JP2000330073A - Projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a device by arranging each constituting element so that each color light emitted from a color light separation optical system is made incident on a corresponding emitting direction control type optical modulator and that each color light reflected is made incident on a color light synthesizing system. SOLUTION: A color light separation prism 200 and a color light synthesizing prism 400 are arranged adjacently such that the intersecting axis of the red color light reflection surface 402R and the blue color light reflection surface 402B of the synthesizing prism 400 forms roughly a straight line with the intersecting axis 202c of the similar red and blue reflection surfaces 202R, 202B of the separation prism 200. In addition, positional relations are adjusted for a lighting optical system 100 and DMD 300R, 300G and 300B for each color light with respect to the separation prism 200 and the synthesizing prism 400 such that each color light separated by the prism 200 is made incident on each corresponding DMD 300R, 300G and 300B and the each color light emitted from the DMD 300R, 300G and 300B for each color light is made incident on the prism 400.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a projection display device for projecting and displaying an image.

[0002]

2. Description of the Related Art An electro-optical device called a light modulator is used for a projection display device. This light modulation device modulates illumination light in accordance with image data, and emits the modulated light as light (image light) representing an image.
As an example of the light modulation device, a digital micromirror device (registered trademark of Texas Instruments (TI), Inc., hereinafter, referred to as “DMD”) can be given.

[0003] The DMD has a plurality of micro mirrors corresponding to a plurality of pixels constituting an image. The inclination of each of the plurality of micromirrors changes according to the image data, and reflects light according to the inclination of each micromirror.
Of the light reflected by each micromirror, light reflected in a predetermined direction is used as light representing an image. That is, the DMD modulates the illumination light by controlling the emission direction of the irradiated light in accordance with the image data, and uses the modulated light as light representing an image (an emission direction control type). Light modulation device).

FIG. 25 is a schematic plan view showing an example of a conventional projection display device. This projection display device 6000
Illumination optical system 6100 and TIR (Total Internal Refle
ction) Prism 6200 and color light separating / combining prism 6
300 and three DMDs 6400R, 6400G, 64
00B and a projection lens 6500.

[0005] The illumination optical system 6100 includes a light source 6110,
A condenser lens 6120 and a reflection mirror 6130 are provided. The light emitted from the light source 6110 is condensed by the condenser lens 6120 and is reflected by the reflection mirror 6.
130, the TIR prism 6200, and the color light separating / combining prism 6300, the DMDs 6400R, 6400G,
It is collected to illuminate 6400B. The light emitted from the condenser lens 6120 is reflected by the reflection mirror 6130
And is incident on the TIR prism 6200. TI
The light that has entered the R prism 6200 is totally reflected inside the prism and enters the color light separation / combination prism 6300.
The light incident on the color light separating / combining prism 6300 is separated into red (R), green (G), and blue (B) light, and the corresponding DMDs 6400R, 6400G, and 64 for each color light.
00B. DMD6400R, 64 for each color light
The light reflected from 00G and 6400B is recombined by the color light separation / combination prism 6300, passes through the TIR prism 6200, and enters the projection lens 6500. The light incident on the projection lens 6500 is projected and a color image is displayed. As you can see from the above explanation,
The TIR prism 6200 is a reflection / transmission prism having a function of totally reflecting light when light first enters and transmitting light when the light enters again.

[0006]

When an emission direction control type optical modulator such as a DMD is used, there is a case where the irradiation angle of the illumination light applied to the DMD is restricted. In order to satisfy this restriction, the illumination light is changed to a DMD 6400 for each color light.
R, 6400G, and 6400B, and a TI for guiding light emitted from these to the projection lens 6500.
In many cases, a reflection / transmission prism such as the R prism 6200 is used.

In many cases, the size of such a reflection / transmission prism is large in order to satisfy the above restrictions, and there has been a problem that it is difficult to reduce the size of the conventional projection display device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a technique for reducing the size of a projection display device using a light emitting device with an emission direction control such as a DMD.

[0009]

Means for Solving the Problems and Actions and Effects Thereof To solve the above-mentioned problems, a projection type display device of the present invention comprises:
An illumination optical system that emits illumination light, a color light separation optical system that separates light emitted from the illumination optical system into three color lights,
Three light modulators provided for each of the three color lights;
A light modulating device for each color light, comprising: a color light synthesizing optical system for synthesizing three color lights emitted from the three light modulating devices; and a projection optical system for projecting the light synthesized by the color light synthesizing optical system. An emission direction control type light modulation device that modulates each color light by controlling the emission direction of each color light reflected on the light irradiation surface of the light modulation device for each color light according to a given signal. Wherein the color light separation optical system reflects a first color light of the three color lights and transmits a second color light and a third color light, and a first color light reflection surface that reflects the second color light. And a second color light reflecting surface that transmits the third color light has a first color selective crossing reflecting surface that crosses in a substantially X-shape, and the color light combining optical system includes the three emission directions. The first color light is reflected from the three color lights emitted from the control type light modulation device, and the second and third color lights are reflected. And a third color light reflecting surface that transmits, second
And a fourth color light reflecting surface that reflects the first color light and transmits the first and third color light has a second color selective crossing reflection surface that intersects substantially in an X-shape, and the color light separation optical system And the color light combining optical system are disposed adjacent to each other such that the intersection axes of the first and second color-selective cross-reflection surfaces are positioned substantially in the same straight line. The two emission direction control light modulation devices, the color light separation optical system, and the color light synthesis optical system are configured such that each color light emitted from the color light separation optical system is incident on the corresponding emission direction control light modulation device, Each of the effective color lights reflected by the light emission direction control type light modulation device is disposed so as to be incident on the color light combining optical system.

In the projection display device of the present invention, the color light separating optical system and the color light combining optical system are arranged adjacent to each other, and each color light emitted from the color light separating optical system corresponds to the emission direction control type. By arranging each component so that each color light incident on the light modulation device and reflected by the emission direction control type light modulation device for each color light is incident on the color light synthesis optical system,
The reflection / transmission type prism provided in the conventional projection display device is omitted. Thus, the size of the projection display device can be reduced.

In the above-mentioned projection type display device, the color light separation optical system emits one light incident surface on which light emitted from the illumination optical system enters, and emits three color lights separated by the color light separation optical system. And the three color light exit surfaces are formed so that the one light incident surface and the three color light exit surfaces are substantially perpendicular to the central axis of light passing through the respective surfaces. Is preferred.

Further, the color light combining optical system includes three color light incidence surfaces on which the three color lights emitted from the three emission direction control type light modulators are incident, and a light combined by the color light combining optical system. One synthetic light emitting surface for emitting light,
It is preferable that the three color light incidence surfaces and the one combined light emission surface are formed so as to be substantially perpendicular to the central axis of light passing through the respective surfaces.

According to the above arrangement, the color light separation optical system accurately separates the light emitted from the illumination optical system into three color lights, and separates the separated color lights in the direction of the corresponding emission direction control type light modulator. Can be injected. Further, the color light combining optical system can accurately combine the color lights emitted from the emission direction control type optical modulators for the respective color lights and emit the combined light in the direction of the projection optical system.

In the above-mentioned projection type display device, the emission direction control type light modulator for each color light has a light irradiation surface having a substantially rectangular outline, and each light irradiation surface is provided with the light irradiation surface. The sides of the surface are arranged so as to be inclined with respect to a predetermined reference plane, and each color light emitted from the emission direction control type optical modulator for each color light is on an optical path until reaching the projection optical system. It is preferable that the positional relationship between the emission direction control type light modulation device for each color light and the color light combining optical system is set so that the number of times of reflection is uniform with an odd number or an even number.

[0015] In this way, the same type of emission direction control type light modulator for each color light can be used.

In the above-mentioned projection type display device, the illumination optical system, the color light separation optical system, the three emission direction control type light modulation devices, the color light combining optical system, and the projection optical system are preferably And the emission direction control type light modulation device for each color light has a light irradiation surface having a substantially rectangular outline, and each light irradiation surface is the light irradiation surface. Are disposed so as to be inclined with respect to the housing plane of the housing, and the projection display device further includes a substantially rectangular image projected when the projection display device is used. It is preferable to provide an inclined support for inclining and supporting the housing so that the erecting member is erected.

According to the above configuration, an upright image can be displayed when the projection display device is used.
In addition, when the projection display device is not used, by disposing the housing without tilting, the arrangement space of the projection display device can be reduced. This can save space when the projection display device is not used.

[0018]

DETAILED DESCRIPTION OF THE INVENTION First Embodiment FIG. 1 is a schematic perspective view showing a main part of an optical system in a projection display apparatus 1000 according to a first embodiment of the present invention. 2 is a schematic plan view, FIG. 3 is a schematic front view, and FIG. 4 is a schematic right side view. In these figures, two axes parallel to the reference plane P among three axes orthogonal to each other are x and z,
Let the vertical axis be y. As shown in FIG. 1, the projection display apparatus 1000 includes an illumination optical system 100, a color light separation prism 200, and three DMDs 300R, 300G, and 30.
0B, the color light combining prism 400, and the projection lens 500
And Further, condenser lenses 250R, 250G, and 25 are provided on the optical path between the color light separating prism 200 and each of the DMDs 300R, 300G, and 300B.
0B, and a λ / 2 phase difference plate 260 (FIG. 4) on the optical path between the DMD 300G for green light and the color light combining prism 400.

FIG. 5 is an explanatory diagram showing the configuration of the illumination optical system 100. The illumination optical system 100 includes a light source 110 and a first light source.
Lens array 120 and second lens array 130
, A polarization conversion optical system 140, and a superposition lens 150. In this figure, for ease of explanation, components arranged on the optical path from the superimposing lens 150 to the illumination target 300 are omitted, and the optical path is shown linearly. Here, the illumination target 300 is a DMD 300R,
It corresponds to 300G and 300B. The axes orthogonal to each other are x, y, and z, and the light emission direction as viewed from the light source 110 is z.
And It is assumed that a direction perpendicular to the paper surface is y, and a direction parallel to the paper surface is x. The light source 110, the first lens array 120, the second lens array 130, the polarization conversion optical system 140, and the superimposing lens 150
0 center optical axis (hereinafter also referred to as “illumination optical axis”) 100L
It is arranged along C. The first and second lens arrays 120 and 130 are arranged such that their respective central axes substantially coincide with the central optical axis (hereinafter, also referred to as “light source optical axis”) 110LC of the light source 110. Polarization conversion optical system 14
0 and the superimposing lens 150 are arranged such that their respective central axes substantially coincide with the illumination optical axis 100LC. The light source optical axis 110LC is displaced parallel to the illumination optical axis 100LC in the -x direction by a predetermined displacement Dp. This shift amount Dp
Will be described later.

The light source 110 has a light source lamp 112 and a concave mirror 114. The light source lamp 112 is a radiation light source that emits a radial light beam. As the light source lamp 112, a high-pressure discharge lamp such as a metal halide lamp or a high-pressure mercury lamp is used. The concave mirror 114 is a light source lamp 112
Is reflected and emitted in the direction of the first lens array 120. As the concave mirror 114, a parabolic mirror or an elliptical mirror is used.

FIG. 6 is a perspective view showing the appearance of the first lens array 120. The first lens array 120 has a configuration in which small lenses 122 having a substantially rectangular outline are arranged in a matrix of M rows and N columns. In this example, M
= 5, N = 4. The second lens array 130 also has a configuration in which the small lenses 133 are arranged in a matrix of M rows and N columns so as to correspond to the small lenses 122 of the first lens array 120. Each of the small lenses 122 of the first lens array 120 divides the light beam emitted from the light source 110 (FIG. 3) into a plurality of (ie, M × N) partial light beams, and divides each of the partial light beams into a second light beam. Has a function of condensing light so as to form an image near each corresponding small lens 133 of the lens array 130. Each small lens 133 of the second lens array 130 has a function of condensing each partial light beam so as to effectively enter a polarization conversion optical system 140 described later.

Each small lens 1 of the first lens array 120
The outer shape of 22 viewed from the z direction is set so as to be substantially similar to the contour shape of the light irradiation surface (the region where the illumination light is modulated according to the image data) of the DMDs 300R, 300G, and 300B as the illumination target 300. Have been. For example, DM
If the aspect ratio (the ratio between the horizontal and vertical dimensions) of the light irradiation surface of D is 4: 3, the aspect ratio of each small lens 122 is also set to 4: 3.

FIG. 7 is an explanatory diagram showing the configuration and function of the polarization conversion optical system 140. FIG. 7A is a perspective view of the polarization conversion optical system 140, and FIG. 7B is an enlarged plan view showing a part thereof. The polarization conversion optical system 140
Light shielding plate 142 and polarizing beam splitter array 144
And a selective phase difference plate 146. The polarization beam splitter array 144 has a shape in which a plurality of columnar translucent plate members 144a each having a parallelogram cross section are alternately bonded. Polarized light separating films 144b and reflecting films 144c are alternately formed on the interface of the light transmitting plate 144a. In addition, the polarizing beam splitter array 144 is formed by laminating a plurality of glass sheets on which these films are formed so that the polarization separating films 144b and the reflecting films 144c are alternately arranged, and cuts obliquely at a predetermined angle. By doing so, it can be produced. Polarization separation film 144
b is a dielectric multilayer film, and the reflection film 144c can be formed of a dielectric multilayer film or an aluminum film.

As shown in FIG. 7A, the light shielding plate 142 has a plurality of light shielding surfaces 142a and a plurality of opening surfaces 142b arranged in a stripe pattern. The arrangement of the light-shielding surface 142a and the opening surface 142b is such that the partial light beam emitted from the second lens array 130 enters only the polarization splitting film 144b of the polarization beam splitter array 144 and does not enter the reflection film 144c. Is set to As the light-shielding plate 142, a light-shielding film (for example, a chromium film, an aluminum film, and a dielectric multilayer film) partially formed on a flat transparent body (for example, a glass plate), or an aluminum plate, for example, is used. A light-shielding flat plate having an opening provided therein can be used.

A non-polarized light beam (shown by a solid line in FIG. 7B) that has passed through the opening surface 142b of the light-shielding plate 142 is incident on the polarization separation film 144b of the polarization beam splitter array 144, and has two types of straight lines. Polarized light (s-polarized light and p-polarized light)
(Indicated by a dashed line in FIG. 7B). Most of the p-polarized light passes through the polarization splitting film 144b as it is. On the other hand, most of the s-polarized light is
b, the light is further reflected by the reflection film 144c, and is substantially parallel to the p-polarized light that has passed through the polarization separation film 144b as it is.
Or the width of the reflection film 144c in the x-axis direction). Polarization separation film 144b of selective retardation plate 146
.Lambda. / 2 retardation layer 146a
Is formed, and the λ / 2 retardation layer is not formed on the exit surface of the light reflected by the reflection film 144c, and the opening layer 146b is formed. Therefore, the polarization separation film 144b
Is converted into s-polarized light by the λ / 2 retardation layer 146a and emitted from the selective retardation plate 146. On the other hand, the s-polarized light reflected by the reflection film 144c is
Since the polarization state does not change at all when passing through the aperture layer 146b, the s-polarized light is emitted from the selective retardation plate 146 as it is. As a result, most of the non-polarized light that has entered the polarization conversion optical system 140 is converted into s-polarized light and emitted.
Of course, by forming the λ / 2 retardation layer 146a of the selective retardation plate 146 only on the exit surface of the light reflected by the reflection film 144c, almost all light beams can be converted into p-polarized light and emitted. . Also, the polarization separation film 144b
May transmit almost s-polarized light and reflect almost p-polarized light.

As can be seen from FIG. 7B, the center of the two s-polarized lights emitted from the polarization conversion optical system 140 (the center of the two s-polarized lights) is the incident non-polarized light (s
(Polarized light + p-polarized light) in the x direction.
This shift amount is equal to half of the width Wp of the λ / 2 retardation layer 146a (that is, the width of the polarization separation film 144b along the x-axis direction). For this reason, as shown in FIG.
0LC is a distance D equal to Wp / 2 from the illumination optical axis LC.
It is set at a position shifted by p.

A plurality of partial light beams emitted from the polarization conversion optical system 140 are superimposed on the illumination target 300 by the superimposing action of the superimposing lens 150. As can be understood from the above description, the two lens arrays 120 and 130 and the superimposing lens 150 constitute a so-called integrator optical system. Accordingly, the illumination optical system 100 can uniformly illuminate the light irradiation surfaces of the DMDs 300R, 300G, and 300B, which are the illumination targets 300, via the color light separation prism 200. When the concave mirror 114 of the light source 110 is an elliptical mirror, the superimposing lens 150 can be omitted.

As shown in FIG. 1, the illumination optical system 100 includes a light irradiation surface 3 of the DMDs 300R, 300G, and 300B.
Numeral 02 is rotationally arranged so as to be inclined with respect to an xz plane which is a reference plane, with a center axis 302c perpendicular to the light irradiation surface 302 as a center. For this reason, the projection display device 1
Actually, the illumination optical system 100 of the first lens array 120 effectively illuminates the light irradiation surfaces 302 of the DMDs 300R, 300G, and 300B with the partial light beams emitted from the small lenses 122 of the first lens array 120. , Illumination optical axis 100L
It is rotated and arranged about C at an angle corresponding to the inclination of the light irradiation surface 302.

The illumination optical system 100 includes an illumination optical axis 10.
OLC is parallel to the yz plane as shown in FIG. 2 and passes through an intersection axis 202c at which a red light reflecting surface 202R and a blue light reflecting surface 202B intersect, as described later, and an xz plane as shown in FIG. Are arranged so as to face obliquely upward at an angle of about 25 degrees. Hereinafter, the xz plane is referred to as a “reference plane P”. Further, in the following description, when the traveling direction of light is described, in order to facilitate the description,
A description will be given focusing on the central ray of light.

The light emitted from the illumination optical system 100 enters the color light separation prism 200 from the light incident surface 204 of the color light separation prism 200 (FIGS. 1 to 4). The color light separating prism 200 converts the light emitted from the illumination optical system 100 into
It has a function as a color light separation optical system for separating into three color light components of red, green and blue. FIG. 8 is an explanatory diagram showing the structure of the color light separation prism 200. FIG. 8 (A)
Shows a perspective view of the front facing the side facing the illumination optical system 100, viewed from obliquely right above the front. FIG. 8B shows a front view thereof, and FIGS. 8C and 8D show a plan view and a right side view thereof. Color light separation prism 2
00 is a heptahedron having ten vertices a to j.

The side surface abfe is a light incident surface 204 on which light emitted from the illumination optical system 100 is incident. For this reason, as shown in FIG. 8D, the light incident surface 204 has an obtuse angle of about 125 degrees with respect to the reference plane P so as to be a surface perpendicular to the illumination optical axis 100LC of the illumination optical system 100. Is formed. Thereby, the light incident surface 20
The light incident from No. 4 can be made to travel straight after it is incident.

FIG. 8 shows the inside of the color light separating prism 200.
As shown in (C), the red light reflecting surface 202R and the blue light reflecting surface 202B are formed in a substantially X shape. The red light reflecting surface 202R and the blue light reflecting surface 202B are formed such that the cross axis 202c intersecting them is perpendicular to the reference plane P as shown in FIGS. 8B and 8D. .
Further, the red light reflecting surface 202R and the blue light reflecting surface 202
8B, each has an angle of about 45 degrees with respect to a plane including the illumination optical axis 100LC of the illumination optical system 100 and perpendicular to the reference plane P, as shown in FIG. 8C. Red light reflecting surface 2
02R is formed with a dielectric multilayer film (red reflection film) that reflects a red light component and transmits a color light component (green light component and blue light component) having a shorter wavelength than the red light component. The blue light reflecting surface 202B reflects a blue light component and emits a color light component (green light component and red light component) having a longer wavelength than the blue light.
A dielectric multilayer film (blue reflective film) that transmits light is formed.

The green light component of the light incident from the light incident surface 204 is reflected by the red light reflecting surface 202R and the blue light reflecting surface 2R.
02B. At this time, the central axis of the green light component is
As shown in FIGS. 8C and 8D, it is directed obliquely upward by about 25 degrees with respect to the reference plane P. The red light component is reflected by the red light reflection surface 202R, and as shown in FIGS. 8B and 8C, the central axis of the red light component is substantially perpendicular to the illumination optical axis 100LC and at the same time with respect to the reference plane P. About 25 degrees obliquely upward. The blue light component is the blue light reflecting surface 2
02B, and as shown in FIGS. 8B and 8C,
The central axis of the blue light component is reflected substantially perpendicularly to the illumination optical axis 100LC and obliquely upward by about 25 degrees with respect to the reference plane P.

The red light, the green light and the blue light separated by the red light reflecting surface 202R and the blue light reflecting surface 202B respectively correspond to the side surfaces daegj, cdji, and b.
cihf. Therefore, the side daeg
j is the red light exit surface 206R, the side surface cdji is the green light exit surface 206G, and the side surface bcihf is the blue light exit surface 206B. Each of these color light emission surfaces 205R, 2R
06G and 206B are the light emitting surfaces 206R and 206 of the respective colors.
Each color light emitted from G and 206B is formed so as to proceed straight after being emitted. Specifically, FIG.
As shown in (B) and (D), about 6
It is formed to have an acute angle of 5 degrees. Accordingly, each color light emitted from each color light emission surface 206R, 206G, 206B can be made to travel straight as it is and emitted upward at an angle of about 25 degrees with respect to the reference plane P.

The bottom surface abcd is parallel to the central axis of the light incident from the light incident surface 204 (parallel to the illumination optical axis 100LC) and the central axis of each color light separated by the red light reflecting surface 202R and the blue light reflecting surface 202B. Plane. Also, the side efh
g is a plane in which the ridge lines ef and gh are parallel to the ridge line ab and perpendicular to the reference plane P. It should be noted that the surfaces (bottom surface abcd, top surface ghij,
The inclination of the side surface efhg) can be set to an arbitrary inclination other than the above.

FIGS. 9 and 10 show the color light separating prism 2.
It is explanatory drawing shown about the method of manufacturing 00. First,
A cross dichroic prism 2000 as shown in FIG. 9A is prepared. The cross dichroic prism 200O is a cubic or cuboid prism having four substantially right-angled prisms joined at right angles to each other and having a substantially square planar shape. Four vertices D,
A red reflecting film is formed on the diagonal surface DBHJ composed of B, H, and J, and the diagonal surface DBHJ corresponds to the red light reflecting surface 202R of the color light separation prism 200. On a diagonal plane ACIG composed of four vertices A, C, I, and G, a blue light reflection film is formed.
G corresponds to the blue light reflecting surface 202B of the color light separating prism 200.

Next, as shown in FIG. 9B, this cross dichroic prism 200O is
By cutting at L1, SL2, SL3 and SL4,
The color light separation prism 200A shown in FIG. 9C is manufactured.

The cut surface SL1 is a surface having an inclination of about 65 degrees toward the side surface ABHG with respect to the bottom surface ABCD and dividing the bottom surface ABCD on a side closer to the ridge line AB than the ridge line CD.
The cutting plane SL2 is a plane parallel to the cutting plane SL1, and is a plane passing near the vertices C and D of the cross dichroic prism 200O. The cut surface SL3 passes near the vertices B and C of the cross dichroic prism 200O, and
The surface has an inclination of about 65 degrees toward the side surface DAGJ with respect to the BCD. The cut surface SL4 passes near the vertices A and D of the cross dichroic prism 200O, and the bottom surface ABC
The surface has an inclination of about 65 degrees toward the side surface BCIH with respect to D.

Next, as shown in FIGS. 10A and 10B, the upper surface G 'of the color light separating prism 200A of FIG. 9C.
Cutting is performed so as to divide the side surface ABH'G 'at a cutting surface SL5 perpendicular to the H'I'J' and the bottom surface ABCD and parallel to the ridge line AB. Also, the color light separation prism 200A
Passes near the vertices A and B with respect to the bottom surface ABCD of
The BCD is cut along a cutting plane SL6 having an inclination of about 25 degrees toward the upper surface G'H'I'J 'with respect to the BCD. As described above, the color light separation prism 200 shown in FIG. 8 can be manufactured.

Note that the vertices A, B, C ', D', E, F, G ', H', shown in FIG. 9 (C) and FIG.
I ′ and J ′ correspond to the vertices a, b, c, d, e, f, g, h, i, and j of the color light separation prism 200 shown in FIG.

The side A of the color light separating prism 200A
BH'G 'is a surface formed by the cut surface SL1, and has a slope of about 125 degrees with respect to the bottom surface ABCD. Therefore, the side surface ABH'G 'is a surface corresponding to the light incident surface 204 of the color light separation prism 200 shown in FIG. Side CDJ 'of color light separating prism 200A
I ′ is a surface formed by the cut surface SL2, and has a tilt of about 65 degrees with respect to the bottom surface ABCD. The side surface DAG'J 'and the side surface BCI'H' are surfaces formed by the cut surface SL3 and the cut surface SL4, and each have a tilt of about 65 degrees with respect to the bottom surface ABCD. Therefore, side surface DAG'J ', side surface CDJ'I', and side surface BCI'H 'are each shown in FIG.
The red light exit surface 206 of the color light separation prism 200 shown in FIG.
R, green light exit surface 206G, and blue light exit surface 206B
This is the aspect corresponding to. On the other hand, the color light separation prism 200
The surface efhj, abcd (FIG. 8A) of the color light separating prism 200A is formed by cutting the color light separating prism 200A as shown in FIG.
This is a surface formed by cutting at L5 and SL6. Since these surfaces efhj and abcd are surfaces through which effective light does not pass as described above, FIG.
As shown in FIG. 5, the surface is formed by cutting unnecessary portions in the color light separating prism 200A. Therefore, these surfaces efhj and abcd do not always need to be formed. Therefore, instead of the color light separation prism 200 of FIG. 8, 200A of FIG. 9C may be used as it is.

The manufacturing method shown in FIG. 9 is an example, and the present invention is not limited to this. Any method can be used as long as the color light separating prisms 200 and 200A having the shapes shown in FIGS. 8 and 9C can be manufactured. Such a method may be used.

Each color light emitted from the color light separation prism 200 is supplied to the corresponding condenser lens 250.
DMD 30 for each color light via R, 250G, 250B
It is incident on 0R, 300G, and 300B (FIGS. 1 to 4).
The condenser lenses 250R, 250G, 250B are
It is provided to convert a plurality of incident partial light beams into parallel light parallel to each principal ray.

DMD 300R, 300G, 3 for each color light
00B is located at the center of each light irradiation surface 302 at the corresponding color light exit surface 206R,
It is arranged so that the central axes of the respective color lights emitted from 06G and 206B are incident. The DMDs 300R and 300B for the red light and the blue light are arranged such that a central axis 302c perpendicular to the respective light irradiation surfaces 302 is parallel to the x-axis, and the DMD 300G for the green light has a central axis 3D.
02c is arranged to be parallel to the z-axis. Therefore, each color light emitted from the color light separation prism 200 is associated with the corresponding color light DMD 300R, 300G, 3D.
00B is incident from the bottom toward the top.

FIG. 11 shows DMDs 300R, 3 for each color light.
It is explanatory drawing which shows the light irradiation surface 302 of 00G and 300B. FIG. 11A shows a light irradiation surface 302 of the DMD 300G for green light, and FIG. 11B shows a light irradiation surface 302 of the DMDs 300R and 300B for red light or blue light. Here, in order to facilitate the explanation, the illumination light applied to the light irradiation surface 302 is changed to a center light (incident light) I
It is represented by R. Also, let h be the horizontal axis of the light irradiation surface 302 and v be the vertical axis of the light irradiation surface 302, passing through the position where the illumination light IR is incident on the light irradiation surface 302.

As shown in FIG. 11A, D for green light is used.
The MD 300G is arranged such that the horizontal axis h of the light irradiation surface 302 is inclined approximately 45 degrees clockwise with respect to the reference plane P. The reason why the light irradiation surface 302 of the DMD 300G is arranged to be inclined is as follows.

On the light irradiation surface 302, a plurality of micromirrors 304 having a substantially square contour are formed in a matrix. Each of the micro mirrors 304 forms a diagonal line connecting the lower left vertex CP1 and the upper right vertex CP2 with the rotation axis 30.
4c is formed to be rotatable in a predetermined rotation range (± θr). Note that, when viewed from the direction of the arrow in FIG.
The angle along the clockwise direction is defined as positive. Each micro mirror 304 corresponds to each pixel constituting an image.

In order to simplify the structure of the apparatus, the illumination light is set so that the plane including the light incident on each micromirror 304 and the reflected light is perpendicular to the rotation axis 304c of each micromirror 304. It is preferable to make IR incident on the light irradiation surface 302. Specifically, DMD300G for green light
The illumination light IR irradiated to the
The light path of the illumination light IR when projected on a plane parallel to 2 has a predetermined inclination θ with respect to the horizontal axis h of the light irradiation surface 302.
h (about 45 degrees). On the other hand, the green light as the illumination light IR emitted from the color light separation prism 200 is incident on the DMD 300G from the lower side to the upper side as described with reference to FIG. Therefore, in this embodiment, as shown in FIG. 11A, the DMD 300G for green light is
2 is approximately 45 clockwise with respect to the reference plane P.
To the rotation axis 3 of each micromirror 304.
04c is oriented in the left-right direction. This allows the illumination light IR to be incident from below to above while maintaining the inclination θh of the green light as the illumination light IR with respect to the horizontal axis h at about 45 degrees.

Similarly, the DMD 300R for red light and the DMD 300B for blue light are also arranged obliquely with respect to the reference plane P. However, these DMD300R, 3
00B is a light irradiation surface 302 as shown in FIG.
Is about 45 counterclockwise with respect to the reference plane P.
It is arranged so that it inclines. The reason will be described later. DMD 30 for red light and blue light in this case
0R and 300B are DMDs of the type having a diagonal line connecting the lower left vertex CP1 and the upper right vertex CP2 of each micromirror 304 such as the green light DMD 300G shown in FIG. Instead, a type of DMD is used in which a diagonal line connecting the upper left vertex CP3 and the lower right vertex CP4 of each micromirror 304 is the rotation axis 304c.

FIG. 12 shows an optical path in a plane including the light incident on the micromirror 304 and the reflected light when viewed from the direction of the arrows in FIGS. FIG. FIG. 12 shows the illumination light I
The case where R is incident from the bottom to the top is shown. The micromirror 304 is pivotally connected to a plane F (shown by a broken line in FIG. 12) parallel to the light irradiation surface 302.
It rotates about ± θr degrees (θr ≒ 10 degrees) about 04c.
Note that the angle along the clockwise direction is positive. Illumination light IR
Is the normal Fn of the plane F (the light irradiation surface 30
2 (a line parallel to the central axis 302c perpendicular to 2) and enters the micromirror 304 from a direction inclined downward by + θL.

The micromirror 304 is positioned at +
In the case where the illumination light IR is inclined by θr, the illumination light IR
Reflected light RR in a direction inclined by −2 · (θL−θr) from
It is reflected as (+ θr). When the micromirror 304 is tilted by −θr with respect to the plane F, the illumination light I
R is reflected as reflected light RR (−θr) in a direction inclined by −2 · (θL + θr) from the illumination light IR. Thus, the illumination light IR applied to the micromirror 304
Are reflected and emitted in different directions according to the rotation angle of the micro mirror 304.

Here, if the projection lens is arranged in the direction of the reflected light RR (+ θr), the reflected light RR (−θr) becomes invalid light UR, and only the reflected light RR (+ θr) is used as effective light (image light) ER. Can be used. That is, when the micromirror 304 is tilted by + θr, the reflected light RR (+ θr) is projected through the projection lens to realize a bright display, and when the micromirror 304 is tilted by −θr, the reflected light RR ( −θr) can be realized without projecting the same through a projection lens. Intermediate gradations can be realized by a method of controlling the ratio of light and dark display of one pixel in accordance with the gradation during a certain time for drawing an image (a method called pulse width modulation). it can. Note that it is also possible to use the reflected light RR (-θr) as effective light and use the reflected light RR (+ θr) as invalid light. In this case, it is possible to display an image obtained by inverting the brightness of the same image data.

In this embodiment, θL = (2 · θr +
θru), when the micromirror 304 is inclined by + θr with respect to the plane F (the light irradiation surface 302), the reflected light RR (+ θr) becomes the normal Fn (the light irradiation surface 302).
The reflected light RR (+ θr) is used as the effective light ER such that the reflected light RR (+ θr) is directed upward by θru with respect to the axis 302c) perpendicular to the axis 302c. In the present embodiment, θru ≒ 5 degrees, and the effective light ER from the DMDs 300R, 300G, and 300B for each color light is directed upward by about 5 degrees with respect to the central axis 302c perpendicular to the light irradiation surface 302. Are emitted. It should be noted that θru = 0 degrees may be set so that each color light as the effective light ER is emitted in a direction parallel to the central axis 302c perpendicular to the light irradiation surface 302.

DMD 300R, 300G, 3 for each color light
Each color light emitted from 00B enters the color light combining prism 400 from the corresponding incident surface 404R, 404G, 404B (FIGS. 1 to 4).

The color light combining prism 400 has a D light for each color light.
It has a function as a color light combining optical system that combines the color lights emitted from the MDs 300R, 300G, and 300B.
FIG. 13 is an explanatory diagram showing the structure of the color light combining prism 400. FIG. 13A is a perspective view of the side facing the projection lens 500 as viewed from the front and obliquely right above. FIG. 13B shows a front view thereof, and FIG.
(D) shows a plan view and a right side view thereof. The color light splitting prism 200 is a hexahedron having six surfaces formed by eight vertices m to t.

The color light combining prism 400 is arranged so that the color light emitted from the DMDs 300R, 300G, and 300B for each color light enters. Specifically, an intersection axis 402c at which a red light reflecting surface 402R and a blue light reflecting surface 402B, which will be described later, intersects with each other.
Is disposed adjacent to the upper side of the color light separating prism 200 so as to be substantially on the same straight line as the intersection axis 202c where the red light reflecting surface 202R and the blue light reflecting surface 202B intersect (FIGS. 1 to 4). . Also, the color light combining prism 400
Is the upper surface qr as shown in FIGS.
The st and the bottom surface mnop are arranged so as to be parallel to the reference plane P.

Side surface pmqt is DMD300R for red light
Light incidence surface 404R on which red light emitted from
The side surface opts is a green light incident surface 404G on which green light emitted from the green light DMD 300G is incident, and the side surface nosr is a blue light incident surface 404B on which blue light emitted from the blue light DMD 300B is incident. It is.
Each of these color light incident surfaces 404R, 404G, 404B
Is formed so that each of the incident color lights proceeds straight as it is after the incidence. Specifically, each R light incident surface 404
As shown in FIGS. 13B and 13D, R, 404G, and 404B have an acute angle of about 85 degrees with respect to the upper surface qrst so as to be a surface perpendicular to the central axis of each color light. Is formed. Thereby, each color light incident surface 404
The color light entering from R, 404G, and 404B can proceed straight as it is.

The inside of the color light combining prism 400 is shown in FIG.
As shown in FIG. 3 (C), the red light reflecting surface 402R and the blue light reflecting surface 402B are formed in a substantially X shape. The red light reflecting surface 402R and the blue light reflecting surface 402B are arranged such that an intersecting axis 402c is perpendicular to the bottom surface mnop (reference plane P) as shown in FIGS. 13B and 13D. Is formed. Further, the red light reflecting surface 402R and the blue light reflecting surface 402B each have an angle of about 45 degrees with respect to a plane including the central axis of each color light and perpendicular to the reference plane P, as shown in FIG. are doing. On the red light reflecting surface 402R, a dielectric multilayer film (red reflecting film) that reflects a red light component and transmits a color light component (green light component and blue light component) having a shorter wavelength than the red light component is formed. I have.
On the blue light reflecting surface 402B, a dielectric multilayer film (blue reflecting film) that reflects a blue light component and transmits a color light component (green light component and red light component) having a longer wavelength than the blue light is formed.

The green light incident from the green light incident surface 404G is oriented such that the center axis of the green light is directed obliquely upward by 5 degrees with respect to the reference plane P as shown in FIGS. 13 (C) and 13 (D). ,
The light passes through the red light reflecting surface 202R and the blue light reflecting surface 202B. The red light incident from the red light incident surface 404R is
As shown in FIGS. 13B and 13C, the central axis of the red light is substantially perpendicular to the central axis before reflection and is inclined at about 5 degrees with respect to the reference plane P on the red light reflecting surface 402R. The light is reflected upward.

The side surface mnrq is a combined light exit surface 406 from which red light, green light and blue light combined by the red light reflecting surface 402R and the blue light reflecting surface 402B are emitted. The combined light exit surface 406 is formed such that the combined light emitted from the combined light emission surface 406 goes straight as it is after the emission. Specifically, as shown in FIG.
The bottom surface m so as to be perpendicular to the central axis of the combined light
It is formed to have an acute angle of about 85 degrees with respect to nop. Thus, the combined light emitted from the combined light exit surface 406 can be made to travel straight as it is and be emitted obliquely upward by about 5 degrees with respect to the reference plane P.

FIG. 14 is an explanatory diagram showing a method of manufacturing the color light combining prism 400. First, FIG.
A cross dichroic prism 4 as shown in FIG.
Prepare 00O. This cross dichroic prism 400O is a columnar prism of the same type as the cross dichroic prism 200O shown in FIG.

Cross dichroic prism 400O
As shown in FIG. 14B, the four cut surfaces SL7 to
Cut at SL10. The cutting plane SL7 has two vertices T,
W, and about 8 on the side QRVU side with respect to the upper surface TUVW
This is a surface having an inclination of 5 degrees. The cut surface SL8 passes through the two vertices U and V, and the side surface SPWT with respect to the upper surface TUVW.
The surface has an inclination of about 85 degrees on the side. Cutting surface SL9
Is a surface passing through two vertices V and W and having an inclination of about 85 degrees toward the side surface PQUT with respect to the upper surface TUVW. The cutting plane SL10 is a plane that is parallel to the cutting plane SL9 and divides the upper surface TUVW on a side closer to the ridge line TW than the ridge line VW.

By cutting the cross dichroic prism 400O at the four cut surfaces SL7 to SL10, the color light combining prism 400 shown in FIG. 13 can be manufactured. Note that the manufacturing method in FIG. 14 is an example, and the present invention is not limited to this. Any method may be used as long as the color light combining prism 400 having the shape shown in FIG. 13 can be manufactured.

The projection lens 500 includes a color light combining prism 4
It is arranged on the optical path of the combined light emitted from 00 (FIGS. 1 to 4). The projection lens 500 has a function as a projection optical system that projects incident light. The combined light emitted from the color light combining prism 400 is projected by the projection lens 500 to display an image.

FIG. 15 shows DMDs 300R, 3 for each color light.
It is explanatory drawing which shows the direction of the light irradiation surface 302 of 00G and 300B, and the projected image of each color. Note that FIG.
-2), (B-2), and (C-2), the projected images of the respective colors show only the reversal of the image in the left-right direction, and the actually projected image is a projection lens. 50
Depending on the configuration of 0, the vertical direction may be reversed.

DMD 300R, 300G, 3 for each color light
Of the light (image light) of each color emitted from 00B, red light and blue light are reflected once by the red light reflecting surface 402R and the blue light reflecting surface 402B of the color light combining prism 400, so that the projected red light And the blue image
DMD300R for red light and DMD30 for blue light
The left and right directions of the image formed on 0B are reversed. on the other hand,
The green light is reflected by the red light reflecting surface 40 of the color light combining prism 400.
Since the transmitted green light is transmitted through the 2R and blue light reflecting surfaces 402B, the projected green image matches the image formed on the DMD 300G for green light in the left-right direction. As a result, FIG.
5 (A-1), (B-1), and (C-1), the images formed on the light irradiation surfaces 302 of the DMDs 300R, 300G, and 300B for the respective color lights are shown in FIG. (B-
As shown in (2) and (C-2), images of each color are projected so as to face the same direction.

As described above, the DMD 300 for each color light
The directions of R, 300G, and 300B are set so that the directions of projected images are the same.
Each is selected according to the number of reflections on the optical path from 300B to the projection lens 500.

The reason why the DMD 300R and 300B for the red light and the blue light of the projection type display device 1000 of this embodiment are different from the DMD 300G for the green light for the above-described reason.

The projection display device 1 of the present embodiment described above.
000, the color light separating prism 200 and the color light combining prism 400 are connected to each other, and the cross axis 402c where the red light reflecting surface 402R and the blue light reflecting surface 402B of the color light combining prism 400 intersect is the red light reflecting prism 200 The surface 202R and the blue light reflecting surface 202B are arranged adjacent to each other so as to be substantially on the same straight line as an intersection axis 202c at which the surface 202R intersects. Each of the color lights separated by the color light separation prism 200 corresponds to the corresponding DMD 300R, 300D.
G, 300B, and DMDs 300R, 3 for each color light.
The color light splitting prism 20 is set so that each color light emitted from the color light combining prism 400G and 300B enters the color light combining prism 400.
0 and illumination optical system 1 for color light combining prism 400
00 and DMD 300R, 300G, 30 for each color light
The positional relationship of 0B is adjusted. Thereby, the reflection / transmission prism used in the conventional projection display device can be omitted, so that the entire projection display device can be reduced in size as compared with the related art.

FIG. 16 is an explanatory diagram showing a method of installing the projection display apparatus 1000. As shown in FIG. 16A-1, the projection display apparatus 1000 is moved to a reference plane P (FIG.
4 (xz plane) is parallel to the plane P1, and for example, when the image is projected and displayed on the rear screen SC, as shown in FIG. 16 (A-2), the DMD 300G for green light is used. Of the light irradiation surface 302 of FIG.
As in (B)), the image is inclined 45 degrees clockwise. In order to eliminate such display inclination, FIG.
As shown in 1), the projection display device 1000 of the present embodiment
Is provided with a support 1010 that can be stored to support the housing in an oblique state.
It can be installed so as to be inclined 45 degrees counterclockwise with respect to. Thereby, as shown in FIG. 16 (B-2),
The inclination of the displayed image can be eliminated. When projection display is not performed by making the support 1010 expandable and contractable or foldable and stored in a housing (box), the support 1010 is installed as shown in FIG. 16A-1. be able to. Thereby, the arrangement space when not in use can be reduced.

By the way, as shown in FIGS. 1 to 4,
In the vicinity of the green light incidence surface 404G of the color light combining prism 400, a λ / 2 phase difference plate 260 is provided. FIG.
Is a color light combining prism 400 and a λ / 2 retardation plate 26.
FIG. This λ / 2 phase difference plate 260
It has a function as a polarization direction adjusting optical system that adjusts the direction of polarization of incident linearly polarized light to linearly polarized light having a polarization direction perpendicular to the direction. DMD300R, 3 for each color light
The color light emitted from 00G and 300B is the illumination optical system 1
It is the same s-polarized light as the light emitted from 00. The green light emitted from the green light DMD 300G is converted into p-polarized light when passing through the λ / 2 retardation plate 260. This is because, as described below, the color light combining prism 40
This is to improve the transmittance of green light at 0.

FIGS. 18 and 19 show the color light combining prism 40.
It is a graph which shows an example of the spectral reflectance characteristic of the red reflection film of red light reflection surface 402R of 0, and the blue reflection film of blue light reflection surface 402B. 18 and 19, the reflectance characteristics for s-polarized light are drawn by broken lines, and the reflectance characteristics for p-polarized light are drawn by solid lines. In this specification, a wavelength region where the reflectance is 50% or more is an “effective reflection wavelength region”, and a wavelength at which the reflectance is 50% is a “cutoff wavelength”.
Call.

The wavelength range of blue light is usually about 400 nm to about 5 nm.
00 nm, and the wavelength range of green light is usually about 500 nm to
The wavelength range of about 580 nm and red light is usually set to about 580 nm to about 700 nm. As can be seen from FIG. 18, the effective reflection wavelength range (about 530 n) for the s-polarized light of the red reflective film
m to about 750 nm) includes an effective reflection wavelength range (about 600 nm to about 700 nm) for p-polarized light, and is a wider wavelength range. Since the red light enters the color light combining prism 400 as s-polarized light, this red light
Almost 100% is reflected by the red reflective film having the following characteristics. On the other hand, since green light is incident on the color light combining prism 400 as p-polarized light, this green light transmits almost 100% through the red reflective film having the characteristics shown in FIG.

On the other hand, as can be seen from FIG. 19, the effective reflection wavelength range (about 390 nm to about 530 nm) of the blue reflection film for s-polarized light includes the effective reflection wavelength range (about 400 nm to about 460 nm) for p-polarized light. , A wider wavelength range. Since the blue light is incident on the color light combining prism 400 as s-polarized light, the blue light is reflected by the blue reflection film having the characteristics shown in FIG. 19 at a considerably high reflectance of about 80% or more. On the other hand, the green light is incident on the color light combining prism 400 as p-polarized light, so that the green light transmits almost 100% through the blue reflective film having the characteristics shown in FIG.

As described above, the red reflective film and the blue reflective film are
The reflectance characteristic for s-polarized light is superior to the reflectance characteristic for p-polarized light. Therefore, red light and blue light are converted to s
By making the polarized light enter the color light combining prism 400 and the green light entering the color light combining prism 400 as the p-polarized light, a high reflectance can be obtained for red light and blue light, while green light can be obtained. , A transmittance can be obtained. As a result, it is possible to increase the use efficiency of the three colors of light.

When the characteristics of the red reflection film and the blue reflection film of the color light combining prism 400 are good, the λ / 2 phase difference plate 260 can be omitted. In this case, the polarization conversion optical system 140 of the illumination optical system 100 can be omitted.

Incidentally, the projection type display device 1000 of this embodiment
Describes an example in which the color lights emitted from the DMDs 300R, 300G, and 300B for the respective color lights are set to be directed upward by about 5 degrees with respect to the reference plane P, but the present invention is not limited to this. Not something. For example, it can be modified as shown below.

FIG. 20 is a schematic side view showing a projection display device 1000A which is a modification of the projection display device 1000. The projection display apparatus 1000A has a D light for each color light.
The MDs 300R, 300G, and 300B are arranged so that these light irradiation surfaces 302 are inclined downward by about 5 degrees, and the arrangement and configuration of other optical systems are changed accordingly. The functions of the system are the same as those of the projection display apparatus 1000.

The illumination optical axis 100LC of the illumination optical system 100
Is set so as to face upward by 30 degrees with respect to the reference plane P, and the color light separating prism 200B is connected to the illumination optical system 1.
In response to the inclination of the illumination optical axis 100LC of 00, the light incident surface 2
04 and the respective color light emission surfaces 206R, 206G, 206B are set.

In the projection display apparatus 1000A, the optical paths of the color lights emitted from the DMDs 300R, 300G, and 300B for the respective color lights can be present on a plane (xz plane) parallel to the reference plane P.

The color light combining prism 400 can be replaced with the same type as the ordinary cross dichroic prism 400O (FIG. 14A) having a rectangular parallelepiped or cubic shape.

FIG. 21 is a schematic side view showing a projection type display device 1000B which is another modification of the projection type display device 1000. In the projection display apparatus 1000B, the incident angle of the color light to be incident on the DMDs 300R, 300G, and 300B for each color light is changed from about 25 degrees to about 20 degrees, and the arrangement and configuration of other optical systems are changed accordingly. Was done,
The function of each optical system is the same as that of the projection display 1000.

The illumination optical axis 100LC of the illumination optical system 100
Is set so as to be directed upward by 20 degrees with respect to the reference plane P, and the color light separating prism 200C is connected to the illumination optical system 1.
In response to the inclination of the illumination optical axis 100LC of 00, the light incident surface 2
04 and the respective color light emission surfaces 206R, 206G, 206B are set. The color light combining prism 400A is of the same type as a normal cross dichroic prism 400O (FIG. 14A) having a rectangular parallelepiped or cubic shape.

The optical path from the color light separating prism 200C to the DMDs 300R, 300G, and 300B for each color light is the same as the arrangement space of the color light combining prism 400A and the optical path from the DMDs 300R, 300G, and 300B for each color light to the color light combining prism 400A. In order to secure them, they are set longer than those of the projection display devices 1000 and 1000A.

Also in the projection display apparatus 1000B, the optical paths of the color lights emitted from the DMDs 300R, 300G, and 300B for the respective color lights can exist on a plane (xz plane) parallel to the reference plane P.

The above modification can be applied to each embodiment described below.

B. FIG. 22 shows a second embodiment of the present invention.
FIG. 2 is a schematic plan view illustrating a main part of an optical system in a projection display apparatus 2000 as an example. This projection display device 2
000 are DMDs 300R and 300B for red light and blue light of the projection display apparatus 1000 of the first embodiment.
D300Ra and 300Ba, and two new reflecting mirrors 270 and 280 are provided to change the arrangement positions of the DMDs 300Ra and 300Ba for red light and green light. 1
This is the same as the embodiment.

DMD300R for red light and blue light
a and 300Ba are the same type of DMD as the green light DMD 300G, and are arranged so as to face the same direction as the green light DMD 300G. The reflection mirror 270 is
It is arranged on the optical path of red light from the color light separation prism 200 to the color light synthesis prism 400, reflects the red light emitted from the color light separation prism 200 in the direction of the DMD 300R, and combines the red light emitted from the DMD 300R with the color light synthesis. The light is reflected in the direction of the prism 400. Reflection mirror 28
0, the color light separating prism 200 to the color light combining prism 4
The blue light emitted from the color light separating prism 200 is reflected in the direction of the DMD 300B, and the blue light emitted from the DMD 300B is reflected in the direction of the color light combining prism 400.

FIG. 23 shows a DMD 300Ra for each color light.
It is explanatory drawing which shows the direction of the light irradiation surface 302 of 300G, 300Ba, and the image which each color projects. D for green light
The green light emitted from the MD 300G enters the projection lens 500 without being reflected once. On the other hand, the light emitted from the red light DMD 300Ra is reflected by the reflecting mirror 270 and the red light reflecting surface 402 of the color light combining prism 400.
It is reflected twice by R. Also, DMD300B for blue light
Light emitted from a is also reflected twice by the reflecting mirror 280 and the blue light reflecting surface 402B of the color light combining prism 400. In this case, although the number of reflections of green light is different from the number of reflections of red and blue, they are the same in the sense that the number of reflections is even. In this specification, “even number” includes 0. As a result, the inclination of the light irradiation surface 302 of the DMDs 300R and 300B for red light and blue light is changed as shown in FIGS. 23 (A-1), (B-1) and (C-1). DMD300G light irradiation surface 30
It can be the same as the inclination of 2. As a result, in the projection display apparatus 2000 of the second embodiment, the DMDs 300R and 300B for red light and blue light in the first embodiment need to use a different type of DMD from the DMD 300G for green light. On the other hand, there is an advantage that the same type of DMD can be used.

C. Third Embodiment: FIG. 24 shows a third embodiment of the present invention.
FIG. 3 is a schematic plan view showing a main part of an optical system in a projection display device 3000 as an example. This projection display device 3
000 are DMDs 300R and 300B for red light and blue light of the projection display apparatus 1000 of the first embodiment.
DDM300G for green light by changing to D300Ra and 300Ba and newly including a reflection mirror 290.
Are changed, and other configurations are the same as those of the first embodiment.

The DMD 300G for green light is disposed so as to face the same direction as the DMD 300Ba for blue light. The reflection mirror 290 is disposed on the optical path of green light from the color light separating prism 200 to the color light combining prism 400, reflects the green light emitted from the color light separating prism 200 in the direction of the DMD 300G, and is emitted from the DMD 300G. The green light is reflected in the direction of the color light combining prism 400. Note that the DMD 300G for green light may be arranged so as to face the same direction as the DMD 300Ra for red light.

The projection display device 3000 is different from the projection display device 2000 (FIG. 22) of the second embodiment in that the positions of the DMDs 300Ra and 300Ba for red light and blue light are changed, and the green light is used instead. DMD300G for
In the example shown in FIG.

The green light emitted from the green light DMD 300G is reflected once by the reflection mirror 290 before entering the projection lens 500. On the other hand, DMD3 for red light
The red light emitted from 00Ra is a color light combining prism 4
The light is reflected once by the red light reflecting surface 402R of 00. Also,
The blue light emitted from the blue light DMD 300Ba is also
The light is reflected once by the blue light reflecting surface 402R of the color light combining prism 400. In this case, the DMD 300Ra for each color light,
The number of reflections of the color light emitted from 300G and 300Ba is the same as one time. As a result, similarly to the projection display device 2000 of the second embodiment, the inclination of the light irradiation surfaces 302 of the DMDs 300Ra and 300Ba for red light and blue light is different from the inclination of the light irradiation surfaces 302 of the DMD 300G for green light. Can be the same. As a result, the projection display apparatus 3000 of the third embodiment also has an advantage that the same type of DMD can be used.

In this embodiment, the DMD 300R for each color light is used.
Although the case where the number of times each of the color lights emitted from a, 300G, and 300Ba is reflected on the optical path until reaching the projection lens 500 is unified as one example is described.
It is not limited to this. DMD30 for each color light
DMD for each color light so that the number of times each color light emitted from ORa, 300G, and 300Ba is reflected on the optical path until reaching the projection lens 500 is an odd number.
A reflecting mirror may be provided on the optical path between 300R, 300G, 300B and the projection lens 500.

The present invention is not limited to the above Examples and Embodiments, but can be implemented in various modes without departing from the gist of the invention.
For example, the following modifications are possible.

(1) In the second embodiment, the DMD 3 for each color light is used.
The number of times that each color light emitted from 00Ra, 300G, and 300Ba is reflected on the optical path until reaching the projection lens 500 is unified with an even number, and the third embodiment is unified with an odd number. . That is, the DM for each color light
The number of times that each color light emitted from the D300Ra, 300G, and 300Ba is reflected on the optical path until reaching the projection lens 500 may be an odd number or an even number. In this way, the same type of DMD can be used as the DMD for each color light.

(2) DMD used in each of the above embodiments
Has a rotation axis of the micro mirror having an inclination of about 45 degrees,
The case where the rotation range is ± 10 degrees is described as an example, but the invention is not limited to this. For example, a case where the rotation axis is oriented in the vertical direction or the horizontal direction may be used. Further, the rotation range need not be ± 10 degrees. In any case, the illumination optical system, the color light separation prism, the three DMDs, and the color light separation prism are emitted from the color light separation prism so that the reflection / transmission type prism conventionally required can be omitted. It is only necessary that the respective colored lights are incident on the corresponding DMDs, and the respective colored lights reflected by the DMDs for the respective colored lights are incident on the color light combining prism.

(3) In each of the above embodiments, the projection type display device using the DMD has been described as an example, but the present invention is not limited to this. The present invention modulates the light applied to the light irradiation surface by controlling the emission direction of the light applied to the light irradiation surface according to given image data (signal),
The present invention is applicable to a projection display device using an emission direction control type light modulation device that emits image light representing an image.

(4) In each of the above embodiments, an example is described in which a polarized illumination optical system that emits s-polarized light is used as the illumination optical system. However, the present invention is not limited to this. An illumination optical system that emits polarized light can also be used. Further, the case where an integrator optical system using a lens array is applied as an illumination optical system has been described as an example, but an integrator optical system using an integrator rod can also be applied. It is also possible to use an illumination optical system to which no integrator optical system is applied.

(5) In each of the above embodiments, a prism having a red light reflecting surface and a blue light reflecting surface formed in a substantially X-shape is used as the color light separating optical system and the color light combining optical system.
A cross dichroic mirror in which a red light reflecting surface and a blue light reflecting surface are formed in a substantially X shape can also be used.

(6) In each of the above embodiments, for ease of explanation, an example in which the optical path from the illumination optical system to the color light separating prism is linearly arranged is shown, but the present invention is not limited to this. . By disposing a reflection mirror on this optical path, the arrangement of the illumination optical system can be changed. Similarly, by disposing a reflecting mirror on the optical path from the color light combining prism to the projection lens, the arrangement of the projection lens can be changed.

[Brief description of the drawings]

FIG. 1 is a projection type display device 1 as a first embodiment of the present invention.
000 is a schematic perspective view showing a main part of the optical system at 000. FIG.

FIG. 2 is a projection type display device 1 as a first embodiment of the present invention.
000 is a schematic plan view showing a main part of the optical system at 000. FIG.

FIG. 3 is a projection display apparatus 1 according to a first embodiment of the present invention.
000 is a schematic front view showing the main part of the optical system at 000. FIG.

FIG. 4 is a projection display 1 according to a first embodiment of the present invention.
000 is a schematic side view showing the main part of the optical system at 000. FIG.

FIG. 5 is an explanatory diagram showing a configuration of the illumination optical system 100.

FIG. 6 is a perspective view showing an appearance of the first lens array 120.

FIG. 7 is an explanatory diagram showing a configuration and a function of a polarization conversion optical system 140.

FIG. 8 is an explanatory diagram showing a structure of a color light separation prism 200.

FIG. 9 is an explanatory diagram illustrating a method of manufacturing the color light separation prism 200.

FIG. 10 is an explanatory diagram illustrating a method of manufacturing the color light separation prism 200.

FIG. 11 shows DMDs 300R, 300G, and 30 for each color light.
It is explanatory drawing which shows the light irradiation surface 302 of 0B.

FIG. 12 shows a micromirror 3 viewed from the direction of the arrow in FIG.
FIG. 8 is an explanatory diagram showing an optical path in a plane including light incident on the optical axis 04 and its reflected light, that is, a cross section perpendicular to the rotation axis 304c.

FIG. 13 is an explanatory diagram showing a structure of a color light combining prism 400.

FIG. 14 is an explanatory diagram illustrating a method of manufacturing the color light combining prism 400.

FIG. 15 shows DMDs 300R, 300G, and 30 for each color light.
FIG. 4 is an explanatory diagram showing the direction of a light irradiation surface 302 of 0B and images projected for each color.

FIG. 16 is an explanatory diagram illustrating a method of installing the projection display apparatus 1000.

17 is a plan view showing a color light combining prism 400 and a λ / 2 retardation plate 260. FIG.

FIG. 18 is a graph illustrating an example of a spectral reflectance characteristic of a red reflective film on a red light reflective surface 402R.

FIG. 19 is a graph showing an example of a spectral reflectance characteristic of a blue reflection film on a blue light reflection surface 402B.

FIG. 20 is a schematic side view showing a projection display device 1000A which is a modification of the projection display device 1000.

FIG. 21 is a schematic side view showing a projection display device 1000B which is another modified example of the projection display device 1000.

FIG. 22 is a schematic plan view showing a main part of an optical system in a projection display apparatus 2000 as a second embodiment of the present invention.

FIG. 23 shows DMDs 300Ra, 300G, and 3 for each color light.
FIG. 4 is an explanatory diagram showing the direction of a light irradiation surface 302 of 00Ba and images projected on each color.

FIG. 24 is a schematic plan view showing a main part of an optical system in a projection display apparatus 3000 as a third embodiment of the present invention.

FIG. 25 is a schematic plan view showing an example of a conventional projection display device.

[Explanation of symbols]

 Reference Signs List 100: illumination optical system 100LC: illumination optical axis 110: light source 110LC: light source optical axis 112: light source lamp 114: concave mirror 120: first lens array 122: small lens 130: second lens array 133: small lens 140: polarized light Conversion optical system 142 ... Light shielding plate 142a ... Light shielding surface 142b ... Opening surface 144 ... Polarization beam splitter array 144a ... Transparent plate material 144b ... Polarization separation film 144c ... Reflection film 146 ... Selection phase difference plate 146a ... λ / 2 phase difference layer 146b Opening layer 150 Superimposing lens 200 Color light separating prism 200A Color light separating prism 200B Color light separating prism 200C Color light separating prism 200O Cross dichroic prism 202B Blue light reflecting surface 202R Red light reflecting surface 202c Cross axis 204 ... Light incident surface 206R Red light emitting surface 206B Blue light emitting surface 206G Green light emitting surface 250R, 250G, 250B Condenser lens 270 Reflecting mirror 280 Reflecting mirror 290 Reflecting mirror 300 Illumination object 300R, 300G, 300B DMD 300Ra, 300Ba ... DMD 302 ... Light irradiation surface 302c ... Center axis 304 ... Micromirror 304 ... Pixel 304c ... Rotation axis 400 ... Color light combining prism 400A ... Color light combining prism 400O ... Cross dichroic prism 402B ... Blue light reflecting surface 402R ... Blue light reflecting surface 402c cross axis 404B blue light incident surface 404G green light incident surface 404R red light incident surface 406 synthetic light exit surface 500 projection lens 1000 projection display device 1010 support 1000A projection display device 100 0B Projection display device 2000 Projection display device 3000 Projection display device 6000 Projection display device 6100 Illumination optical system 6110 Light source 6120 Condenser lens 6130 Reflection mirror 6200 TIR prism 6200 Prism 6300 Color light Separating / combining prism 6400R, 6400G, 6400B ... DMD 6500 ... Projection lens

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H04N 9/31 H04N 9/31 CF term (Reference) 2H088 EA14 HA13 HA21 HA25 HA28 MA20 2H091 FA05Z FA14Z FA26X FA26Z FA29Z FA41Z LA11 MA07 5C060 BA03 BA08 BC05 EA00 GA01 GB02 GB06 HC00 HC01 HC20 HC25 JA00 JB06 5G435 AA18 BB17 CC12 DD02 DD05 DD09 FF03 FF05 FF13 GG03 GG08 GG10 GG28

Claims (5)

[Claims] 1. A projection display device for projecting and displaying an image, comprising: an illumination optical system for emitting illumination light; and a color light separation optical system for separating light emitted from the illumination optical system into three color lights. Three light modulators provided for each of the three color lights; a color light combining optical system that combines the three color lights emitted from the three light modulators; and light combined by the color light combining optical system. And a projection optical system for projecting the light, the light modulation device for each color light, the emission direction of each color light reflected on the light irradiation surface of the light modulation device for each color light, according to a given signal An emission direction control type light modulator that modulates each of the color lights by controlling the color light separation optical system, wherein the color light separation optical system reflects the first color light of the three color lights and transmits the second and third color lights. A first color light reflecting surface, and a first and a second A second color light reflecting surface that transmits the first color light has a first color-selective cross-reflecting surface that intersects in a substantially X-shape, and the color light combining optical system includes the three emission direction control type lights. A third color light reflecting surface that reflects the first color light of the three color lights emitted from the modulation device and transmits the second and third color lights;
A fourth color light reflection surface that reflects the second color light and transmits the first and third color lights has a second color selection cross reflection surface that crosses substantially in an X-shape; The optical system and the color light combining optical system are arranged adjacent to each other so that a cross axis of the first and second color-selective cross-reflection surfaces is positioned substantially in a straight line. The three emission direction control light modulation devices, the color light separation optical system, and the color light synthesis optical system, each color light emitted from the color light separation optical system is incident on a corresponding emission direction control light modulation device, A projection display device, wherein the effective color lights reflected by the emission direction control type light modulators for the respective color lights are arranged to be incident on the color light combining optical system. 2. The projection display device according to claim 1, wherein the color light separation optical system includes one light incident surface on which light emitted from the illumination optical system is incident, and the color light separation optical system. And three color light emission surfaces from which three color lights to be separated are emitted. The one light incidence surface and the three color light emission surfaces are substantially perpendicular to a central axis of light passing through each surface. A projection display device that is formed as follows. 3. The projection type display device according to claim 2, wherein the color light combining optical system is configured to emit three light beams emitted from the three emission direction control type light modulation devices.
Three color light incident surfaces on which three color lights are incident, and one combined light exit surface from which the light combined by the color light combining optical system exits, the three color light incident surfaces and the one combined light exit surface Is a projection display device formed so as to be substantially perpendicular to the central axis of light passing through each surface. 4. The projection display device according to claim 1, wherein the emission direction control type light modulation device for each color light has a substantially rectangular contour. Each light irradiation surface is disposed such that a side of each light irradiation surface is inclined with respect to a predetermined reference plane, and from the emission direction control type light modulation device for each color light. The emission direction control type light modulator for each color light and the color light combining device so that the number of times each emitted color light is reflected on the optical path up to the projection optical system is unified with an odd number or an even number. A projection display device in which a positional relationship with an optical system is set. 5. The projection display device according to claim 1, wherein the illumination optical system, the color light separation optical system, and the three emission direction control light modulation devices. The color light combining optical system,
The projection optical system is housed in a predetermined housing, and the emission direction control type light modulation device for each color light has a light irradiation surface having a substantially rectangular contour. The surface is arranged such that a side of each of the light irradiation surfaces is inclined with respect to a housing plane of the housing, and the projection display device further comprises: A projection display device, comprising: an inclined support for inclining and supporting the housing so that the projected substantially rectangular image is erected.