JPH07101266B2 - Color liquid crystal display - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color liquid crystal display device in which two layers of liquid crystal display elements in which color polarizers are respectively arranged are laminated to perform so-called full color display.

2. Description of the Related Art Conventionally, there has been proposed a color liquid crystal display device configured by combining a TN (twisted nematic) mode liquid crystal display element with a neutral polarizer and a color polarizer.
In this color liquid crystal display device, the neutral polarizer is arranged upstream of the liquid crystal display element in the light incident direction, and the color polarizer is formed in the liquid crystal layer of the substrate on the downstream side of the liquid crystal display element in the light incident direction. Placed on the side.

The color polarizer is formed, for example, by sticking a uniaxially stretched polyvinyl alcohol (PVA) film on the substrate surface and dyeing the PVA film with a dichroic dye. In the case of performing full-color display, in the liquid crystal display device, for example, corresponding to a plurality of display images arranged in a matrix, the PVA film is red, green,
It is selectively dyed with a blue dichroic dye.

For example, a color polarizer formed using a red dichroic dye absorbs light other than red when the incident light is linearly polarized light parallel to the absorption axis direction. Further, when linearly polarized light perpendicular to the absorption axis is incident, there is no influence on this linearly polarized light. Therefore,
When the absorption axis of the color polarizer and the absorption axis of the neutral polarizer are orthogonal to each other and the twist angle of the liquid crystal molecules in the liquid crystal layer of the liquid crystal display element is 90 degrees, no voltage is applied to the liquid crystal layer. In the state, red light is observed, and in the state where a voltage is applied to the liquid crystal layer, colorless light is observed.

Therefore, full-color display can be performed by selectively applying a voltage to the liquid crystal layer in the portion corresponding to the display pixel in which the color polarizer of each color is formed.

However, in such a color liquid crystal display device, in the case of monochromatic display of red, green, and blue, there is a problem that only one-third of the whole can contribute to the display and a problem that black display cannot be performed. . In order to solve such a problem, a color liquid crystal display device is proposed in which two layers of TN mode liquid crystal display elements each having a color polarizer are laminated. In such a color liquid crystal display device, in the first liquid crystal display element arranged on the upstream side in the light incident direction, the substrate on the downstream side in the light incident direction has absorption characteristics over the entire area of the substrate. Color polarizers having a complementary color relationship with each other are formed in two layers, and the absorption axes of the color polarizers are orthogonal to each other.
That is, for example, a color polarizer dyed with a cyan dichroic dye and a color polarizer dyed with a red dichroic dye are laminated from the substrate side such that their absorption axis directions are orthogonal to each other.

Further, in the second liquid crystal display element arranged on the downstream side in the light incident direction, on the substrate on the downstream side in the light incident direction,
The absorption characteristics are different from those of the color polarizer formed in the first liquid crystal display element, and the absorption characteristics have a complementary color relationship with each other, and the absorption axis directions thereof are orthogonal to each other. A color polarizer of the layer is formed over the area of the substrate involved in the display. That is, for example, a color polarizer dyed with a green dichroic dye from the substrate side,
A color polarizer dyed with a magenta dichroic dye is laminated so that the absorption axis directions thereof are orthogonal to each other.

Further, on the upstream side in the light incident direction of the first liquid crystal display element,
A neutral polarizer that is orthogonal to the absorption axis of either one of the two-layer color polarizers formed in the first and second liquid crystal display elements is arranged.

In each of the first and second liquid crystal display elements, a plurality of transparent electrodes to which a signal voltage corresponding to a video signal is applied are patterned on the side of the color polarizer facing the liquid crystal layer. On the surface of the substrate facing the transparent electrode of the display element, a plurality of scanning electrodes to which a scanning pulse is applied are formed in a time division manner. In this way, in each liquid crystal display element, a voltage is selectively applied to the liquid crystal layer of the portion corresponding to the plurality of display pixels of the color liquid crystal display device.

In such a color liquid crystal display device, two states can be selected for each of the first and second liquid crystal display elements in each display pixel, and four states can be arbitrarily set.

That is, in the first liquid crystal display element, a red color polarizer / cyan color polarizer can be selected by voltage application / non-application, and transmitted light can be colored in red or cyan (green / blue). . In the second liquid crystal display element, a green color polarizer / magenta color polarizer can be selected by applying or not applying a voltage, and transmitted light can be limited to green / magenta (red / blue). .

Therefore, when a voltage is applied to the liquid crystal layer of the first liquid crystal display element in a certain display pixel, for example, cyan (green / blue) light is emitted from the first liquid crystal display element to the second liquid crystal display. It is incident on the element. In this case, the second
When a voltage is applied to a portion of the liquid crystal layer of the liquid crystal display element corresponding to the display pixel, for example, transmitted light is limited to green, and green display is performed in this display pixel. If no voltage is applied to the second liquid crystal display element, the transmitted light of the second liquid crystal display element is limited to magenta (red / blue), and blue display is performed in the corresponding display pixel. Be seen.

Further, in the state where no voltage is applied to the first liquid crystal display element, red light is incident on the second liquid crystal display element. In this case, when no voltage is applied to the corresponding liquid crystal layer of the second liquid crystal display element, the magenta color polarizer is selected and red light can be transmitted. Further, if a voltage is applied to the second liquid crystal display element, the transmitted light is limited to green, so that the red light incident on the second liquid crystal display element is blocked and the corresponding display pixel is black. Becomes

According to such a configuration, it is possible to display black and further display red, green, and blue for each display pixel. Therefore, when performing monochrome display, 3/3 of the display pixels Can contribute to the display, and thus a bright display can be performed on the whole.

However, in the color liquid crystal display device as described above, since the first and second liquid crystal display elements are TN mode liquid crystal display elements, the response of the liquid crystal to voltage application / non-application is slow.

FIG. 4 is a schematic cross-sectional view showing an arrangement state of liquid crystal molecules in a liquid crystal layer of a TN mode liquid crystal display element. Fourth
FIG. 1A shows a state in which no electric field is applied to the liquid crystal layer, and FIG. 4B shows a state in which an electric field is applied to the liquid crystal layer. When no electric field is applied between the substrates 41 and 42,
The long axis direction of the liquid crystal molecules is substantially parallel to the transparent substrates 41 and 42, and is the direction perpendicular to the transparent substrates 41 and 42 when an electric field is applied. It takes a relatively long time (30 to 50 msec at room temperature) for the alignment state of liquid crystal molecules to change from the state shown in FIG. 4 (2) to the state shown in FIG. 4 (1). Therefore, in a color liquid crystal display device using a TN mode liquid crystal display element, it is not possible to switch display colors at high speed, and there is a problem in that color reproducibility is poor. In particular, when the colors are switched at high speed, it is impossible to perform clear color display by mixing the colors displayed before and after the switching, or by trailing the image.

The object of the present invention is to switch display colors at high speed,
Another object of the present invention is to provide a color liquid crystal display device in which the display contrast is remarkably improved.

Means for Solving the Problems The present invention is a color liquid crystal display device in which a first liquid crystal display element and a second liquid crystal display element in which nematic liquid crystal is filled between substrates are laminated along the incident direction of light. A neutral polarizer disposed upstream of the first liquid crystal display element in the light incident direction, and disposed downstream of the first liquid crystal display element in the light incident direction of the first liquid crystal display element,
A first color polarizer having an absorption axis parallel or perpendicular to the absorption axis direction of the neutral polarizer, and laminated on the first color polarizer, having an absorption axis perpendicular to the absorption axis direction, And a second color polarizer having an absorption characteristic that has a complementary color relationship with the first color polarizer, and a second color polarizer disposed on the downstream side in the light incident direction of the second liquid crystal display element,
A third color polarizer having an absorption axis parallel to or perpendicular to the absorption axis direction of the neutral polarizer, and laminated on the third color polarizer, and having an absorption axis perpendicular to the absorption axis direction, And a nematic liquid crystal layer of the first and second liquid crystal display elements, which has a twist angle of 180 degrees, and a third color polarizer and a fourth color polarizer having an absorption characteristic having a complementary color relationship. In addition, a color liquid crystal display device is formed by arranging liquid crystal molecules so that the tilt directions are opposite to each other on two substrates facing each other.

Function In the present invention, the color liquid crystal display device is configured by stacking the first liquid crystal display element in which the nematic liquid crystal is filled between the substrates and the second liquid crystal display element along the light incident direction. A neutral polarizer is arranged on the upstream side in the light incident direction of the first liquid crystal display element. A first color polarizer having an absorption axis parallel or perpendicular to the absorption axis direction of the neutral polarizer is arranged on the downstream side of the light incident direction of the first liquid crystal display element. A second color polarizer having an absorption axis perpendicular to the absorption axis direction and having absorption characteristics in a complementary color relationship with the first color polarizer is laminated on the child.

In the second liquid crystal display element, a third color polarizer having an absorption axis parallel or perpendicular to the absorption axis direction of the neutral polarizer is arranged on the downstream side in the light incident direction.
A fourth color polarizer having an absorption axis perpendicular to the absorption axis direction and having absorption characteristics in a complementary color relationship with the third color polarizer is laminated on the color polarizer of FIG. In such a nematic liquid crystal layer in the first and second liquid crystal display elements, the liquid crystal molecules have a twist angle of 180 degrees,
In addition, the tilt directions are opposite to each other on the two substrates facing each other.

The absorption axis direction of the neutral polarizer is a direction that forms an angle of 45 degrees with the long axis direction of the liquid crystal molecules near the surface of the substrate arranged on the neutral polarizer side in the first liquid crystal display element. As a result, the linearly polarized light incident on the liquid crystal layer of the first liquid crystal display element is rotated by 90 degrees in the state where no voltage is applied to the liquid crystal layer of the first liquid crystal display element. Further, when no voltage is applied to the first liquid crystal layer, incident light is incident on the second liquid crystal display element without any influence.

In the second liquid crystal display element, the long axis direction of the liquid crystal molecules on the upstream side in the light incident direction is selected so as to form an angle of 45 degrees with the absorption axis direction of the neutral polarizer. Therefore,
The light that has entered the second liquid crystal display element is rotated by 90 degrees when no voltage is applied to the liquid crystal layer, and when the voltage is applied, the light is incident on the fourth color polarizer while maintaining the polarization direction at the time of incidence. Incident.

Therefore, by applying / non-applying a voltage to the liquid crystal layer of the first liquid crystal display element, it is possible to select the first or second color polarizer and absorb the light. By applying / non-applying a voltage to the liquid crystal layer, the third or fourth color polarizer can be selected to absorb light. In this way, for example black,
The color of transmitted light can be different for each color of red, green, and blue.

In the first and second liquid crystal display elements, each nematic liquid crystal layer has a twist angle of liquid crystal molecules between each substrate.
Since they are arranged so as to be 180 degrees, for example, even when driving a plurality of display pixels in a time-division manner, it is possible to reliably select the color of light transmitted through each liquid crystal display element.
Therefore, display with high color reproducibility and display contrast can be performed. Furthermore, in the nematic liquid crystal layers of the first and second liquid crystal display elements, the liquid crystal molecules are arranged so that the tilt directions are opposite to each other on the two substrates facing each other. The time required to return to the non-applied state is relatively short, which allows high-speed switching of display colors.

Embodiment FIG. 1 is a sectional view showing the basic structure of a color liquid crystal display device 1 which is an embodiment of the present invention. Light is incident on the color liquid crystal display device 1 in the arrow 2 direction. The incident light first enters the neutral polarizer 3 and becomes linearly polarized light. The neutral polarizer 3 has an absorption axis in the direction indicated by reference numeral 4 in FIG. That is, for example, the neutral polarizer 3
The absorption axis direction of is at an angle of 45 degrees with respect to the horizontal direction in FIG. 1 within a plane perpendicular to the light incident direction.

The linearly polarized light from the neutral polarizer 3 is incident on the transparent substrate 5 made of a material such as glass. On the surface of the transparent substrate 5 on the downstream side in the light traveling direction, for example, a plurality of transparent electrodes 6 extending in the left-right direction in FIG. 1 are patterned. The transparent electrode 6 is formed by using a material such as ITO (Indiun-Tin-Oxide), and covers the portion of the transparent substrate 5 related to the display area on the downstream side in the light incident direction in such a state. The alignment film 7 is formed.

The transparent substrate 8 is arranged so as to face the alignment film 7. On the surface of the transparent substrate 8 on the transparent substrate 5 side, a cyan color polarizer 9GB, which will be described later, which is a first color polarizer, is formed, and this color polarizer 9GB is a second color polarizer. The red color polarizer 9R is stacked. The color polarizers 9GB and 9R are formed in association with the entire display area. The color polarizer 9R is further patterned with a plurality of transparent electrodes 10 extending in a direction orthogonal to the transparent electrodes 6. In such a state, the alignment film 11 is formed by being laminated so as to cover the portion related to the display region.

In the gap formed by the alignment films 7 and 11, for example, the optically active substance cholesteryl nonanoate is 0.3 to 0.5% by weight.
The added nematic liquid crystal ZLI-3281 (manufactured by Merck Ltd.) is filled to form the liquid crystal layer 12.

The alignment films 7 and 11 are made of, for example, a polyimide film, and the surfaces thereof are rubbed and subjected to an alignment treatment so that the liquid crystal molecules are aligned with a predetermined pretilt angle.
At this time, the alignment films 7 and 11 are rubbed in the same direction, for example, the left-right direction in FIG. 1, and the alignment films 7 and 11 are arranged to face each other so that the tilt directions of the liquid crystal molecules are opposite to each other. It In this way, in the liquid crystal layer 12, the long axis direction of the liquid crystal molecules is in the vicinity of the alignment film 7 and in the vicinity of the alignment film 11,
It is rotated 180 degrees, in other words, the twist angle is 1
The liquid crystal molecules are set to 80 degrees, and thus the liquid crystal molecules forming the liquid crystal layer 12 have a twisted orientation of 180 degrees between the alignment films 7 and 11. Such twisted orientation can be eliminated by applying a voltage between the transparent electrodes 6 and 10.

On the surface of the transparent substrate 8 on the downstream side in the light traveling direction, a transparent electrode 13 similar to the transparent electrode 6 is patterned. In such a state, an alignment film 14 is formed so as to cover a region that is exposed on the opposite side of the transparent electrode 13 and the transparent substrate 8 from the liquid crystal layer 12 and is involved in display.

A transparent substrate 15 is arranged to face the alignment film 14. On the surface of the transparent substrate 15 facing the alignment film 14, a third color polarizer, which will be described later, and a green color polarizer 9G is formed in association with the display area of the color liquid crystal display device 1.
On this color polarizer 9G, a magenta color polarizer 9RB which will be described later and is a fourth color polarizer is laminated. A transparent electrode 16 similar to the transparent electrode 10 is patterned on the color polarizer 9RB. In such a state, the alignment film 17 is formed so as to cover the entire area related to the display area.

The alignment films 14 and 17 are subjected to the same alignment treatment as that of the alignment films 7 and 11, and a nematic liquid crystal is filled in the gap formed by the alignment films 14 and 17, and a liquid crystal similar to the liquid crystal layer 12 is formed. Layer 18 is formed.

The transparent substrates 5 and 8, the transparent electrodes 6 and 10, and the color polarizer 9
The first liquid crystal display element 21 is configured to include R, 9GB, etc.,
Transparent substrates 8 and 15, transparent electrodes 13 and 16, and color polarizer 9G,
The second liquid crystal display element 22 is configured to include 9RB and the like. In the first and second liquid crystal display elements 21 and 22, in the respective liquid crystal layers 12 and 18, liquid crystal molecules form a twisted orientation of 180 degrees between the alignment films 7 and 11 and between the alignment films 14 and 17. It is a so-called π cell.

The color polarizers 9GB, 9R, 9G, 9RB each have an absorption axis in the direction indicated by reference numerals 91 to 94 in FIG.
That is, the color polarizers 9GB, 9G have an absorption axis parallel to the absorption axis direction of the neutral polarizer 3, and the color polarizers 9R, 9G
RB is orthogonal to the absorption axis of the neutral polarizer 3. In other words, each has an absorption axis in a direction orthogonal to the absorption axis directions of the color polarizers 9GB and 9G.

Color polarizers 9GB, 9R, 9G, 9RB are made of, for example, uniaxially stretched polyvinyl alcohol (PVA) film as transparent substrate 8,15.
Alternatively, it is formed by sticking it on the color polarizer 9GB, 9G and then dyeing this polyvinyl alcohol with a dichroic dye of a corresponding color. For example, the color polarizer 9R dyed with a red dichroic dye is
When 9R receives linearly polarized light in the direction indicated by reference numeral 92, it absorbs light other than red light. When linearly polarized light in the direction orthogonal to the direction indicated by reference numeral 92 is incident, the color polarizer 9R has no influence on such incident light. The same applies to the color polarizers 9GB, 9G, and 9RB.When linearly polarized light parallel to the absorption axis direction of each color polarizer enters each color polarizer, the green and blue colors of the cyan color polarizer 9GB Light can be transmitted, the magenta color polarizer 9RB can transmit only red and blue light, and the green color polarizer 9G can transmit only green light.

In the liquid crystal layer 12 (18), the liquid crystal molecules have a twisted orientation of 180 degrees between the alignment films 7 and 11 (between the alignment films 14 and 17) as described above. Between (alignment film 1
4 and 17), as shown in a simplified form in FIG. 2 (1), the tilt directions are opposite to each other on the two substrates facing each other, that is, the spray arrangement.
FIG. 2 (2) shows a simplified arrangement state of liquid crystal molecules when a voltage is applied between the transparent electrodes 6, 10 (13, 16).

That is, when no voltage is applied to the liquid crystal layer 12 (18), the alignment of the liquid crystal molecules has a so-called spiral structure. In this way, the liquid crystal molecules of the liquid crystal layers 12 and 18 are arranged to face each other.
By setting the tilt directions to be opposite to each other on one substrate, the arrangement state of the liquid crystal molecules is changed from the arrangement state when the voltage is applied (the state of FIG. 2 (2)) to the state where no voltage is applied (see FIG. The time (hereinafter, referred to as “fall time”) for returning to () state) can be set to about several msec, and the alignment state of liquid crystal molecules can be converted at high speed.

FIG. 3 is a diagram for explaining the operation principle of the π cell. FIG. 3 (1) shows a state in which no electric field is applied to the liquid crystal layer of the π cell 31, and FIG. 3 (2) shows a state in which an electric field is applied to the liquid crystal layer of the π cell 31. Linearly polarized light in the direction indicated by reference numeral 32 is incident on the π cell 31 in the direction of arrow 33. In the π cell 31, the major axis directions of the liquid crystal molecules on the upstream side and the downstream side in the incident direction of light are both parallel to the vertical direction in FIG. 3 and the upstream side in the incident direction of light when no electric field is applied. , 180 degrees twisted between the downstream side. Therefore, the direction indicated by the reference numeral 32 is inclined by 45 degrees with respect to the long axis direction of the liquid crystal molecules on the upstream side in the light incident direction of the π cell 31. In the π cell 31, only the component LV in the direction indicated by the reference symbol V (hereinafter, such a direction is referred to as a “vertical direction”) is affected by the linearly polarized light in such a direction. That is, the direction indicated by the reference symbol H (hereinafter, such a direction is referred to as “horizontal direction”)
The component LH of is not affected.

The vertical component LV is π with respect to the horizontal component LH.
Only the phase shifts and the light is emitted from the π cell 31. In other words, the component LV in the vertical direction has its polarization direction rotated by 180 degrees and is emitted from the π cell 31. As a result, π
When the linearly polarized light in the direction indicated by the reference numeral 32 enters the cell 31, the π cell 31 radiates the linearly polarized light in the direction indicated by the reference numeral 34.

When an electric field is applied to the liquid crystal layer of the π cell 31, the molecular arrangement of the liquid crystal layer becomes uniform, so that the light emitted from the π cell 31 is represented by reference numeral 35 parallel to the direction indicated by reference numeral 32. It becomes the linearly polarized light shown. In this way, in the π cell 31, it is possible to make the polarization directions of the incident linearly polarized light different from each other by 90 degrees by applying / not applying a voltage.

The operation of the color liquid crystal display device 1 will be described with reference to FIG. 1 again. In FIG. 1, the first liquid crystal display element
No voltage is applied between the transparent electrodes 101 and 102 and the transparent electrode 6 among the plurality of transparent electrodes 10 of 21.
A voltage is applied between 104 and the transparent electrode 6. In addition, in the second liquid crystal display element 22, no voltage is applied between the transparent electrodes 161, 164 and the transparent electrode 13 among the plurality of transparent electrodes 16, and between the transparent electrodes 162, 163 and the transparent electrode 13. Is being applied with voltage. FIG. 1 shows a simplified arrangement state of liquid crystal molecules in such a case.

The light incident on the display pixel defined by the transparent electrodes 6, 101, 13, 161 via the light path L1 is first converted into linearly polarized light in the direction indicated by reference numeral 4 by the neutral polarizer 3. The polarization direction of such linearly polarized light is rotated by 90 degrees in the liquid crystal layer 12. Therefore, in the red color polarizer 9R,
Light other than red is absorbed at the position indicated by reference sign A1.
However, the cyan color polarizer 9GB has no influence because its absorption axis direction is orthogonal to the polarization direction of light. Therefore, the red linearly polarized light polarized in the direction of the arrow 92 enters the liquid crystal layer 18 of the second liquid crystal display element 22. This red linearly polarized light has its polarization direction rotated 90 degrees in the liquid crystal layer 18. Therefore, the polarization direction of the linearly polarized light is parallel to the absorption axis direction of the green color polarizer 9G. This gives magenta color polarizer 9RB
In, the red linearly polarized light is not affected at all, but is absorbed at the position indicated by reference numeral B1 in the green color polarizer 9G. Therefore, this display pixel serves as a light-shielding area and black display is performed.

The light incident on the display pixel defined by the transparent electrodes 6, 102, 13, 162 via the light path L2, the transmitted light is red at the position indicated by the reference mark A2 of the red color polarizer 9R in the same manner as the above case. Limited to linearly polarized light only. In this way, the red linearly polarized light incident on the liquid crystal layer 18 is not affected by this liquid crystal layer 18 at all, so that the polarization direction is the direction of the absorption axis of the magenta color polarizer 9RB, that is, reference numeral 94. Since the direction is as shown, it is affected at the position indicated by reference numeral B2 in this magenta color polarizer 9RB. Since the magenta color polarizer 9RB limits the transmitted light to red and blue, the red linearly polarized light incident on the second liquid crystal display element 22 via the optical path L2 is transmitted through the magenta color polarizer 9RB. can do. In this way, red display is performed in this display pixel.

Light incident on the display pixel defined by the transparent electrodes 6, 103, 13, 163 via the light path L3 is first converted into linearly polarized light indicated by reference numeral 4 in the neutral polarizer 3. Since this linearly polarized light is not affected by the liquid crystal layer 12 of the first liquid crystal display element 22, in the cyan color polarizer 9GB whose absorption axis direction is parallel to the polarization direction of the linearly polarized light, the reference numeral A3 is used. Affected at the indicated position. The cyan color polarizer 9GB can only transmit green and blue light. Although such light enters the liquid crystal layer 18 of the second liquid crystal display element 22, the polarization direction is not changed in this liquid crystal layer 18. Therefore, since the polarization direction of the linearly polarized light passing through the liquid crystal layer 18 is parallel to the absorption axis direction of the green color polarizer 9G, this green color polarizer
At 9G, it is affected at the position indicated by reference sign B3 and the transmitted light is limited to green light. In this way, green display is performed in this display pixel.

Light incident on the display pixel defined by the transparent electrodes 6, 104, 13, 164 via the light path L4 proceeds in the same manner as described above, and is affected at the position indicated by reference numeral A4 in the cyan color polarizer 9GB, Therefore, the liquid crystal layer 18 has a reference mark.
Linearly polarized light in the direction indicated by 91, and only blue and green light is incident. This linearly polarized light has its polarization direction rotated by 90 degrees in the liquid crystal layer 18. Therefore, the liquid crystal layer
The linearly polarized light passing through 18 has its polarization direction parallel to the absorption axis direction of the magenta color polarizer 9RB. Therefore, in this magenta color polarizer 9RB, the linearly polarized light incident on this color polarizer 9RB is affected by the position indicated by reference numeral B4 and the transmitted light is limited to red and blue. Since it is only blue,
In this display pixel, blue display is performed.

In this way, the color liquid crystal display device 1 can display black, red, green, and blue for each display pixel.
Display pixels can contribute to the display. Thereby, a bright display can be performed on the whole. When displaying white, the red, green, and blue lights are respectively transmitted from the display pixels adjacent to each other so that the observer perceives white display by additive color mixing. do it.

In each of the first and second liquid crystal display elements 21 and 22, each liquid crystal layer 1
In Nos. 2 and 18, liquid crystal molecules are arranged so that the twist angle is 180 degrees and the tilt directions are opposite to each other on the two substrates facing each other. This allows the transparent electrodes 10,16
In the case of applying a signal voltage corresponding to a video signal to the plurality of transparent electrodes 6 and sequentially and cyclically applying a scan pulse to drive the liquid crystal layers 12 and 18 in a time-division manner, Since you can be sure to choose the desired state,
The display contrast is significantly improved. Further, since the tilt directions are opposite to each other on the two substrates facing each other in the arrangement of the liquid crystal molecules, the color of the transmitted light can be switched at high speed in each display pixel, and the color reproducibility is good. It becomes possible to display a clear image.

Although the color polarizers 9GB and 9R are sequentially stacked from the transparent substrate 8 in the first liquid crystal display element 21 in the above-described embodiment, this stacking order may be arbitrarily selected. The same applies to the color polarizers 9G and 9RB in the second liquid crystal display element 22. Further, the two-layer color polarizer used in the first liquid crystal display element 21 may be another combination as long as the absorption characteristics thereof are in a complementary color relationship with each other. The same applies to the first and second liquid crystal display elements 21, 2
It suffices that the color polarizers used in 2 have different absorption characteristics.

Furthermore, in the above-described embodiment, in the first liquid crystal display element 21, the direction of the absorption axis of the color polarizer 9GB laminated on the transparent substrate 8 side is selected to be parallel to the direction of the absorption axis of the neutral polarizer 3. However, the absorption axis direction of this color polarizer 9GB may be selected to be orthogonal to the absorption axis direction of the neutral polarizer 3, and in such a case, the absorption axis direction of the color polarizer 9R is neutral. It is selected parallel to the absorption axis direction of the polarizer 3. The same applies to the second liquid crystal display element 22.

The direction of the absorption axis of the color polarizer 9GB laminated on the transparent substrate 8 side in the first liquid crystal display element 21 and the color polarizer 9G laminated on the transparent substrate 15 side in the second liquid crystal display element 22. The directions of the absorption axes of may be chosen to be mutually orthogonal.

EFFECTS OF THE INVENTION As described above, according to the present invention, the display colors can be switched at high speed, and the display contrast is improved.
Therefore, it is possible to display a clear image with good color reproducibility.

[Brief description of drawings]

FIG. 1 is a color liquid crystal display device 1 which is an embodiment of the present invention.
2 is a cross-sectional view showing the basic structure of the liquid crystal display device, FIG. 2 is a view for explaining the alignment state of liquid crystal molecules in the liquid crystal layers 12 and 18, and FIG. 3 is a view for explaining the operation principle of the π cell, and FIG. The figure is a view for explaining the arrangement state of liquid crystal molecules in a liquid crystal layer in a TN mode liquid crystal display element. 1 ... Color liquid crystal display device, 3 ... Neutral polarizer, 5,8,15
...... Transparent substrate, 6,10,13,16,101 to 104,161 to 164 …… Transparent electrode, 9GB, 9R, 9G, 9RB …… Color polarizer, 12,18 …… Liquid crystal layer, 21 …… First liquid crystal display Element, 22 ... Second liquid crystal display element

Claims (1)

[Claims] 1. A first device in which a nematic liquid crystal is filled between substrates.
Is a color liquid crystal display device in which the liquid crystal display element and the second liquid crystal display element are laminated along the light incident direction, and the neutral liquid crystal display element is arranged on the upstream side in the light incident direction of the first liquid crystal display element. The polarizer and the first liquid crystal display element are arranged on the downstream side in the light incident direction,
A first color polarizer having an absorption axis parallel or perpendicular to the absorption axis direction of the neutral polarizer, and laminated on the first color polarizer, having an absorption axis perpendicular to the absorption axis direction, And a second color polarizer having an absorption characteristic that has a complementary color relationship with the first color polarizer, and a second color polarizer disposed on the downstream side in the light incident direction of the second liquid crystal display element,
A third color polarizer having an absorption axis parallel to or perpendicular to the absorption axis direction of the neutral polarizer, and laminated on the third color polarizer, and having an absorption axis perpendicular to the absorption axis direction, And a nematic liquid crystal layer of the first and second liquid crystal display elements, which has a twist angle of 180 degrees, and a third color polarizer and a fourth color polarizer having an absorption characteristic having a complementary color relationship. Further, a color liquid crystal display device is formed by arranging liquid crystal molecules so that the tilt directions are opposite directions on two substrates facing each other.