JPH09185053A - Liquid crystal display - Google Patents

Abstract

(57) Abstract: To reduce the size and weight of a liquid crystal display device. The utilization efficiency of light from the parallel illumination light source is improved, light absorption of the polarizing plate is suppressed, and a bright image display is obtained. SOLUTION: A polarization separation element 4 including a plurality of polarization beam splitters 4a having a minute size or stripes is
The liquid crystal display element 3 is arranged along the light incident surface. In addition, the polarization separation element 5 having the same structure as the polarization separation element 4 is
The liquid crystal display element 3 is arranged along the light emitting surface. The polarization separation element 4 transmits the P-polarized light P ₁ and converts the S-polarized light S ₁ into 9
0 ° Change the angle and reflect. The liquid crystal display element 3 controls the polarization state of the incident linearly polarized light and makes it output to the polarization separation element 5. In the polarization splitting element 5, similarly, the P-polarized light P ₁
Is transmitted, and the S-polarized light S ₁ is reflected by changing the angle by 90 °. As a result, a light beam with a uniform traveling direction is output,
The image is displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a polarization separation element such as a polarization beam splitter for separating natural light from a light source into linearly polarized light, and controls the polarization state of the linearly polarized light separated by the polarization separation element. However, the present invention relates to a liquid crystal display device that forms an image.

[0002]

2. Description of the Related Art Conventionally, a TN (Twisted Nematic) type liquid crystal display element has been known as a typical field effect type light modulating element. A liquid crystal display device using a TN type liquid crystal display element irradiates the TN type liquid crystal display element with linearly polarized light separated by a polarization separation element such as a polarization beam splitter to perform light modulation and display. is there.

In the above-mentioned TN type liquid crystal display element, usually, two polarizing plates called a polarizer and an analyzer are respectively disposed on the light beam incident side and the light emitting side across the liquid crystal layer, and their polarization directions are orthogonal to each other. As shown in the figure, the liquid crystal layer is sandwiched between them.

When no electric field is applied to the liquid crystal layer, the light passing through the incident side polarizing plate rotates (rotates) along the twist of the liquid crystal molecules due to the effect of the optical anisotropy of the liquid crystal molecules.
As a result, the light passes through the exit side polarization plate, and a bright state is obtained. On the other hand, when an electric field is applied to the liquid crystal layer, the twisted orientation of the liquid crystal molecules is released, and the effect of rotating the plane of polarization is no longer present. Therefore, the light that has passed through the incident side polarization plate is blocked by the emission side polarization plate, and a dark state is obtained.

By the way, in the liquid crystal display device using the TN type liquid crystal display element which operates as described above, there have conventionally been the following problems. That is, the effective components of the illumination light that can be used by the TN type liquid crystal display element are limited to those along the azimuth of the polarizing plate, and unnecessary components that could not be transmitted are absorbed by the polarizing plate, and heat is absorbed. Since the light is converted, the light utilization efficiency becomes 1/2 or less, and there is a problem that a bright display cannot be obtained. In addition, there is a problem that the characteristics of the polarizing plate are deteriorated due to heat absorption of the polarizing plate itself, and the liquid crystal undergoes a phase change due to a temperature rise of the TN type liquid crystal display element, thereby deteriorating the display characteristics.

Therefore, a liquid crystal display device which has tried to solve the above problems is disclosed in, for example, Japanese Patent Laid-Open No. 4-178683.
No. 6,086,045. FIG. 8 shows a polarization conversion optical system of the liquid crystal display device disclosed in the above publication.

As shown in FIG. 8, this polarization conversion optical system includes a parallel illumination light source 51, a cube-type broadband polarization beam splitter 52 (or an optical element having a function equivalent thereto), and a polarization rotation element 53. , A reflector 54, a prism 55, and a liquid crystal display element 56.

The white random polarized light emitted from the parallel illumination light source 51 is converted by the broadband polarization beam splitter 52.
It is separated into P-polarized light a ₁ and S-polarized light a ₂ . The broadband polarization beam splitter 52 transmits a specific polarization component (P-polarized light a _{1 in} FIG. 8) and reflects a polarization component (S-polarized light a _{2 in} FIG. 8) orthogonal to the specific polarization component in the side direction to separate it. .

The P-polarized light a ₁ transmitted through the broadband polarization beam splitter 52 enters the prism 55 as it is.
On the other hand, the S-polarized light a ₂ reflected in the side direction is transmitted through the polarization rotator 53, so that its plane of polarization is rotated by 90 degrees. As a result, the above S-polarized light a ₂ becomes P
The P-polarized light a ₂ ′ is aligned in the same polarization direction as the polarized light a _1.
Becomes Then, the P-polarized light a ₂ ′ is reflected by the reflector 54.
Is reflected by and is incident on the prism 55. Then, the _two light fluxes of the P-polarized light a ₁ and the P-polarized light a ₂ ′ are combined by the prism 55 and applied to the liquid crystal display element 56. As described above, in the above-described configuration, the polarization planes of the two light fluxes of the P-polarized light a ₁ and the S-polarized light a ₂ are aligned and irradiated on the liquid crystal display element 56, so that the light utilization efficiency is improved and the incident side polarization plate is It suppresses light absorption (not shown) and temperature rise.

Further, in JP-A-2-106792 and JP-A-6-324329, the liquid crystal display element is used as it is as P-polarized light and S-polarized light without aligning the polarization planes of the two light fluxes as described above. An illuminating liquid crystal display device is disclosed.

FIG. 9 shows an optical system of the liquid crystal display device disclosed in the former Japanese Patent Laid-Open No. 2-106792. This figure 9
The optical system shown in FIG. 1 includes a radiation source 61, a first polarization-sensitive beam splitter 62, and a second polarization-sensitive beam splitter 6
3, a reflector 64, 65, 66, 67, a liquid crystal display element 68, and a projection lens system 69.

The illumination light emitted from the radiation source 61 is
Is incident on the polarization sensitive beam splitter 62 and is separated into S-polarized light b ₁ and P-polarized light b ₂ whose polarization directions are orthogonal to each other. The S-polarized light b ₁ and the P-polarized light b ₂ are reflected toward the same side of the liquid crystal display element 68 by the reflectors 64 and 65, respectively, and are modulated by the liquid crystal display element 68. The S-polarized light b ₁ and the P-polarized light b ₂ are generated by the liquid crystal display element 68.
After passing through the second
Is reflected toward the polarization sensitive beam splitter 63.
The S-polarized light b ₁ and the P-polarized light b ₂ are combined by the second polarization-sensitive beam splitter 63 and projected onto a projection panel (not shown) via the projection lens system 69. Thus, in the configuration of the above publication, the above-mentioned Japanese Patent Laid-Open No. 4-1786.
As in the configuration of Japanese Patent Publication No. 83, the polarization rotation element is not used to align the polarization planes of the two light fluxes and both P and S polarized lights are used to improve the light utilization efficiency.

On the other hand, FIG. 10 shows a liquid crystal display device disclosed in the latter Japanese Patent Laid-Open No. 6-324329. FIG.
Shows a state in which a light beam from a light source (not shown) mainly enters the liquid crystal display panel 72 via the polarization selecting means 71. The liquid crystal display panel 72 includes a glass substrate 74 on which a transparent electrode 73 is formed and a pixel 7 including the transparent electrode.
A glass substrate 76 on which 5A and 75B are formed is provided so as to face it, and a liquid crystal 77 is filled between them. A microlens array 78 is mounted on the light flux incident side of the liquid crystal display panel 72, and a polarizer 79 is mounted on the light flux outgoing side.

The microlens array 78 has microlenses 80 arranged without a gap, and is arranged at a pitch twice the pixel pitch in one direction and the same as the pixel pitch in the other direction. They are arranged on a pitch. That is, one minute lens 80 corresponds to two pixels 75A and 75B.

According to the above structure, a light source (not shown)
Of the light beams emitted from the light beam of one polarization component c ₁
Is transmitted through the polarization selecting means 71 as it is, and is focused on one pixel 75A by the microlens array 78. Further, the light beam c ₂ of the other polarization component has its traveling direction changed by the polarization selecting means 71 and is condensed on the other pixel 75B. The light flux that has passed through the liquid crystal display panel 72 is analyzed by a polarizer 79 having a constant polarization plane, and one pixel 75A (or 75B) produces a so-called normally white image in which white display is performed when no voltage is applied. . Also,
In the other pixel 75B (or 75A), a so-called normally black image is displayed in which black is displayed when no voltage is applied. As described above, in the above publication, all the luminous fluxes emitted from the light source (not shown) pass through the liquid crystal display panel 72 to improve the light utilization efficiency.

[0016]

However, in the structure of the above-mentioned Japanese Patent Laid-Open No. 4-178683, the liquid crystal display element 56 is used.
As the display area of the cube becomes larger, the volume of the cube-type broadband polarization beam splitter 52 must be increased accordingly. As a result, the size of the optical system increases,
There is a problem that the wide band polarization beam splitter 52 can be used only in the liquid crystal projector type.

Further, in the configuration of the above publication, since the liquid crystal display element 56 is illuminated from two directions to combine the light fluxes, the incident angle of the illumination light becomes large. When the angle of incidence of the illumination light is increased in this way, the characteristics of dichroic mirrors, microlenses, optical fibers, etc., which are often used in liquid crystal projectors, change, so there is the problem that they cannot be used easily. .
Further, when the incident angle of the illumination light increases, the illumination light is blocked by the projection lens surface unless the projection lens (not shown) is upsized, so that the light utilization rate cannot be improved. However, increasing the size of this projection lens directly leads to higher costs. Further, in the configuration of the above publication, since the polarization rotating element 53 for aligning the plane of polarization is used, there is a problem that the number of parts of the illumination system is large.

On the other hand, in the structure disclosed in Japanese Patent Laid-Open No. 2-106792, the first polarization sensing beam splitter 62, the second polarization sensing beam splitter 63, and the reflectors 64 and 6 are included.
Since 5, 66, 67, etc. are arranged, the size of the optical system becomes large, which causes a problem that it can be used only in the liquid crystal projector type. Further, since the reflectors 66 and 67 are used on the side of the projection optical system, there arises a problem that an image on one liquid crystal display element 68 is inverted by two light fluxes. Further, in order to solve this problem, a configuration in which a reflector is further added is presented, but this causes a further increase in the size of the optical system, which causes a problem that a compact liquid crystal display device cannot be obtained.

Further, in the structure of Japanese Patent Laid-Open No. 6-324329, the display operation modes are normally white and normally black for each of the pixels 75A and 75B.
Therefore, one of the pixels 75A and 75B
If the A (or 75B) electrode signal is not inverted, display unevenness will occur due to the difference in performance between the operation modes.

The present invention has been made to solve the above problems, and its purpose is to improve the utilization efficiency of light from a light source, to display a bright image, and to prevent liquid crystal from becoming uneven. It is an object of the present invention to provide a display device and a small-sized and lightweight liquid crystal display device.

[0021]

In order to solve the above-mentioned problems, a liquid crystal display device according to the invention of claim 1 controls an illuminating means for emitting parallel light and a polarization state of incident linearly polarized light. And a light-transmissive liquid crystal display element that performs display, and transmits one of two types of linearly polarized light whose polarization directions are orthogonal to each other and reflects the other, thereby separating the parallel light into the two types of linearly polarized light. A first polarization separation element having a plurality of polarization separation elements arranged side by side along a light incident surface of the liquid crystal display element and for allowing the two types of linearly polarized light to enter the liquid crystal display element; It has a polarization splitting means and a polarization splitting element that transmits one of the two types of linearly polarized light that has passed through the liquid crystal display element and reflects the other of the two types of linearly polarized light. Lined up along the exit surface It is characterized by comprising a second polarization separator being.

According to the above arrangement, the parallel light emitted from the illumination means is incident on the first polarized light separating means. The first polarized light separating means is composed of a polarized light separating element such as a plurality of polarizing beam splitters having a minute size or stripes. The plurality of polarization separation elements are arranged side by side along the light incident surface of the liquid crystal display element.

The polarization splitting element splits the parallel light emitted by the illuminating means into two types of linearly polarized light whose polarization directions are orthogonal to each other. Then, of the two types of separated linearly polarized light, one linearly polarized light passes through the polarization separation element and enters the liquid crystal display element. The other linearly polarized light is reflected by the polarization separation element and enters the liquid crystal display element.

The above liquid crystal display element is a light transmission type liquid crystal display element, and controls the polarization state of two types of incident linearly polarized light, and then transmits the two types of linearly polarized light. That is,
When P-polarized light is incident on the liquid crystal display element, if the liquid crystal display element performs light modulation, the P-polarized light becomes S-polarized light. When the liquid crystal display element does not perform light modulation, the incident P-polarized light remains P-polarized light. The linearly polarized light whose polarization state has been controlled in this way is transmitted through the liquid crystal display element and emitted.

The two types of linearly polarized light emitted from the liquid crystal display element enter the second polarized light separating means. Similar to the first polarized light separating means, the second polarized light separating means is composed of, for example, a polarized light separating element such as a plurality of polarizing beam splitters having a minute size or stripes. The plurality of polarization separation elements are arranged side by side along the light emitting surface of the liquid crystal display element.

Of the two types of linearly polarized light that have entered the polarization separation element of the second polarization separation means, one of the linearly polarized light is transmitted through the polarization separation element and emitted. The other linearly polarized light is reflected by the polarization separation element and emitted. At this time,
The two types of linearly polarized light having different traveling directions that are incident on the polarization separating element are emitted from the polarization separating element in the same traveling direction. An image is displayed using the above two types of linearly polarized light.

Therefore, according to the above construction, a plurality of minute polarization separation elements are used as the first polarization separation means and the second polarization separation means, and in particular, in the first polarization separation means, a plurality of polarization separation elements are used. Since the polarized light separating element can separate the polarized light, it is not necessary to use a heavy and large polarized light separating element as in the conventional case, and as a result, the liquid crystal display device itself can be downsized and lightened.

Further, unlike the conventional case, a polarization rotating element is not used, but two kinds of linearly polarized light having different polarization directions are used,
Since the image can be displayed, the number of parts of the illumination system can be reduced because the polarization rotator is not used, and the light utilization rate can be significantly improved compared to the conventional case without using the polarization rotator. , You can get a bright display. Further, since it is not necessary to use an absorption type polarizing plate, it is possible to avoid temperature rise and heat generation due to light absorption of the polarizing plate.

In order to solve the above-mentioned problems, the liquid crystal display device according to a second aspect of the present invention is a light reflection device for displaying by illuminating means for emitting parallel light and controlling the polarization state of the incident linearly polarized light. Type liquid crystal display element and a polarization separation element that separates the parallel light into the two types of linearly polarized light by transmitting one of the two types of linearly polarized light whose polarization directions are orthogonal to each other and reflecting the other. A plurality of the polarization splitting elements are provided along the light incident / exiting surface of the liquid crystal display element, and the two types of linearly polarized light are made incident on the liquid crystal display element, and the two types of light reflected by the liquid crystal display element are provided. And a polarized light separating means arranged in parallel so as to guide the linearly polarized light to the outside of the liquid crystal display element.

According to the above structure, the parallel light emitted from the illumination means is incident on the polarization separation means. The polarization separation means is composed of a polarization separation element such as a plurality of polarization beamsplitters having a minute size or stripes. The plurality of polarization separation elements are arranged side by side along the light incident / emission surface of the liquid crystal display element.

The polarization splitting element splits the parallel light emitted by the illuminating means into two types of linearly polarized light whose polarization directions are orthogonal to each other. Then, of the two types of separated linearly polarized light, one linearly polarized light passes through the polarization separation element and enters the liquid crystal display element. The other linearly polarized light is reflected by the polarization separation element and enters the liquid crystal display element.

The above liquid crystal display element is a light reflection type liquid crystal display element, and controls the polarization states of two types of incident linearly polarized light. That is, when, for example, P-polarized light is incident on the liquid crystal display element, if the liquid crystal display element performs light modulation, the P-polarized light becomes S-polarized light. When the liquid crystal display element does not perform light modulation, the incident P-polarized light remains P-polarized light. The linearly polarized light whose polarization state has been controlled in this way is reflected by the liquid crystal display element and again enters the polarization separation element.

Of the two types of linearly polarized light that have entered the polarization separation element again, one linearly polarized light is transmitted through the polarization separation element and emitted. The other linearly polarized light is reflected by the polarization separation element and emitted. At this time, the two types of linearly polarized light entering the polarization separation element are emitted from the polarization separation element in the same traveling direction. An image is displayed using the above two types of linearly polarized light.

Therefore, according to the above configuration, since a plurality of minute size polarization separation elements can be used as the polarization separation means to perform polarization separation, it is necessary to use a heavy and large polarization separation element as in the conventional case. As a result, the liquid crystal display device itself can be reduced in size and weight. Further, since the above-mentioned configuration uses the light reflection type liquid crystal display element, it is only necessary to dispose one polarization separating means on the light input / output surface of the liquid crystal display element, and the light transmission type liquid crystal display element is used. It is possible to make the device more compact than in the case and reduce the cost.

Further, unlike the conventional case, a polarization rotating element is not used, and two kinds of linearly polarized light having different polarization directions are used,
Since the image can be displayed, the number of parts of the illumination system can be reduced because the polarization rotator is not used, and the light utilization rate can be significantly improved compared to the conventional case without using the polarization rotator. , You can get a bright display. Further, since it is not necessary to use an absorption type polarizing plate, it is possible to avoid temperature rise and heat generation due to light absorption of the polarizing plate.

In order to solve the above-mentioned problems, a liquid crystal display device according to a third aspect of the present invention is, in addition to the structure of the first or second aspect, a parallel direction for restricting the traveling direction of the parallel light emitted from the illumination means. This is a configuration including a light traveling direction regulating means.

According to the above structure, in the structure of claim 1 or 2, the polarization splitting element of the liquid crystal display element is configured so that two kinds of linearly polarized light whose polarization directions are orthogonal to each other are incident on the liquid crystal display element. A plurality of them are arranged side by side along the entrance surface (or the entrance / exit surface). Therefore, in order to make the two types of linearly polarized light separated by the polarization separation element incident on the liquid crystal display element, the illuminating means is arranged at a position facing the light incident surface of the polarization separation element and is parallel. It is necessary to make light incident perpendicularly to the light incident surface of the polarization separation element.

Here, if parallel light traveling direction regulating means for regulating the traveling direction of the parallel light emitted from the illuminating means is disposed between the illuminating means and the polarization separating means, the illuminating means Need not be disposed at a position facing the light incident surface of the polarization separation element. That is,
Even if the illuminating means is not arranged at a position facing the light incident surface of the polarization separating element, the parallel light from the illuminating means is converted into the light of the polarization separating element by the parallel light traveling direction regulating means. It is possible to make the light incident perpendicularly to the incident surface.

Therefore, by providing parallel light advancing direction restricting means for restricting the advancing direction of the parallel light emitted from the illuminating means as in the above structure, the illuminating means is directed to the light incident surface of the polarization separation element. It is also possible to arrange the illuminating means at positions other than the facing positions, and to appropriately select the arranging position of the lighting means. In addition, this allows the liquid crystal display device itself to be further miniaturized, and the optical system of the present invention can be easily adapted to a conventional liquid crystal display device for easy use.

In order to solve the above-mentioned problems, a liquid crystal display device according to a fourth aspect of the present invention, in addition to the structure of the first or second aspect, is provided with a linearly polarized light obtained by passing a liquid crystal display element and a polarization separation means in this order. This is a configuration including linearly polarized light traveling direction regulating means for regulating the traveling direction.

According to the above structure, in the structure of claim 1 or 2, two kinds of linearly polarized light whose polarization directions are orthogonal to each other, which have passed through the liquid crystal display element and the polarization separation means in this order, are applied to the liquid crystal display element. On the other hand, the light is emitted in an oblique direction, for example. However, the traveling directions of the two types of linearly polarized light that are emitted are regulated by the linearly polarized light traveling direction regulating means. Of these, the linearly polarized light required for image display is emitted by the linearly polarized light advancing direction regulating means, for example, in a direction perpendicular to the liquid crystal display element. Also,
The linearly polarized light unnecessary for image display is totally reflected by adjusting the inclination and the refractive index of the linearly polarized light advancing direction regulating means, and is not emitted to the emission side.

Therefore, by using the linearly polarized light advancing direction regulating means, two kinds of linearly polarized light are emitted, for example, in a direction perpendicular to the liquid crystal display element. It can be easily adapted to the display device and used easily. Further, by adjusting the inclination and the refractive index of the linearly polarized light advancing direction regulating means, it is possible to eliminate the linearly polarized light unnecessary for image display.

[0043]

BEST MODE FOR CARRYING OUT THE INVENTION

[Embodiment 1] An embodiment of the present invention will be described below with reference to FIGS.

First, FIG. 6 shows a sectional view of the liquid crystal display device 1 of the present invention. The direct-view type liquid crystal display device 1 includes a parallel illumination light source 2 (illuminating means), a liquid crystal display element 3, a polarization separation element 4 (first polarization separation means) provided on the light flux incident side of the liquid crystal display element 3, Between the polarization separation element 5 (second polarization separation means) provided on the light flux emission side of the liquid crystal display element 3, the angle regulation plate 6 provided on the projection side, and between the parallel illumination light source 2 and the polarization separation element 4. The Fresnel prism element 7 (parallel light advancing direction restricting means) provided and the Fresnel prism element 7 (linear polarization advancing direction restricting means) provided between the polarization separation element 5 and the angle restricting plate 6 are provided. There is.

The parallel illumination light source 2 is a light source that emits substantially parallel light. Further, the liquid crystal display element 3 has an O
It is a light-transmissive liquid crystal display element that performs display by controlling the polarization states of two types of incident linearly polarized light, that is, P-polarized light and S-polarized light, by N / OFF. Thereby, it is possible to perform optical modulation of the polarization direction of linearly polarized light.

A polarization separation element 4 is provided on the light beam incident side of the liquid crystal display element 3. A polarization separation element 5 is provided on the light flux emission side of the liquid crystal display element 3. Here, the polarization separation element 4 and the polarization separation element 5 will be described in detail with reference to FIGS. 1A and 1B.

1 (a) and 1 (b) are sectional views showing the arrangement of the polarization separation element 4, the polarization separation element 5 and the liquid crystal display element 3. As shown in FIG. The polarization separation element 4 is composed of a plurality of polarization beam splitters 4 each having a minute size or stripe shape.
a. The plurality of polarization beam splitters 4a are arranged in a planar array so as to cover the entire screen of the liquid crystal display element 3 on the light beam incident side. That is,
A plurality of the polarization beam splitters 4a are arranged along the light incident surface of the liquid crystal display element 3 and arranged so that two kinds of linearly polarized light, that is, P-polarized light and S-polarized light are incident on the liquid crystal display element. It is set up. In addition to this,
The plurality of polarization beam splitters 4a are juxtaposed such that their polarization planes are perpendicular to the surface of the liquid crystal display element 3.

The polarization beam splitter 4a transmits one of two types of linearly polarized light whose polarization directions are orthogonal to each other and reflects the other, thereby causing the parallel illumination light source 2 to travel.
It has a function of separating the parallel light emitted from (see FIG. 6) into the above two types of linearly polarized light. That is, the polarization beam splitter 4a has two types of linearly polarized light, that is,
Of the P-polarized light and the S-polarized light, the P-polarized light is transmitted, and the S-polarized light is reflected at a 90 ° angle to reflect the parallel light emitted from the parallel illumination light source 2 (see FIG. 6). It has the function of separating two types of linearly polarized light.

On the other hand, the polarization separation element 5 is composed of a plurality of polarization beam splitters 5a having a minute size or stripes. The plurality of polarization beam splitters 5a are arranged in a planar array so as to cover the entire screen of the liquid crystal display element 3 on the light beam exit side. In other words, a plurality of the polarization beam splitters 5a are arranged along the light exit surface of the liquid crystal display element 3 and have two types of linearly polarized light, that is, P-polarized light and S-polarized light, on the opposite side of the liquid crystal display element. They are arranged side by side so as to emit light. In addition to this, the plurality of polarization beam splitters 5a are arranged in parallel so that the polarization plane thereof is perpendicular to the surface of the liquid crystal display element 3.

The polarization separation element 5 transmits one of the two types of linearly polarized light that has passed through the liquid crystal display element 3,
It has the function of reflecting the other. That is, the polarization separation element 5 transmits the P-polarized light of the two types of linearly polarized light that has passed through the liquid crystal display element 3, that is, the P-polarized light and the S-polarized light, and the S-polarized light is 90 °. It has the function of changing the angle and reflecting.

In addition, as shown in FIG.
The angle regulating plate 6 used in (1) is a sheet-shaped structure in which cylinders are arranged in a honeycomb shape, and a light-shielding layer is formed on the side surface.
The angle of the emitted light is controlled by the thickness of the angle control plate 6 and the diameter of each cylinder.

In the first embodiment, as shown in FIGS. 1A and 1B, since the polarization separation element 4 is arranged, the illumination light from the parallel illumination light source 2 (see FIG. 6) is used. To
Perpendicular to the light incident surface of the polarization beam splitter 4a,
That is, it is necessary to make the liquid crystal display element 3 enter obliquely. Further, as shown in FIGS. 1A and 1B, since the polarization separation element 5 is arranged, the light emitted from the liquid crystal display element 3 is emitted obliquely to the liquid crystal display element 3. However, in order to adapt the liquid crystal display device 1 of the present invention to a conventional liquid crystal display device, or to simply use the liquid crystal display device 1, the illumination light from the parallel illumination light source 2 (see FIG. 6) is used. It is better to make the liquid crystal display element 3 enter in a vertical direction. Further, it is preferable that the light emitted from the liquid crystal display element 3 is emitted in a direction perpendicular to the liquid crystal display element 3. Therefore, in the first embodiment, the Fresnel prism element 7 as shown in FIG. 3 is provided on the light flux incident side and the light flux exit side of the liquid crystal display element 3.

The Fresnel prism element 7 shown in FIG. 3 is a sheet-shaped prism element having a sawtooth cross-sectional shape. The Fresnel prism element 7 has the same function as the prism element 8 shown in FIGS. 4 (a) and 4 (b). Here, the function of the prism element 8 will be specifically described below with reference to FIGS. 4A and 4B, and will be used as an alternative to the description of the function of the Fresnel prism element 7.

For example, as shown in FIG. 4A, when the prism element 8 is arranged on the light-incident side of the liquid crystal display element 3, the parallel illumination light source 2 (FIG. The parallel light emitted from the reference element is refracted in the prism element 8. That is, the parallel illumination light source 2 (see FIG.
The prism element 8 regulates the traveling direction of the parallel light emitted from As a result, the illumination light is emitted from the polarization beam splitter 4a (see FIGS. 1A and 1B).
It is possible to make the light incident perpendicularly to the light incident surface (see), that is, obliquely to the liquid crystal display element 3.

Further, as shown in FIG. 4B, when the prism element 8 is arranged on the luminous flux exit side of the liquid crystal display element 3,
The prism element 8 has a function of restricting the traveling direction of linearly polarized light that has passed through the liquid crystal display element 3 and the polarization separation element 5 (see FIGS. 1A and 1B) in this order. . That is, the outgoing light obliquely emitted from the liquid crystal display element 3 is similarly refracted in the prism element 8. As a result, the emitted light can travel in the direction perpendicular to the liquid crystal display element 3. Further, in the latter case, by adjusting the inclination and the refractive index of the prism element 8, it is possible to totally reflect a light beam unnecessary for image display and prevent the above light beam from being emitted to the emission side.

The Fresnel prism element 7 having a function equivalent to the above-mentioned function can be formed into a sheet as a whole because the cross-section is a sawtooth type, and the prism element 8 is used.
More compact than that. Therefore, in the first embodiment, the Fresnel prism element 7 is used on both the light flux incident side and the light flux exit side of the liquid crystal display element 3. Also,
The Fresnel prism element 7 is manufactured by using the same method as a known method for manufacturing a Fresnel lens, using high refractive index glass, plastic, resin, or the like, so that it can be manufactured easily and at a low cost. This has the advantage that the prism element 7 can be obtained.

Next, the operation of the liquid crystal display device 1 of the present invention will be described with reference to FIGS. 1 (a), 1 (b) and 6.

In FIG. 6, the illumination light emitted from the parallel illumination light source 2 is refracted by the Fresnel prism element 7 and is incident on the polarization separation element 4 at a required angle. The incident illumination light is separated into P-polarized light and S-polarized light by the polarization separation element 4, and enters the liquid crystal display element 3. The P-polarized light and the S-polarized light have an applied voltage of 0 in the liquid crystal display element 3.
In the N state, the polarization azimuth is modulated and emitted toward the polarization separation element 5. Moreover, in the OFF state of the applied voltage,
The polarization directions of the P-polarized light and the S-polarized light are not modulated and are emitted toward the polarization separation element 5.

Here, the above-mentioned illumination light is the polarization separation element 4
FIG. 1A and FIG. 1B show how the light enters the liquid crystal display element 3 through the, and how it exits the liquid crystal display element 3 through the polarization separation element 5.
The details will be described based on FIGS. 1A and 1B. In addition, in FIG. 1A and FIG. 1B, the illumination light from the parallel illumination light source 2 (see FIG. 6) is represented by a light ray A ₁ and a light ray A ₂ .

First, FIG. 1A shows a state in which the applied voltage to the liquid crystal display element 3 is OFF, that is, a state in which the liquid crystal display element 3 does not modulate the polarization azimuth of linearly polarized light.

The light ray A ₁ is P-polarized light P by the polarization separation element 4.
₁ and S-polarized light S ₁ . Of these, the P-polarized light P ₁ passes through the polarization separation element 4 and enters the liquid crystal display element 3. Since the liquid crystal display element 3 does not modulate the polarization direction, the P-polarized light P ₁ is incident on the polarization separation element 5 as it is as P-polarized light. This polarization separation element 5 also transmits the P-polarized light P ₁ ,
The light is emitted from the polarization separation element 5 (it is emitted to the lower right in FIG. 1A).

On the other hand, the light beam A ₂ is separated by the polarization separation element 4 into P-polarized light P ₂ and S-polarized light S ₂ . Of these, the S-polarized light S ₂ is reflected by the polarization separation element 4 and enters the liquid crystal display element 3. Since the liquid crystal display element 3 does not modulate the polarization direction, the S-polarized light S ₂ is incident on the polarization separation element 5 as it is as S-polarized light. The S-polarized light S ₂ is also reflected by the polarization separation element 5 and is emitted from the polarization separation element 5 (see FIG. 1).
In (a), the light is emitted to the lower right.

Next, FIG. 1B shows a state in which the applied voltage to the liquid crystal display element 3 is ON, that is, a state in which the liquid crystal display element 3 modulates the polarization azimuth of linearly polarized light.

The light beam A ₁ is P-polarized light P by the polarization separation element 4.
₁ and S-polarized light S ₁ . Of these, the P-polarized light P ₁ is transmitted through the polarization separation element 4 and the liquid crystal display element 3
Incident on. Since the liquid crystal display element 3 modulates the polarization azimuth, the P polarized light P ₁ becomes S polarized light S ₁ ′, which is emitted from the liquid crystal display element 3 and enters the polarization separation element 5. Then, the S-polarized light S ₁ ′ is reflected by the polarization separation element 5 and emitted from the polarization separation element 5 (in FIG. 1B,
It is emitted to the lower left).

On the other hand, the light beam A ₂ is separated by the polarization separation element 4 into P-polarized light P ₂ and S-polarized light S ₂ . Of these, the S-polarized light S ₂ is reflected by the polarization separation element 4 and enters the liquid crystal display element 3. Since the liquid crystal display element 3 modulates the polarization direction, the S-polarized light S ₂ becomes P-polarized light P ₂ ′,
The light is emitted from the liquid crystal display element 3 and enters the polarization separation element 5. After that, the P-polarized light P ₂ ′ passes through the polarization separation element 5 and is emitted from the polarization separation element 5 (it is emitted to the lower left in FIG. 1B).

After that, the emitted light is emitted through the Fresnel prism element 7 and the angle regulating plate 6, as shown in FIG. The emitted light is transmitted through the Fresnel prism element 7 and becomes a light ray perpendicular to the liquid crystal display element 3. Further, the Fresnel prism element 7 and the angle regulating plate 6 block the light flux in an unnecessary direction and display an image.

As described above, the emitted light emitted from the polarization beam splitting element 5 is changed depending on the ON / OFF state of the applied voltage in the liquid crystal display element 3 as shown in FIGS. 1 (a) and 1 (b). Separated into directions. Then, by outputting only the light fluxes aligned on one side of the light fluxes in the two directions, an image is displayed and the liquid crystal display device can be directly observed.

If a projection lens 9 is used as shown in FIG. 7 instead of the angle regulating plate 6, it can be used as a projection type liquid crystal display device. That is, by making the light emitted from the Fresnel prism element 7 incident on the projection lens 9 via the field lens 10, it is possible to block a light flux unnecessary for image display.
Then, an image is displayed by projecting the light flux that has passed through the projection lens onto the screen 11. Thus, by appropriately selecting the angle regulation plate 6, the projection lens 9 and the like, it is possible to use both the direct-view type and the projection type.

It should be noted that, as described above, 2
By displaying images using linearly polarized light of various types,
The light utilization rate is remarkably improved as compared with the conventional one, and there is no need to use an absorption type polarizing plate, and the temperature rise and heat generation of the polarizing plate itself can be avoided. Further, unlike the conventional case, since the display operation mode does not differ for each pixel, the liquid crystal display device of the present invention does not cause display unevenness in an image.

Further, if it is not necessary to further improve the luminance, the luminance of the light source can be reduced, that is, the power consumption of the light source can be reduced and the power consumption of the liquid crystal display device can be reduced.

With the above structure, a plurality of polarization beam splitters 4a, 5a having a minute size or stripes are formed.
Since the polarization separating elements 4 and 5 are formed by arranging them in a plane array, it is not necessary to use a heavy and large polarization beam splitter as the polarization separating element as in the conventional case. The system itself can be made compact and lightweight.

Two types of linearly polarized light having different polarization directions, that is, P-polarized light P ₁ , S-polarized light S ₂ , or P-polarized light P ₂ ′, S-polarized light S ₁ ′, are used. Since the light is emitted in a uniform traveling direction from the light source and an image can be displayed using these two linearly polarized lights, the light utilization rate is significantly improved as compared with the conventional case without using a polarization rotation element. be able to. Further, the number of parts of the illumination system can be reduced because no polarization rotation element is used. Further, by using the projection lens 9 and the like as described above,
Besides the direct-view type, a liquid crystal display device can be used as a projection type.

[Embodiment 2] Next, a liquid crystal display device as another embodiment of the present invention will be described. In the second embodiment, a light reflection type liquid crystal display element is used instead of the light transmission type liquid crystal display element 3 (see FIG. 1) used in the first embodiment. For convenience of explanation, members having the same functions as members used in Embodiment 1 are given the same member numbers, and descriptions thereof are omitted. Then, in the following, mainly regarding this light reflection type liquid crystal display element, FIG.
A description will be given based on (a), FIG. 2 (b), and FIG.

FIGS. 2A and 2B are sectional views of the light reflection type liquid crystal display element 21. The liquid crystal display element 21 is a light reflection type liquid crystal display element that performs display by controlling the polarization state of incident linearly polarized light. Also,
The polarization separation element 4 is arranged so as to cover the entire screen of the liquid crystal display element 21. By the way, the polarization separation element 4
Is composed of a plurality of polarization beam splitters 4a having a minute size or stripes, as in the first embodiment. Then, the plurality of polarization beam splitters 4a
Are arranged in a planar array so as to cover the entire screen of the liquid crystal display element 21 on the light flux entrance / exit side. That is, a plurality of the polarization beam splitters 4a are provided in the liquid crystal display element 2 described above.
The two types of linearly polarized light, that is, the P-polarized light and the S-polarized light, are incident on the liquid crystal display element 21 and are reflected by the liquid crystal display element 21 along the light input / output surface of 1. Are arranged side by side so as to guide the linearly polarized light of the above to the outside of the liquid crystal display element 21. In addition to this, the plurality of polarization beam splitters 4a are arranged in parallel so that the polarization plane thereof is perpendicular to the surface of the liquid crystal display element 21.

Next, the operation of the light reflection type liquid crystal display element 21 will be described with reference to FIGS. 2 (a) and 2 (b). In FIGS. 2A and 2B, the illumination light from the parallel illumination light source (not shown) is represented by rays A ₁ and A ₂ .

First, FIG. 2A shows a state in which the applied voltage to the liquid crystal display element 21 is OFF, that is, a state in which the liquid crystal display element 21 does not modulate the polarization direction of the linearly polarized light.

The light ray A ₁ is P-polarized light P by the polarization separation element 4.
₁ and S-polarized light S ₁ . Of these, the P-polarized light P ₁ is transmitted through the polarization separation element 4 and the liquid crystal display element 2
Incident on 1. Here, since the liquid crystal display element 21 does not modulate the polarization direction, the P-polarized light P ₁ is reflected as it is as P-polarized light and is incident on the polarization separation element 4 again. The P-polarized light P ₁ is also transmitted through this polarization separation element 4 and is emitted from the polarization separation element 4 (it is emitted to the upper right in FIG. 2A).

On the other hand, the light beam A ₂ is separated by the polarization separation element 4 into P-polarized light P ₂ and S-polarized light S ₂ . Of these, the S-polarized light S ₂ is reflected by the polarization separation element 4 and enters the liquid crystal display element 21. Here, the liquid crystal display element 21
Does not modulate the polarization azimuth, the S-polarized light S ₂ is reflected as S-polarized light and is incident on the polarization separation element 4 again. The S-polarized light S ₂ is reflected by the polarization separation element 4 and is emitted from the polarization separation element 4 (it is emitted to the upper right in FIG. 2A).

Next, FIG. 2B shows a state in which the applied voltage in the liquid crystal display element 21 is ON, that is, the state in which the liquid crystal display element 21 modulates the polarization direction of the linearly polarized light.

The light beam A ₁ is P-polarized light P by the polarization separation element 4.
₁ and S-polarized light S ₁ . Of these, the P-polarized light P ₁ is transmitted through the polarization separation element 4 and the liquid crystal display element 2
Incident on 1. Here, since the liquid crystal display element 21 modulates the polarization direction, the P-polarized light P ₁ becomes the S-polarized light S ₁ ′,
The light is reflected by the liquid crystal display element 21 and again enters the polarization separation element 4. The incident S-polarized light S ₁ ′ is reflected again by the polarization separation element 4 and is emitted from the polarization separation element 4 (it is emitted to the upper left in FIG. 2B).

On the other hand, the light beam A ₂ is separated by the polarization separation element 4 into P-polarized light P ₂ and S-polarized light S ₂ . Of these, the S-polarized light S ₂ is reflected by the polarization separation element 4 and enters the liquid crystal display element 21. Here, since the liquid crystal display element 21 modulates the polarization azimuth, the S-polarized light S ₂ becomes P-polarized light P ₂ ′, which is reflected by the liquid crystal display element 21 and enters the polarization separation element 4 again. The incident P-polarized light P ₂ ′
Is transmitted through the polarization separation element 4 and is emitted from the polarization separation element 4 (emitted to the upper left in FIG. 2B).

As described above, the emitted light emitted from the polarization separation element 4 is turned ON / OFF of the applied voltage in the liquid crystal display element 21 as shown in FIGS. 2 (a) and 2 (b).
Depending on the state, they are separated in two directions.

In FIG. 2A and FIG. 2B, it is possible to display by outputting only the linearly polarized light which is aligned on one side among the outputted linearly polarized lights in two directions. In particular, in the optical system shown in FIGS. 2 (a) and 2 (b),
Considering the surface reflection and the like of the light reflection type liquid crystal display element 21, if an angle regulating plate 6 (see FIG. 5), a Fresnel prism element 7 (see FIG. 3), etc. are used, linearly polarized light in an unnecessary direction is shielded. As a result, a high-brightness liquid crystal display device having a good contrast ratio can be obtained.

As shown in FIG. 11, the lens 25, the Fresnel prism element 7, and the parallel illumination light source 2 are provided so as to face each other.
By providing the polarization separation element 4 and the liquid crystal display element 21 and disposing the mirror 26 and the projection lens 9 between the parallel illumination light source 2 and the lens 25, it is possible to display a projection image on the screen 11. Besides the direct-view type, it can be used as a projection type liquid crystal display device.

Further, as described above, the two polarization directions differ from each other.
By displaying images using linearly polarized light of various types,
The light utilization rate is remarkably improved as compared with the conventional one, and there is no need to use an absorption type polarizing plate, and the temperature rise and heat generation of the polarizing plate itself can be avoided. Further, unlike the conventional case, since the display operation mode does not differ for each pixel, the liquid crystal display device of the present invention does not cause display unevenness in an image.

With the above configuration, a plurality of polarization beam splitters 4a having a minute size or stripes are used, and they are arranged in a plane array to form the polarization separation element 4. In addition, it is not necessary to use a heavy and large polarization beam splitter as the polarization separation element, and the optical system itself can be made compact and lightweight. Further, since the above-described configuration uses the light reflection type liquid crystal display element 21, it is sufficient to dispose one polarization separation element 4 on the light flux incident side (emission side) of the liquid crystal display element 21. As compared with the case of using the liquid crystal display element, the device itself can be made more compact and the cost can be reduced.

Two kinds of linearly polarized light having different polarization directions, that is, P-polarized light P ₁ , S-polarized light S ₂ , or P-polarized light P ₂ ′, S-polarized light S ₁ ′ are used. Since the light is emitted in a uniform traveling direction from the light source and an image can be displayed using these two linearly polarized lights, the light utilization rate is significantly improved as compared with the conventional case without using a polarization rotation element. be able to. Further, in the above configuration, since the polarization rotation element is not used, the number of parts of the illumination system can be reduced. Furthermore, a projection image can be displayed by using the projection lens 9 and the like. With this, a bright image can be displayed without using a polarizer even in a projection type liquid crystal display device other than the direct-view type.

[0088]

The liquid crystal display device according to the invention of claim 1
As described above, the illuminating means for emitting parallel light, the light transmission type liquid crystal display element for displaying by controlling the polarization state of the incident linearly polarized light, and the polarization directions orthogonal to each other 2
There is provided a polarization separating element for separating the parallel light into the two kinds of linearly polarized light by transmitting one of the kinds of linearly polarized light and reflecting the other, and a plurality of the polarization separating elements are provided.
First polarized light separating means arranged along the light incident surface of the liquid crystal display element and arranged so as to make the two types of linearly polarized light incident on the liquid crystal display element, and the two types of light transmitted through the liquid crystal display element. A second polarization splitting means having a polarization splitting element that transmits one of the linearly polarized lights and reflects the other, and a plurality of the polarization splitting elements are arranged in parallel along the light exit surface of the liquid crystal display element. It is a configuration provided with.

Therefore, a plurality of minute size polarization separation elements are used as the first polarization separation means and the second polarization separation means, and particularly, in the first polarization separation means,
Since the polarization separation can be performed by a plurality of polarization separation elements, it is not necessary to use a heavy and large polarization separation element as in the past, and as a result, the liquid crystal display device itself can be downsized and lightened. .

Further, unlike the conventional case, a polarization rotating element is not used, and two kinds of linearly polarized light having different polarization directions are used,
Since the image can be displayed, the number of parts of the illumination system can be reduced because the polarization rotator is not used, and the light utilization rate can be significantly improved compared to the conventional case without using the polarization rotator. , You can get a bright display. In addition, it is not necessary to use an absorption type polarizing plate, and it is possible to avoid temperature rise and heat generation due to light absorption of the polarizing plate.

As described above, the liquid crystal display device according to the invention of claim 2 is a light-reflecting liquid crystal display for performing display by controlling the illumination means for emitting parallel light and the polarization state of the incident linearly polarized light. The element and a polarization separation element that separates the parallel light into the two types of linearly polarized light by transmitting one of the two types of linearly polarized light whose polarization directions are orthogonal to each other and reflecting the other are provided. A plurality of elements are arranged along the light incident / exiting surface of the liquid crystal display element and allow the two types of linearly polarized light to be incident on the liquid crystal display element, and the two types of linearly polarized light reflected by the liquid crystal display element are And a polarized light separating means arranged in parallel so as to be guided to the outside of the liquid crystal display element.

Therefore, since a plurality of minute size polarization separation elements can be used as the polarization separation means to perform the polarization separation, there is no need to use a heavy and large polarization separation element as in the conventional case. The liquid crystal display device itself can be made compact and lightweight. Further, since the above-mentioned configuration uses the light reflection type liquid crystal display element, it is only necessary to dispose one polarization separating means on the light input / output surface of the liquid crystal display element, and the light transmission type liquid crystal display element is used. It is possible to make the device more compact than in the case and reduce the cost.

Further, unlike the conventional case, a polarization rotating element is not used, and two kinds of linearly polarized light having different polarization directions are used,
Since the image can be displayed, the number of parts of the illumination system can be reduced because the polarization rotator is not used, and the light utilization rate can be significantly improved compared to the conventional case without using the polarization rotator. , You can get a bright display. In addition, it is not necessary to use an absorption type polarizing plate, and it is possible to avoid temperature rise and heat generation due to light absorption of the polarizing plate.

As described above, in the liquid crystal display device according to the invention of claim 3, in addition to the configuration of claim 1 or 2, the parallel light traveling direction regulation for regulating the traveling direction of the parallel light emitted from the illumination means is provided. It is a configuration including means.

Therefore, in addition to the effect of the structure of claim 1 or 2, the illuminating means can be arranged at a position other than the position facing the light incident surface of the polarization separating element, and The arrangement position can be suitably selected. In addition, the liquid crystal display device itself can be further miniaturized, and the optical system of the present invention can be easily adapted to the conventional liquid crystal display device and can be easily used.

As described above, in the liquid crystal display device according to the invention of claim 4, in addition to the structure of claim 1 or 2, the traveling direction of the linearly polarized light passing through the liquid crystal display element and the polarization separating means in this order is regulated. This is a configuration including a linearly polarized light traveling direction regulating means.

Therefore, in addition to the effect of the structure of claim 1 or 2, by using the linearly polarized light traveling direction regulating means, two kinds of linearly polarized light are, for example, perpendicular to the liquid crystal display element. Since the light is emitted, the optical system of the present invention can be easily adapted to a conventional liquid crystal display device and used easily. Further, by adjusting the inclination and the refractive index of the linearly polarized light advancing direction regulating means, it is possible to remove the linearly polarized light unnecessary for image display.

[Brief description of the drawings]

FIG. 1 (a) shows a liquid crystal display device according to the present invention.
Is the arrangement of the polarization separation element and the transmissive liquid crystal display element, and when the liquid crystal display element does not perform light modulation of linearly polarized light,
It is explanatory drawing which shows the optical path of the light beam illuminated from the parallel illumination light source, (b) is arrangement | positioning of a polarization separation element and a transmissive liquid crystal display element, and when a liquid crystal display element performs the light modulation of linearly polarized light, It is explanatory drawing which shows the optical path of the light beam illuminated from the parallel illumination light source.

FIG. 2A shows an arrangement of a polarization separation element and a reflective liquid crystal display element, and an optical path of a light beam illuminated from a parallel illumination light source when the liquid crystal display element does not perform optical modulation of linearly polarized light. FIG. 3B is an explanatory diagram showing the arrangement of the polarization separation element and the reflective liquid crystal display element, and the optical path of the light beam illuminated from the parallel illumination light source when the liquid crystal display element performs linearly polarized light modulation. FIG.

FIG. 3 is a cross-sectional view showing a cross section of a Fresnel prism element.

FIG. 4A is an explanatory diagram showing an optical path of a light beam emitted from a parallel illumination light source when passing through a prism, and FIG. 4B is a diagram showing an emitted light beam emitted from a liquid crystal display element;
It is explanatory drawing which shows the optical path when transmitting a prism.

FIG. 5 is a cross-sectional view showing a cross section of an angle control plate.

FIG. 6 is a cross-sectional view showing a configuration of a direct-viewing type liquid crystal display device of the present invention.

FIG. 7 is a sectional view showing a configuration of a projection type liquid crystal display device of the present invention.

FIG. 8 is a cross-sectional view showing a configuration of a conventional liquid crystal display device.

FIG. 9 is a plan view showing the configuration of another conventional liquid crystal display device.

FIG. 10 is a cross-sectional view showing the configuration of still another conventional liquid crystal display device.

FIG. 11 is a cross-sectional view showing the configuration of another projection type liquid crystal display device of the present invention.

[Explanation of symbols]

2 parallel illumination light source (illuminating means) 3 liquid crystal display element 4 polarization separation element (first polarization separation means) 4a polarization beam splitter (polarization separation element) 5 polarization separation element (second polarization separation means) 5a polarization beam splitter (polarization separation) Element 7 Fresnel prism element (parallel light traveling direction regulating means, linearly polarized light traveling direction regulating means) 21 liquid crystal display element

Claims (4)

[Claims] 1. An illumination means for emitting parallel light, a light-transmissive liquid crystal display element for displaying by controlling the polarization state of incident linearly polarized light, and two kinds of linearly polarized light whose polarization directions are orthogonal to each other. A polarization splitting element that splits the parallel light into the two types of linearly polarized light by transmitting one and reflecting the other is provided, and a plurality of the polarization splitting elements are provided on the light incident surface of the liquid crystal display element. A first polarized light separating means that is arranged in parallel so as to allow the two types of linearly polarized light to enter the liquid crystal display element; and one of the two types of linearly polarized light that has passed through the liquid crystal display element, and the other Has a polarization separation element that reflects
A liquid crystal display device, wherein a plurality of the polarization splitting elements are provided with second polarization splitting means arranged in parallel along the light emitting surface of the liquid crystal display element. 2. An illumination means for emitting parallel light, a light reflection type liquid crystal display element for displaying by controlling the polarization state of incident linearly polarized light, and two kinds of linearly polarized light whose polarization directions are orthogonal to each other. A polarization splitting element that splits the parallel light into the two types of linearly polarized light by transmitting one and reflecting the other is provided. Of the two types of linearly polarized light that are incident on the liquid crystal display element along with the above, and the two types of linearly polarized light reflected by the liquid crystal display element are guided in parallel to outside the liquid crystal display element. And a liquid crystal display device. 3. The liquid crystal display device according to claim 1, further comprising a parallel light traveling direction regulating means for regulating a traveling direction of the parallel light emitted from the illuminating means. 4. The liquid crystal according to claim 1, further comprising a linearly polarized light traveling direction regulating means for regulating a traveling direction of linearly polarized light which has passed through the liquid crystal display element and the polarized light separating means in this order. Display device.