversion device 16. Furthermore, since the rod integrator 12A can increase the inclination angle of the taper shape as compared with the rod integrator 12, a higher dispersion angle reduction effect can be obtained, which also improves the light utilization efficiency.

  FIG. 3 is an explanatory view showing another example of the projection display apparatus of the present invention. The difference from the projection display apparatus shown in FIG. 2 is that an illumination device 51G-3 ′ is provided instead of the illumination device 51G-3 described above. The illumination device 51G-3 spectrally separates the light incident from the side surface of the polarization conversion device 16, whereas the illumination device 51G-3 ′ used in this configuration spectrally separates the light incident from the back surface side of the polarization conversion device 16A. In addition, the S polarization direction is aligned. The polarization conversion device 16A includes a phase plate 16a on the light output side of the polarization beam splitter on the front stage side so that the light is aligned in the S polarization direction.

  FIG. 4 is an explanatory view showing another example of the projection display apparatus of the present invention. A difference from the projection display apparatus shown in FIG. 2 is that an illumination device 51G-4 is provided instead of the illumination device 51G-3. Although this illuminating device 51G-4 has a structure equivalent to the illuminating device 51G-1 including the polarization conversion device 13, it is arranged horizontally (parallel to the illuminating device 51B). The half mirror 17 is disposed to face the dichroic prism 2GB at an angle of 45 °, and the mirror 18 is disposed to face the dichroic prism 2GR at an angle of 45 °, so that the green light emitted from the illumination device 51G-4 is emitted. The light is split and incident on the dichroic prisms 2GB and 2GR, respectively.

  Even in such a configuration, even if one side wavelength of green light is partially reflected (cut) in the dichroic prism 2GR and dichroic prism 2GB, part of both side wavelengths as shown in FIG. 7 is reflected (cut). However, since only half of the light is reflected (cut), the light utilization efficiency of the green light is improved as compared with the structure using the cross dichroic prism 2.

  FIG. 5 is an explanatory view showing another example of the projection display apparatus of the present invention. A difference from the projection display apparatus shown in FIG. 4 is that an illuminating device 51G-4 ′ is provided instead of the illuminating device 51G-4. The illuminating device 51G-4 ′ enters light from the right side of the half mirror 17, whereas the illuminating device 51G-4 ′ enters light from the back side of the half mirror 17. The illumination device 51G-4 ′ includes a polarization conversion device 13 ′ instead of the polarization conversion device 13. The polarization conversion device 13 ′ has the same configuration as the polarization conversion device 16. The green light emitted from the LED 11 is incident on the side surface of the polarization conversion device 13 ′ via the rod integrator 12, and is aligned with the S-polarized light by the polarization conversion device 13 ′.

  In the projection display apparatus shown in FIG. 1 to FIG. 5, all the liquid crystal display panels 1 for each color are irradiated with S-polarized light. Here, the liquid crystal display panel includes a parallel type in which the light transmission axes of the incident side polarizing plate and the outgoing side polarizing plate are orthogonal to each other and a parallel type. By aligning the liquid crystal display panel 1 for each color in either type, the polarization direction of each color image light is aligned. Of course, the polarization directions of the respective color image lights may not be aligned. In this case, the phase plate in the polarization conversion device 16 and the phase plate in the polarization conversion device 13 ′ are unnecessary. Even if both types are mixed, the polarization direction of each color image light can be made uniform by setting the polarization direction of the emitted light in the illumination device to a predetermined polarization direction.

  FIG. 8 is an explanatory view showing another example of the projection display apparatus of the present invention. The difference from the projection display apparatus shown in FIG. 1 is that polarization beam splitters (polarized light combining means) 21 and 21 are provided instead of the dichroic prisms 2RG and 2BG. In addition, the illumination devices 51G-1 and 51G-2 include a polarization conversion device 13A that aligns light with P-polarized light instead of the polarization conversion device 13, and the first green image light and the second green image light are provided. S-polarized light is used. Red image light and blue image light are P-polarized light. As a result, the first green image light and the red image light are combined due to the polarization dependency, and the second green image light and the blue image light are combined due to the polarization dependency. With such a configuration, since the polarization beam splitters 21 and 21 are provided instead of the dichroic prisms 2RG and 2BG, it is possible to avoid the color light cut that occurs when the dichroic prism is used and to improve the light utilization efficiency.

  In the configuration example shown in FIG. 8, narrowband phase difference plates 22A and 22B for converting the polarization direction of only light in a predetermined wavelength band by 90 ° are provided on the light exit side of the polarization beam splitters 21 and 21. The narrow band phase difference plates 22A and 22B may convert the polarization direction by 90 ° only for light in the green wavelength band, for example. Alternatively, the narrow band phase difference plate 22A may convert the polarization direction of the red wavelength band by 90 °, and the narrow band phase difference plate 22B may convert the polarization direction of the blue wavelength band by 90 °. Of course, when it is not necessary to align the polarization direction of each color image light, a configuration without a narrow-band phase difference plate can be adopted. The same applies to the following configuration examples.

  FIG. 9 is an explanatory view showing another example of the projection display apparatus of the present invention. The difference from the projection display apparatus shown in FIG. 2 is that polarization beam splitters 21 and 21 are provided instead of the dichroic prisms 2GR and 2GB. In addition, the illumination devices 51R and 51B include a polarization conversion device 13A that aligns the light with the P-polarized light instead of the polarization conversion device 13, so that the red video light and the blue video light become S-polarized light. Yes. The first green image light and the second green image light are P-polarized light. As a result, the first green image light and the red image light are combined due to the polarization dependency, and the second green image light and the blue image light are combined due to the polarization dependency.

  FIG. 10 is an explanatory view showing another example of the projection display apparatus of the present invention. A difference from the projection display apparatus shown in FIG. 9 is that an illuminating device 51G-3 ′ is provided instead of the above-described illuminating device 51G-3. The illumination device 51G-3 splits the light incident from the side surface of the polarization conversion device 16 by polarization dependence, whereas the illumination device 51G-3 ′ used in this configuration is incident from the back side of the polarization conversion device 16A. The light is split by polarization dependence and aligned in the S polarization direction. The polarization conversion device 16A includes a phase plate 16a on the light output side of the polarization beam splitter on the front stage side so that the light is aligned in the S polarization direction.

  FIG. 11 is an explanatory view showing another example of the projection display apparatus of the present invention. The difference from the projection display apparatus shown in FIG. 4 is that polarization beam splitters 21 and 21 are provided instead of the dichroic prisms 2GR and 2GB. In addition, the illumination devices 51R and 51B include a polarization conversion device 13A that aligns the light with the P-polarized light instead of the polarization conversion device 13, so that the red video light and the blue video light become S-polarized light. Yes. The first green image light and the second green image light are P-polarized light. As a result, the first green image light and the red image light are combined due to the polarization dependency, and the second green image light and the blue image light are combined due to the polarization dependency.

  FIG. 12 is an explanatory view showing another example of the projection display apparatus of the present invention. The difference from the projection display apparatus shown in FIG. 11 is that an illumination device 51G-4 ′ is provided instead of the illumination device 51G-4. The illuminating device 51G-4 ′ enters light from the right side of the half mirror 17, whereas the illuminating device 51G-4 ′ enters light from the back side of the half mirror 17. The illumination device 51G-4 ′ includes a polarization conversion device 13 ′ instead of the polarization conversion device 13. The polarization conversion device 13 ′ has the same configuration as the polarization conversion device 16. The green light emitted from the LED 11 is incident on the side surface of the polarization conversion device 13 ′ via the rod integrator 12, and is aligned with the S-polarized light by the polarization conversion device 13 ′.

  In the above description, two green video lights are generated assuming that the amount of green light is insufficient from the viewpoint of white balance. However, the present invention is not limited to this, and the amount of light of other colors may be insufficient. For example, the insufficient color light image light may be generated.

  In the above description, a dichroic prism (which may be a dichroic mirror) is used for both the combination of the first green image light and the red image light and the combination of the second green image light and the blue image light in the two projection systems. Although a configuration example using a polarization beam splitter is shown in both the configuration example and the above, a dichroic prism (may be a dichroic mirror) is used for color image light synthesis in one projection system, and color image light synthesis in another projection system is used. A configuration using a polarizing beam splitter can also be adopted. In addition to these dichroic prisms (which may be dichroic mirrors) and polarizing beam splitters, if an optical element that synthesizes two image lights is provided, the projection type image display of the present application using such an optical element as a synthesis means An apparatus can also be constructed.

It is explanatory drawing which showed the projection type video display apparatus of embodiment of this invention. It is explanatory drawing which showed the other example of the projection type video display apparatus of embodiment of this invention. It is explanatory drawing which showed the other example of the projection type video display apparatus of embodiment of this invention. It is explanatory drawing which showed the other example of the projection type video display apparatus of embodiment of this invention. It is explanatory drawing which showed the other example of the projection type video display apparatus of embodiment of this invention. It is explanatory drawing explaining reflection (cut) of each color light by a cross dichroic prism. It is explanatory drawing explaining the green light cut by a cross dichroic prism. It is explanatory drawing which showed the projection type video display apparatus of embodiment of this invention. It is explanatory drawing which showed the other example of the projection type video display apparatus of embodiment of this invention. It is explanatory drawing which showed the other example of the projection type video display apparatus of embodiment of this invention. It is explanatory drawing which showed the other example of the projection type video display apparatus of embodiment of this invention. It is explanatory drawing which showed the other example of the projection type video display apparatus of embodiment of this invention. It is the graph which showed the comparison of light quantity. It is the reference figure which showed the projection type video display apparatus using the cross dichroic prism. It is the reference figure which showed the projection type video display apparatus using the cross dichroic prism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel 2BG, 2GB, 2RB, 2BR Dichroic prism 3 Projection lens 11 LED
12, 12A Tapered rod integrator 15 Cuboid rod integrator 21 Polarizing beam splitter (polarized light combining means)
51 Lighting equipment

Claims (20)

First video light generation means for generating first color video light, second video light generation means for generating second color video light, and second color light using two light valves. Three first image light generating means for generating one, and first dichroic combining means for combining the first color image light and one of the third color image light using wavelength selectivity of light, Wavelength selectivity of first projection means for projecting composite image light emitted from the first dichroic composition means, and one of the second color image light and the third color image light. A projection-type image display device comprising: second dichroic combining means for combining using the first and second projecting means for projecting composite image light emitted from the second dichroic combining means. 2. The projection image display apparatus according to claim 1, wherein the third image light generating means includes two independent illumination systems that respectively irradiate each light valve with the third color light. Type image display device. 3. The projection display apparatus according to claim 2, wherein each dichroic combining unit is configured to reflect the third color light. 2. The projection image display device according to claim 1, wherein the third image light generating unit divides light emitted from the illumination system by irradiating a third color light, and divides each light into the light. A projection-type image display apparatus comprising: a spectroscopic unit that leads to two light valves. 5. The projection display apparatus according to claim 4, wherein the spectroscopic means includes two polarization beam splitters or one polarization beam splitter and a reflection member. 6. The projection display apparatus according to claim 5, wherein a phase difference plate is provided so as to align the polarization direction of the light emitted from the spectroscopic means. 5. The projection display apparatus according to claim 4, wherein the spectroscopic means includes a half mirror. 8. The projection type image display device according to claim 1, wherein each color image light emitted from each image light generating means has the same polarization direction. Video display device. First image light generating means for generating first color image light that is predetermined polarized light, second video light generating means for generating second color image light that is predetermined polarized light, and first light that is predetermined polarized light. A third image light generating means for generating two image lights of three colors using two light valves; and polarization of the first color image light and one of the third color image lights. First polarized light combining means for combining using dependency, first projection means for projecting the combined image light emitted from the first polarized light combining means, the second color image light and the third color light Second polarized light synthesizing means for synthesizing another one of the image lights using the polarization dependence of the light, second projection means for projecting the synthesized image light emitted from the second polarized light synthesizing means, A projection-type image display apparatus comprising: 10. The projection type image display device according to claim 9, wherein the third image light generating means includes two independent illumination systems that respectively irradiate each light valve with the third color light. Type image display device. 10. The projection image display device according to claim 9, wherein the third image light generating means divides the light emitted from the illumination system by irradiating a third color light, and divides each light into the light. A projection-type image display apparatus comprising: a spectroscopic unit that leads to two light valves. 10. The projection display apparatus according to claim 9, wherein the spectroscopic means includes two polarization beam splitters or one polarization beam splitter and a reflection member. 13. The projection display apparatus according to claim 12, further comprising a phase difference plate so as to align the polarization direction of light emitted from the spectroscopic means. 12. The projection display apparatus according to claim 11, wherein the spectroscopic means includes a half mirror. 14. The projection display apparatus according to claim 8, wherein the polarization directions of the two color image lights emitted from the first polarized light combining unit and the second polarized light combining unit are the same. Thus, a projection-type image display device comprising a narrow-band phase difference plate on the light exit side of each polarized light combining means. First video light generation means for generating first color video light, second video light generation means for generating second color video light, and second color light using two light valves. Third image light generating means for generating, first combining means for combining the first color image light and one of the third color image lights, and a composition emitted from the first combining means. The first projection means for projecting image light, the second composition means for synthesizing the second color image light and the other one of the third color image light, and the second composition means. And a second projection means for projecting the synthesized image light. 17. The projection type image display device according to claim 16, wherein the third image light generating means includes two independent illumination systems that respectively irradiate each light valve with the third color light. Type image display device. 17. The projection type image display device according to claim 16, wherein the third image light generating means divides light emitted from the illumination system by irradiating a third color light, and divides each light into the light. A projection-type image display apparatus comprising: a spectroscopic unit that leads to two light valves. 19. The projection display apparatus according to claim 1, wherein the third image light generating unit that generates two image lights of the third color has a relationship of interpolating between pixels. A projection-type image display apparatus that generates three third-color image lights. 17. The projection display apparatus according to claim 1, wherein the third color is green.

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