JP3284427B2 - Liquid crystal display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a matrix type liquid crystal display device.

[0002]

2. Description of the Related Art At the beginning of the liquid crystal display device, a figure-of-eight segment display called a 7-segment or an 8-segment was mainly used, but with the increase in display capacity, the display has gradually shifted to a matrix-type display. The matrix type display has an excellent feature that it can display not only numbers and alphabets but also very complicated displays such as kanji and figures.
FIGS. 10A and 10B show an example in which "8" is displayed on a conventional matrix type liquid crystal display device. FIG. 10A shows a positive display in which the background is white and pixels are black when lit, and FIG. This is a negative display in which pixels sometimes become white.

[0003]

However, such a conventional matrix-type liquid crystal display device has a problem that since it performs display with a set of discrete dots, only an unnatural display inferior to segment display can be performed. . In addition, particularly in the case of a positive display, there is also a problem that a high contrast cannot be obtained because a space between pixels is whitened even when the entire surface is lit.

One means for solving such a problem is disclosed in Japanese Patent Application Laid-Open No. 5-72543. This is because, in a matrix type liquid crystal display device similar to the present application, when the distance between signal electrodes is set to less than half the thickness of the liquid crystal layer, an electric field wraps around, and the liquid crystal in the space between the electrodes operates similarly to the liquid crystal in the pixel portion. It is a method that can be done. However, the fact that the distance between the electrodes is equal to or less than half the thickness of the liquid crystal layer means that it is generally equal to or less than 3 μm. This publication uses a black matrix for the space between the scanning electrodes, and requires an extra step. The present application focuses on the alignment direction of the liquid crystal, and adopts an arrangement that maximizes the electric field wraparound effect, whereby the liquid crystal can be operated similarly to the pixel even in a relatively large space between electrodes. This is an invention that is one step ahead of JP-A-5-72543.

In order to realize the liquid crystal display device of the present invention, it is easier to use a laser than a photolithography method in patterning a transparent electrode. Such patterning using a laser has already been disclosed in JP-A-51-30970, JP-A-51-30971, JP-A-53-121599, and JP-A-57-2.
05908, JP-A-57-208007,
JP-A-58-1128, JP-A-59-14677
JP, JP-A-60-84717, JP-A-60-84717
176022, JP-A-60-260392, JP-A-60-260393, JP-A-60-2
No. 61142, JP-A-61-98324, JP-A-63-18330, JP-A-63-41828
JP, JP-A-2-259727, JP-A-4-7
It is disclosed in, for example, Japanese Patent No. 8820 and is a known technique. However, it is needless to say that these publications do not disclose the idea of the present invention to operate the liquid crystal between the electrodes similarly to the pixel.

Another problem of the conventional matrix type liquid crystal display device exists only in a liquid crystal display device of a type in which a signal electrode is divided into upper and lower portions. As shown in FIG. 9A, the space 63 between the upper and lower signal electrodes 61 and 62 is usually arranged so as to fit in the space between the scanning electrodes. However, if a misalignment occurs when assembling the upper and lower substrates, FIG.
As shown in (3), 63 enters the pixel, the area of the pixel is reduced, and regions having different brightness and contrast are generated in one horizontal line. This is called center line unevenness. Such a problem can be easily solved because the space 63 can be operated in the same manner as a normal pixel in the present invention. JP-A-4-291238 and JP-A-4-324822 disclose inventions similar to the present invention in which only the process of dividing a signal electrode into upper and lower portions is performed by a laser. This is an invention aiming at removal, and since the part of the two divided parts has been cut in advance by the photolithography method, the effect as in the present invention cannot be expected.

As described above, the conventional matrix type liquid crystal display device has problems such as unnatural display, low contrast, and easy occurrence of center line unevenness. The present invention solves such a problem, and the purpose is to operate the liquid crystal in the space between the electrodes similarly to the liquid crystal in the pixel, so that the display is smooth,
An object of the present invention is to provide a liquid crystal display device having high contrast and no unevenness.

[0008]

A liquid crystal display device according to the present invention comprises: a substrate having a plurality of signal electrodes; a substrate having a plurality of scanning electrodes arranged to intersect the signal electrodes;
In a matrix type liquid crystal display device having a liquid crystal layer sandwiched between them, the interval between the scanning electrodes is smaller than the interval between the signal electrodes, and both intervals are smaller than the thickness of the liquid crystal layer. However, the “spacing of the scanning electrodes” here is the spacing between adjacent scanning electrodes, and corresponds to 12 in FIG. Similarly, the “interval between signal electrodes” is the interval between adjacent signal electrodes, and is 1 in FIG.
Equivalent to 4. Note that this condition is satisfied only in a general arrangement in which the scanning electrodes extend in the left and right directions, the signal electrodes extend in the vertical direction, and the major axis direction of the liquid crystal molecules located at the center of the liquid crystal layer is in the vertical direction. More generally, in the same liquid crystal display device, the distance between each of the signal electrode and the scanning electrode is smaller than the thickness of the liquid crystal layer, and the major axis direction of the liquid crystal molecules located at the center of the liquid crystal layer. The distance between the electrodes extending at an angle closer to the right angle is smaller than the distance between the other electrodes.

A matrix type liquid crystal display device having a substrate provided with a plurality of signal electrodes, a substrate provided with a plurality of scanning electrodes arranged to intersect the signal electrodes, and a liquid crystal layer sandwiched therebetween. The distance between each of the signal electrode and the scanning electrode is smaller than the thickness of the liquid crystal layer, and the major axis direction of the liquid crystal molecules located at the center of the liquid crystal layer is the overlapping portion of the scanning electrode and the signal electrode. It intersects the contour line of a certain pixel at an angle of less than 60 degrees.

The distance between the signal electrode and the scanning electrode is greater than half the thickness of the liquid crystal layer.

A substrate having a plurality of vertically divided signal electrodes, a substrate having a plurality of scanning electrodes arranged to intersect the signal electrodes, and a matrix having a liquid crystal layer sandwiched therebetween. In the liquid crystal display device of the type, a distance between the upper and lower signal electrodes is smaller than a thickness of the liquid crystal layer. Further, the major axis direction of the liquid crystal molecules located at the center of the liquid crystal layer is aligned with the extending direction of the signal electrode.
It intersects at an angle of 0 degree or more.

The liquid crystal display device is characterized in that the steepness γ of the electro-optical characteristics is 1.03 or less. The value of γ is defined as the ratio of the voltage at which the transmittance changes by 10% to the voltage at which the transmittance changes by 90%. It is desirable that the γ value is as small as possible. Particularly, when the γ value is set to 1.03 or less, the liquid crystal in the space between the electrodes operates at the electrode interval of about the thickness of the liquid crystal layer regardless of the liquid crystal alignment direction. When).

Further, Δn of the liquid crystal in the liquid crystal layer is 0.11.
It is characterized by the following. When Δn is 0.11 or less, the thickness of the liquid crystal layer becomes 8 μm or more. Therefore, the electrode interval necessary for operating the liquid crystal in the space between the electrodes is widened, and at least one of the scanning electrode and the signal electrode can be patterned by the photolithography method.

[0014]

【Example】

(Embodiment 1) A liquid crystal display device according to Embodiment 1 of the present invention has an upper polarizing plate 1, a retardation plate 2, an upper substrate 3 of a liquid crystal cell, a liquid crystal layer as schematically shown in FIG. 4,
The liquid crystal cell comprises a lower substrate 5 and a lower polarizer 6. The upper substrate includes a scanning electrode 7 and an alignment layer 9, and the lower substrate includes a signal electrode 8 and an alignment layer 9. The liquid crystal of the liquid crystal layer is a liquid crystal for STN manufactured by Merck, ZLI-4621 (Δn = 0.1
252), and the thickness of the liquid crystal layer was 6.9 μm. As the retardation plate, a uniaxially stretched polycarbonate film of Δn × d = 0.32 μm was used.

FIG. 2 is an enlarged view of a pixel portion of the liquid crystal display device as viewed from the front. The band-shaped scanning electrodes 7 extending left and right have a width 11 of 297 μm, and 480 lines are arranged in parallel. The interval 12 between adjacent scanning electrodes is 3 μm. On the other hand, the band-like signal electrode 8 extending vertically has a width 13 of 294 μm,
640 lines are arranged in parallel. Interval 1 between adjacent signal electrodes
4 is 6 μm. Such fine patterning,
This was realized by a method in which the second harmonic of the YAG laser was focused on a spot of 3 μm or 6 μm, and ITO was sublimated sequentially. As described above, even if only the signal electrode side is used, patterning at a wide interval is effective in improving the processing speed and reducing short-circuit defects.
In the drawing, a hatched portion 15 is a pixel region where the scanning electrode and the signal electrode overlap, and non-hatched portions 16 and 17 are a space between the scanning electrodes and a space between the signal electrodes, respectively.

FIG. 3 is a diagram showing the relationship between the axes of the liquid crystal display device. Here, the angle 31 between the polarization axis direction 21 of the upper polarizer and the stretching direction 22 of the retarder is set to 53 degrees to the right, 22
Is the angle 3 between the rubbing direction 23 of the upper substrate of the liquid crystal cell and
2 is 85 degrees to the left, and the twist angle 33 of the liquid crystal determined by 23 and the rubbing direction 24 of the lower substrate of the liquid crystal cell is 240 to the left.
Degree, the angle 34 between the polarization axis direction 25 of the lower polarizer and 24
Was set to 40 degrees to the right. At this time, the direction of the liquid crystal molecules in the center of the liquid crystal layer is the major axis direction of the ellipse 26, and the angle 35 between the direction 27 in which the scanning electrode extends and the angle 36 between the direction 28 in which the signal electrode extends is 0 degree. Become.

In order to maximize the effect of the electric field wraparound, it is necessary to consider the relationship between the direction of the liquid crystal molecules at the center of the liquid crystal layer and the direction in which the electrodes extend. FIG. 4 is a cross-sectional view of the liquid crystal cell. As shown in FIG.
The liquid crystal molecules 41 at the center of the liquid crystal layer form a narrow space 42 between the electrodes.
4B, the liquid crystal molecules 41 are parallel to the direction in which the electrode 43 extends as shown in FIG. 4B, rather than in the direction perpendicular to the direction in which the electrode 43 extends.
The liquid crystal between the electrodes is easy to operate. In the first embodiment, the liquid crystal molecules at the center of the liquid crystal layer are orthogonal to the direction in which the scanning electrode extends,
It is parallel to the direction in which the signal electrode extends. Therefore, the liquid crystal in the space between the scanning electrodes (16 in FIG. 2) is difficult to respond,
The liquid crystal in the space between the signal electrodes (17 in FIG. 2) is easy to respond. In order for the liquid crystal in either space to operate equally, it is necessary to make the interval between the scanning electrodes smaller than the interval between the signal electrodes. In the first embodiment, the interval between the scanning electrodes is 3 μm and the interval between the signal electrodes is 6 μm.

A curve 51 shown in FIG. 5 shows a voltage transmittance characteristic of the liquid crystal display device. The liquid crystal in the space 16 between the scanning electrodes and the liquid crystal in the space 17 between the signal electrodes in FIG. 2 operate in the same manner as the liquid crystal in the pixel unit 15 due to the electric field wraparound. It is because. Note that the value of the steepness γ is 1.028, and 1 /
When driven at 240 duty, a display contrast of 1:31 was obtained. It goes without saying that the higher the steepness and the lower the duty ratio, the easier the liquid crystal in the space between the electrodes is to operate.

FIG. 6A shows an example in which "8" is displayed on the liquid crystal display device according to the first embodiment of the present invention. This is a positive display, but a negative display of FIG. 6B is also possible by changing the direction of the polarizing plate. Compared to FIG. 10 showing a conventional display example, the displayed image is very smooth, because the liquid crystal in the space between the electrodes operates similarly to the liquid crystal in the pixel portion.

(Embodiment 2) The liquid crystal display device according to Embodiment 2 of the present invention has the structure and the axial relationship shown in FIGS. 1, 2 and 3 as in Embodiment 1, except that the liquid crystal has Δn of 0. 10
It is characterized in that the thickness of the liquid crystal layer is increased to 8.0 μm by using Merck's ZLI-4455-000, which is as small as 94. Accordingly, a sufficient effect can be obtained even if the interval between the scanning electrodes and the interval between the signal electrodes are widened.

In FIG. 2, the width 11 of the scanning electrode is set to 296.
μm, the interval 12 between adjacent scanning electrodes is 4 μm, the width 13 of the signal electrode is 292 μm, and the interval 14 between adjacent signal electrodes is 8 μm.
m. The laser method was used for patterning on the scanning electrode side as in Example 1, but patterning was performed on the signal electrode side by photolithography. Even if only the signal electrode side was used, the photolithography method could be adopted, so that the processing speed was improved, and the short circuit between the electrodes was reduced, so that mass productivity was significantly improved.

(Embodiment 3) A liquid crystal display device according to Embodiment 3 of the present invention has the structure shown in FIG. 1 similarly to Embodiment 1, but in FIG.
The interval 12 between adjacent scanning electrodes is 5 μm, and the width 13 of the signal electrode
Was set to 295 μm, and the interval 14 between adjacent signal electrodes was set to 5 μm. The reason why the widths of the scanning electrode and the signal electrode can be made equal and wider than the width of the scanning electrode of the first embodiment is that the orientation direction of the liquid crystal molecules is devised.

FIG. 7 is a diagram showing the relationship between the axes of the liquid crystal display device. Here, the angle 31 between the polarization axis direction 21 of the upper polarizer and the stretching direction 22 of the retarder is set to 53 degrees to the right, 22
Is the angle 3 between the rubbing direction 23 of the upper substrate of the liquid crystal cell and
2 is 85 degrees to the left, and the twist angle 33 of the liquid crystal determined by 23 and the rubbing direction 24 of the lower substrate of the liquid crystal cell is 240 to the left.
Degree, the angle 34 between the polarization axis direction 25 of the lower polarizer and 24
Was set to 40 degrees to the right. At this time, the direction of the liquid crystal molecules in the center of the liquid crystal layer is the major axis direction of the ellipse 26, and the angle 35 between the direction 27 in which the scanning electrode extends and the direction 28 in which the signal electrode extends 28 is 45 degrees. Become.

As described above, since the liquid crystal molecules at the center of the liquid crystal layer make an angle of 45 degrees with respect to the direction in which they extend with respect to both the scanning electrodes and the signal electrodes, the intervals between the respective electrodes are equal and wider. Can be taken.

(Embodiment 4) Like Embodiment 3, Embodiment 4 is a device for widening the interval between the scanning electrodes. 1 and 3
Is similar to the first embodiment in having the structure and the axial relationship.

FIG. 8 is an enlarged view of the pixel portion of the liquid crystal display device as viewed from the front. It is characterized in that the scanning electrodes 7 extending to the left and right meander zigzag. Its width 11 is 29
The distance 12 between adjacent electrodes is 5 μm. The bending angle is set to 18 as 2θ. The band-shaped signal electrode 8 extending vertically has a width 13 of 294 μm and an interval 14 between adjacent signal electrodes of 6 μm. The hatched portion 15 in the figure is the pixel region where the scanning electrode and the signal electrode overlap, and the hatched portions 16 and 17 are not shown.
Are the spaces between the scanning electrodes and the spaces between the signal electrodes, respectively.

When the scanning electrode is formed in such a shape, there is no side of the contour of the pixel that is orthogonal to the liquid crystal molecules at the center of the liquid crystal layer. In Embodiment 4, θ is set to 60 degrees, and
However, when θ was set to 60 degrees or more, a part of the space between the scanning electrodes where the liquid crystal did not operate appeared.

(Embodiment 5) A liquid crystal display device according to a fifth embodiment of the present invention is directed to a liquid crystal display device in which a signal electrode is divided into upper and lower portions. The structure and axial relationship are as shown in FIGS. 1 and 3 as in the first embodiment, but the width 11 of the scanning electrode 7 is 270 μm in FIG.
The interval 12 between adjacent scanning electrodes is 30 μm, the width 13 of the signal electrode 8 is 270 μm, and the interval 14 between adjacent signal electrodes is 30 μm.
m. Each of the scanning electrode and the signal electrode was patterned by a photolithography method.

FIG. 9 is an enlarged view of the vicinity of the two divided signal electrodes at the center of the liquid crystal display device according to the fifth embodiment of the present invention. Normally, as shown in FIG. 9A, the space 63 between the upper signal electrode 61 and the lower signal electrode 62 is
It is arranged to fit in the space 12 between the scanning electrodes.
However, if a misalignment occurs when assembling the upper and lower substrates, 63 enters the pixel 15 as shown in FIG. 9B, reducing the area of the pixel, and the center line having different brightness and contrast in a horizontal line. Unevenness may occur.
In the fifth embodiment, the space 12 is 3
By patterning with a width of μm, the space 12
Was operated in the same manner as the pixels, and the center line unevenness was made inconspicuous.

By making the space 12 about 5 μm and taking the liquid crystal alignment direction as shown in FIG.
Similar effects can be obtained.

Further, by irradiating a laser from outside the substrate after assembling the liquid crystal cell and patterning the space 12, the unevenness of the center line can be completely eliminated.

Comparative Example 1 Comparative Example 1 is a conventional liquid crystal display device in which the distance between the scanning electrode and the signal electrode is increased.
The point having the structure and the axial relationship of FIGS.
2, the width 11 of the scanning electrode 7 was 270 μm, the interval 12 between adjacent scanning electrodes was 30 μm, the width 13 of the signal electrode 8 was 270 μm, and the interval 14 between the adjacent signal electrodes was 30 μm. Both the scanning electrode and the signal electrode were patterned by the photolithography method.

A curve 52 shown in FIG. 5 shows the voltage transmittance characteristic of the liquid crystal display device of Comparative Example 1. The reason why the voltage does not become very dark even when the voltage is applied is that the liquid crystal in the space 16 between the scanning electrodes and the liquid crystal in the space 17 between the signal electrodes in FIG.
This is because it does not operate together with the liquid crystal of the pixel unit 15. Therefore, when driven at 1/240 duty, on average: 1:
Only a display contrast of 6 was obtained.

FIG. 10A shows an example in which “8” is displayed on the liquid crystal display device of Comparative Example 1. This is a positive display, but if the direction of the polarizing plate is changed, the negative display of FIG. 10B is also possible. Compared to FIG. 6 showing the display example of the first embodiment, the individual dots are discrete and the display is unnatural.

Comparative Example 2 The liquid crystal display device in Comparative Example 2 has the structure and axial relationship shown in FIGS. 1, 2 and 3 as in Example 1, but in FIG.
1 is 297 μm, the interval 12 between adjacent scanning electrodes is 3 μm,
It is characterized in that the width 13 of the signal electrode is 297 μm and the interval 14 between adjacent signal electrodes is 3 μm.

Even with such a configuration, the same effect as that of the present invention exists, but it is not only useless to reduce the interval between the signal electrodes as well as the interval between the scan electrodes, but also the processing speed is reduced. However, there is a demerit that a short-circuit defect easily occurs.

[0037]

As described above, according to the present invention, by operating the liquid crystal in the space between the electrodes in the same manner as the liquid crystal in the pixel, a liquid crystal display device with smooth display, high contrast and no unevenness can be provided. Can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a liquid crystal display device according to an example of the present invention and a comparative example.

FIG. 2 is an enlarged front view of a pixel portion of a liquid crystal display device according to Examples 1, 2, 3, 5 and Comparative Examples 1 and 2 of the present invention.

FIG. 3 is a relationship diagram of each axis of a liquid crystal display device in Examples 1, 2, 4, and 5 of the present invention and Comparative Examples 1 and 2.

FIG. 4 is a cross-sectional view of a liquid crystal cell illustrating the relationship between the direction of liquid crystal molecules at the center of a liquid crystal layer and the direction in which an electrode extends.

FIG. 5 is a diagram showing voltage transmittance characteristics of the liquid crystal display devices according to Example 1 of the present invention and Comparative Example 1.

FIG. 6 is an example in which “8” is displayed on the liquid crystal display device according to the first embodiment of the present invention.
(B) is a figure which shows a negative display.

FIG. 7 is a relationship diagram of each axis of a liquid crystal display device according to a third embodiment of the present invention.

FIG. 8 is an enlarged view of a pixel portion of a liquid crystal display device according to a fourth embodiment of the present invention when viewed from the front.

FIG. 9 is an enlarged view of a central portion of a liquid crystal display device according to a fifth embodiment of the present invention.

FIG. 10 is an example in which “8” is displayed on the liquid crystal display device in Comparative Example 1, (a) showing a positive display, and (b) showing a negative display.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 upper polarizing plate 2 phase difference plate 3 upper substrate of liquid crystal cell 4 liquid crystal layer 5 lower substrate of liquid crystal cell 6 lower polarizing plate 7 scanning electrode 8 signal electrode 9 alignment layer 11 width of scanning electrode 12 interval of scanning electrode 13 signal Electrode width 14 Signal electrode interval 15 Pixel region 16 Space between scanning electrodes 17 Space between signal electrodes 18 Bending angle 2θ of zigzag scanning electrode 21 Polarization axis direction of upper polarizer 22 Stretching direction of retardation plate 23 Liquid crystal cell The rubbing direction of the upper substrate of the liquid crystal cell 24 The rubbing direction of the lower substrate of the liquid crystal cell 25 The polarization axis direction of the lower polarizer 26 The liquid crystal molecules in the center of the liquid crystal layer 27 The direction in which the scanning electrode extends 28 The direction in which the signal electrode extends 31 21 is 22 The angle formed by the angle 32 22 and 23 33 The twist angle 34 of the liquid crystal 34 The angle formed by 25 35 The angle formed by 26 and 27 36 The angle formed by 26 and 28 Angle 41 Liquid crystal molecules in the center of liquid crystal layer 42 Narrow space between electrodes 43 Electrode 44 constituting electrode 44 Electrode facing 43 43 Voltage transmissivity characteristics of liquid crystal display device in Example 1 of the present invention 52 Liquid crystal display device in Comparative Example 1 Voltage transmission characteristic 61 Upper signal electrode 62 Lower signal electrode 63 Space between 61 and 62

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1343 G09G 3/36

Claims (8)

(57) [Claims] 1. A matrix type liquid crystal display device comprising: a substrate provided with a plurality of signal electrodes; a substrate provided with a plurality of scanning electrodes arranged so as to intersect with the signal electrodes; and a liquid crystal layer sandwiched therebetween. 2. The liquid crystal display device according to claim 1, wherein an interval between the scanning electrodes is smaller than an interval between the signal electrodes, and each interval is smaller than a thickness of the liquid crystal layer. 2. A matrix type liquid crystal display device comprising: a substrate provided with a plurality of signal electrodes; a substrate provided with a plurality of scanning electrodes arranged to intersect with the signal electrodes; and a liquid crystal layer sandwiched between the two. The distance between each of the signal electrode and the scanning electrode is smaller than the thickness of the liquid crystal layer, and on the side of the liquid crystal molecule located at the center of the liquid crystal layer, the side extending at an angle more orthogonal to the major axis direction. A liquid crystal display device, wherein an interval between the electrodes is smaller than an interval between the other electrodes. 3. A matrix type liquid crystal display device comprising: a substrate provided with a plurality of signal electrodes; a substrate provided with a plurality of scanning electrodes arranged to intersect with the signal electrodes; and a liquid crystal layer sandwiched therebetween. The distance between each of the signal electrode and the scanning electrode is smaller than the thickness of the liquid crystal layer, and the major axis direction of the liquid crystal molecules located at the center of the liquid crystal layer is the overlapping portion of the scanning electrode and the signal electrode. A liquid crystal display device which intersects a contour line of a pixel at an angle of 60 degrees or less. 4. The liquid crystal display device according to claim 1, wherein a distance between each of the signal electrode and the scanning electrode is larger than a half of a thickness of the liquid crystal layer. 5. A matrix having a plurality of vertically divided signal electrodes, a plurality of scanning electrodes arranged to intersect the signal electrodes, and a liquid crystal layer sandwiched therebetween. In the liquid crystal display device of the type, a distance between the upper and lower signal electrodes is smaller than a thickness of the liquid crystal layer. 6. The liquid crystal display device according to claim 5, wherein a major axis direction of liquid crystal molecules located at a center of the liquid crystal layer intersects with an extending direction of the scan electrode at an angle of 60 degrees or less. 7. The liquid crystal display device according to claim 1, wherein the steepness γ of the electro-optical characteristic of the liquid crystal display device is 1.03 or less. 8. The liquid crystal display device according to claim 1, wherein Δn of the liquid crystal in the liquid crystal layer is 0.11 or less.