JPH08292410A - Display device - Google Patents

Abstract

PURPOSE: To provide a liquid crystal display device which enables a stereophonic image to be seen without using any lenticular lens, etc., and further to use a transparent display screen and see a distant display image or a stereophonic image with high brightness as its background. CONSTITUTION: The display device is constituted by arraying pixels 8 and 9 where a volume phase type hologram is formed in periodic structure of liquid crystal and macromolecules; and diffracted light from a 1st pixel group 6 reaches the left eye of an observer and diffracted light from a 2nd pixel group 7 reaches the right eye of the observer. The pixels 8 and 9 are switched by voltage application between a state wherein illumination light is diffracted and a state wherein the illumination light is transmitted, and consequently an optional image constituted in a dot matrix can be displayed. A parallactic image for the left eye is displayed on the 1st pixel group 6 and a parallactic image for the right eye is displayed on the 2nd pixel group 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device capable of displaying a stereoscopic image using polymer dispersed liquid crystal.

[0002]

2. Description of the Related Art A dispersion type liquid crystal display device in which liquid crystal is dispersed in a polymer and the scattered light is used has an advantage that a bright image can be obtained as compared with a TN type liquid crystal display device because a polarizing plate is not used. , Its development is becoming active. FIG. 13 shows an example of a conventional polymer dispersed liquid crystal display device. In this figure, 51 is a polymer dispersed liquid crystal layer, 52 is a transparent substrate, 53 and 54 are transparent electrodes, 55 is a light absorbing plate, and 56 is a color filter.

When a voltage is applied between the pair of transparent electrodes 53 and 54 facing each other with the polymer dispersed liquid crystal layer 51 in between, the liquid crystal dispersed in the polymer matrix is randomly disordered (scattered state). , Transition to an orderly arrangement (transparent state). The reverse process is also possible. The pair of transparent electrodes 53 and 54 is formed as a pattern forming a pixel on the transparent substrate 52.

This liquid crystal display device displays an image by using external light such as natural light or room light. The light incident through the color filter 56 passes through the polymer dispersed liquid crystal layer 51 in the pixel in the transparent state, and the light absorption plate 55.
Since it is absorbed by, it looks black to the observer. On the other hand, a part of the light incident on the pixel (hatched portion) in the scattering state is scattered and again passes through the color filter 56 and is emitted at a wide angle, so that the light enters the eyes of the observer as colored light.

As a conventional stereoscopic image display device, as shown in FIG. 14, a combination of a lenticular lens 57 and a display device 58 is well known. The lenticular lens 57 is formed by arranging a large number of elongated cylindrical lenses and is arranged in front of a display device 58 such as a CRT or a liquid crystal display.

The image displayed on the display device 58 is divided into two sets of frames composed of stripes alternately arranged, as shown by a plain stripe and a stripe with diagonal lines in the figure. That is, the solid stripes form the first frame 59, and the diagonal stripes form the second frame 60.

When the right-eye parallax image is displayed on the first frame 59 and the left-eye parallax image is displayed on the second frame 60, the left-eye parallax image is in a predetermined position by the action of the lenticular lens. Only the left eye of the person 61 can see the parallax image for the right eye and only the right eye. With this principle,
To the observer 61, the image emerges from the display screen of the display device and looks like a stereoscopic image.

[0008]

However, in the conventional liquid crystal display device as described above, only an image with low brightness can be obtained for the following reason. As shown in FIG. 15, the light incident on the polymer-dispersed liquid crystal layer passes through it and forms scattered light. This is generally called forward scattering. On the other hand, backscattering (incident side) is called backscattering, but due to the nature of the polymer dispersed liquid crystal layer, backscattering does not exceed forward scattering. Therefore, in the above-described conventional configuration, more than half of the light incident on the pixels in the scattered state is absorbed by the light absorbing plate 55. Therefore, only an image with low brightness can be obtained at all times, and it is difficult to form a direct-view display.

Further, in the above conventional structure, the polymer dispersed liquid crystal layer 51 and the transparent electrodes 53 and 54 are sandwiched between the light absorbing plate 55 and the color filter 56, so that the polymer dispersed liquid crystal layer 51 is transparent when a voltage is applied. The feature of becoming is not fully utilized. Furthermore, it is not possible to display a stereoscopic image with this conventional configuration. The stereoscopic image display device shown in FIG. 14 requires a lenticular lens, and it is impossible to form a transparent display screen.

The present invention has been made in view of the above situation, and an object thereof is a display device capable of displaying a stereoscopic image without using a lenticular lens or the like.
It is to provide a direct-view bright display device, a display device having a transparent image display unit, and a display device capable of color display.

[0011]

According to a first constitution of a display device of the present invention, electrode layers are provided inside two substrates which face each other, and a liquid crystal phase and a polymer phase are provided between these electrode layers. Is provided as a hologram, and at least one of the two substrates and the electrode layer is transparent, and the electrode layer is patterned to form pixels arranged in a matrix. The dimming layer sandwiched between the electrode layers is composed of a first pixel group and a second pixel group, which are substantially evenly distributed in a stripe shape or a mosaic shape, and is formed in each pixel forming the first pixel group. Is formed with a hologram that diffracts the illumination light and directs it to the vicinity of the observer's left eye, and each pixel that constitutes the second pixel group has a hologram that diffracts the illumination light and directs it to the vicinity of the observer's right eye. That it is formed And butterflies.

According to this structure, the voltage applied to the electrode layer is controlled for each pixel, the left-eye parallax image is displayed in the first pixel group, and the right-eye parallax image is displayed in the second pixel group. By displaying, a stereoscopic image can be displayed without using a lenticular lens or the like. In addition, the two sets of the substrate and the electrode layer are both transparent, and by illuminating light at a predetermined incident angle from the rear, the image display unit is transparent, and the display image can be superimposed on the background with high brightness. Display device can be realized.

In a second configuration of the display device according to the present invention, the first pixel group diffracts red, blue, or green illumination light and directs it toward the vicinity of the left eye of the observer, and is a hologram of red, blue, and green. Pixels are distributed substantially uniformly, and the second pixel group diffracts red, blue, or green illumination light and directs it toward the vicinity of the right eye of an observer. Red, blue, and green hologram pixels are substantially uniform. It is characterized by being distributed in. For example,
Red, blue, and green hologram pixels may be sequentially and repeatedly arranged in the longitudinal direction of each stripe-shaped pixel group. With such a configuration, color display is possible.

In a third configuration of the display device according to the present invention, each pixel forming the first pixel group diffracts illumination light and directs a plurality of holograms in the vicinity of the left eyes of a plurality of observers at different positions. Are multiply formed, and each pixel forming the second pixel group is multiply formed with a plurality of holograms that diffract the illumination light and direct it toward the right eyes of a plurality of observers at different positions. Characterize.

With such a structure, the same stereoscopic image can be provided to a plurality of observers. Also in this configuration, similarly to the above, color display is possible by distributing the hologram pixels of red, blue, and green in each pixel group substantially uniformly.

According to a fourth structure of the display device of the present invention, an electrode layer is provided inside two opposing substrates,
A light control layer having a structure in which a liquid crystal phase and a polymer phase are distributed as holograms is provided between these electrode layers, and at least one of the two sets of substrates and electrode layers is transparent, and the electrode layer Are patterned to form pixels arranged in a matrix, and in the light control layer sandwiched between the electrode layers, when n is a natural number of 2 or more, 2n kinds of pixel groups are stripe-shaped or mosaic. When k is a natural number less than or equal to n, a hologram that diffracts the illumination light and directs it toward the left eye of the observer is formed. The kth
A hologram for diffracting the illumination light and directing it toward the vicinity of the right eye of the observer is formed in each pixel forming the + n pixel group.

With such a configuration, it is possible to provide independent images, that is, different images to a plurality of observers at different positions. Also in this configuration, color display can be performed by distributing the red, blue, and green hologram pixels in each pixel group substantially uniformly.

In each of the above-mentioned structures, by forming a hologram in each pixel in which the diffracted light has a spread within the predetermined angle range in the left-right direction, a desired image can be obtained even if the position of the observer is laterally displaced to some extent. You will be able to see it. Further, if a hologram is formed in which the diffracted light has a predetermined divergence angle, the observer's positional deviation is allowed to some extent not only in the horizontal direction but also in the vertical direction.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described with reference to some examples and drawings. (First Embodiment) FIG. 1 shows the arrangement of a display device according to the first embodiment. In FIG. 1, 1 and 2 are transparent glass substrates, and 3 and 4 are transparent electrode layers. Reference numeral 5 denotes a light control layer, which is configured by alternately arranging first pixel groups 6 and second pixel groups 7 in stripes. In FIG. 1, a pixel group 6 is configured by vertically arranging pixels 8 shown as plain rectangular parallelepiped cells, and a pixel group 7 includes pixels 9 shown as hatched rectangular parallelepiped cells. It is arranged in the vertical direction. Further, 10 is a light source, which illuminates the illumination light 11 from the back surface of the transparent glass substrate 2. Although the light control layer 5 and the electrode layer 3 are depicted separately in this figure for the sake of clarity, the two are actually in close contact with each other.

In FIG. 2, the pixels 8 forming the above-mentioned pixel group 6 are shown.
A typical structure of is schematically shown in a simplified form. As shown in the figure, the pixel 8 has a periodic structure in which a polymer phase 12 and a liquid crystal phase 13 are alternately formed, the pitch thereof is about 0.3 μm, and the pixel thickness is about 10 μm. It is micron. Direction of periodic structure, that is, grating vector 14
Is inclined by about 0.28 degrees to the left and about 34.7 degrees downward from the normal line direction of the pixel surface.

The pixels 9 forming the pixel group 7 also have the same periodic structure as shown in FIG. The azimuth of a typical periodic structure, that is, the grating vector 15 is inclined downward by about 34.7 degrees in the same manner as the pixel 8 in the vertical direction, but is about 0 to the right in the horizontal direction, which is the reverse of the pixel 8. It is tilted by 28 degrees.

In the periodic structure as described above, a precursor in which a photosensitive monomer and / or an oligomer, a nematic liquid crystal, a polymerization initiator and a sensitizer are mixed is used as a precursor of the electrode layers 3 and 4 inside the glass substrates 1 and 2. It was sandwiched between them and irradiated with interference fringes formed by a 515 nm argon laser to print a pattern, and then the entire surface was polymerized by uniform ultraviolet irradiation with a low pressure mercury lamp.

Suitable monomers for preparing the light control layer by the photopolymerization method include liquid or low melting point ethylenically unsaturated monomers, especially acrylic or methacrylic acid esters. These may be polyfunctional monomers such as trimethylol propane triacrylate or oligomers such as polyethylene glycol diacrylate, urethane acrylate. These may be used alone or in combination. Furthermore, if necessary, other monomers such as styrene and carbazole may be used in combination.

These monomers and oligomers are not particularly limited. Usually, various kinds of compounds known to those skilled in the art, such as those used for preparing polymer-dispersed liquid crystals, or photopolymerizable compositions for preparing volume holograms as described in JP-A-2-3082. Monomers, oligomers and the like can be appropriately selected and used. In order to photopolymerize with coherent light, a sensitizing dye suitable for the wavelength, an appropriate photopolymerization initiator, etc. are required. These may be selected from many combinations such as cyanine dyes, dyes such as cyclopentanones, diphenyliodonium salts and combinations thereof with dyes, various quinones, triphenylimidazoyl dimers and hydrogen donors. it can. Further, as the liquid crystal, one having a large birefringence and a large dielectric anisotropy and a small elastic constant is suitable and can be selected from various commercially available ones.

The functions of the pixels 8 and 9 thus constructed will be described with reference to FIG. FIG. 4 is a generalized schematic view of a pixel having a periodic structure like the pixels 8 and 9. As shown in FIG. 4A, the polymer phase 12 shown by the inclined solid line and the liquid crystal phase 13 between the solid lines cause periodic phase separation.

In the liquid crystal phase 13, liquid crystal molecules are aggregated to form a liquid crystal droplet 18. These liquid crystal droplets 18 are dispersed in random directions,
The average refractive index of the liquid crystal phase 13 defined equivalently is larger than the refractive index of the polymer phase 12 (for example, 1.5) (for example, 1.5).
6) has been set.

Polymer phase 12 and liquid crystal phase 13 having different refractive indices
The periodic structure formed by and forms a so-called volume phase hologram. Therefore, as shown in FIG. 4A, the loss when the incident light 16 incident at a predetermined Bragg angle is converted into the diffracted light 17 is very small. That is, the incident light 16 is highly efficiently deflected and reaches the eyes of the observer 19.

Next, as shown in FIG. 4B, the light control layer 5
When a voltage is applied between the electrode layers 3 and 4 that sandwich the liquid crystal, the liquid crystal droplets 18 in the liquid crystal phase 13 are arranged in the electric field direction. As a result, the refractive index difference between the polymer phase 12 and the liquid crystal phase 13 disappears, and the ability of the light control layer 5 to diffract the light is lost, so that the incident light 16 passes through the light control layer 5 as it is and the transmitted light 2 is transmitted.
It becomes 0. Therefore, this light does not reach the eyes of the observer 19, and the display device including the light control layer 5 and the transparent electrode layers 3 and 4 looks transparent to the observer 19.

Incidentally, the diffraction efficiency of each pixel in this embodiment exceeds 70%. In an experiment using a 100 W halogen lamp as the light source 10, the brightness of the display surface reached 2000 cd / m ² . The directivity of the diffracted light was very high, and it was not observed from a position off the course of the diffracted light. That is, the display device looked transparent from a position other than the observer 19 in FIG. Also,
When an AC voltage of 100 V was applied between the electrode layers 3 and 4, the brightness on the display surface was reduced to 100 cd / m ² or less.

As shown in FIG. 5, when the illumination light 11 is incident from the rear of the pixels 8 and 9 having the above-mentioned function at an incident angle of about 60 degrees, the illumination light 11 is diffracted by the pixel 8 and is observed from the front (observation). The light ray 21 emitted to the observer side is horizontal in the direction of the observer and is emitted in a direction inclined by about 0.85 degrees to the left. Similarly, a light beam 22 diffracted by the pixel 9 and emitted from the front thereof
Is emitted in a direction horizontal to the observer and inclined to the right by about 0.85 degrees. Therefore, only the light ray 21 reaches the left eye and only the light ray 22 reaches the left eye of the observer at a predetermined position. This is a unique effect due to the angular selectivity of thick holograms.

As described above, the pixels 8 and 9 are the pixel group 6
Or, it is a pixel representing 7. The pixels constituting each of the pixel groups 6 and 7 are slightly different between the upper and lower adjacent pixels, so that the diffracted light from the pixel group 6 as a whole is transmitted to the left eye of the observer and from the pixel group 7. Of the diffracted light reaches the right eye of the observer.

A hologram having a structure in which stripe-shaped pixel groups 6 and 7 corresponding to the left and right eyes of the observer are alternately arranged as described above, as shown in FIG. 6, has a width d corresponding to the stripe width. Mask plate MK in which every other slit is lined up
Can be created using. As shown in the side view of FIG. 6A and the plan view of FIG. 6B, a pair of concave lenses provided at positions corresponding to the left and right eyes of the observer set at a predetermined distance from the front surface of the display device 23. The object light OL is radiated through the display device 23 so as to spread over the entire display device 23, and the reference light RL is radiated to the display device 23 from the direction of the incident angle of 60 degrees, and the interference fringes of both lights are displayed on the display device 23. Bake on the light control layer.

At this time, as shown in FIG. 6B, a mask plate MK is placed in front of the display device 23 so that the slits are oriented in the vertical direction, and first, only the object light OL for the left eye is placed. Irradiate. As a result, the interference fringes for the left eye are printed to form the stripe-shaped first pixel group 6.
Next, the mask plate MK is shifted in the left-right direction by the stripe width (slit width) d, and the object light OL for the right eye is irradiated.
As a result, the interference fringes for the right eye are printed to form the stripe-shaped second pixel group 7.

As shown in FIG. 1, the structure in which the light control layer 5 of the display device is sandwiched between the transparent electrode layers 3 and 4 inside the transparent glass substrates 1 and 2 is basically normal. It is the same as the transmissive liquid crystal display. The transparent electrode layers 3 and 4 are patterned so as to form pixels arranged in a matrix. That is, the transparent electrode layer 3,
The voltage applied during 4 can be controlled in pixel units, whereby an arbitrary image composed of a dot matrix can be displayed. However, "displaying an image" here means that the diffracted light of the pixels forming the image reaches the observer because a voltage is not applied between the electrodes of the pixels forming the image. As the voltage is applied to the other pixels, it is transparent as described above,
The viewer will see the background of the display device.

A simple experiment was performed using such a display device. As shown in FIG. 7, the number “8” is assigned to each of the first pixel group 6 for the left eye (solid stripe portion) and the second pixel group 7 for the right eye (striped portion with diagonal lines). , It was displayed with a slight shift to the left and right. For easy understanding, in FIG. 7, the left-eye image 24 displayed in the first pixel group 6 is shown by white dots, and the right-eye image 25 displayed in the second pixel group 7 is shown by black dots.

When this display device 23 is placed at a position 50 cm away from the observer 19 and irradiated with irradiation light at an incident angle of 60 degrees from the rear, when the observer 19 looks at the display device 23, it is behind the display device 23. The character "8" was visible at a position approximately 2 m from the observer.

As described above, since the portion of the display device 23 where "8" is not displayed is transparent, the above-mentioned character "8" that appears to be visible is located 2 m from the observer. It seems to overlap the background. As described above, the effect that the image display portion is transparent and the displayed image is superposed on the background of the display device and looks three-dimensional is a characteristic effect of the present invention that has not been present. By applying this, it is possible to realize the far focus function of a head-up display of an automobile or the like.

The position at which the above-mentioned image "8" appears to be visible, that is, the distance from the observer is determined by the left-eye image displayed on the first pixel group 6 of the display device 23 and the second pixel group 7. It is geometrically determined by the distance from the right-eye image to be displayed. As can be seen from FIG. 7, the farther the distance between the two images is, the more distant the image is from the observer. Further, if the image for the left eye and the image for the right eye displayed on the display device 23 are shifted in opposite directions, the image can be displayed in front of the display device 23.

Further, instead of the character "8" in the above example, a pair of slightly different images corresponding to the binocular parallax when a certain three-dimensional object is seen is displayed as a first pixel group 6 and a second pixel group 7. When the observer 19 looks at the display device 23, the three-dimensional object appears three-dimensionally by displaying the three-dimensional objects separately. That is, it is possible to configure a stereoscopic display device that utilizes binocular parallax without using a lenticular lens or the like as in the related art. If the same image is displayed on both pixel groups 6 and 7 instead of displaying different images according to the binocular parallax, a stereoscopic image cannot be obtained, but as in the experiment described above, the background image overlaps. It is possible to obtain a high-intensity image that appears as if it were floating on the screen.

In this embodiment, as shown in a side view in FIG. 8A, the light source 10 is arranged behind the display device 26, and the diffracted light transmitted through the display device 26 reaches the eyes of the observer. However, as shown in FIG. 8B, a light source may be arranged in front of the display device 26 so that the diffracted light reflected by the display device 26 reaches the eyes of the observer. Further, as shown in FIG. 8C, room light or natural light 27 is used as illumination light without disposing a dedicated light source, and the transmitted diffracted light or reflected diffracted light reaches the observer's eyes. It is also possible. In this regard, when the reflected and diffracted light of the illumination light from the front of the display device 26 reaches the viewer, the substrate and the electrode on the back side do not need to be transparent.

Further, by forming the hologram pixel so that the diffracted light from the hologram pixel spreads in the left-right direction within a predetermined angle range, even if the position of the observer slightly shifts to the left or right, the observer can obtain a predetermined image. Can be seen. Further, by configuring the hologram pixel so that it also spreads in the vertical direction within a predetermined angle range, that is, the diffracted light from the hologram pixel has a divergence angle within the predetermined angle range, the position of the observer moves up and down. An observer can see a predetermined image even if the image is slightly shifted to the left or right.

In the above embodiment, the first pixel group 6
And the second pixel group 7 are formed by substantially uniformly distributing the red, blue, and green hologram pixels that diffract red, blue, or green illumination light and direct them toward the left or right eye of the observer. This enables color display.

As a concrete structure in which the red, blue, and green hologram pixels are substantially evenly distributed in the stripe-shaped first pixel group 6 and the second pixel group 7, red is provided in the vertical direction of each pixel group.
A structure in which blue and green hologram pixels are repeatedly arranged in order is common. In such a structure, in the method for forming interference fringes shown in FIG. 6, instead of the mask plate MK having slits arranged side by side, square holes corresponding to one pixel are arranged every other side in the left-right direction. It can be formed by using a mask plate formed in a matrix shape with every other two in the vertical direction.

By irradiating the red, blue, and green object lights and the reference light in order while shifting the mask plate in the vertical direction, the above-described red, blue, and green hologram pixels are sequentially arranged. A group of pixels arranged repeatedly is obtained. Therefore, the first pixel group is formed by printing the hologram pattern three times while shifting the mask in the vertical direction, and the second pixel group is formed by shifting the mask in the horizontal direction and printing the hologram pattern three times in the same manner. After all, the display device capable of stereoscopic display and color display can be manufactured by printing the hologram pattern 6 times. However, this method is only an example.

The above description is based on controlling the voltage applied between the electrode layers sandwiching the light control layer for each pixel.
Although it is assumed that a display device displays an arbitrary image formed of a dot matrix, a fixed image may be printed as a hologram pattern on the light control layer of the display device 28 as shown in FIG. In FIG. 9, two hologram patterns 29 and 30 displaying the numeral “8” are printed at positions shifted to the left and right.
The first hologram pattern 29 directs the diffracted light to the left eye of the observer, and the second hologram pattern 30 directs the diffracted light to the right eye of the observer. Such a hologram pattern
It is formed by printing interference fringes of object light containing image information such as reflected light or transmitted light of an object and reference light on the light control layer of the display device 28.

Even in the case of the fixed image display as described above, by controlling the voltage applied between the electrode layers for each pixel or collectively, the observer can display the display device 28.
It is possible to display or not display the image in the background when viewing.

(Second Embodiment) In the first embodiment described above, the display device was constructed on the premise of one observer, but according to the second embodiment described below, a plurality of observers can be used. You can see the same image. Note that this embodiment will be described focusing on the pixel configuration different from that of the first embodiment.

FIG. 10 shows the functions of the pixels 31 and 32 which form the display device of this embodiment. These pixels 3
Reference numerals 1 and 32 denote multi-hologram pixels that diffract incident light from one direction in a plurality of directions. 31
Is a multi-hologram pixel for the left eye that directs diffracted light to the left eyes of a plurality of observers, and 32 is a multi-hologram pixel for the right eye that directs diffracted light to the right eyes of a plurality of observers.

These multi-hologram pixels are formed by superimposing a plurality of periodic structures composed of the polymer phase 12 and the liquid crystal phase 13 in the same volume. As described in the first embodiment, a precursor composed of a photosensitive monomer (oligomer), a nematic liquid crystal, a polymerization initiator, a sensitizer and the like was sandwiched between the glass substrates 1 and 2 and the electrode layers 3 and 4. 515n
When the pattern is printed by irradiating the interference fringes formed by the argon laser of m, the first pattern is printed, then the second pattern, the third pattern, and the like are sequentially printed, and finally by the low-pressure mercury lamp. A multi-hologram pixel can be formed by polymerizing the entire surface by uniform ultraviolet irradiation. Specifically, when forming a structure in which stripe-shaped pixel groups corresponding to the left and right eyes are alternately arranged by the method using the mask plate MK shown in FIG. 6, depending on the expected position of the observer. The patterns of the first, second, third, ... Patterns may be sequentially printed by shifting the positions of the pair of concave lenses corresponding to the left and right eyes.

The left-eye multi-hologram pixel 31 thus produced generates left-eye diffracted light 33 in n different directions with respect to the illumination light 11, and the right-eye multi-hologram pixel 32 produces the illumination light. The right-eye diffracted light 34 is generated in n different directions with respect to 11. Then, the diffracted light 32 for the left eye
The i-th diffracted light 35 and the i-th diffracted light 36 of the right-eye diffracted light 34 reach the left and right eyes of one observer.

In FIG. 11, the i-th and i + 1-th diffractive display lights are taken out in order to facilitate understanding of the relationship between the display device and the observer, and these are the first observer 37 and the second observer 37.
Reaching each of the observers 38 and 38. Figure 11
Pixel group 3 for the left eye shown as a plain stripe as shown in
9 and a right-eye pixel group 40 shown by a stripe with diagonal lines
And are arranged alternately. The pixel group 39 for the left eye is shown in FIG.
The left-eye multi-hologram pixels 31 are vertically arranged, and the right-eye pixel group 40 is also the right-eye multi-hologram pixels 32 vertically arranged.

The i-th diffracted light 41 emitted from the left-eye pixel group 39 reaches the left eye of the first observer 37, and the i + 1-th diffracted light 42 reaches the left eye of the second observer 38. To do. Similarly, the i-th diffracted light 43 emitted from the right-eye pixel group 40 reaches the right eye of the first observer 37, and the i + 1-th diffracted display light 44 reaches the right eye of the second observer 38. To reach. In this way, the same image is presented to two observers.

As in the first embodiment, a different image corresponding to the binocular parallax is displayed on the left-eye pixel group 39 and the right-eye pixel group 40, so that the stereoscopic image display can be performed by the observer. Of course, it is possible to provide a high-brightness and transparent display device by displaying the same image without giving binocular parallax. Other modifications such as colorization described in the first embodiment can be similarly applied to this embodiment.

(Third Embodiment) In the second embodiment, the structure of the display device for providing the same image to a plurality of observers has been described. However, the display device for providing a plurality of observers with different images. Can also be configured. This will be described below as a third embodiment. As shown in FIG. 12, a case where different images are provided to the first observer 45 and the second observer 46 will be described.

In FIG. 12, 47 is a first observer 45.
First pixel group for directing diffracted light to the left eye of the second observer, 48 is a second pixel group for directing diffracted light to the left eye of the second observer 46, and 49 is diffracted light to the right eye of the first observer 45. Is a third pixel group, and 50 is a fourth pixel group that directs the diffracted light to the right eye of the second observer 46. In this way, four types of stripe-shaped pixel groups are repeatedly formed in order.

According to such a pixel configuration, the pixel group 47
And the pixel groups 48 and 50 formed by 49 and 49
The image formed by can be a different image. Therefore, not only the same stereoscopic image but also different stereoscopic images can be separately provided to the two observers 45 and 46.

In order to obtain a structure in which four types of stripe-shaped pixel groups are repeatedly formed in order as described above, the mask plate in which every other slit is arranged in FIG. 6 described in the first embodiment is used. Instead of MK, a mask plate having three slits arranged side by side may be used, and the hologram pattern may be printed four times while shifting the mask plate left and right.

Generally, in order to provide n independent stereoscopically visible images to n observers, it is necessary to repeatedly form 2 × n kinds of stripe pixel groups in order. Then, when k ≦ n, the diffracted light of the kth pixel group and the k + nth pixel
The diffracted light of the pixel group may reach the left and right eyes of one observer.

Note that, in this embodiment as well, the modified examples such as the colorization described in the above-described embodiments can be similarly applied.

[Brief description of drawings]

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

FIG. 2 is a schematic diagram for explaining a function of one pixel forming a first pixel group of the display device of FIG.

FIG. 3 is a schematic diagram for explaining the function of one pixel forming the second pixel group of the display device of FIG.

FIG. 4 shows a fine structure of each pixel in the display device of FIG. 1, FIG.
(B) is a schematic diagram when a voltage is applied

5 is a perspective view showing the relationship between illumination light and diffracted light in the display device of FIG.

6 is a first stripe-shaped display device of FIG.
FIG. 6 is a diagram showing a method for manufacturing a structure in which pixel groups and second pixel groups are alternately formed.

7 is a diagram showing the configuration of an experiment conducted using the display device of FIG.

8A and 8B show modified examples of the light source of the display device in FIG. 1, FIG. 8A is a basic example in which the light source is arranged in the rear of the display device, FIG. 8B is a modified example in which the light source is arranged in the front of the display device, and FIG. Is a side view showing a modification in which room light or natural light is used as a light source.

9 is a perspective view showing a configuration in which a hologram pattern of a fixed image is printed on a light control layer of the display device as a modified example of the display device of FIG.

FIG. 10 is a perspective view illustrating functions of pixels of a display device according to a second exemplary embodiment of the present invention.

11 is a perspective view showing a relationship between a pixel group and an observer of the display device shown in FIG.

FIG. 12 is a perspective view showing a relationship between a pixel group and a viewer of a display device according to a third embodiment of the present invention.

FIG. 13 is a sectional view of a conventional dispersion type liquid crystal display device.

FIG. 14 is a perspective view of a conventional stereoscopic image display device.

FIG. 15 is a schematic diagram showing how light is scattered in a conventional dispersion type liquid crystal display device.

[Explanation of symbols]

 1, 2 Transparent glass substrate 3, 4 Transparent electrode layer 5 Light control layer 6 First pixel group 7 Second pixel group 8, 9 Pixel 10 Light source 11 Illumination light 12 Polymer layer 13 Liquid crystal layer 14, 15 Grating vector 21, 22 Diffracted light 23 Display device MK mask OL Object light RL Reference light

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area G03H 1/22 G03H 1/22

Claims (11)

[Claims] 1. An electrode layer is provided inside two opposing substrates, and a light control layer having a structure in which a liquid crystal phase and a polymer phase are distributed as holograms is provided between the two electrode layers. At least one of the pair of substrates and electrode layers is transparent, the electrode layers are patterned to form pixels arranged in a matrix, and the dimming layer sandwiched between the electrode layers is a stripe. Hologram that is composed of a first pixel group and a second pixel group that are substantially evenly distributed in a circular shape or a mosaic shape, and diffracts illumination light to each pixel that constitutes the first pixel group and directs it to the vicinity of the left eye of an observer. And a hologram for diffracting the illumination light and directing it toward the vicinity of the right eye of the observer is formed in each pixel forming the second pixel group. 2. An electrode layer is provided on the inside of two substrates facing each other, and a light control layer having a structure in which a liquid crystal phase and a polymer phase are distributed as holograms is provided between the two electrode layers. At least one of the pair of substrates and electrode layers is transparent, the electrode layers are patterned to form pixels arranged in a matrix, and the dimming layer sandwiched between the electrode layers is a stripe. Consisting of a first pixel group and a second pixel group that are substantially evenly distributed in a circular or mosaic pattern, and the first pixel group diffracts illumination light of red, blue, or green in the vicinity of the left eye of an observer. Red, blue, and green hologram pixels to be directed are configured to be substantially evenly distributed, and the second pixel group diffracts red, blue, or green illumination light and directs it to the vicinity of the right eye of an observer, It consists of blue and green hologram pixels that are distributed almost evenly. A display device characterized by: 3. An electrode layer is provided inside two substrates facing each other, and a light control layer having a structure in which a liquid crystal phase and a polymer phase are distributed as holograms is provided between the two electrode layers. At least one of the pair of substrates and electrode layers is transparent, the electrode layers are patterned to form pixels arranged in a matrix, and the dimming layer sandwiched between the electrode layers is a stripe. A first pixel group and a second pixel group, which are substantially evenly distributed in the shape of a circle or a mosaic, and each pixel constituting the first pixel group diffracts the illumination light to provide a plurality of observers at different positions. A plurality of holograms directed toward the vicinity of the left eye are formed in multiple, and a plurality of holograms directed toward the vicinity of the right eye of a plurality of observers located at different positions by diffracting illumination light in each pixel forming the second pixel group. Are multiply formed A display device characterized by the above. 4. An electrode layer is provided inside two opposing substrates, and a light control layer having a structure in which a liquid crystal phase and a polymer phase are distributed as holograms is provided between the two electrode layers. At least one of the pair of substrates and electrode layers is transparent, the electrode layers are patterned to form pixels arranged in a matrix, and the dimming layer sandwiched between the electrode layers is a stripe. A first pixel group and a second pixel group that are substantially evenly distributed in a circular or mosaic pattern, the first pixel group diffracting red, blue, or green illumination light and making a plurality of observations at different positions. A plurality of holograms directed toward the left eye of the person are formed in a multi-layered manner, and the hologram pixels of red, blue, and green are substantially evenly distributed, and the second pixel group is illumination light of red, blue, or green. Observers diffracting light at different positions The display device is characterized in that red, blue, and green hologram pixels in which a plurality of holograms directed toward the vicinity of the right eye are formed in a substantially uniform distribution. 5. The display device according to claim 1, wherein a parallax image for the left eye is displayed on the first pixel group, and a parallax image for the right eye is displayed on the second pixel group. 6. An electrode layer is provided inside two substrates facing each other, and a light control layer having a structure in which a liquid crystal phase and a polymer phase are distributed as holograms is provided between the two electrode layers. At least one set of the set of substrates and electrode layers is transparent, the electrode layers are patterned to form pixels arranged in a matrix, and the light control layer sandwiched between the electrode layers is 2n when n is a natural number of 2 or more
Pixel groups of various types are arranged in a stripe or mosaic pattern and are distributed substantially uniformly. When k is a natural number of n or less, each pixel forming the k-th pixel group diffracts illumination light and observes A hologram directed to the vicinity of the left eye is formed, and a hologram directed to the vicinity of the right eye of the observer by diffracting the illumination light is formed on each pixel forming the k + nth pixel group. A display device configured to provide independent images to a plurality of observers present. 7. An electrode layer is provided inside two opposing substrates, and a light control layer having a structure in which a liquid crystal phase and a polymer phase are distributed as holograms is provided between the two electrode layers. At least one set of the set of substrates and electrode layers is transparent, the electrode layers are patterned to form pixels arranged in a matrix, and the light control layer sandwiched between the electrode layers is 2n when n is a natural number of 2 or more
When the pixel groups of the types are configured to be distributed in a stripe shape or a mosaic shape substantially uniformly, and k is a natural number of n or less, the kth pixel group is red,
The hologram pixels of red, blue, and green, which diffract the illumination light of blue or green and direct the illumination light toward the vicinity of the left eye of the observer, are configured to be substantially evenly distributed, and the k + nth pixel group includes red, blue, or green. Red, blue, and green hologram pixels that are diffracted to direct the illumination light to the vicinity of the right eye of the observer are configured to be evenly distributed,
A display device configured to provide independent color images to a plurality of observers at different positions. 8. The display device according to claim 6, wherein a left-eye parallax image is displayed on the k-th pixel group, and a right-eye parallax image is displayed on the k + n-th pixel group. 9. The display device according to claim 1, wherein a hologram is formed in each pixel such that the diffracted light has a spread within a predetermined angle range in the left-right direction. 10. A hologram in which each pixel has a hologram such that the diffracted light has a predetermined divergence angle.
The display device according to claim 1. 11. A light source for supplying illumination light which is emitted at a predetermined incident angle from the back or front of the screen.
10. The display device according to any one of items 10 to 10.