JP2001091894A - Display optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display optical device with high resolution having a constitution with good efficiency even on a display panel whose pixel pitch is small. SOLUTION: As to this display optical device which is provided with an illumination optical system separating light from a light source in different directions by each specified wavelength area, shifting the separated light as illuminating light in a consecutive state or in a fine pitch state, and illuminating the display panel, and which illuminates plural pixels adjacent to each other on the display panel with the light of the same color in the illuminating light having the three colors of RGB mutually and plurally arranged; the illuminating optical system is provided with a mask plate having an aperture part controlling a light source picture, and a color resolving optical system separating the light from the light source in the different directions by each specified wavelength area behind the mask plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display optical device for projecting an image on a reflective display panel.

[0002]

2. Description of the Related Art Conventionally, as one of the methods for displaying an image, for example, a projection type display optical device is known. In such a display optical device, a so-called reflective display panel such as a reflective liquid crystal display panel is mainly used recently. In order to efficiently and uniformly illuminate an optical image on such a reflective display panel, an illumination optical system is used, and illumination light from the illumination optical system is guided to the reflective display panel. For this purpose, a microlens array or the like arranged immediately before the reflective display panel is used.

[0003] Specifically, for example, a reflection type display panel is used as a so-called single plate in which R, G, and B colors are sequentially arranged for each pixel, and illumination light is divided into RGB in advance. The angle is changed for each RGB, and one picture element (one picture element is a set of three RGB pixels on the display panel) or a plurality of picture elements is incident on each microlens on the microlens array, and each is a reflection type display. Light is condensed on the R, G, and B pixels of the panel.

FIG. 22 schematically shows a relationship between a microlens array and a display panel, which is an example of the related art. As described in JP-A-4-60538, this is adopted in a projector optical system using a transmission type liquid crystal for a display panel in a single-panel system. Here, the display panel 16 is a single plate, and R, G
And B are sequentially arranged.
Is divided into RGB in advance, the angle is changed for each of RGB, and one pixel is incident on each microlens 61a of the microlens array 61 by one pixel.
, G, and B pixels. Thereby, efficient illumination can be performed. The left and right sides of the microlens array 61 and the display panel 16 are not shown.

FIG. 23 is a diagram schematically showing a relationship between a microlens array and a display panel, which is another conventional example, described in JP-A-9-318904.
As shown in FIG.
Light 9 from the light source 1 per microlens 62a
, Not as three RGB, but as a luminous flux of a plurality of picture elements in the order of RGBRGB.
Light is condensed on the G and B pixels. The left and right sides of the microlens array 62 and the display panel 16 in FIG.

In such a display panel having pixels arranged in the order of RGB, it is desirable to be able to perform color display with the same resolution as that of the so-called three-panel system without increasing the number of pixels, despite the so-called single-panel system. . For this reason, conventionally, a so-called color pixel time division method has been performed in which three cycles are temporally overlapped so that RGB is sequentially shifted.

[0007]

However, in a structure such as the conventional example shown in FIG. 22, a recent liquid crystal display panel used as a display panel has a small pixel pitch, so that an efficient structure is required. In this case, the distance between the microlens 61a and each pixel of the display panel 16 becomes very short, which makes it impossible to actually configure. In particular,
Recent liquid crystal display panels have a pixel pitch of 10 to 20 μm in order to increase the number of pixels.

When each pixel of the display panel 16 is illuminated with one light beam for each of RGB as in the microlens array 61 of a conventional example, the distance between the microlens 61a and each pixel of the display panel 16 is 100 μm or less. It is a distance, and it is practically impossible to create them. Even if it can be actually made, the curvature of the microlens is large and aberrations and the like occur, so that good illumination cannot be performed.

To solve these problems, FIG.
Although the other conventional example shown in FIG. 3 is effective, in such a configuration, the interval between the color-divided light beams is set in advance by a one-stage integrator using a lens array (not shown). In order to eliminate illumination unevenness in a large span such as the periphery with respect to the center, the lens array must be divided very finely. For example, even in the long side direction where the division is coarse, 4 to 7 divisions or more are required. In this case, on the contrary, the microlenses 62a and the pixels of the display panel 16 are largely separated from each other, and the F-number of each microlens 62a becomes darker than the diffraction limit.

More specifically, the light 9 from the light source 1 is previously converted into RGB, RGB,.
When the light beam is divided into the light beams, the distance between the micro lens 62a and each pixel of the display panel 16 is as large as about 500 to 800 μm, but the F number of each micro lens 62a is F
20 or more, and the amount of blurring of the image due to diffraction (1.22 ×
(Wavelength λ × F number) becomes more than ten microns, which is equivalent to the pixel pitch. At this time, the RGB light beams that are finely divided substantially protrude from each pixel on the pixel surface, causing a reduction in color purity and a significant reduction in efficiency.

In general, when a microlens array having one microlens per picture element is placed immediately in front of a display panel, the F-number of the microlens array is dark, and diffraction is more difficult than image formation on a pixel. In this case, the image is more blurred, which is inefficient. In the case of a microlens array having one microlens per a plurality of picture elements (this is almost the embodiment described in Japanese Patent Application Laid-Open No. 9-318904), a light source image contributing between adjacent picture elements is generated. Because of the difference, the difference in the brightness of the light source image causes illumination unevenness in a small span such as between adjacent picture elements.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high-resolution display optical device capable of efficiently configuring a display panel having a fine pixel pitch.

[0013]

In order to achieve the above object, according to the present invention, light from a light source is separated in different directions for each predetermined wavelength region, and the separated illumination light is continuously emitted. An illumination optical system for illuminating the display panel by shifting the display light or at a minute pitch, wherein the illumination light includes a plurality of RGB three-color lights alternately arranged, and each of the same-color lights is adjacent to the display panel. In a display optical device that illuminates a plurality of pixels, the illumination optical system includes a mask plate having an opening that regulates a light source image, and the light from the light source is directed to a different direction for each predetermined wavelength region after the mask plate. And a color separation optical system for separating the light into a color image.

[0014] Further, the configuration of the second aspect of the present invention is the plural number of the opening.

Further, the illumination optical system includes an integrator including a lens array, and the mask plate is arranged such that the opening regulates an opening width of each cell of the lens array. The structure of claim 3 described in the above.

4. The method according to claim 3, wherein the opening width of each cell is one third or less of the total width of each cell.
Configuration.

Further, the opening width of each cell becomes narrower nearer to the periphery of the lens array.
The structure of claim 5 described in the above.

[0018] Further, the present invention has a configuration according to any one of claims 1 to 5, wherein a density filter is used in an opening of the mask plate.

The width of the opening of the mask plate can be adjusted.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram schematically showing the display optical device according to the first embodiment of the present invention. Although the arrangement of each part is originally three-dimensional, it is described in a planar shape to facilitate understanding. In the figure,
1 is a light source, and 2 is a reflector arranged so as to surround the light source 1. Reference numeral 7 denotes a UVIR cut filter that is disposed so as to cover the light emission port 2 a of the reflector 2 and that cuts ultraviolet light and infrared light included in the light from the light source 1 and the reflector 2.

Behind the UVIR cut filter 7 (below the figure), dichroic mirrors R _m , R (red), G (green), and B (blue) reflect light in respective wavelength ranges.
G _m and B _m are arranged at different inclinations. Then, the light 9 transmitted through the UVIR cut filter 7 on the optical axis L is reflected by the dichroic mirrors of R _m , G _m , and B _m , and the optical axes L _R ,
At L _G and L _B , the light reaches the first lens array 4 arranged rearward (rightward in the figure). Incidentally, the dichroic mirror _Bm may be a total reflection mirror. The light 9 reflected by the dichroic mirror is not shown.

Behind the first lens array 4, the second lens array 6 is slightly separated from the second lens array 6.
Is arranged. Although not shown here, the first lens array 4 has cells combined in a lattice shape, and the second lens array 6 is combined in a different lattice shape from the first lens array 4. Each cell. Further, the first lens array 4 has a birefringent diffraction grating, and the light source 1 is arranged in the short side direction of each cell of the second lens array 6.
And the polarization separation of the light 9 from the reflector 2 is performed. First
The polarization conversion is performed through the lens array 4 and the second lens array 6, and the light 9 from the light source 1 and the reflector 2 comes out with being aligned to a specific polarization. This configuration is called a polarization conversion device. The detailed relationship between them will be described later.

Further, the first lens array 6 and the superimposed lens 8 immediately after the second lens array 6 allow the first panel to be mounted on a display panel described later.
The images of the cells of the lens array 4 are made to overlap. The illumination optical system 1 immediately after the superimposing lens 8
3 illuminates the display panel telecentrically.
The superimposing lens 8 may be formed integrally with the second lens array 6. The above-described first lens array 4 to the superimposing lens 8 are integrated into an integrator optical system I.
And the optical axis is La.

Further, behind the illumination optical system 13, a TIR
A prism 22 is provided. TIR prism 22
Is configured such that certain surfaces of large and small prisms 22b and 22a made of glass or the like each having a triangular prism shape face each other. The prism 22b has an entrance surface 22ba, a total reflection surface 22bb also serving as an exit surface, and an entrance / exit surface 22bc. The prism 22a has an entrance surface 22aa and an exit surface 2bc.
2ab. Total reflection surfaces 22 facing each other
The distance between bb and the incident surface 22aa is several μm to several tens μm.

The light 9 from the light source 1 and the reflector 2 that has passed through the illumination optical system 13 is first applied to the prism 22b along the optical axis La along with the immediately preceding condenser lens 2
After that, the light enters the incident surface 22ba. When the light 9 is incident on the total reflection surface 22bb at an incident angle exceeding the critical angle, most of the light 9 is reflected, exits from the entrance / exit surface 22bc, and travels toward the display panel 16. Immediately before that, a birefringent microcylinder lens array 15a that brings a microlens effect to predetermined polarized light is arranged. The configuration described above is an example of an illumination optical device.

The display panel 16 is composed of a DMD, and reflects the illuminated light 9 on a micromirror in an ON state or a micromirror in an OFF state according to display information for each pixel. At this time, the reflected light of ON is
Via the birefringent microcylinder lens array 15a,
The light enters the entrance / exit surface 22bc and returns to the prism 22b.

Then, the light enters the total reflection surface 22bb at an incident angle within the critical angle and transmits therethrough, further enters the incident surface 22aa, transmits through the prism 22a, exits from the exit surface 22ab, and exits through the optical axis Lb. Along the projection optical system 24 as light 21 as projection light. The projection optical system 24 projects display information on the display panel 16 onto a screen (not shown). The light 21 is not shown. On the other hand, OF
The reflected light of F transmits through the prisms 22b and 22a,
Finally, the light is emitted in a direction that does not reach the projection optical system 24.
The configuration of the projection optical system and the screen described above is an example of a projection optical device.

The optical axis L of the light 21 which is the ON reflected light
b is the display panel 16 as described later in this embodiment.
The projection optical system 24 must be a non-axial projection optical system that is not a coaxial system. As a specific example of the off-axis projection optical system, for example, one described in Example 4 of Japanese Patent Application Laid-Open No. Hei 9-179064 has been proposed.

FIGS. 2A and 2B are enlarged schematic views showing a main part of the display optical device according to the first embodiment of the present invention. FIG. 2A is an overall view, and FIG. It is a side view of a system part. In the same manner as described with reference to FIG. 1, the light 9 incident along the optical axis L is reflected by the respective dichroic mirrors R _m , G _m , and B _m , and the optical axes L _R , L at different angles. _G, reaching the first lens array 4 arranged behind (FIG lower) in L _B. It should be noted that the light 9 is not shown in FIG.

Behind the first lens array 4, the second lens array 6 is slightly separated, and immediately thereafter, the superimposing lens 8.
Is arranged. The first lens array 4 has cells 4a combined in a lattice, and the second lens array 6 has cells 6a combined in a different lattice from the first lens array 4. ing. The light 9 arriving at the first lens array 4 from different directions in RGB forms an image on the individual cells 6a of the second lens array 6 which is arranged a little behind at every individual cell 4a. At this time,
Since the directions of light are different between RGB, light source images for each of RGB can be formed. Almost each color comes at each position, but RGB color filters are provided to increase color purity. The loss of light quantity by this color filter is small.

Further, the first lens array 4 is shown in FIG.
As shown in (2), it has a birefringent diffraction grating, and performs polarization separation of light 9 in the short side direction of each cell of the second lens array 6. Here, the first lens array 4 and the second lens array 6
Through which the light 9 is converted into a specific polarization. The principle of this polarization conversion will be described again with reference to FIG. First, the light 9 is a non-polarized light beam and enters the integrator optical system I. The integrator optical system I
The first lens array 4, the half-wave plate 5, the second lens array 6, and the superposing lens 8 are arranged in the order in which the light flux advances. The first lens array 4 includes a substrate 4b made of glass or the like.
A blazed birefringent diffraction grating 4c is formed thereon, and a birefringent optical material 4
d is filled and sealed with a glass plate 4e.

The birefringent optical material 4d exhibits different refractive indices for light beams having different polarization directions. In this embodiment, the birefringent optical material 4d has a refractive index for the light beam L1 having a polarization plane along the paper surface and a polarization surface perpendicular to the paper surface. Is different from the refractive index for the light beam L2 having The shape of the birefringent diffraction grating 4c is a shape that deflects light that goes straight. Here, by making the refractive index for the light ray L1 having the polarization plane along the paper plane equal to the refractive index of the substrate material, the light ray L1 having the polarization plane along the paper plane becomes birefringent as shown by the solid line. Diffraction grating 4c
Does not exist, and the light beam L2 having a polarization plane perpendicular to the paper surface travels in a state where the birefringent diffraction grating 4c exists as shown by a dashed line, so that it is deflected.

On the other hand, the first lens array 4
Is spatially divided to form an image on the second lens array 6. The light ray L1 having a plane of polarization along the plane of the paper goes straight and forms an image,
The light beam L2 having a polarization plane perpendicular to the paper surface is deflected to form an image. Therefore, the light ray L1 having a plane of polarization along the paper surface
And the light beam L2 having a polarization plane perpendicular to the paper surface forms an image at a spatially different position. Therefore, by disposing the half-wave plate 5 in the space where the light beam having any one of the above-mentioned polarization planes is formed in the vicinity of the light source side of the second lens array 6, the light beam having any one of the polarization planes is obtained. It can be aligned.

Here, a half-wave plate 5 for the light beam L2 is used.
Is used. Therefore, from the integrator optical system I, polarized light, all of which is aligned on a polarization plane parallel to the paper surface, is emitted as illumination light. The birefringent optical material can be obtained, for example, by subjecting a liquid crystal material to an alignment treatment in a predetermined direction. In addition, since a liquid crystal material that cures when irradiated with ultraviolet light or the like is known, ultraviolet light irradiation or the like may be performed after the above-described alignment treatment using such a liquid crystal material.

Next, returning to FIG.
The image of each cell of the first lens array 4 is overlapped on the display panel 16 by the second lens array 6 and the superimposing lens 8 immediately after the second lens array 6. Then, the display panel 1 is provided by the illumination optical system 13 immediately after the superimposing lens 8.
6 is telecentrically illuminated. Here, as shown in FIG. 1, immediately before the display panel 16, the birefringent micro-cylinder lens array 1 made of a birefringent material is used.
5a is arranged.

The light 9 separated into RGB by the dichroic mirror and the first and second lens arrays passes through the illumination optical system 13 and the TIR prism 22, and
Each pixel 16b of the display panel 16 is illuminated for each color by each microcylinder lens 15aa of the birefringent microcylinder lens array 15a. Incidentally, a diffraction lens may be used instead of the micro cylinder lens 15aa. The left and right sides of the birefringent microcylinder lens array 15a and the display panel 16 in FIG.
Illustration is omitted. The quarter-wave plate 10 is arranged between them, which will be described later.

In the present embodiment, the distance between the birefringent microcylinder lens array 15a and the display panel 16 is 2 m.
m to 3 mm, and there is sufficient space for disposing the birefringent microcylinder lens array 15a outside the protective glass 16a that protects the DMD pixels 16b of the display panel 16. In FIG. 2A, four pixels are illuminated per color.
When the thickness of the protective glass 16a is about 2 mm, it is necessary to illuminate 6 to 10 pixels per color, and it is necessary to secure an arrangement space for the birefringent microcylinder lens array 15a.

In this manner, the microcylinder lens array is separated from the surface of the DMD element by 2 to 3 mm to illuminate the area of each color of RGB every several pixels. In this embodiment, the birefringent microcylinder lens is further provided. Array 1
As shown by the arrow Aw in FIG. 1 or FIG. 1, 5a is driven at a fine pitch or continuously in one frame along the surface to move the illumination light on the pixel. By performing pixel display in conjunction with this, it is possible to perform good color display on the entire screen. Details will be described later. In this case, as shown in FIG. 1, instead of the birefringent microcylinder lens array 15a, a part of the lenses of the illumination optical system 13 is driven perpendicular to the optical axis La as shown by an arrow Bw, or A configuration may be adopted in which a mirror is provided inside 13 and this is driven to rotate.

FIG. 3 is a schematic diagram showing a material configuration of a birefringent microcylinder lens array. In the present embodiment, the display panel 16 is a reflective display panel DM.
In this case, the birefringent microcylinder lens array 15a (a lenticular type having a lens-shaped cross section) is provided with the display panel 1 in this case.
Both the light 9 (illumination light, indicated by a solid line) incident on 6 and the light 21 (projection light, indicated by a two-dot chain line) reflected from each pixel 16b of the display panel 16 pass through. The light 9 entering the display panel 16 acts as described above, but the reflected light 21 is disturbed by the birefringent microcylinder lens array 15a as it is, and the image quality deteriorates.

In order to cope with this, in the present embodiment, the birefringent microcylinder lens array 15a is made of an isotropic optical material and an optical material having birefringent characteristics. The 波長 wavelength plate 10 is arranged between the display panel 15 a and the display panel 16. In the figure, light 9 incident on a display panel 16 is shown.
Has a certain plane of polarization, for example, a plane of polarization along the plane of the paper, and among the light reflected by the display panel 16, light 21 effective for displaying an image has a plane of polarization that is rotated, for example, perpendicular to the plane of the paper. With a strong polarization plane. This is because these lights combined 1 /
This is due to receiving the function as a half-wave plate when reciprocating through the four-wavelength plate 10.

Therefore, the micro cylinder lens 1 constituting the birefringent micro cylinder lens array 15a
The refractive index of the isotropic optical material above 5aa is N, the refractive index of the birefringent material below the microcylinder lens 15aa with respect to the polarization plane of light 9 is Ne, and the refraction of light 21 with respect to the polarization plane is The rate is set to No. At this time,
By setting N = No, the birefringent microcylinder lens array 15a functions as a microcylinder lens array for the light 9 and becomes a mere transparent flat plate for the light 21. As a result, even if the reflective display panel is used, the image quality of the light 21 does not deteriorate.

By the way, instead of disposing such a birefringent microcylinder lens array between the TIR prism 22 and the display panel 16, the birefringent microcylinder lens array is disposed between the condenser lens 23 and the TIR prism 22 shown in FIG. There is a method of disposing as a microcylinder lens array. According to this, a sufficient distance from the display panel 16 can be ensured, and only the illumination light passes through the micro-cylinder lens array, which causes a problem that the projection light is disturbed as described with reference to FIG. Will not be
The need for polarization conversion by the integrator optical system I is eliminated, and the birefringence effect in the microcylinder lens array is also eliminated. At this time, since the microcylinder lens array and the DMD panel are largely separated from each other, the configuration illuminates several tens of pixels per color.

FIGS. 4 and 5 are diagrams for explaining the principle of performing color display by moving the above-mentioned illumination light on the pixel. Here, FIG. 4 shows the relationship between the position on the display panel and the illumination light, with the horizontal axis representing the position and the vertical axis representing the intensity of the illumination light. FIGS. 5A to 5C show the relationship between time and illumination light in each pixel, where the horizontal axis represents time and the vertical axis represents illumination light intensity. FIG. 6D shows the movement of the micro-cylinder lens array, in which the horizontal axis represents time and the vertical axis represents the movement amount of the micro-cylinder lens array. This may be the movement amount of the illumination optical system described above.

First, referring to FIG.
, One of the pixels 16b is selected, and number 1 is assigned to it. Then, from here, 1 to the right pixel
The integer numbers are assigned one by one. Here, by driving the birefringent microcylinder lens array 15a (or the illumination optical system 13), the illumination area of each color is indicated by an arrow C.
Move all at once to the right as shown by w. It is assumed that the illumination area of each of the R, G, and B colors has an intensity distribution close to, for example, the upper half of the ellipse, as indicated by broken lines, solid lines, and dotted lines. Although the number of pixels for one color illumination area is four in the figure, it is of course not limited to this.

Now, focusing on the pixel of number 1, FIG.
As shown in (a), when displaying white here, the ON display time is made continuous as shown by the solid line T, and R,
All the colors of G and B should be displayed. Next, paying attention to the pixel of No. 7, as shown in FIG. 7B, when displaying a blue-violet display of medium brightness here, as shown by solid lines T1 and T2, the R illumination areas are respectively shown. When the illumination is performed by the peripheral portion (low intensity) and the central portion (high intensity) of the illumination area of B, ON display may be performed for a short time and a long time, respectively.

Further, paying attention to the pixel of No. 10, as shown in FIG. 9C, when green display of medium brightness is performed here, as shown by a solid line T3, the G illumination area It is sufficient to display ON only during the period of illumination from the periphery to the center. As described above, the display time corresponding to the illumination area of each color is divided, and by combining the divided times, the hue and the gradation expression in each pixel are performed. Here, an example is shown in which the display time is divided into four, but the display time is not limited to this, and more subtle display can be performed by further dividing the display time.

Incidentally, when performing a so-called full-color display, a display of 255 gradations is necessary. Conventionally, in order to express the gradation of display, the ON time during uniform illumination light is digitally controlled in 255 steps. However, when the intensity distribution changes in the illumination area as in the present embodiment, it is not necessary to reduce the display time corresponding to the illumination area of each color to 255 divisions, and the display times relatively coarsely divided may be combined. Thus, full-color display at the same level can be performed.

Finally, as shown in FIG. 4D, in this example, the birefringent microcylinder lens array 15a is driven at a fine pitch or continuously with one frame time indicated by arrow Dw as one cycle. However, a blank time indicated by an arrow Ew for returning to the original position is required therein, and the display is not performed only during the blank time.
Note that the configuration for performing color display by moving the illumination light on the pixel described above is not necessarily a DM panel.
It is not necessary to use D, for example, ON,
An element having good responsiveness of OFF switching may be used.

FIG. 6 is a configuration diagram schematically showing a display optical device according to a second embodiment of the present invention. Although the arrangement of each part is originally three-dimensional, it is described in a planar shape to facilitate understanding. This embodiment is the first embodiment shown in FIG.
However, here, instead of driving the birefringent micro-cylinder lens array, the projection lens 24a constituting the projection optical system 24 is perpendicular to the optical axis Lb as shown by an arrow Fw. , One in one frame
Driving at the pixel pitch (or continuously), the screen 2
The projection light on 0 is moved in units of one pixel. By performing pixel display in conjunction with this, it is possible to perform good color display on the entire screen.

FIGS. 7 and 8 are diagrams for explaining the principle of performing color display by moving the above-described projection light on the screen. Here, FIG. 7 shows the relationship between the position on the screen and the projection light based on the change over time, with the horizontal axis representing the position and the vertical axis representing the time. In addition, FIG.
(C) shows the relationship between time and projection light at a position on the screen corresponding to each pixel, with the horizontal axis representing time and the vertical axis representing the intensity of projection light. Then, FIG.
Shows the state of movement of the projection lens, where the horizontal axis represents time and the vertical axis represents the movement amount of the projection lens.

First, referring to FIG.
One of the pixels projected on the screen 20 corresponding to each pixel is selected, and number 1 is assigned to this pixel.
Then, the integer numbers are assigned one by one to the right pixel in order from here. For convenience of explanation, the numbers to be assigned are from 1 to 14. At this time, it is assumed that the illumination areas of each color correspond to four pixels in the order of B, R, and G, as indicated by the dotted line, the broken line, and the solid line in FIG. Of course, it is not limited to this. Here, the projection lens 24
By driving a, the illumination area of each color and the pixels corresponding thereto move one pixel at a time to the right on the screen, as shown in FIGS. In fact, it moves further.

In FIG. 8, it is assumed that the illumination area of each color of B, R, and G has an intensity distribution in a shape close to, for example, the upper half of an ellipse as shown by a dotted line, a broken line, and a solid line, respectively. Now, paying attention to the position a on the screen shown in FIG. 7, as shown in FIG. 8A, when performing white display here, all the pixels are turned ON as indicated by solid lines, All the colors of B, R, and G may be displayed.

Next, paying attention to the position b on the screen shown in FIG. 7, as shown in FIG. 8 (b), when a medium-brightness blue-violet display is performed, the corresponding pixel is indicated by a solid line. As shown, for example, the pixel of No. 8 in the peripheral portion (low intensity) of the R illumination region and the pixels of No. 2 and 3 in the central portion (high intensity) of the B illumination region are turned ON. The other pixels may be turned off as shown by the broken lines.

Further, position c on the screen shown in FIG.
Note that, when green display of medium brightness is performed here, as shown in FIG. 11C, the corresponding pixel is indicated by a solid line from the periphery to the center of the G illumination area.
For example, the pixels of numbers 11 and 12 are turned ON. And
The other pixels may be turned off as shown by the broken lines.
As described above, by combining each pixel corresponding to the illumination area of each color, the color tone and the gradation expression at each position on the screen are performed. Here, the division of the display time is determined based on the size of the pixel. However, by further finely dividing the ON time of each pixel, a more delicate display can be performed. That is, gradation display is performed by the product of the time division of each pixel and the number of pixels in each illumination area.

Finally, as shown in FIG. 8D, in this example, the projection lens 24a is moved at one pixel pitch (or continuously) with one frame time indicated by the arrow Dw as one cycle.
In this case, the driving is performed in the reverse direction at the intermediate point of one frame, and the driving is finally returned to the original state, so that the blank time is not required. However, the present invention is not limited to this driving method, and the method shown in FIG. 5D may be used. In the configuration in which the illumination light is moved in the first embodiment, FIG. ) May be used. In the above-described configuration for performing color display by moving the projection light on the screen, it is not always necessary to use the DMD for the display panel, and for example, good response of ON / OFF switching of a ferroelectric liquid crystal or the like is achieved. An element may be used.

FIGS. 9 to 11 described below are perspective views schematically showing the configuration near the TIR prism. Note that a predetermined short side of the display panel 16 is c and a long side is d.
First, FIG. 9 shows a conventional configuration. As shown in the figure, from the integrator I not shown here,
At an azimuth angle of 45 degrees with respect to the short side c of the display panel 16,
Light 9 as illumination light that has reached the TIR prism 22 along the optical axis La is incident on the incident surface 22ba of the prism 22b. Then, the light is reflected by the total reflection surface 22bb, exits from the entrance / exit surface 22bc, and travels toward the display panel 16. Immediately before that, the birefringent microcylinder lens array 15
a is arranged. The azimuth angle may be based on the long side.

Each pixel 16 in the ON state of the display panel 16
b (ON reflected light) passes through the birefringent microcylinder lens array 15a, and enters the entrance / exit surface 22bc.
And returns to the prism 22b, and transmits through the total reflection surface 22bb. Further, the light enters the incident surface 22aa and the prism 2
2a, the light 21 being the projection light from the exit surface 22ab
Then, the light is emitted along the optical axis Lb to reach a projection optical system (not shown). On the other hand, the reflected light (OFF reflected light) from each of the pixels 16b in the OFF state of the display panel 16 passes through the prism in the same manner as the ON reflected light, but finally the projection optics along the optical axis Lc. Injects in a direction away from the system.

Next, FIG. 10 shows a configuration in the first embodiment. As shown in the drawing, the integrator I (not shown) sets the TI along the optical axis La at an azimuth angle of approximately 0 degrees with respect to the short side c of the display panel 16.
The light 9 as illumination light that has reached the R prism 22 is incident on an incident surface 22ba of the prism 22b. Then, the light is reflected by the total reflection surface 22bb, exits from the entrance / exit surface 22bc, and travels toward the display panel 16. Hereinafter, the description is the same as that in FIG.

FIG. 11 shows the configuration of the second embodiment. As shown in the figure, the integrator I (not shown) emits light 9 as illumination light reaching the TIR prism 22 along the optical axis La at an azimuth angle of about 148 degrees with respect to the short side c of the display panel 16.
Is incident on the incident surface 22ba of the prism 22b. Then, the light is reflected by the total reflection surface 22bb, exits from the entrance / exit surface 22bc, and travels toward the display panel 16. Immediately before that, a birefringent microcylinder lens array 15a is arranged.

Each pixel 16 in the ON state of the display panel 16
b (ON reflected light) passes through the birefringent microcylinder lens array 15a, and enters the entrance / exit surface 22bc.
And returns to the prism 22b, and transmits through the total reflection surface 22bb. Further, the light enters the incident surface 22aa and the prism 2
2a, the light 21 being the projection light from the exit surface 22ab
Then, the light is emitted along the optical axis Lb to reach a projection optical system (not shown). On the other hand, the reflected light (OFF reflected light) from each pixel 16b in the OFF state of the display panel 16 returns to the prism 22b in the same manner as the ON reflected light.
The light is reflected by 2bb and finally returned to the illumination side along the optical axis Ld.

The reason for such a configuration is as follows. That is, in the DMD, the illumination light is reflected by the micromirror in the OFF state in a direction away from the projection optical system. However, since the OFF light actually passes through the TIR prism, a part of the light is Reaches the projection optics and appears as flare on the screen.

More specifically, as shown in FIG.
In FIG. 12 schematically showing the configuration near the IR prism, light 9 as illumination light is applied to a prism 22b.
Along the optical axis La, the light enters the incident surface 22ba via the condenser lens 23 immediately before. And the total reflection surface 22
When the light 9 is incident on bb at an incident angle exceeding the critical angle, most of the light 9 is reflected, exits from the entrance / exit surface 22bc, and travels toward the display panel 16. Immediately before that, a birefringent microcylinder lens array 15a that brings a microlens effect to predetermined polarized light is arranged.

The display panel 16 is formed of a DMD, and reflects the light 9 illuminated by a micromirror in an ON state or a micromirror in an OFF state according to display information for each pixel. At this time, the reflected light of ON is
Via the birefringent microcylinder lens array 15a,
The light enters the entrance / exit surface 22bc and returns to the prism 22b. Then, the light enters the total reflection surface 22bb at an incident angle within the critical angle and transmits therethrough, further enters the incident surface 22aa, transmits through the prism 22a, exits from the exit surface 22ab, and travels along the optical axis Lb. Projection optical system 24 as light 21 which is projection light
To reach. The projection optical system 24 projects display information on the display panel 16 onto a screen (not shown).

On the other hand, the OFF reflected light is
b and 22a, the light exits along the optical axis Lc in a direction that does not finally reach the projection optical system 24, but a part of the light reaches the projection optical system 24, particularly the edge portion. Then, it appears as a flare on the screen. In order to prevent this, a configuration as shown in FIG. 11 that completely blocks the OFF reflected light is employed.

FIGS. 13 to 15 to be described below are diagrams showing the angular relationship between the illumination light and the projection light.
11 corresponds to the configuration of FIG. In each drawing, the incident angle of the illumination light and the reflection angle of the projection light with respect to the display panel 16 are indicated by concentric circles having a radius proportional to the angle. Also, the short side c direction of the display panel 16 is indicated by a horizontal axis passing through the center O of the concentric circle, the right direction is set to 0 degree azimuth angle, and the long side d direction is indicated by a vertical axis passing through the center O of the concentric circle. The upward direction is an azimuth angle of 90 degrees.

A circle 51 indicated by a broken line in FIG.
The angular range of the luminous flux of the illumination light incident on the prism 22 is shown, and a circle 52 indicated by a dotted line indicates the angular range of the luminous flux of the illumination light incident on the display panel 16. A circle 53 indicated by a solid line indicates an angle range of a light beam of ON reflected light (projection light) emitted from the display panel 16, and a circle 54 indicated by a dashed line indicates a light beam of an OFF reflected light emitted from the display panel 16. The angle range is shown. Each circle has an F-number of 3.
3 shows the luminous flux range. Further, an arc 55 indicated by a solid line indicates a boundary of an angle range in which the light is reflected or transmitted by the total reflection surface of the TIR prism, and a side indicated by oblique lines is a transmission area.

First, FIG. 13 shows an angle range between the illumination light and the projection light in the above-mentioned conventional configuration. In the figure, the azimuth angle of the illumination light incident on the TIR prism 22 indicated by a circle 51 is 45 degrees, and the incident angle on the display panel 16 is about 105 degrees. The azimuth angle of the illumination light incident on the display panel 16 indicated by the circle 52 is 45 degrees, and the incident angle is 20 degrees. The reflection angle of the ON reflected light (projection light) emitted from the display panel 16 indicated by the circle 53 is 0 degree. Further, the azimuth angle of the OFF reflected light emitted from the display panel 16 indicated by the circle 54 is 225.
The degree and the reflection angle are 40 degrees.

The azimuth angle of the TIR prism 22 indicated by the arc 55 is 45 degrees, and the inclination of the total reflection surface with respect to the display panel 16 is 30.5 degrees. As shown in the figure, in the conventional configuration, the illumination light incident on the display panel 16 indicated by a circle 52 and the ON reflected light (projection light) emitted from the display panel 16 indicated by a circle 53 are in close contact. , TI indicated by arc 55
Since it is barely separated by the R prism 22, a bright lens with a small F number cannot be used here.

FIG. 14 shows an angle range between the illumination light and the projection light in the configuration of the first embodiment. In the figure, the azimuth angle of the illumination light incident on the TIR prism 22 indicated by a circle 51 is 0 degree, and the incident angle on the display panel 16 is less than 100 degrees. The azimuth angle of the illumination light incident on the display panel 16 indicated by the circle 52 is about 30 degrees, and the incident angle is less than 30 degrees. And
The azimuth angle of the ON reflected light (projection light) emitted from the display panel 16 indicated by the circle 53 is 180 degrees, and the reflection angle is about 10 degrees. Further, the azimuth angle of the OFF reflected light emitted from the display panel 16 indicated by the circle 54 is more than 210 degrees, and the reflection angle is more than 45 degrees.

The azimuth angle of the TIR prism 22 indicated by the arc 55 is -12 degrees, and the inclination of the total reflection surface with respect to the display panel 16 is 34 degrees. As shown in the figure, in the first embodiment, the illumination light incident on the display panel 16 indicated by a circle 52 and the ON light emitted from the display panel 16 indicated by a circle 53
Reflected light (projection light) has room for the range of F3, and a brighter lens with a small F number can be used here. In addition, since the illumination light incident on the TIR prism 22 is incident from a direction along the short side c of the display panel 16, the TIR prism 22 can be configured to be thin, and the lens back of the projection optical system 24 can be shortened. Can do things.

In this manner, the F-number can be obtained by inclining the projection light in a direction slightly along the short side from the vertical direction of the display panel and further using the non-axis projection optical system. In addition, by making the illumination light substantially coincide with the direction of the short side by the configuration method of the TIR prism, the size of the TIR prism can be reduced, and the configuration of the illumination optical system can be simplified.

In general, D which forms each pixel of the display panel
MD micromirror (for short side of display panel)
If the illuminating light incident on the display panel is within the range of 15 ° to 40 ° azimuth angle and 17 ° to 45 ° incident angle with respect to the configuration having an azimuth angle of 45 ° and a tilt of 10 °, the illuminating light incident on the TIR prism will be described. Is illuminated from the direction along the short side of the display panel (azimuth angle 0 °), it is possible to secure brightness of F number 3 or more. At this time, by setting the azimuth angle of the TIR prism to -11 degrees to -13 degrees, the illuminating light incident on the TIR prism has an azimuth angle near 0 degrees.

On the other hand, when the illuminating light incident on the display panel has an azimuth angle of 40 degrees or more and an incident angle of 17 degrees or less,
Only about F number 4 can be secured. When the azimuth angle is 15 degrees or less and the incident angle is 45 degrees or more, the reflection angle of the ON reflected light (projection light) emitted from the display panel becomes 30 degrees or more, and a non-axial optical system is used as the projection optical system. However, aberration correction becomes difficult. That is, here, the projection optical system may be configured to have the principal ray within an angle range of 3 to 30 degrees with respect to the normal direction of the display panel surface.
In conclusion, the azimuth angle of the DMD micromirror is Φ
(Angle formed by the plane perpendicular to the rotation axis on which the micromirror rotates and the short side of the display panel) When the inclination of the mirror is θ, the azimuth angle of the illumination light incident on the display panel is 0.3.
3Φ to 0.9Φ, and the incident angle may be 1.7θ to 4.5θ.

Finally, FIG. 15 shows an angle range between the illumination light and the projection light in the configuration of the second embodiment.
In the figure, the azimuth angle of the illumination light incident on the TIR prism 22 indicated by a circle 51 is about 148 degrees, and the display panel 16
Is less than 90 degrees. The azimuth angle of the illumination light incident on the display panel 16 indicated by the circle 52 is 90 degrees, and the incident angle is less than 15 degrees. The azimuth angle of the ON reflected light (projection light) emitted from the display panel 16 indicated by the circle 53 is 0 degree, and the reflection angle is less than 15 degrees. Further, the display panel 1 indicated by a circle 54
The azimuth angle of the OFF reflected light emitted from 6 is more than 240 degrees, and the reflection angle is more than 30 degrees.

The azimuth angle of the TIR prism 22 indicated by the arc 55 is 155 degrees, and the inclination of the total reflection surface with respect to the display panel 16 is 43.5 degrees. As shown in FIG.
In the embodiment, the illumination light incident on the display panel 16 indicated by a circle 52 and the ON reflected light (projection light) emitted from the display panel 16 indicated by a circle 53 are in close contact, and a TIR prism indicated by an arc 55 Since the lens is barely separated by 22, a bright lens with a small F-number cannot be used here. Also, TIR prism 2
2 cannot be made to enter from the direction along the short side c of the display panel 16, so that the size of the TIR prism cannot be reduced.

In the present embodiment, however, the OFF reflected light emitted from the display panel 16 indicated by the circle 54 can be brought to the reflection area of the total reflection surface of the TIR prism 22. The light can be totally reflected by the prism 22 so as not to pass through. This allows
OFF reflected light does not reach the projection optical system,
Flare on the screen can be prevented. In conclusion, assuming that the azimuth angle of the micromirror is Φ and the inclination of the mirror is θ, the azimuth angle of the illumination light incident on the display panel is 1.8Φ to 3Φ and the incident angle is 1θ to 2θ.

Here, when the azimuth angle is 1.8Φ or less and the incident angle is 1θ or less, only a value darker than the F number 4 can be secured under the condition that the OFF reflected light is totally reflected by the TIR prism. In addition, azimuth angle 3Φ or more,
When the incident angle is 2θ or more, the light is emitted from the display panel.
The reflection angle of the reflected light (projection light) becomes 30 degrees or more, and it becomes difficult to correct aberration even if a non-axial optical system is used as the projection optical system. That is, here, the projection optical system may be configured to have the principal ray within an angle range of 10 to 30 degrees with respect to the normal direction of the display panel surface.

When the pitch of one micro (cylinder) lens is much larger than the pixel pitch as in the first and second embodiments, the pitch of the micro lens = pixel pitch × 8 due to electrical control. It is better to be a multiple of. In digital processing, 8 bits are often handled as the minimum data unit. As can be seen from FIG. 2 and the like, since illumination in the same phase is performed for each pitch of the microlenses, digital control is difficult if the conditions are not satisfied.

FIG. 16 is a view schematically showing the configuration of a display optical device according to the third embodiment of the present invention. In the figure,
1 is a light source, and 2 is a reflector arranged so as to surround the light source 1. Reference numeral 7 denotes a UVIR cut filter that is disposed so as to cover the light emission port 2 a of the reflector 2 and that cuts ultraviolet light and infrared light included in the light from the light source 1 and the reflector 2. A birefringent diffraction grating 3, a first lens array 4, a second lens array 6 slightly apart, and a superimposing lens 8 immediately after the birefringent diffraction grating 3, a first lens array 4, are arranged behind the UVIR cut filter 7.

Although not shown here, the first lens array 4 has cells combined in a lattice, and the second lens array 6 has a rectangular shape divided in a direction different from that of the first lens array 4. Have each cell combined in a lattice shape. The birefringent diffraction grating 3 includes a second lens array 6
The light 9 from the light source 1 and the reflector 2 is polarized and separated in the long side direction of each cell. Polarization conversion is performed through the birefringent diffraction grating 3, the first lens array 4, and the second lens array 6, and light 9 from the light source 1 and the reflector 2 emerges with specific polarization. This configuration is called a polarization conversion device. The detailed relationship between them will be described later.

The second lens array 6 and the superimposing lens 8 immediately after the second lens array 6 allow the images of the respective cells of the first lens array 4 to be superimposed near a focal position of the superimposing lens 8 described later. In addition, the superposition lens 8
May be formed integrally with the second lens array 6. Further, instead of the birefringent diffraction grating 3, there is a type in which a birefringent prism array or the like is arranged between the first lens array 4 and the second lens array 6. The above-described first lens array 4 to the superimposing lens 8 are called an integrator optical system, and the optical axis is L. This superimposed lens 8
The display panel 16 is arranged at the focal position of the.

Then, first, R (red), G (green), B (blue) are provided between the superimposing lens 8 and the display panel 16.
Dichroic mirrors R _m , G _m , and B _m as color separation devices that reflect light in the respective wavelength regions are arranged with different inclinations, and a PBS (polarizing beam splitter) is provided behind the dichroic mirror (upper part of the figure). ) A prism 14 is arranged. At this time, the light 9 transmitted through the superimposing lens 8 on the optical axis L is reflected by the respective dichroic mirrors R _m , G _m , and B _m , and the optical axes L _R , L _G , and L _{B at} different angles. With PBS prism 14,
Eventually, it reaches the display panel 16.
Incidentally, the dichroic mirror _Bm may be a total reflection mirror. The light 9 reflected by the dichroic mirror is not shown.

The PBS prism 14 has a property of reflecting S-polarized light and transmitting P-polarized light. On the other hand, the light 9 from the light source 1 and the reflector 2 is incident on the PBS prism 14 while being substantially aligned with S-polarized light by the above-described polarization conversion. Therefore, the PBS prism 14
Most of the light 9 is reflected, and the display panel 16 on the left side of FIG.
Head for.

The birefringent microlens array 15 is arranged immediately before the display panel 16. This microlens array may be a microcylinder lens array (a lenticular type having a lens-shaped cross section). The light 9 that has been color-separated by the dichroic mirror is
Different pixels of the display panel 16 are illuminated for each color as illumination light. Details will be described later. With this illumination, the entire display panel 16 is sequentially illuminated in a stripe shape by each of the R, G, and B colors, and the pixels illuminated by each color perform information display of each color.

The display panel 16 is a reflection type liquid crystal display panel. The light illuminated here is rotated (ON) or not (OFF) by rotating the polarization plane according to display information for each pixel. reflect. At this time, the OFF reflected light returns to the PBS prism 14 via the birefringent microlens array 15, but remains as S-polarized light, so it is reflected here and returned to the light source side. On the other hand, the reflected light of ON is
Since the light has been converted into P-polarized light, it returns to the PBS prism 14 via the birefringent microlens array 15 and transmits therethrough to reach the next projection optical system 17. In particular, when a high-speed response is required, for example, as a reflective liquid crystal display panel, a ferroelectric liquid crystal (F) that modulates by changing the axial direction of birefringence.
LC) is used. The optical axis of the projection optical system 17 is L
b.

The projection optical system 17 allows the display panel 1
6 is projected on a screen (not shown). Some of the lenses of the projection lens group forming the projection optical system 17 serve as an image shifting lens 18 as an actuator 19.
Is driven at high speed in the direction perpendicular to the optical axis Lb as shown by the arrow α. This makes it possible to increase the number of pixels of display information. Details will be described later.

FIG. 17 is an exploded perspective view schematically showing the relationship between the birefringent diffraction grating and the first and second lens arrays in the present embodiment. In the figure, some of the cells in the lens array are shown as representatives. As shown in the figure, in the present embodiment, the side direction of each cell indicated by a solid line of the first lens array 4 is different from the side direction of each cell indicated by a broken line of the second lens array 6, and birefringence diffraction is performed. Blaze 3a of lattice 3
Is made along the side direction of each cell of the second lens array 6. Specifically, the diagonal direction of the side direction of each cell of the first lens array 4 is set to be the side direction of each cell of the second lens array 6.

The light 9 from the light source 1 and the reflector 2 (not shown) located diagonally below and to the left of the figure is illuminated by the blaze 3a of the birefringent diffraction grating 3 with light 9a having a predetermined polarization plane indicated by a solid line and perpendicular to the light 9a. The light is polarized and separated into light 9b indicated by a broken line having an appropriate polarization plane. These lights are transmitted through the individual cells A, B, C, and D arranged in the lattice of the first lens array 4 and are arranged in a rectangular lattice divided in a direction different from that of the first lens array 4. On each of the cells Aa, Ba, Ca, and Da of the two-lens array 6, a light source image having a predetermined polarization plane and a light source image having a polarization plane perpendicular thereto are created.

In order to form a light source image from cells A, B, C, and D in cells Aa, Ba, Ca, and Da arranged in different directions, the cells A, B, C, and D of the first lens array 4 are Each lens is slightly tilted or the lens apex is decentered. That is, the lens vertex is shifted from the center of the cell. Similarly, the second
Each of the cells Aa, Ba, Ca, and Da of the lens array 6 is also individually inclined or the vertex of the lens is decentered.

The light source images of these two light sources are
, That is, in the long side direction of each cell of the second lens array 6, and form a correct row. These light source images are projected with a certain size onto individual cells of the second lens array 6 as indicated by solid and broken ellipses (circles when viewed from the front of the lens array). You. By the way,
The coordinate system of the present example has the y-axis above the front of the first lens array 4 and the x-axis to the right as viewed from the light source side, and the side of each cell toward the front of the second lens array 6. The diagonally upper right direction along the direction is the ya axis, and the diagonally lower right direction is the xa axis.

According to such a configuration, the light source images in the second lens array 6 are less overlapped, and efficient polarization conversion can be performed. At this time, for example, a half-wave plate 5 in a strip shape may be attached along the row of the light source image indicated by the broken line ellipse, and the polarization planes of the separated light source images may be aligned. Incidentally, the size of the light source of the present embodiment and the area of the cells of the second lens array 6 are equal to those of the conventional system in which the cells of the first and second lens arrays are arranged in the same column direction (side direction is the same).

When the integrator has one stage as in the present embodiment, the cells of the first lens array 4 are
Should be approximately equal to the aspect ratio. Even in such a case, by making the side direction of each cell of the first lens array 4 and the side direction of each cell of the second lens array 6 different, efficiency is higher than in the conventional case where the side directions are the same. Good. FIG. 18 shows the first and the first cases when the integrator has one stage.
FIG. 9 is a front view schematically illustrating the positional relationship of the second lens array, and shows a case where the aspect ratio is 4: 3. As shown in the drawing, here, one diagonal direction of each cell indicated by a solid line of the first lens array 4 is set to be the long side direction of each cell indicated by a broken line of the second lens array 6.

The light 9 from the light source 1 and the reflector 2 (not shown) is polarized by the birefringent diffraction grating 3 (not shown) into light having a predetermined polarization plane and light having a polarization plane perpendicular thereto. Separated. These lights are the first
The lens array 4 has a rectangular lattice shape that transmits the individual cells A, B, C, D, E, and F arranged in a lattice shape having an aspect ratio of 4: 3 and is divided in a direction different from that of the first lens array 4. , The individual cells Aa, Ba, of the second lens array 6
A light source image having a predetermined polarization plane and a light source image having a polarization plane perpendicular thereto are created on Ca, Da, Ea, and Fa, respectively.

The light source images of these two light sources are
In the direction of separation by These light source images are projected with a certain size onto individual cells of the second lens array 6 as indicated by solid and broken circles. Incidentally, the coordinate system of the present example has the y-axis above the front of the first lens array 4 as viewed from the light source side and the x-axis to the right, and each cell toward the front of the second lens array 6. The yaw axis is the diagonally upper right direction along the side direction of
The diagonally lower right direction is the xa axis.

In the present embodiment, as shown in FIG. 17, the birefringence direction of the birefringent diffraction grating 3 is aligned with the ya axis direction which is the groove direction of the blaze 3a. The two types of light 9a and 9b shown, and the two types of light source images shown by the solid line and the broken line ellipse, have polarization planes in the xa-axis and ya-axis directions, respectively. However, for the optical system in which these lights are incident next, the polarization planes must be aligned in the y-axis direction. Therefore, different optical axes that intersect each other at 45 ° are arranged in each of the two light source image columns. The polarization planes are simultaneously aligned by using a band-shaped half-wave plate.

As another method of aligning the polarization planes, first, a stripe of the light source image in one of the two types of light source images is added to the column.
After using a two-wavelength plate to align the polarization plane with the other light source image, the entire polarization plane is aligned at once in the y-axis direction.
It is also possible to use a two-wave plate on the entire surface of the second lens array 6. Further, the birefringence direction of the birefringent diffraction grating 3 is not set in the groove direction of the blaze 3 a, that is, in the long side or short side direction of each cell of the second lens array 6, but in the long side or short side of each cell of the first lens array 4. The direction may be the side direction. Also,
A polarization separation method other than the method using the birefringent diffraction grating may be performed.

FIG. 19 is a diagram schematically showing the relationship between the birefringent microlens array and the display panel in the present embodiment. As shown in FIG. 16, a birefringent microlens array 15 made of a birefringent material is arranged immediately before the display panel 16. Then, the light 9 separated into RGB by the dichroic mirror 9
The birefringent microlens array 15 illuminates the same plurality of adjacent pixels on the display panel 16 for each color. In the present embodiment, two identical pixels are adjacent to each other and are arranged for each color, that is, R
1, R2, G1, G2, B1, B2.

Here, the light 9 is incident on each microlens 15b of the birefringent microlens array 15 in units of a plurality of pixels (here, two pixels) × three colors while changing the angle for each of RGB, and the display panel 16 R1, R2, G
The light is condensed on pixels 1, G2, B1, and B2. Thus, by arranging the same plural pixels adjacent to each other, the focal length of each microlens becomes long, and an efficient configuration can be realized. The left and right sides of the birefringent microlens array 15 and the display panel 16 in FIG.

FIG. 20 is a schematic diagram showing a material configuration of a birefringent microlens array. In the present embodiment, since a reflective liquid crystal display panel is used as the display panel 16, in this case, the birefringent microlens array 15 immediately before the display panel 16 has the light 9 incident on the display panel 16.
Both (illumination light) and light 21 (projection light) reflected from the display panel 16 pass through. The light 9 incident on the display panel 16 acts as described above, but the reflected light 21
In this case, the light rays are disturbed by the birefringent microlens array 15 as it is, and the image quality deteriorates.

To cope with this, in the present embodiment, the birefringent microlens array 15 is made of an isotropic optical material and an optical material having birefringent characteristics. In the figure, the light 9 incident on the display panel 16 has a specific polarization plane, for example, a polarization plane perpendicular to the paper surface. Of the reflected light, the light 21 effective for displaying an image has its polarization plane rotated. And has, for example, a plane of polarization along the plane of the paper.

Therefore, the birefringent microlens array 15
The refractive index of the isotropic optical material above the microlens 15b is defined as N, and the microlens 15b
The refractive index of the lower birefringent material with respect to the polarization plane of the light 9 is Ne, and the refractive index of the light 21 with respect to the polarization plane is No. At this time, by setting N = No, the birefringent microlens array 15 functions as a microlens array for the light 9 and becomes a simple transparent flat plate for the light 21. Thus, even if the reflective display panel is used, the light 2
1 does not degrade the image quality.

In the figure, for the sake of explanation, the light 9 enters the display panel 16 in an oblique direction and is reflected as the light 21 in the opposite oblique direction. The main optical axis of each of the light 9 and the light 21 is perpendicular to the display panel 16. The birefringent microlens array 1 shown in FIG.
5 and the left and right sides of the display panel 16 are not shown.
The configuration from the light source 1 to the birefringent microlens array 15 described above is referred to as an illumination optical system.

FIG. 21 is a perspective view schematically showing the principle of pixel shift in the projection optical system. In this embodiment,
Since the display panel 16 is a single plate, for example, in order to display an image with a resolution of XGA (1024 pixels × 768 pixels), pixels are required for each of the RGB colors. Three times as many pixels as XGA pixels are required, and the display panel becomes large and costly. Therefore, the number of pixels of the display panel is the same as that of XGA even though it is a single plate, and the pixels to be displayed on the screen are shifted at high speed, thereby enabling color XGA display.

More specifically, a part of the lens of the projection optical system 17 shown in FIG. 9 is driven as an image shift lens 18 at a high speed in the direction perpendicular to the optical axis Lb as shown by the arrow α. At this time, paying attention to the light of B representatively from the projected light from the display panel 16, as shown by the arrow β, the position which was the row of B1 and B2 on the screen 20 in FIG. The rows of G1 and G2 are made to come in FIG. 6B, and the rows of R1 and R2 are made to come in FIG. Finally, the state returns to the state shown in FIG. The three states are repeated at high speed as described above. In addition, control is performed by switching the display content according to each state, and color display is performed by shifting and temporally superimposed images.

The image shift lens 18 is driven by the actuator 19 shown in FIG. 16 in the same order as the pixel size, that is, in a unit of 10 μm to several tens μm.
As the actuator, for example, an MC (moving coil), MM (moving magnet), or the like is suitable for high-power and high-speed driving.

The configuration of the above-described pixel shift is shown again as Example 1 as follows. R1R2G1G2B1B2 (first frame) R1R2G1G2B1B2 R1R2G1G2B1B2 R1R2G1G2B1B2 (second frame)

In this example, the shift is performed in three stages in one frame by a mechanism for shifting a plurality of pixels of the same color on the display panel by a plurality of pixels on the screen, and the process returns to the beginning of the next frame. If the light source has intensity unevenness, a difference in brightness occurs between pixels (for example, R1 and R2) of the same color at different locations.

The configuration of the pixel shift for preventing this is shown as Example 2 below. R1R2G1G2B1B2 (1st frame) R1R2G1G2B1B2 R1R2G1G2B1B2 R1R2G1G2B1B2 ... R1R2G1G2B1B2 ... R1R2G1G2B1B2 R1R2G1G2B1B2 ... (2nd frame)

In this example, the pixel is shifted in six stages in one frame by a mechanism for shifting the pixel so that the pixel of the same color of the display panel at another place overlaps on the screen, and returns to the beginning of the next frame. It is a configuration to return. This makes it possible to suppress brightness unevenness, but here, it is necessary to frequently perform drive control of pixel shift.

A configuration of a pixel shift for preventing brightness unevenness with a margin for drive control is shown below as Example 3. R1R2G1G2B1B2 (1st frame) R1R2G1G2B1B2 R1R2G1G2B1B2 R1R2G1G2B1B2 (2nd frame) R1R2G1G2B1B2 ... R1R2G1G2B1B2 R1R2G1G2B1B2 ... (3rd frame)

In this example, the shift is performed in three stages in one frame by a mechanism for shifting a plurality of pixels of the same color on the display panel by a plurality of pixels on the screen, and at the beginning of the next frame,
This is a configuration in which the display panel returns to the position where the pixel of the same color and another place overlaps, shifts in three steps in the same manner, and returns to the initial position at the beginning of the next frame. In the above-described pixel shift configuration, an example is shown in which two pixels of the same color are arranged side by side. However, the present invention is not limited to this, and a configuration in which several pixels are adjacent to each other is also possible. Various combinations of pixel shift configurations are also conceivable.

FIG. 24 is a configuration diagram schematically showing a display optical device according to the fourth embodiment of the present invention. Although the arrangement of each part is originally three-dimensional, it is described in a planar shape to facilitate understanding. In the figure, 1 is a light source, 2
Is a reflector arranged so as to surround the light source 1. Reference numeral 7 denotes a UVIR cut filter that is disposed so as to cover the light emission port 2 a of the reflector 2 and that cuts ultraviolet light and infrared light included in the light from the light source 1 and the reflector 2.

Behind the UVIR cut filter 7 (to the right in the figure), the first lens array 4, the second lens array 6 slightly apart, and the superimposing lens 8 immediately after it are arranged. Although not shown here, the first lens array 4 has cells combined in a lattice shape, and the second lens array 6 is combined in a different lattice shape from the first lens array 4. Each cell. The ratio of the length of the long side to the short side of each cell is the same as that of the display surface of the display panel described later, that is, has a similar shape. Further, a mask plate 31 described later is provided between the second lens array 6 and the superimposing lens 8.

The first lens array 4 has a birefringent diffraction grating, and separates the light 9 from the light source 1 and the reflector 2 in the short side direction of each cell of the second lens array 6. . First lens array 4, second lens array 6
The polarization conversion is performed through the light source 1 and the reflector 2
From the light 9 (not shown) comes out in alignment with a specific polarization. This configuration is called a polarization conversion device. The detailed relationship between them will be described later.

Further, the first lens array 6 and the superimposing lens 8 immediately behind the second lens array 6 allow the first panel to be described later on a display panel.
The images of the cells of the lens array 4 are made to overlap. The superimposing lens 8 may be formed integrally with the second lens array 6. The above-described first lens array 4 to the superimposing lens 8 are called an integrator optical system I, and the optical axis is L. The condenser lens 32 is arranged at the focal position of the superimposing lens 8. Alternatively, in order to further improve the efficiency of illumination, the combined focal position of the superimposing lens 8 and the condenser lens 32 may be used as a display panel. In this case, for ease of explanation, the former configuration is adopted.

Then, between the superposing lens 8 and the condenser lens 32, R (red), G (green), B (blue)
Dichroic mirrors R _m , G _m , and B _m as color separation optical systems that reflect light in the respective wavelength regions are arranged at different inclinations. And UVIR at the optical axis L
The light 9 transmitted through the cut filter 7 is R _m , G _m ,
B _m are reflected by the respective dichroic mirrors, and are directed to the condenser lens 32 disposed at the rear (lower side in the figure) behind the optical axes L _R , L _G , and L _B (indicated by broken lines, solid lines, and dotted lines) at different angles. Trying to reach.
Incidentally, the dichroic mirror _Bm may be a total reflection mirror.

A micro cylinder lens array 33 is arranged behind the condenser lens 32 (below the figure). This micro cylinder lens array may be a micro lens array. Further behind it,
A PBS (polarizing beam splitter) prism 14 is provided. The PBS prism 14 has a property of reflecting S-polarized light and transmitting P-polarized light. On the other hand, the light 9 from the light source 1 and the reflector 2 is substantially aligned to the S-polarized light on the PBS prism 14 by the above-described polarization conversion, and is incident along the optical axis La.

Therefore, the PBS prism 14
Most of the light 9 is reflected, and the display panel 16 on the left side of FIG.
Head for. The light 9 that has been color-separated by the dichroic mirror is illuminated by the micro-cylinder lens array 33 into the display panel 1 for each color as illumination light.
Illuminate 6 different pixels. Details will be described later. With this illumination, the entire display panel 16 is sequentially illuminated in a stripe shape by each of the R, G, and B colors, and the pixels illuminated by each color perform information display of each color. The configuration described above is an example of an illumination optical device.

The display panel 16 is a reflection type liquid crystal display panel, and an element having a high ON / OFF switching response such as a ferroelectric liquid crystal or a high-speed TN type liquid crystal is used. The light illuminated here is reflected by rotating (ON) or not rotating (OFF) the polarization plane according to the display information for each pixel. At this time, the OFF reflected light returns to the PBS prism 14 but remains S-polarized light, so it is reflected here and returned to the light source side.

On the other hand, since the ON reflected light has been converted to P-polarized light, it returns to the PBS prism 14 and transmits therethrough, and is projected along the optical axis Lb as light 21 as the next projected optical system 17. To reach. The projection optical system 17 projects display information on the display panel 16 onto a screen (not shown). The light 21 is not shown. The configuration of the projection optical system and the screen described above is an example of a projection optical device.

FIG. 25 is a view schematically showing the configuration of a display optical device according to a fifth embodiment of the present invention. Although the arrangement of each part is originally three-dimensional, it is described in a planar shape to facilitate understanding. In the figure, 1 is a light source, 2
Is a reflector arranged so as to surround the light source 1. Reference numeral 7 denotes a UVIR cut filter that is disposed so as to cover the light emission port 2 a of the reflector 2 and that cuts ultraviolet light and infrared light included in the light from the light source 1 and the reflector 2.

Behind the UVIR cut filter 7 (to the right in the figure), the first lens array 4, the second lens array 6 slightly apart, and the superimposing lens 8 immediately after it are arranged. Although not shown here, the first lens array 4 has cells combined in a lattice shape, and the second lens array 6 is combined in a different lattice shape from the first lens array 4. Each cell. The ratio of the length of the long side to the short side of each cell is the same as that of the display surface of the display panel described later, that is, has a similar shape. Further, a mask plate 31 described later is provided between the second lens array 6 and the superimposing lens 8.

Further, the first lens array 6 and the superimposing lens 8 immediately behind the second lens array 6 allow the first panel to be attached to a display panel described later.
The images of the cells of the lens array 4 are made to overlap. The superimposing lens 8 may be formed integrally with the second lens array 6. The above-described first lens array 4 to the superimposing lens 8 are called an integrator optical system I, and the optical axis is L. The condenser lens 32 is arranged at the focal position of the superimposing lens 8.

Then, between the superposing lens 8 and the condenser lens 32, R (red), G (green), B (blue)
Dichroic mirrors R _m , G _m , and B _m as color separation optical systems that reflect light in the respective wavelength regions are arranged at different inclinations. And UVIR at the optical axis L
The light 9 transmitted through the cut filter 7 is R _m , G _m ,
B _m are reflected by the respective dichroic mirrors, and are directed to the condenser lens 32 disposed at the rear (lower side in the figure) behind the optical axes L _R , L _G , and L _B (indicated by broken lines, solid lines, and dotted lines) at different angles. Trying to reach.
Incidentally, the dichroic mirror _Bm may be a total reflection mirror.

A micro-cylinder lens array 33 is arranged behind the condenser lens 32 (below the figure). This micro cylinder lens array may be a micro lens array. Behind the micro cylinder lens array 33, a TIR prism 2
2 are arranged. The TIR prisms 22 are prisms 22b and 22 made of glass or the like having a triangular prism shape, respectively.
a has a configuration in which certain surfaces face each other. The prism 22b has an entrance surface 22ba, a total reflection surface 22bb also serving as an exit surface, and an entrance / exit surface 22bc.
a has an entrance surface 22aa and an exit surface 22ab. Total reflection surface 22bb and incidence surface 22 facing each other
The distance from aa is several μm to several tens μm.

The light 9 transmitted from the light source 1 and the reflector 2 transmitted through the condenser lens 32
With respect to 2b, it is incident on the incident surface 22ba along the optical axis La. When the light 9 is incident on the total reflection surface 22bb at an incident angle exceeding the critical angle, most of the light 9 is reflected,
The light exits from the entrance / exit surface 22bc and travels toward the display panel 16 as illumination light. The configuration described above is an example of an illumination optical device. The display panel 16 is composed of a DMD,
The illuminated light 9 is converted into O in accordance with display information for each pixel.
The light is reflected by the micromirror in the N state or the micromirror in the OFF state. At this time, the ON reflected light is incident on the entrance / exit surface 22bc and returns to the prism 22b.

Then, the light enters the total reflection surface 22bb at an incident angle within the critical angle, transmits therethrough, further enters the incident surface 22aa, passes through the prism 22a, exits from the exit surface 22ab, and exits from the optical axis Lb. Along the projection optical system 24 as light 21 as projection light. The projection optical system 24 projects display information on the display panel 16 onto a screen (not shown). The light 21 is not shown. On the other hand, OF
The reflected light of F transmits through the prisms 22b and 22a,
Finally, the light is emitted in a direction that does not reach the projection optical system 24.

The configuration of the projection optical system and the screen described above is taken as an example of the projection optical device. The display panel 1
A ferroelectric liquid crystal, a high-speed TN type liquid crystal, or the like can be used instead of the DMD as 6, but in that case, a polarizing plate is separately required. Specifically, polarizing plates are disposed on the illumination light incident side and the projection light exit side of the TIR prism 22 such that their polarization planes are orthogonal to each other.
It is necessary to arrange a polarizing plate between the prism 22 and the display panel 16.

FIGS. 26A and 26B are enlarged schematic views showing main parts of the display optical device according to the fourth or fifth embodiment of the present invention. FIG. 26A is an overall view, and FIG. It is a side view of the integrator optical system part. The light 9 incident along the optical axis L is the same as described with reference to FIGS.
Reaches the first lens array 4 of the integrator optical system I. Behind the first lens array 4 (below the figure),
The second lens array 6 is disposed slightly away, and the superimposed lens 8 is disposed immediately after the second lens array 6. Between the second lens array 6 and the superimposed lens 8, there is provided a mask plate 31 having a slit 31 a which is an opening for regulating the opening width of each cell of the second lens array 6. Details will be described later.

The first lens array 4 has cells 4a combined in a lattice, and the second lens array 6
Has each cell 6 a combined in a grid shape different from the first lens array 4. In each of these cells, the left-right direction in FIG. The light 9 arriving at the first lens array 4 forms an image on each cell 6a of the second lens array 6 which is arranged at a distance behind the individual cell 4a for each individual cell 4a.

Also, the first lens array 4 is shown in FIG.
As shown in (2), it has a birefringent diffraction grating, and performs polarization separation of light 9 in the short side direction of each cell of the second lens array 6. Here, the first lens array 4 and the second lens array 6
Through which the light 9 is converted into a specific polarization. The principle of this polarization conversion is described in FIG.
The contents are the same as those described in. However, such a polarization converter uses a DMD and TIR prism as shown in FIG.
This is not necessary in the configuration of the fifth embodiment shown in FIG.

Next, returning to FIG. 26A, the image of each cell of the first lens array 4 is displayed on a display panel 16 described later by the second lens array 6 and the superimposing lens 8 immediately after the second lens array 6. I try to overlap. Light 9 emitted from the superimposing lens 8 is reflected by dichroic mirrors of R _m , G _m , and B _m , color-separated into RGB, and optical axes L _R , L _G , and L _{B at} different angles. The light reaches the condenser lens 32 disposed rearward (right side in the figure) at a position indicated by a broken line, a solid line, and a dotted line.

Then, the light passes through the micro-cylinder lens array 33 and the illumination / projection separation optical system 34, and by the operation of each micro-cylinder lens 33a of the micro-cylinder lens array 33, the display panel 16 for each color.
To illuminate. Note that a diffraction lens may be used instead of the micro cylinder lens 33a. The illumination / projection separation optical system 34 is, for example, the PBS prism 14 in the fourth embodiment shown in FIG. 24 or the TIR prism 22 in the fifth embodiment shown in FIG.
It means an optical system that separates illumination light and projection light.

By arranging the micro-cylinder lens array immediately before the illumination / projection separation optical system (illumination-side incident position) in this way, illumination is performed for each tens of pixels in areas of RGB colors. The microcylinder lens array 33 is driven at a fine pitch or continuously in one frame along its surface as shown by an arrow Gw in FIG. 26 or FIG. 24, FIG. ing. By performing pixel display in conjunction with this, it is possible to perform good color display on the entire screen.

More specifically, as shown in FIG. 27, stripe-shaped illumination (hereinafter, referred to as RGB) on the display panel 16 in each of RGB colors.
(Referred to simply as a stripe), and is moved in the direction indicated by the arrow Gw with one frame time as one cycle.
Here, the pitch of the stripes s is 1 to 2 mm, which is coarse as compared with the size of the pixels of the display panel 16. In this way, R
GB light is sequentially illuminated.

FIG. 28 is a diagram schematically showing the configuration of the above-described mask plate 31. As shown in FIG. FIG. 3A shows a schematic configuration of the mask plate 31 and a positional relationship between the mask plate 31 and the second lens array 6 as viewed from the optical axis. FIG. 2B is a graph showing the relationship between the position on the display panel and the light intensity as viewed from the cross-sectional direction of each of the stripes as the illumination light. First, in FIG. 2A, in the second lens array 6, the cells 6a are arranged in a lattice, and the entire lens array is substantially square. Specifically, four cells 6a are arranged in the long side direction and six in the short side direction.

However, the present invention is not limited to such an arrangement. For example, four to eight cells 6a are arranged in the long side direction, and in the short side direction, the entire lens array is substantially square. As many as the number corresponding to the ratio of the length of the long side and the length of the short side are arranged. Here, the second lens array 6 is opened only at the slit 31a thereof by the mask plate 31 arranged on the second lens array 6. That is, light is transmitted only in this portion. Specifically, at the center of each cell 6a of the second lens array 6, a width a ₀ of 1/3 in the long side direction.
Only in the open state. The slit may be a state in which a hole is simply opened or a state in which this part is transparent.

With such a configuration, the width of the light source image Li on each cell is regulated, and as a result, the width of each stripe illuminated on the display panel is regulated, so that the interference between adjacent stripes can be calculated. Can be prevented. However, in the state where the aperture is １ ／ wide as described above, the width of each stripe is not sufficiently regulated due to errors and aberrations, as shown in FIG. That is, the B stripe indicated by the dotted line and the R stripe indicated by the broken line, or the R stripe and the G stripe indicated by the solid line still partially interfere with each other, which causes a reduction in color purity of an image.

Accordingly, the width of the opening is further restricted. FIG. 29 is a diagram schematically showing a configuration of a mask plate 31 with a reduced opening width. FIG. 2A shows a schematic configuration of the mask plate 31 and a positional relationship between the mask plate 31 and the second lens array 6 as viewed from the optical axis. FIG. 3B is a graph showing the relationship between the position of each stripe on the display panel and the light intensity in this configuration.

In FIG. 15A, if the opening width of the slit 31a near the center of the mask plate 31 is a ₁ and the opening width of the slit 31a near the periphery is a ₂ , a ₁ is, for example, a
A 0.7 to 0.95 times the _0, a ₂ has a smaller value than a _1. In other words, the closer the slit 31a is to the periphery, the smaller the opening width is. This is because the light source image Li on each cell closer to the periphery among the cells of the lens array is distorted in an elliptical shape due to the influence of aberration and becomes smaller. Thus, the width of each of the stripes is effectively regulated while suppressing the deterioration of the illumination efficiency, interference between the stripes is prevented, and the color purity is not impaired.

With such a configuration, as shown in FIG. 14B, the width of each stripe is sufficiently regulated, and adjacent stripes, that is, a stripe B indicated by a dotted line and an R stripe indicated by a broken line, or Since the R stripe and the G stripe indicated by the solid line do not interfere with each other and do not separate from each other, the illumination efficiency and the color purity are maintained.

Further, there is a method using a density filter as a configuration for more effectively satisfying both the illumination efficiency and the regulation of the width of each stripe. This is because, as shown in FIG. 30, in the vicinity of the periphery of the aperture width a ₀ of each slit 31a of the mask plate 31, a configuration in which the transmittance was set to continue to decrease as it approaches the periphery thereof. As a result, the width of each stripe can be more effectively regulated while maintaining the illumination efficiency, and interference between the stripes can be prevented so that the color purity is not impaired.

As another configuration, there is a method of making the opening width of the slit variable. For example, as shown in FIG. 31, a mask plate 31 shown by a solid line and a mask plate 35 shown by a broken line are overlapped, and a portion where the slits 31a and 35a overlap is used as an actual slit. In this case, the mask plates 31 and 35 are configured to be driven in opposite directions in conjunction with each other along an arrow Hw that is the width direction of the slit opening in FIG. Accordingly, the opening width can be adjusted without the center position of the slit being shifted with respect to each cell 6a of the second lens array 6.

The opening width is adjusted according to the intensity of light outside the device. That is, when an image is projected using the display optical device of the present embodiment, the opening width of the slit is changed according to the brightness of the room to be used. That is, when the room is relatively bright, the opening width of the slit is increased to make the projected image bright and easy to see, and when the room is relatively dark, the image quality is emphasized with emphasis on the color purity of the projected image. In order to increase the width, the opening width of the slit is reduced. Alternatively, the device may be adjusted and fixed to have a standard opening width before shipment of the device.

The driving of the mask plate may be performed by a method in which the intensity of external light is detected by a sensor (not shown) provided in the apparatus, and the detected light intensity is fed back by a motor or the like (not shown). The method may be performed manually while viewing the image. It should be noted that the configuration using the mask plate as described above can be used in the above-described first and second embodiments after the arrangement of the integrator optical system and the dichroic mirror for performing color separation are changed. it can.

Now, a method of driving the above-described micro cylinder lens array 33 will be described below. FIG.
2 schematically shows an example in which the micro cylinder lens array is driven back and forth. In the figure, the micro cylinder lens array 33 is drawn in a state viewed from the optical axis direction. Of the micro cylinder lens array 33,
A cam 36 is in contact with the vicinity of the center of the side surface 33b along the longitudinal direction of each micro cylinder lens 33a,
The opposite side surface 33 c is urged by, for example, a spring 37 and presses the micro-cylinder lens array 33 against the cam 36.

At this time, when the cam 36 rotates around the axis 36a, the eccentricity causes the micro-cylinder lens array 33 to become one of the arrangements of the micro-cylinder lens 33a.
It is driven back and forth by the pitch p in the direction of arrow Gw. Thereby, the illumination light on the pixels of the display panel 16 (not shown) can be moved.

FIG. 33 is a perspective view showing an example in which the micro cylinder lens is continuously driven. Here, a large number of micro cylinder lenses 38a are connected in a belt shape to form a ring shape. This is called a micro cylinder lens group 38. Micro cylinder lens group 38
Is connected to the two pulleys 39 supported by the shaft,
The PBS prism 14 is disposed between the pulleys 39. Now, when the pulley 39 is rotated in the direction of each arrow by a motor or the like (not shown), the micro cylinder lens group 38 is rotated, and the micro cylinder lens 38a is continuously driven in the arrangement direction, that is, the direction shown by the arrow Gw.

At this time, when the light 9 enters the micro-cylinder lens group 38 from the optical axis direction indicated by the arrow, it reaches the PBS prism 14 via the micro-cylinder lens 38a and is reflected there to illuminate the lower display panel 16. I do. Here, the illumination light on the display panel 16 moves continuously. The positional relationship between the micro cylinder lens, the PBS prism, and the display panel in FIG.
Are slightly different from those shown in FIG.

Incidentally, the illumination optical system referred to in the claims is:
This corresponds to the illumination optical device in the embodiment.

[0151]

As described above, according to the present invention,
It is possible to provide a high-resolution display optical device capable of efficiently configuring a display panel having a fine pixel pitch.

In particular, by providing the illumination optical system with a mask plate having an opening for regulating the light source image and having a predetermined arrangement, the width of each of the RGB stripes to be illuminated on the display panel is regulated. Interference between matching stripes can be prevented.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing a display optical device according to a first embodiment of the present invention.

FIG. 2 is an enlarged schematic diagram illustrating a main part of the display optical device according to the first embodiment.

FIG. 3 is a schematic diagram showing a material configuration of a birefringent microcylinder lens array.

FIG. 4 is an explanatory diagram (configuration) of a principle of performing color display by moving illumination light on a pixel.

FIG. 5 is an explanatory diagram (operation) of a principle of performing color display by moving illumination light on a pixel.

FIG. 6 is a configuration diagram schematically showing a display optical device according to a second embodiment of the present invention.

FIG. 7 is an explanatory diagram (configuration) of a principle of performing color display by moving projection light on a screen.

FIG. 8 is an explanatory diagram (operation) of a principle of performing color display by moving projection light on a screen.

FIG. 9 is a perspective view schematically showing a configuration near a TIR prism (conventional example).

FIG. 10 is a perspective view schematically showing a configuration near a TIR prism (first embodiment).

FIG. 11 is a perspective view schematically showing a configuration near a TIR prism (second embodiment).

FIG. 12 is a diagram schematically showing a configuration near a conventional TIR prism.

FIG. 13 is a diagram showing an angle range between illumination light and projection light in a conventional configuration.

FIG. 14 is a diagram showing an angle range between illumination light and projection light in the configuration of the first embodiment.

FIG. 15 is a diagram illustrating an angle range between illumination light and projection light in the configuration of the second embodiment.

FIG. 16 is a configuration diagram schematically showing a display optical device according to a third embodiment of the present invention.

FIG. 17 is an exploded perspective view schematically showing a relationship between a birefringent diffraction grating and first and second lens arrays.

FIG. 18 is a front view schematically showing the positional relationship between the first and second lens arrays when the number of integrators is one;

FIG. 19 is a diagram schematically showing a relationship between a birefringent microlens array and a display panel.

FIG. 20 is a schematic diagram showing a material configuration of a birefringent microlens array.

FIG. 21 is a perspective view schematically showing the principle of pixel shift in the projection optical system.

FIG. 22 is a diagram schematically illustrating a relationship between a microlens array and a display panel, which is an example of the related art.

FIG. 23 is a view schematically showing a relationship between a microlens array and a display panel, which is another example of the related art.

FIG. 24 is a configuration diagram schematically showing a display optical device according to a fourth embodiment of the present invention.

FIG. 25 is a configuration diagram schematically showing a display optical device according to a fifth embodiment of the present invention.

FIG. 26 is an enlarged schematic diagram showing a main part of a display optical device according to a fourth or fifth embodiment of the present invention.

FIG. 27 is a diagram schematically showing a manner in which stripe-like illumination is performed on the display panel in each of RGB colors.

FIG. 28 is a diagram schematically showing a configuration of a mask plate.

FIG. 29 is a diagram schematically showing a configuration of a mask plate having a reduced opening width.

FIG. 30 is a diagram schematically showing a configuration of a mask plate using a density filter.

FIG. 31 is a diagram schematically showing a configuration of a mask plate in which an opening width of a slit is variable.

FIG. 32 is a schematic view showing an example in which a micro cylinder lens array is driven back and forth.

FIG. 33 is a perspective view showing an example of continuously driving a micro cylinder lens array.

[Explanation of symbols]

Reference Signs List 1 light source 2 reflector 3 birefringent diffraction grating 4 first lens array 6 second lens array 7 UVIR cut filter 8 superimposing lens 14 PBS prism 15 birefringent microlens array 16 display panel 17 projection optical system 18 image shifting lens 19 actuator 22 TIR prism 23, 32 Condenser lens 31, 35 Mask plate 33 Micro cylinder lens array 34 Illumination / projection separation optical system R _m , G _m , B _m Dichroic mirror

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H091 FA02X FA07X FA14X FA21X FA29X FA41Z FD07 HA12 LA21 LA30 5G435 AA00 BB12 BB16 BB17 CC12 DD02 DD04 FF03 FF05 FF13 GG01 GG02 GG03 GG04 GG11 GG16 GG28 LL

Claims (7)

[Claims] 1. Illumination for illuminating a display panel by separating light from a light source in different directions for each predetermined wavelength region and shifting the separated illumination light continuously or at a fine pitch. A display optical device comprising an optical system, wherein a plurality of light beams of three colors RGB are alternately arranged as the illumination light, and each of the same color lights illuminates a plurality of adjacent pixels of the display panel; A display having a mask plate having an opening for regulating a light source image, and a color separation optical system for separating light from the light source in different directions for each predetermined wavelength region after the mask plate. Optical device. 2. The display optical device according to claim 1, wherein the number of the openings is plural. 3. The illumination optical system includes an integrator including a lens array, and the mask plate is arranged such that the opening regulates an opening width of each cell of the lens array. The display optical device according to claim 1. 4. The display optical device according to claim 3, wherein an opening width of each cell is equal to or less than one third of a total width of each cell. 5. The display optical device according to claim 3, wherein an opening width of each of the cells becomes narrower nearer to a periphery of the lens array. 6. The display optical device according to claim 1, wherein a density filter is used in an opening of said mask plate. 7. The display optical device according to claim 1, wherein the width of the opening of the mask plate can be adjusted.