JPH11231303A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make visible information on both top and reverse surfaces and to actualize low cost, thin constitution, light weight, and low power consumption by providing a liquid crystal element which has liquid crystal sandwiched between a couple of 1st and 2nd substrates, reflection type polarizing plates provided outside the 1st and 2nd substrates, and absorption type polarizing plates outside the reflection type polarizing plates. SOLUTION: An SNT liquid crystal element 16 is composed of the 1st substrate 1 on which a 1st electrode 3 is formed, the 2nd substrate 2 on which a 2nd electrode 4 is formed, a seal material 5 sticking the 1st and 2nd substrates 1 and 2 on each other, and the nematic liquid crystal 6 sandwiched between the 1st and 2nd substrates 1 and 2. The 1st reflection type polarizing plate 8 is arranged and the 1st absorption type polarizing plate 10 is arranged thereupon. Then a phase difference plate 13 is arranged between an SNT liquid crystal element 16 and the 1st reflection type polarizing plate 8. A 2nd reflection type polarizing plate 9 is arranged below the SNT liquid crystal element 16 and a 2nd absorption type type polarizing plate 11 is arranged below it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display, and more particularly to a reflection type liquid crystal display.

[0002]

2. Description of the Related Art Conventionally, liquid crystal display devices have been characterized by low power consumption, thinness and light weight. However, while pursuing visibility and color reproducibility, a liquid crystal display device with a backlight has been developed. As the process progressed, the original characteristics of the liquid crystal display device were not sufficiently exhibited. However, recently, with the rapid spread of small portable terminal devices, reflection type liquid crystal display devices used for these devices have been making rapid use of their features.

The greatest feature is low power consumption. Most small portable terminal devices operate on batteries, and their battery life greatly affects the performance of the devices. In such a device, a liquid crystal display device is an optimal device. In particular, a reflective liquid crystal display device without a backlight can reduce power consumption so as to improve the battery life in several hours.

Next, the operation of the conventional reflection type liquid crystal display device will be described with reference to FIG.

[0005] The liquid crystal panel 1001 has a 2
The liquid crystal is sandwiched between two substrates. The LCD has 90
° Twisted TN liquid crystal or 180-270 ° twisted S
TN liquid crystals are often used. Polarizing plates (not shown) are adhered to both sides of the liquid crystal panel 1001. The easy transmission axis direction of each polarizing plate is arranged in accordance with the liquid crystal. A reflection plate 1002 is disposed below a liquid crystal panel 1001 to which a polarizing plate is bonded. The reflection plate 1002 has a structure in which aluminum or silver is formed on a film, and has a high reflectance.

Here, when the liquid crystal panel 1001 is viewed with the liquid crystal panel 1001 facing upward, the incident light is transmitted through the liquid crystal panel 1001, then reflected by the reflector 1002, and returned to the viewing side. Since the liquid crystal panel 1001 functions as an optical shutter,
The amount of reflected light can be controlled, and characters and the like can be displayed with contrast between reflection and non-reflection.

[0007]

However, in the conventional reflection type liquid crystal display device, the reflection plate 1 is provided on the back of the liquid crystal panel 1001.
If the liquid crystal panel 1001 is disposed on the viewer side to dispose the liquid crystal panel 002, good display can be obtained.
If the two sides are arranged on the observer side, external light is blocked by the back surface of the reflection plate 1002 and the external light cannot reach the liquid crystal panel, so that the display cannot be viewed at all.

This is a matter of course because the conventional reflection type liquid crystal display device uses a reflection plate. Previously, such issues were not raised as issues. However, considering that reflection type liquid crystal display devices have low power consumption and small size, light weight, thinness and many advantages, and are most suitable for display devices of small portable terminals, considering that they are the best candidates for paperless in the future, If information can be displayed on both sides in the same way as paper, the amount of information on one sheet will not only double, but it will also lead to application applications and the use of liquid crystal display devices will expand.

Here, to make it possible to display information on both sides like paper using a conventional liquid crystal display device, two
A method of attaching two reflective liquid crystal display devices to each other is considered. However, this method requires two liquid crystal display devices, which increases the cost. In addition, there has been a problem that the thickness, the weight, and the power consumption are two times worse and cannot be put to practical use.

An object of the present invention is to provide a liquid crystal display device which solves the above-mentioned problems, enables information to be visually recognized from both front and back sides of the liquid crystal display device, and further satisfies low cost, thinness, light weight and low power consumption. It is to be.

[0011]

In order to achieve the above object, according to the present invention, a liquid crystal display device according to the present invention comprises a first substrate having a first electrode and a second electrode. A liquid crystal element having a liquid crystal sandwiched between the second substrate and the pair of substrates, a reflective polarizer provided outside the first substrate, and an absorption polarizer provided outside the reflective polarizer A liquid crystal display device comprising: a plate; a reflective polarizer provided outside the second substrate; and an absorption polarizer provided outside the reflective polarizer.

According to a second aspect of the invention, there is provided a liquid crystal display device comprising a first substrate having a first electrode, a second substrate having a second electrode, and a pair of substrates. A light-scattering member provided outside at least one of the first substrate and the second substrate; a reflective polarizing plate provided outside the first substrate; A liquid crystal display device comprising: an absorption-type polarizing plate provided outside; a reflection-type polarizing plate provided outside the second substrate; and an absorption-type polarizing plate provided outside the reflection-type polarizing plate.

According to a third aspect of the invention, there is provided a liquid crystal display device having a twist alignment of 180 ° to 270 ° between a first substrate having a first electrode and a second substrate having a second electrode. 3. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is an STN liquid crystal element holding the nematic liquid crystal.

Further, in the liquid crystal display device according to the present invention, the first substrate having the first electrode and the second substrate having the second electrode are twisted by about 90 °. 3. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is a TN liquid crystal element holding a nematic liquid crystal.

Further, in the liquid crystal display device according to the present invention, a ferroelectric liquid crystal is interposed between a first substrate having a first electrode and a second substrate having a second electrode. 3. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is a ferroelectric liquid crystal element.

According to a sixth aspect of the present invention, there is provided a liquid crystal display device comprising: a first substrate having a first electrode; a second substrate having a second electrode;
A STN liquid crystal element holding a twisted nematic liquid crystal, a retardation plate provided outside the first substrate, a reflective polarizing plate provided outside the retardation plate, An absorption-type polarizing plate provided outside the polarizing plate;
A liquid crystal display device comprising: a light scattering member provided outside the substrate; a reflective polarizing plate provided outside the light scattering member; and an absorption polarizing plate provided outside the reflective polarizing plate.

According to a seventh aspect of the present invention, in the liquid crystal display device, the reflective polarizing plate is a sheet that transmits a vibrating surface parallel to the axis of easy transmission and reflects a vibrating surface orthogonal to the axis. Is a sheet that transmits a vibration plane parallel to the easy transmission axis and absorbs a vibration plane perpendicular to the axis.

(Operation: FIGS. 6 and 7) The operation of the liquid crystal display device according to the present invention will be described with reference to FIGS. 6 and 7. FIG.
The first absorption type polarizing plate 10 is a general polarizing plate produced by dyeing a stretched film of iodine or a dichroic dye, and transmits light vibrating in the direction of the easy transmission axis 10a, and transmits light that vibrates in the direction of the easy transmission axis 10a. Light oscillating in the direction rotated by 90 ° with 10a is absorbed.

On the other hand, the first reflective polarizing plate 8 has a structure in which a thin film is multilayered on a transparent base film.
Light oscillating in the direction a is transmitted, and light oscillating in a direction rotated by 90 ° with respect to the easy transmission axis 8a is reflected.

The white display (FIG. 6) as viewed from the front A (FIG. 6) corresponds to the easy transmission axis 10a of the first absorption polarizer 10 disposed on the front and the first transmission axis 10a disposed adjacent thereto. Since the easy-to-transmit axis 8a of the reflective polarizing plate 8 is parallel, the component of the incident light that is parallel to the easy-to-transmit axis is transmitted, passes through the light scattering member 12, and reaches the second reflective polarizing plate 9. I do. The easy transmission axis 9a of the second reflection type polarizing plate 9 is set at 90.degree.
Since it has been rotated by degrees, the incident light is reflected and returned to the viewing side. At this time, since the returned incident light has passed through the light scattering member 12 twice, the incident light is appropriately scattered and shows a white display color when viewed from the front A.

On the other hand, the black display (FIG. 7) viewed from the front A is the first absorption type polarizing plate 1 disposed on the front.
The incident light transmitted through the first and second reflective polarizing plates 8 passes through the light scattering member 12 and reaches the second reflective polarizing plate 9.
Since the easy transmission axis 9a of the second reflective polarizer 9 is parallel to the vibration direction of the incident light, the incident light is transmitted and enters the second absorption polarizer 11. Since the easy transmission axis 11a of the second absorption type polarizing plate 11 is parallel to the vibration direction of the incident light, it is also transmitted and transmitted in the direction of back B. The incident light transmitted through the back B does not return to the viewing side because there is no member that reflects the light.
Therefore, when viewed from the front A, the display color is black.

Next, the white display (FIG. 6) as viewed from the back B (FIG. 6) shows the easy-to-transmit axis 11a of the second absorption-type polarizing plate 11 arranged on the back and the second reflection-type axis arranged adjacent thereto. Since the easy transmission axis 9a of the polarizing plate 9 is parallel, a component of the incident light parallel to the easy transmission axis is transmitted and the light scattering member 12
And reaches the first reflective polarizing plate 8. The easy transmission axis 8a of the first reflection type polarizing plate 8 is
Since it is rotated by 0 degrees, the incident light is reflected and returned to the viewing side. At this time, the returned incident light makes the light scattering member 12
Since the light has passed twice, the incident light is appropriately scattered, and shows a white display color when viewed from the back B.

On the other hand, in the black display (FIG. 7) when viewed from the back B, the incident light transmitted through the second absorbing polarizer 11 and the second reflective polarizer 9 arranged on the back is light. The light passes through the scattering member 12 and reaches the first reflective polarizing plate 8. First
Since the easy transmission axis 8a of the reflective polarizer 8 is parallel to the vibration direction of the incident light, the incident light is transmitted and enters the first absorption polarizer 10. Since the easy transmission axis 10a of the first absorption type polarizing plate 10 is parallel to the vibration direction of the incident light, it is also transmitted and transmitted in the direction of the front A. The incident light transmitted through the front A does not return to the viewing side because there is no member that reflects the light. Therefore, when viewed from the back B, the display color is black.

Instead of rotating the axis of easy transmission of the second absorption type polarizing plate 11 and the second reflection type polarizing plate 9, the position between the first reflection type polarizing plate 8 and the second reflection type polarizing plate 9 is changed. When a TN (twisted nematic) liquid crystal element having a twist orientation of 90 ° is provided, the angle of incidence of the linearly polarized light component on the second reflective polarizer 9 can be adjusted when viewed from the front A by the voltage applied to the TN liquid crystal element. When viewed from the back B, the angle of incidence of the linearly polarized light component on the first reflective polarizing plate 8 can be changed by about 90 °, and the liquid crystal displays white and black on both the front and back sides. It can be a display device.

Furthermore, instead of the TN liquid crystal element having a twist orientation of 90 °, a ST orientation having a twist orientation of 180 ° to 270 ° is used.
When an N (super twisted nematic) liquid crystal element is used, the sharpness of the liquid crystal element is improved, the contrast characteristic is improved, and a multi-segment liquid crystal display device can be realized.
Light that has passed through the liquid crystal element is in an elliptically polarized state, and the background color is colored or the display color is changed.

However, in the present invention, 180 ° to 2 °
By using an STN liquid crystal element having a twist of 70 ° and a retardation plate, it is possible to provide a liquid crystal display device having good contrast characteristics and displaying white and black on both the front and back surfaces.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment: FIGS. 1 and 2) The configuration and effects of a liquid crystal display device in the best mode for carrying out the present invention will be described below with reference to the drawings.

First, the structure of the liquid crystal display device according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view for explaining components of the liquid crystal display device according to the first embodiment of the present invention, and FIG. 2 is a plan view showing an arrangement relationship of the components. Hereinafter, the configuration of the liquid crystal display device of the present invention will be described with reference to FIGS. 1 and 2 alternately.

The liquid crystal display of the present embodiment has a first substrate 1 made of a 0.7 mm thick glass plate on which a first electrode 3 made of ITO is formed, and a second substrate made of ITO.
Thickness O on which the electrode 4 is formed. A second substrate 2 made of a 7 mm glass plate, a sealing material 5 for bonding the pair of substrates, and a 240 sandwiched between the pair of substrates.
か ら STN from the twisted nematic liquid crystal 6
A liquid crystal element 16 is formed.

An alignment film (not shown) is formed on the surfaces of the first electrode 3 and the second electrode 4, and the first substrate 1 is rubbed upward in the left direction in the direction of -30 ° with respect to the horizontal direction. By the treatment, the upper liquid crystal molecular orientation direction 16a becomes -30 ° upward and rubbing in the 30 ° upward direction.
0 °, and the STN liquid crystal element 16 having a counterclockwise twist of 240 ° is formed.

The difference Δ in the birefringence of the nematic liquid crystal 6 used
n is 0.148, and the cell gap d, which is the gap between the first substrate 1 and the second substrate 2, is 5.45 μm. Therefore, the Δnd value of the STN liquid crystal element 16 represented by the product of the birefringence difference Δn of the nematic liquid crystal 6 and the cell gap d is 807 nm.

The first reflective polarizer 8 is disposed so that the easy transmission axis 8a is at 10 ° to the horizontal axis, and the first absorptive polarizer 10 is placed on top of the first reflective polarizer 8. Is disposed such that the easy transmission axis 10a is at an angle of 10 ° with respect to the horizontal axis, and the retardation plate 13 having a retardation value of 580 nm is disposed between the STN liquid crystal element 16 and the first reflective polarizing plate 8. Phase axis 13
It is arranged so that a is at 50 ° to the horizontal axis. ST
The light scattering member 12 is disposed below the N liquid crystal element 16, and the second reflection type polarizing plate 9 is disposed below the light scattering member 12 such that the easy transmission axis 9 a is −20 ° with respect to the horizontal axis. Place,
A second absorption type polarizing plate 11 is provided below the second reflection type polarizing plate 9.
Are arranged such that the easy transmission axis 11a is at −20 ° to the horizontal axis.

The STN liquid crystal element 16 and the retardation plate 13 are bonded using an acrylic adhesive (not shown). The first reflection-type polarizing plate 8 and the first absorption-type polarizing plate 10 are also bonded using an acrylic pressure-sensitive adhesive (not shown). Further, the second reflective polarizing plate 9 is bonded to the STN liquid crystal element 16 by a light scattering member 12 also serving as an adhesive. The second absorption type polarizing plate 11 is bonded using an acrylic pressure-sensitive adhesive (not shown).

The phase difference plate 13 has a refractive index nx in the slow axis direction, a refractive index ny in the Y axis direction,
A biaxial retardation plate having a refractive index nz in the thickness direction satisfying nx>nz> ny was used. Of course, there is no problem with a uniaxial retardation plate.

The first reflective polarizing plate 8 is a sheet that transmits light components that vibrate in the easy-to-transmit axial direction and reflects light components that vibrate in the orthogonal direction. In the present embodiment, a trade name D-BEF manufactured by Sumitomo 3M Limited is used. This D
-BEF is a product generally used for increasing the brightness of a backlight, but also functions sufficiently as a reflective polarizing plate as in this embodiment.

The second reflective polarizing plate 9 and the light scattering member 12 use R-DEFC (trade name, manufactured by Sumitomo 3M Limited). R-DEFC has a configuration in which an adhesive containing a scattering material is applied to a reflective polarizing plate, and the adhesive also serves as a light scattering member. The surface of the reflective polarizing plate opposite to the adhesive remains the surface of the reflective polarizing plate. There is also a trade name R-DEF, which has a black impermeable film formed on the surface opposite to the surface coated with the adhesive. In this embodiment, R-DEFC without a black impermeable film is used.

(Explanation of Specific Examples: FIG. 1, FIG. 2, FIG. 4) Next, in the liquid crystal display device according to the first embodiment of the present invention, the contrast is high when viewed from both sides of front A and back B. A specific example of displaying will be described. First, the case where the user visually recognizes the image from the front A will be described. In the liquid crystal display device of the present invention, when no voltage is applied when viewed from the front A, linearly polarized light incident on the first absorption type polarizing plate 10 and rotated by 90 ° with respect to the direction of the easy transmission axis 10a is absorbed. , Easy transmission axis 1 incident on first absorption type polarizing plate 10
The linearly polarized light in the 0a direction is incident parallel to the easy transmission axis of the first reflective polarizing plate 8. Since the incident linearly polarized light is parallel to the easy transmission axis 8a of the first reflective polarizing plate 8, it is also transmitted and enters the STN liquid crystal element 16. When the retardation plate 13 is not provided, the light passes through the STN liquid crystal element 16 to be in an elliptically polarized state, cannot be completely reflected by the second reflective polarizing plate 9, is colored by birefringence, and has no display. It is enough.

However, since the phase difference plate 13 is disposed between the first reflection type polarizing plate 8 and the STN liquid crystal element 16, the linearly polarized light incident on the phase difference plate 13 through the first reflection type polarizing plate 8 is: It becomes an elliptically polarized state. The elliptically polarized light is corrected during transmission through the STN liquid crystal element 16 and is almost linearly polarized light.
Approximately 60 with respect to the easy transmission axis 8a of the first reflection type polarizing plate 8
゜ Rotate and emit from a position 70 ° to the horizontal.

The emitted linearly polarized light component is scattered by the light scattering member 12 and enters the second reflective polarizing plate 9. The easy transmission axis 9a of the second reflection type polarizing plate 9 is arranged at -20 ° with respect to the horizontal. Therefore, the linearly polarized light transmitted through the light scattering material 12 is incident from a direction rotated by 90 ° with respect to the easy transmission axis 9 a of the second reflective polarizing plate 9, and is reflected by the second reflective polarizing plate 9. Then, it is returned to the front side A on the viewing side. At this time, by passing through the light scattering member 12 again, the appropriately polarized linearly polarized light is reflected on the front A. Therefore, as shown when no voltage is applied when viewed from the front A in FIG. 4, all light is reflected and a white display is obtained.

Next, when a voltage is applied between the first electrode 3 and the second electrode 4, the molecules of the nematic liquid crystal 6 rise, the birefringence of the STN liquid crystal element 16 changes, and the emitted linearly polarized light becomes approximately It rotates 90 ° and becomes -20 ° with respect to the horizontal.

Accordingly, the light is incident parallel to the easy transmission axis 9a of the second reflection type polarizing plate 9, so that the incident light as shown at the time of voltage application when viewed from the front A in FIG. Are transmitted through the second reflective polarizer 9, are also transmitted through the second absorption polarizer 11, and are transmitted through the back B. Since the transmitted linearly polarized light component does not have a reflector in the direction of back B, it is not reflected and returned to the front side A on the viewing side. Therefore, a black display is obtained.

Next, the case of visual recognition from the back B will be described. The same operation is performed except that the position where the light scattering member 12 passes before and after the light scattering member 12 is incident on the liquid crystal element 16 and the position of the retardation plate 13 are different from the case where the light is viewed from the front A. In the state where no voltage is applied when viewed from the back B, the direction of the easy transmission axis 11a incident on the second absorption type polarizing plate 11 is
The linearly polarized light rotated by 0 ° is absorbed, and the linearly polarized light incident on the second absorption type polarizing plate 11 in the easy transmission axis 11a direction is
In parallel with the easy transmission axis 9a of the reflective polarizing plate 9 of FIG.
Since the incident linearly polarized light is parallel to the easy transmission axis 9a of the second reflective polarizing plate 9, it is also transmitted, scattered by the light scattering member 12, and enters the STN liquid crystal element 16. When emitted from the STN liquid crystal element 16, the linearly polarized light is in an elliptically polarized state, and when there is no phase difference plate 13, the light cannot be completely reflected by the first reflective polarizing plate 8 and is colored by birefringence, resulting in display failure. It is enough.

However, since the retardation plate 13 is disposed between the first reflection type polarizing plate 8 and the STN liquid crystal element 16, the light enters the phase difference plate 13 through the second reflection type polarization plate 9 and the STN liquid crystal element 16. The elliptically polarized light is corrected while transmitting through the retardation plate 13, is substantially linearly polarized, rotates about −60 ° with respect to the easy transmission axis 9 a of the second reflective polarizing plate 9, and − − with respect to the horizontal. The light exits from the 80 ° position.

The emitted linearly polarized light component enters the first reflective polarizing plate 8. Easy transmission axis 8 of first reflective polarizing plate 8
a is arranged at 10 ° to the horizontal. Therefore,
The incident linearly polarized light is incident from a direction rotated by 90 ° with respect to the easy transmission axis 8a of the first reflection type polarizing plate 8, so that it is reflected by the first reflection type polarizing plate 8 and the back side B on the viewing side. Is returned to. At this time, by passing through the light scattering member 12 again, the appropriately polarized linearly polarized light is reflected on the back B. Accordingly, as shown when no voltage is applied when viewed from the back B in FIG. 4, all light is reflected and a white display is obtained.

Next, when a voltage is applied between the first electrode 3 and the second electrode 4, the molecules of the nematic liquid crystal 6 rise, the birefringence of the STN liquid crystal element 16 changes, and the emitted linearly polarized light is approximately Rotate 90 ° to a direction of 10 ° to the horizontal.

Accordingly, the light is incident parallel to the easy transmission axis 8a of the first reflective polarizing plate 8, and as shown at the time of voltage application when viewed from the back B in FIG. The light passes through the first reflective polarizer 8, further passes through the first absorption polarizer 10, and passes through the front A. Since the transmitted linearly polarized light component does not have a reflector in the direction of the front A, it is reflected and does not return to the viewing side B. Therefore, a black display is obtained.

As a liquid crystal element, an STN liquid crystal element 1
By using 6, the deformation of the six molecules of the nematic liquid crystal with respect to the applied voltage becomes steep, and the steepness of the optical characteristics is improved. Therefore, even with simple matrix driving, the number of scanning lines can be increased to 100 to 400, and a large-sized liquid crystal display device or a high-density liquid crystal display device can be provided. Also, the viewing angle characteristics are improved.

As described above, according to the present invention, it is possible to provide a liquid crystal display device which allows visual recognition from both sides of the front and back, provides a display with higher contrast, and has a good viewing angle characteristic.

(Modification of First Embodiment) In the present embodiment, the light scattering member 12 is connected to the second reflection type polarizing plate 9 and the STN.
The light scattering member 12 is disposed between the liquid crystal elements 16.
May also be arranged between the first reflective polarizing plate 8 and the STN liquid crystal element 16.

Hereinafter, a modification of the first embodiment will be described with reference to FIG. In order from the front A, the first absorption-type polarizing plate 10, the first reflection-type polarizing plate 8, the light scattering member 14,
Retardation plate 13, STN liquid crystal element 16, light scattering member 1
2, the second reflective polarizer 9 and the second absorption polarizer 1
1 and are arranged. The relationship between the axes of easy transmission of the respective polarizing plates is arranged as shown in FIG. 2 as in the present embodiment.

Here, in a modification of the present embodiment, R-DEFC (trade name, manufactured by Sumitomo 3M Limited) is used for the first reflective polarizing plate 8 and the light scattering member 14. R-DEFC is a product in which an adhesive material serving as a scattering material is applied to a reflective polarizing plate, and is a product having both functions of a light scattering member and a reflective polarizing plate. Similarly, R-DEFC is used for the second reflective polarizing plate 9 and the light scattering member 12. In the modification of the present embodiment, since the same member can be used for the first reflective polarizing plate 8 and the second reflective polarizing plate 9, the cost and mass productivity are excellent.

In the display according to the modification of the embodiment, since the arrangement of the easy transmission axes of the respective polarizing plates is the same as that of the embodiment, it is apparent that white and black displays can be visually recognized from both sides. The only difference is that the light scattering material 14 has a front A
Since it is added to the side, the difference in the light scattering state between when viewed from the front A and when viewed from the back B is reduced.

In the present embodiment, the liquid crystal element has the ST
Although the N liquid crystal element 16 was used, it is clear that the same effect can be obtained even with a twisted nematic liquid crystal element having a twist angle of about 90 °.

In this embodiment, a 225 ° twisted STN liquid crystal element is used as the STN liquid crystal element 16. However, a similar effect can be obtained with a 180 ° to 270 ° twisted STN liquid crystal element.

In the present embodiment, one retardation plate 13 is used in order to return the elliptically polarized light state of the STN liquid crystal element 16 to linearly polarized light. Returning to linearly polarized light, better contrast is obtained. A plurality of retardation plates may be provided on one side, or ST
It is also possible to arrange on both sides of the N liquid crystal element 16.

In this embodiment, the light scattering member 1
R-DE with adhesive applied to reflective polarizers 2, 14
Although FC is used, a similar effect can be obtained by using a light scattering material such as a diffusion sheet in which a material in which acrylic beads are mixed with an adhesive in a polycarbonate film is applied as a diffusion layer, or an embossed film. In addition, if the reflection type polarizing plate is formed by embossing the reflection type polarizing plate itself, the reflection type polarizing plate also serves as the light scattering member, so that it is not necessary to separately arrange the light scattering member. In these cases, the light scattering function preferably has a haze value of 30 or more. The light transmittance is preferably 80% or more.

In this embodiment, the light scattering member is used. However, the light scattering member is used to scatter the light reflected by the reflection type polarizing plate to perform white display. It is also possible to omit it. For example, Sumitomo 3M D-BEF has a glossy reflected light,
Gives a metallic look. If this metallic feeling is used for display, it is not necessary to insert a scattering member. Even if the scattering member is not inserted, there is no problem in the operation of the present embodiment, and it is apparent that the operation is visible from both sides of the front as described above. The white color of the display color only becomes the metallic color.

[0058]

As is clear from the above description, the liquid crystal display device of the present invention comprises an absorption polarizer, a reflective polarizer,
By providing a phase difference plate, an STN liquid crystal element, a light scattering member, a reflection type polarizing plate, and an absorption type polarizing plate, a high contrast that displays black and white on both sides of the front and the viewing angle is provided. A liquid crystal display device having favorable characteristics can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a plan view showing an arrangement relationship of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to a modification of the first embodiment of the present invention.

FIG. 4 is an explanatory diagram for explaining a display state according to the present invention.

FIG. 5 is an explanatory diagram for explaining a conventional technique of the present invention.

FIG. 6 is an explanatory diagram for explaining a display principle of the present invention.

FIG. 7 is an explanatory diagram for explaining a display principle of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st board | substrate 2 2nd board | substrate 3 1st electrode 4 2nd electrode 5 Sealing material 6 Nematic liquid crystal 8 1st reflection-type polarizing plate 8a Easy transmission axis of 1st reflection-type polarizing plate 9 2nd Reflective polarizer 9a Easy transmission axis of second reflective polarizer 10 First absorption polarizer 10a Easy transmission axis of first absorption polarizer 11 Second absorption polarizer 11a Second absorption type Easy transmission axis of polarizing plate 12 Light scattering member 13 Phase difference plate 13a Slow axis 14 Light scattering member 16 STN liquid crystal element (240 ° twist) 16a Lower liquid crystal molecule alignment direction 16b Upper liquid crystal molecule alignment direction 1001 Liquid crystal panel 1002 Reflector

Claims (7)

[Claims] A first substrate having a first electrode, a second substrate having a second electrode, and a liquid crystal element having a liquid crystal interposed between the pair of substrates; A reflective polarizer provided outside, an absorption polarizer provided outside the reflective polarizer, a reflective polarizer provided outside the second substrate, and an absorption type provided outside the reflective polarizer A liquid crystal display device comprising: a polarizing plate. 2. A liquid crystal element comprising a first substrate having a first electrode, a second substrate having a second electrode, and a liquid crystal interposed between the pair of substrates; A light scattering member provided outside at least one of the second substrate, a reflective polarizing plate provided outside the first substrate, an absorption polarizing plate provided outside the reflective polarizing plate; A liquid crystal display device comprising: a reflective polarizing plate provided outside the substrate; and an absorption polarizing plate provided outside the reflective polarizing plate. 3. The liquid crystal element is provided between a first substrate having a first electrode and a second substrate having a second electrode.
3. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is an STN liquid crystal element having a nematic liquid crystal twisted at 0 ° to 270 °. 4. The method according to claim 1, wherein the liquid crystal element is disposed between a first substrate having a first electrode and a second substrate having a second electrode.
The liquid crystal display device according to claim 1, wherein the liquid crystal display device is a TN liquid crystal element having a nematic liquid crystal twisted at 0 °. 5. The liquid crystal element is a ferroelectric liquid crystal element in which a ferroelectric liquid crystal is held between a first substrate having a first electrode and a second substrate having a second electrode. The liquid crystal display device according to claim 1 or 2, wherein: 6. A substrate between a first substrate having a first electrode, a second substrate having a second electrode, and the pair of substrates.
An STN liquid crystal element that holds a nematic liquid crystal that is twist-aligned to {270}, a retardation plate provided outside the first substrate, a reflective polarizing plate provided outside the retardation plate, An absorption type polarizing plate provided outside the reflection type polarizing plate, a light scattering member provided outside the second substrate, a reflection type polarizing plate provided outside the light scattering member, and an outside of the reflection type polarizing plate And a light-absorbing polarizing plate provided in the liquid crystal display device. 7. A reflection type polarizing plate is a sheet that transmits a vibration plane parallel to an easy transmission axis and a sheet that reflects a vibration plane orthogonal thereto, and an absorption type polarization plate is a sheet that transmits a vibration plane parallel to the easy transmission axis. 7. The liquid crystal display device according to claim 1, wherein the orthogonal vibration surface is an absorbing sheet.