JP2000075405A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an object existing behind a screen visible by using a polarized light scattering plate as a screen and displaying an image by projecting this image to this polarized light scattering plate. SOLUTION: The polarized light scattering plate 12 having dependency on polarized light is used as the screen for projecting and displaying the video by a liquid crystal projector 11 which is the display device. The video is formed on the polarized light scattering plate 12 which is disposed in such a direction where the light parallel with the polarization direction of the exit light from the liquid crystal projector 11 is scattered. In such a case, the object (for example, a turtle) 13 is placed in the position behind the polarized light scattering plate 12 which is the screen when viewing from a person 14 viewing the video, by which the effective video expression to enable the person to have the depth feel between the object 13 and the video projected to the polarized light scattering plate 12 which is the screen is made possible. Namely, the person 14 is able to view the image of the object 13 existing behind the polarized light scattering plate 12 simultaneously with the displayed image projected to the polarized light scattering plate 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an apparatus for displaying images.

[0002]

2. Description of the Related Art FIG. 11 is a schematic view of a projector according to the prior art. As shown in FIG. 11, in the projector 01, the incident light from the light source is linearly polarized by the polarizing plate and is incident on the twisted nematic liquid crystal panel 02.
The image displayed on the liquid crystal panel 02 is formed on the screen 04 via the lens 03, and the display of an image is realized.

[0003]

Since the conventional screen is opaque, there is a problem that an object on the back side of the screen or a display on another screen cannot be synthesized.

[0004]

The invention of claim 1 for solving the above-mentioned problem is characterized in that an image is projected on a polarization scattering plate and displayed.

According to a second aspect of the present invention, in the display device of the first aspect, a device that emits polarized light, such as a liquid crystal projector, is used as a device for projecting an image, and the direction in which the scattering property of the scattering plate indicates the scattering property is changed. It is characterized by matching the direction. By arranging two screens so as to be transparent, a display with a depth can be realized.

According to a third aspect of the present invention, in the device of the first aspect, two polarization scattering plates having polarization directions different from each other by 90 degrees are arranged.

According to a fourth aspect of the present invention, in the device of the third aspect, a panel for projecting light onto each of the two polarization scattering plates is disposed so that polarized light is orthogonal to each other, and an image is formed by a lens. Features.

The invention of claim 5 is characterized in that, in the apparatus of claim 1, polarized lenticular lenses are arranged on the image projection device side of the two polarizing scattering plates.

The invention of claim 6 is characterized in that a polarization diffraction grating is used as a clean, and an image is projected on the polarization diffraction grating and displayed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but the present invention is not limited to these embodiments.

FIG. 9 shows a projection type display device using the polarization scattering plate of the present invention. As shown in FIG. 9, the display device of the present invention uses a polarization scattering plate 12 having polarization dependency as a screen for projecting and displaying an image by a liquid crystal projector 11. As shown in FIG. 9, display is realized by forming a polarization component L ₁ parallel to the plane of the drawing from the projector 11 on the polarization scattering plate 12. At this time, the polarization scattering plate 12 is arranged so as to scatter light parallel to the paper surface and transmit light perpendicular thereto. On the other hand, of the light from the object (for example, a turtle) 13, the polarized light component L ₂ perpendicular to the paper surface is transmitted as it is and reaches the human eyes.

That is, the human 14 can see the image of the object 13 located beyond the polarization scattering plate 12 simultaneously with the display image projected on the polarization scattering plate 12 which is a polarization-dependent screen.

The polarized light scattering plate 12 is a scattering plate having the property of transmitting a specific linearly polarized light component as it is and scattering light of a polarized light component orthogonal to the specific linearly polarized light component like ground glass.

The polarized light scattering plate 12 is, for example, a birefringent medium 31 formed by polymerizing a polymer liquid crystal A as shown in FIG.
Has a structure in which isotropic droplets as the particles 32 are randomly dispersed in a film made of polymerized liquid crystal. In general, when light enters a transparent object, its electric field induces a vibrating dipole, but in a uniform birefringent medium 31, the dipole is uniformly induced, so that scattering by individual dipoles does not occur. . Here, if the refractive index of the dispersed particles 32 is equal to the ordinary refractive index of the birefringent medium 31, a difference in the refractive index in the optical axis direction occurs between the droplets as the particles 32 and the birefringent medium 31. The size of the vibration dipole in the direction of the optical axis differs only in the portion of the droplet which is the particle 32. In relative terms, this is equivalent to the existence of a vibrating dipole having a scattering cross section only for polarized light in the direction of the optical axis only in the portion of the droplet that is the granular material 32. Thus, a scattering plate that scatters light can be realized.

Here, the birefringent medium 31 is a birefringent resin, a birefringent thin film, or the like, and is formed by polymerizing a polymer material or a liquid crystal. The granules 32 are, for example, one-component solid particles such as glass beads, or droplets of an isotropic liquid such as glycerin. Therefore, by adopting a structure in which the isotropic particles 32 are dispersed in the birefringent medium 31, an operation of scattering a specific polarization component without an electric field becomes possible.

As shown in FIG. 10, an electric field is applied between the electrodes 41 and 41 inserted between the alignment film 33 and the glass plate 34, and the non-polymerizable liquid crystal B
By changing the orientation direction of (the particles constituting the particles 32), the refractive index of the particles 32 in the optical axis direction of the birefringent medium 31 which is a film made of polymerizable liquid crystal (UV cured liquid crystal) A is compared. The refractive index of the liquid crystal can be different. As a result, it is possible to realize the optical element 40 that can scatter the polarized light component in the optical axis direction of the birefringent medium 31 more strongly than other polarized light components.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.
The present invention is not limited to this.

(Embodiment 1) FIG. 1 is a schematic view showing an apparatus of the present invention. As shown in FIG. 1, the display device according to the present embodiment uses a polarization scattering plate 12 having polarization dependency as a screen for projecting and displaying an image by a liquid crystal projector 11 as a display device. LCD projector 1
An image is formed on the polarization scattering plate 12 arranged in such a direction as to scatter the light parallel to the polarization direction of the light emitted from the light source 1. When an object (for example, a turtle) 13 is placed at a position over the polarizing scattering plate 12 as a screen as viewed from a person 14 who views the image, the depth between the object 13 and the image projected on the polarizing scattering plate 12 as the screen is increased. An effective image expression that allows the user to feel the feeling is possible.

(Embodiment 2) FIG. 2 shows a display device of this embodiment. As shown in FIG. 2, the display device of the present embodiment is provided with two first polarization scattering plates 12-1 and second polarization scattering plates 12-2 whose polarization directions are different by 90 degrees. Liquid crystal projectors (the first liquid crystal projector 11-1, the second
The liquid crystal projector 11-2) is used to project an image on each of the polarization scattering plates 12-1 and 12-2.
At this time, the polarization direction of the projection light of the liquid crystal projectors 11-1 and 11-2 is made to coincide with the direction in which the scattering plate to be projected exhibits scattering properties. Since the polarization directions of the polarized light scattering plates 12-1 and 12-2 are orthogonal to each other, the person 14
-2, the image of the first projector 11-1 projected on the first polarization scattering plate 12-1 and the second projector 11-2 projected on the second polarization scattering plate 12-2 Can be viewed at the same time. Therefore, the person 14 watching the image can experience a display with a sense of depth corresponding to the difference in the position of the polarization scattering plate.

(Embodiment 3) FIG. 3 shows a display device of this embodiment. As shown in FIG. 3, the display device of the present embodiment is provided with two first polarization scattering plates 12-1 and second polarization scattering plates 12-2 whose polarization directions are different by 90 degrees. Liquid crystal projectors (the first liquid crystal projector 11-1, the second
Half mirror 1 using a liquid crystal projector 11-2)
5 and the respective scattering plates (polarization scattering plates 12-1, 1
The image is projected in 2-2). At this time, the half mirror 15
The efficiency can be improved by using a polarization beam splitter such as a polarization beam splitter. At this time, the polarization direction of the projection light of the liquid crystal projector is made to coincide with the direction in which the polarized light scattering plate to be projected exhibits scattering properties. Since the polarization directions of the polarized light scattering plates are orthogonal to each other, a person can use the second polarized light scattering plate 12.
-2, the image of the first projector 11-1 projected on the first polarization scattering plate 11-1 and the second projector 11-2 projected on the second polarization scattering plate 12-2 Can be viewed at the same time. Therefore, the person 14 watching the video can experience a display with a sense of depth corresponding to the difference in the position of the scattering plate.

(Embodiment 4) FIG. 4 shows a display device of this embodiment. As shown in FIG. 4, the display device of the present embodiment is provided with two first polarization scattering plates 12-1 and second polarization scattering plates 12-2 whose polarization directions are different by 90 degrees. Of two first display panels 16- capable of spatially modulating the polarization components of
1, the first display panel 16-2 is disposed so that polarized light is orthogonal, and is illuminated by one light source 17;
This is realized by forming an image on the polarized light scattering plate 12-1 and the second polarized light scattering plate 12-2. The focus adjustment of the image formation is performed by the lenses 18 of the first and second display panels 16-1 and 16-2.
It is realized by adjusting the distance from. 1st, 2nd
The display panels 16-1 and 16-2 used are a guest-host type liquid crystal panel with homogeneous alignment, an alignment type polymer dispersed liquid crystal made of UV cured liquid crystal, and a polymer dispersed liquid crystal whose liquid crystal is aligned by tensile stress. it can. Since the polarization directions of the first polarized light scattering plate 12-1 and the second polarized light scattering plate 12-2 are orthogonal to each other, the human 14 transmits through the second polarized light scattering plate 12-2 and receives the first polarized light. Polarization scattering plate 12-1
Can be viewed simultaneously with the image of the second panel 16-2 projected on the second panel 16-2 and the image of the first panel 16-1 projected on the second polarization scattering plate 12-2. Therefore, human 1
4 denotes a first polarized light scattering plate 12-1 and a second polarized light scattering plate 1
It is possible to experience a display with a sense of depth corresponding to the difference in the installation position with respect to 2-2. Since this embodiment is suitable for miniaturization, a small and lightweight head mounted display can be realized.

Hereinafter, the guest host panel will be described. The homogeneously aligned guest-host liquid crystal panel is a homogeneously aligned liquid crystal panel made of a liquid crystal containing a dichroic dye. The dichroic dye absorbs only light polarized in the molecular long axis direction and is aligned in the same direction as the liquid crystal.
In an electric field-free state, it absorbs only specific polarized light, and in an electric field, it transmits all light. That is, the display element can control the absorption and transmission of only one polarized light without affecting other polarized light components.

(Embodiment 5) FIG. 5 shows a display device of the present invention. In the display device according to the second embodiment, the first polarized light scattering plate 1
2-1, the first and second polarization lenticular lenses 19-1, 1 and 1 are respectively provided on the front surface of the second polarization scattering plate 12-2.
9-2.

Here, the polarized lenticular lens is
An optical element that transmits one linearly polarized light and refracts the other linearly polarized light as a lenticular lens. This lens can be manufactured by forming a lens structure with a birefringent material such as calcite, and filling the dents of the lens with a material having a refractive index equal to either the ordinary refractive index or the extraordinary refractive index. Alternatively, it can also be realized by forming a lens structure on a transparent plate such as acrylic and filling it with a birefringent fluid such as liquid crystal, in which either the ordinary refractive index or the extraordinary refractive index is equal to acrylic. The polarization direction in which the lens effect of the polarization lenticular lens 19 causes the polarization direction is made to coincide with the polarization direction in which the polarization scattering plate 12 arranged behind scatters.

In this configuration, each polarization scattering plate 12
Since -1 and 12-2 realize lenticular stereoscopic display, the human 14 can perform binocular stereoscopic vision on each polarization scattering plate surface. As a result, it is possible to experience a display with a more sense of depth than the display devices of the second to fourth embodiments.

Here, the lenticular stereoscopic display system will be described. For example, the focal plane of a lenticular lens is placed on a screen, and the left and right eye images are adjusted to the cycle of the lens, as shown in Figure 2.14 of Asakura Shoten's Takataka Ogoshi “Three-dimensional image engineering” ISBN4-254-20804-9 P20 This is a method of ensuring the directivity of display by alternately displaying in a strip shape. That is, as shown in FIG. 6, the three-dimensional image using the lenticular lens 19 sees different images for the right eye and the left eye, so that the three-dimensional image is recognized.

In the present embodiment, a display device having an improved sense of depth has been described using the display device of the second embodiment. However, the present invention is not limited to this. For example, the display devices of the third and fourth embodiments are described. May be applied.

(Embodiment 6) FIG. 7 shows a display device of this embodiment. The display device according to the present embodiment is different from the display device according to the second embodiment in that a first polarization diffraction grating 20-1 and a second polarization diffraction grating 20-2 are used instead of the polarization scattering plates 12-1 and 12-2, respectively. It is arranged. Here, the polarization diffraction grating used for the first polarization diffraction grating 20-1 and the second polarization diffraction grating 20-2 is an optical element that transmits one linearly polarized light and diffracts the other directly polarized light. . This diffraction grating can be manufactured by forming a grating structure with a birefringent substance such as calcite, and filling the dents of the grating with a material having a refractive index equal to either the ordinary refractive index or the extraordinary refractive index. Alternatively, make a diffraction grating on a transparent plate like acrylic,
It can also be realized by filling with a birefringent fluid such as liquid crystal, in which either the ordinary refractive index or the extraordinary refractive index is equal to acrylic. Alternatively, a polymer dispersed liquid crystal diffraction grating produced by irradiating a mixture of a UV cured liquid crystal and a liquid crystal with interference fringes may be used.

In this embodiment, the reason why there is no polarization scattering plate as in the second embodiment is to diffract light having a small divergence angle to generate light whose directivity is controlled. .

In this configuration, since each polarization diffraction grating realizes stereoscopic display, a person can perform binocular stereoscopic vision with each polarization diffraction grating. You can experience. In this embodiment, the display device according to the second embodiment is used. However, the present invention is not limited to this, and may be applied to, for example, the display devices according to the third and fourth embodiments.

In the fifth embodiment, a period exhibiting a lenticular lens effect is used as the diffraction grating structure.
Thus, the effect of having a sense of depth as described above can be obtained.

Here, a diffraction grating exhibiting lenticular characteristics will be described. When the period of the diffraction grating composed of parallel stripes is reduced toward the outside, the diffraction angle increases toward the outside. By controlling the interval so that the diffracted light crosses in a straight line when the parallel light is irradiated, it is possible to realize an optical element such as a lenticular lens that exhibits a characteristic of focusing linearly.

Also, by changing the diffraction grating structure,
Multi-view stereoscopic display can also be realized. Hereinafter, the multi-view stereoscopic display method will be described. For example, 3D image confer lens
'98 Lecture Papers (July 1 and 2, 1998) "Color Reproduction in 3D Video Systems" (Takahashi Printing Co., Ltd., Takahashi et al.) Different diffraction directions as shown in Fig. 1 of pp.111-116. A display device can be obtained by using a polarizing plate realized by arranging diffraction gratings in an array.
The principle of the stereoscopic image display of the 3D video system is realized by displaying parallax images corresponding to each direction in a plurality of different directions. In this method, by increasing the number of parallax images, it is possible to observe a wraparound image when the viewpoint is moved, and to obtain a more natural stereoscopic effect. As shown in FIG. 8, parallax is generated by combining an LCD panel and a diffraction grating. The diffraction grating is composed of elements corresponding to each parallax. FIG. 8 shows a case where four parallaxes are shown for explanation, and four diffraction grating arrays 21-1 are shown.
21 to 21-4 are constituted by a group of diffraction gratings composed of four types of curves having different angles. When the illumination light 22 is incident on the diffraction grating arrays 21-1 to 21-4, for example, the first diffraction grating The light incident on 21-1 is on the left,
The light incident on the diffraction grating 21-4 is diffracted in a predetermined direction, such as to the right.
The LCD panel 24 is brought into close contact with the incident side of the diffraction grating,
The pixels 22-1 to 22-4 and the diffraction grating are arranged so as to correspond to each other on a 1: 1 basis. Since the illumination light 23 incident on the element of the diffraction grating becomes light transmitted through the corresponding cell of the LCD, by driving the LCD panel and controlling the transmittance,
It is possible to modulate the luminous intensity of the illumination light for each element of the diffraction grating, thereby generating parallax.
Thereby, multi-view stereoscopic display is also possible.

[0034]

According to the present invention, a polarizing scattering plate is used as a screen, and an image is projected and displayed on the polarizing scattering plate, so that an object over the screen can be seen. Further, a polarization diffraction grating may be used instead of the polarization scattering plate.

Further, by making the screen transparent and arranging two screens, a display with depth can be realized.

In addition, by disposing a polarization lenticular lens which transmits one linearly polarized light and refracts the other linearly polarized light as a lenticular lens on each polarization scattering plate, a lenticular type stereoscopic display can be realized. In addition, a human can perform binocular stereoscopic vision on the polarization scattering plate surface, which is each screen, and can further experience a display with a sense of depth.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a display device according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a display device according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram showing a display device according to a third embodiment of the present invention.

FIG. 4 is a schematic diagram showing a display device according to a fourth embodiment of the present invention.

FIG. 5 is a schematic view showing a display device according to a fifth embodiment of the present invention.

FIG. 6 is a schematic diagram showing a three-dimensional image.

FIG. 7 is a schematic view showing a display device according to a sixth embodiment of the present invention.

FIG. 8 is a schematic diagram of a stereoscopic image display.

FIG. 9 is an explanatory diagram illustrating an operation of the display element of the present invention.

FIG. 10 is a schematic view of an optical element.

FIG. 11 is a schematic view showing a conventional technique.

[Explanation of symbols]

 Reference Signs List 11 liquid crystal projector 11-1 first liquid crystal projector 11-1 second liquid crystal projector 12 polarization scattering plate 12-1 first polarization scattering plate 12-1 second polarization scattering plate 13 object 14 human 15 half mirror 16- Reference Signs List 1 first display panel 16-2 second display panel 17 light source 18 lens 19-1 first polarized lenticular lens 19-2 second polarized lenticular lens 20-1 first polarized diffraction grating 20-2 Second polarization diffraction grating 21-1 to 21-4 Diffraction grating array 22-1 to 22-4 Pixel 23 Illumination light 24 LCD panel

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) G09F 9/00 361 G09F 9/00 361 H04N 5/74 H04N 5/74 C (72) Inventor Kenya Kato Nippon Telegraph and Telephone Corporation 3-1-2, Nishi-Shinjuku, Shinjuku-ku, Tokyo (72) Inventor Masatojo Uehira 3-2-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo F-term in Nippon Telegraph and Telephone Corporation (reference) 2H021 BA23 BA27 2H049 BA02 BA42 BA44 BC22 5C058 BA35 EA01 EA13 EA26 EA32 EA35 5G435 AA00 BB12 BB17 CC11 DD02 DD07 FF05 GG02 GG06 GG09 GG46 LL15

Claims (6)

[Claims] 1. A display device comprising a polarizing scattering plate as a screen, wherein an image is projected on the polarizing scattering plate and displayed. 2. The apparatus according to claim 1, wherein a liquid crystal projector that emits polarized light is used as a device for projecting an image, and a direction of the scattering property of the polarization scattering plate is matched with the polarization direction. Display device. 3. The display device according to claim 1, wherein two polarization scattering plates whose polarization directions are different from each other by 90 degrees are arranged. 4. The display device according to claim 3, wherein panels for projecting light onto each of the two polarization scattering plates are arranged so that polarized light is orthogonal, and an image is formed by a lens. 5. The display device according to claim 1, wherein polarization lenticular lenses are arranged on the image projection device side of the two polarization scattering plates. 6. A display device comprising a polarizing diffraction grating used as a screen, and displaying an image by projecting the image on the polarizing diffraction grating.