JP2009250989A - Liquid crystal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make it hard to view pits on a surface of a glass substrate. <P>SOLUTION: A liquid crystal device has a first substrate 10 having a first electrode 14 and a second electrode 15, a second substrate 20 disposed opposite the first substrate 10, and a liquid crystal layer 30 sandwiched between the first substrate 10 and second substrate 20. The second substrate 20 has a transparent substrate 20A, a polarizing plate 25 provided to the transparent substrate 20A on the opposite side from the liquid crystal layer 30, and a laminate film 40 provided between the transparent substrate 20A and polarizing plate 25 in contact with the transparent substrate 20A. The laminate film 40 includes an electrostatic shield film 23 having transparency, and a low-refractive-index film 24 provided in contact with the electrostatic shield film 23 and having transparency and a lower refractive index than the electromagnetic shield film 23 and transparent substrate 20A. The electromagnetic shield film 23 or low-refractive-index film 24 is provided in contact with the transparent substrate 20A. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid crystal device.

Conventionally, liquid crystal devices have been widely used as display units for personal computers, mobile phones, television receivers, and the like. One method for driving a liquid crystal device is a lateral electric field method. A horizontal electric field type liquid crystal device includes, for example, an element substrate provided with a first electrode and a second electrode,
A color filter substrate disposed opposite thereto, a liquid crystal sandwiched between the substrates, and the like are provided. An electric field (lateral electric field) parallel to the substrate surface is generated between the first electrode and the second electrode, and the liquid crystal molecules of the liquid crystal layer can be driven by the lateral electric field.

By the way, the color filter substrate does not require conductive portions such as electrodes and wiring, and if not provided, the color filter substrate may be charged by static electricity or the like. Then, an unexpected vertical electric field is generated between the substrates, the horizontal electric field is disturbed, and display defects may occur. In order to prevent this, a technique of providing an electrostatic shield film on a color filter substrate has been proposed (for example, Patent Document 1).

Such a horizontal electric field type liquid crystal device is manufactured, for example, as follows.
First, a switching element, a 1st electrode, a 2nd electrode, etc. are formed in a glass substrate, and an element substrate is formed. In addition to the element substrate, a color material portion and the like are formed on a glass substrate to form a color filter substrate. Then, after these substrates are arranged facing each other and bonded together via a spacer or the like, the substrates are thinned by etching or the like from the outside. Then, indium tin oxide (ITO) or the like is formed on the outside of the color filter substrate to form an electrostatic shield film, and a polarizing plate or the like is appropriately formed.
A liquid crystal device is obtained by sealing a liquid crystal layer between these substrates.
JP-A-9-105918

Although it is considered that display defects due to static electricity can be prevented by using the technique of Patent Document 1, display quality may be deteriorated for the following reasons.
As described above, the color filter substrate is thinned after being bonded to the element substrate. This is for securing the thickness (strength) of the color filter substrate at the time of bonding from the viewpoint of preventing the color filter substrate from being damaged by the pressing at the time of bonding. When the glass substrate constituting the color filter substrate is thinned due to such circumstances, minute pits and scratches on the surface of the glass substrate become apparent by etching (thinning).

In addition, since the electrostatic shielding film is required to have translucency and conductivity, IT
O or the like is used. The electrostatic shield film made of ITO is greatly different in refractive index from that of the glass substrate, and the reflectance at the interface between the electrostatic shield film and the glass substrate is high. For this reason, the reflected light on the surface of the glass substrate is likely to be visually recognized, and the display quality is lowered due to the conspicuous pits and the like.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a good liquid crystal device that prevents a deterioration in display quality due to pits or the like.

The liquid crystal device of the present invention is sandwiched between a first substrate having a first electrode and a second electrode, a second substrate disposed opposite to the first substrate, and the first substrate and the second substrate. A liquid crystal layer containing liquid crystal molecules driven by an electric field generated between the first electrode and the second electrode, the second substrate comprising: a transparent substrate; and the liquid crystal layer in the transparent substrate; A polarizing plate provided on the opposite side, and a laminated film provided in contact with the transparent substrate between the transparent substrate and the polarizing plate, wherein the laminated film has a translucent static property. An electrostatic shield film, and a low refractive index film that is provided in contact with the electrostatic shield film, has translucency, and has a lower refractive index than the electrostatic shield film and the transparent substrate. A shield film or the low refractive index film is disposed in contact with the transparent substrate. It is characterized in.

In this way, if the laminated film is provided in contact with the second substrate, the transparent substrate and the laminated film out of the light (external light) incident from the opposite side (outside) of the liquid crystal layer in the second substrate of the liquid crystal device. The reflected light at the interface between the electrostatic shield film and the low refractive index film can be made to interfere with the reflected light on the surface of the transparent substrate. When the reflected light on the surface of the transparent substrate is weakened, it becomes difficult to be visually recognized from the outside of the liquid crystal device, and when pits or scratches are generated on the surface layer of the transparent substrate, these are hardly visible. Therefore, the display quality is prevented from being deteriorated due to the visual recognition of the pits and the like, and the liquid crystal device can obtain a high quality image.

Further, since the polarizing plate is not disposed between the laminated film and the transparent substrate, the reflected light on the transparent substrate surface can be weakened without being affected by the thickness, refractive index, optical characteristics, etc. of the polarizing plate. This makes it easier to design the laminated film and optimize the laminated film than when a polarizing plate or the like is disposed between the laminated film and the transparent substrate, and improves the reflectance on the surface of the transparent substrate. It can be significantly reduced.
The electrostatic shield film can also be used for removing static electricity on the second substrate side, so that the second
Display defects due to charging of the substrate can also be prevented. In addition, the electrostatic shield film contributes to the prevention of visual recognition of pits and the like and also contributes to the removal of static electricity, and the configuration of the liquid crystal device is simplified as compared with the case where these are shared by independent members.

Further, the electrostatic shield film may be provided on the opposite side of the low refractive index film from the transparent substrate, that is, the low refractive index film may be in contact with the transparent substrate.
Such a configuration can be obtained by continuously forming a low refractive index film and an electrostatic shield film on a transparent substrate. If the low refractive index film and the electrostatic shield film are continuously formed, it is possible to prevent foreign matter from entering between the layers of the laminated film and to form the laminated film efficiently. Further, since the electrostatic shield film is exposed after the continuous film formation, it is easy to electrically connect the electrostatic shield film to the ground.

The electrostatic shield film may be provided on the transparent substrate side of the low refractive index film, that is, the electrostatic shield film may be in contact with the transparent substrate.
In this case, as will be described later in [Example], the reflection of external light reflected on the surface of the transparent substrate is greater than when the electrostatic shield film is provided on the opposite side of the low refractive index film to the transparent substrate. The rate can be lowered.

The electrostatic shield film is made of indium tin oxide and has a thickness of 10 nm or more.
It is preferably 0 nm or less. In this case, the low refractive index film is made of silicon oxide and has a thickness of 14 nm to 26 nm, or the low refractive index film is made of magnesium fluoride and has a thickness of 15 nm to 34 nm. It is preferable that
Since indium tin oxide (ITO) has a track record as a light-transmitting conductive material, it can be used as an excellent electrostatic shield film. If the thickness is 10 nm or more, the transparent substrate is not partially exposed due to film formation failure or the like, and the electrostatic shield film functions well. If the thickness is 20 nm or less, the thermal load on the components of the liquid crystal device due to the formation of the electrostatic shield film is reduced to a level that does not damage the components.

Moreover, when this inventor employ | adopted the electrostatic shield film which consists of ITO and is 10 nm or more and 20 nm or less in thickness, it investigated about the reflectance which external light reflects on the transparent substrate surface. The details will be described later in [Example]. When a low refractive index film made of silicon oxide is employed, the effect of the present invention can be enhanced by setting the thickness to 14 nm or more and 26 nm or less. Further, when a low refractive index film made of magnesium fluoride is employed, the thickness is set to 15 n.
The effect of the present invention can be enhanced by setting it to m or more and 34 nm or less.

Hereinafter, although one embodiment of the present invention is described, the technical scope of the present invention is not limited to the following embodiment. In the following description, various structures are illustrated using drawings, but in order to show the characteristic parts of the structures in an easy-to-understand manner, the structures in the drawings are shown in different sizes and scales from the actual structures. There is.

The liquid crystal device according to the present embodiment performs image display by controlling the azimuth angle of liquid crystal molecules by a lateral electric field orthogonal to the traveling direction of light. Such a method includes FFS (Fringe).
Field Switching) and IPS (In Plane Switchi)
ng) method and the like are known. Here, description will be made based on a liquid crystal device capable of full color display in the FFS method.

FIG. 1A is a plan view showing an enlarged pixel, and FIG. 1B is a plan view showing a schematic configuration of a sub-pixel. The liquid crystal device 1 of the present embodiment has a large number of pixels P, and FIG.
As shown, the pixel P is composed of three sub-pixels Pr, Pg, and Pb. Subpixel Pr
, Pg, and Pb emit red light, green light, and blue light, respectively, and these colors are mixed and visually recognized, thereby enabling full color display. Here, the light shielding region D is between the sub-pixels Pr, Pg, and Pb and between the plurality of pixels P.

Hereinafter, the XYZ orthogonal coordinate system shown in FIG. 1A is set, and the positional relationship of the members will be described based on this. In this XYZ rectangular coordinate system, the X direction and the Y direction are along the plane on which the pixel P is arranged, the direction in which the sub-pixels Pr, Pg, and Pb are arranged is the X direction, and the direction orthogonal to the X direction is the Y direction. . A direction orthogonal to the arrangement plane of the pixels P is defined as a Z direction.

The liquid crystal device 1 is provided with a large number of scanning lines extending in the X direction and a large number of data lines extending in the Y direction. The scanning line is electrically connected to a scanning line driving circuit that supplies a scanning signal, and the data line is electrically connected to a data line driving circuit that supplies an image signal. In the present embodiment, the common electrode (described later) also serves as a capacitor line. However, for example, a capacitor line may be provided in parallel with the scanning line.
Hereinafter, the configuration of the liquid crystal device 1 will be described based on the sub-pixel Pg, but the sub-pixels Pr and Pb have the same configuration.

As shown in FIG. 1B, one of the areas defined by the scanning lines 11 and the data lines 12 corresponds to one of the sub-pixels Pr, Pg, and Pb. The subpixel Pg has a thin film transistor (TFT) 13, a pixel electrode (first electrode) 14, and a common electrode (second electrode) 15. The TFT 13 is disposed in the vicinity of the intersection of the scanning line 11 and the data line 12 and has a semiconductor layer provided so as to overlap the scanning line 11. In the TFT 13, the scanning line 11 functions as a gate electrode, and an image signal from the data line 12 is appropriately switched and transmitted to the pixel electrode 14. The pixel electrode 14 of the present embodiment has a substantially rectangular shape that is long in the Y direction, and has a slit-like opening extending in the X direction. The pixel electrode 14 is Z
The pixel electrode 14 and the common electrode 1 are arranged so as to overlap with the common electrode 15 in the direction.
An insulating film (not shown) is interposed between the two.

FIG. 2 is a cross-sectional view taken along the line AA ′ of FIG. As shown in FIG. 2, the liquid crystal device 1
Includes an element substrate (first substrate) 10 having a pixel electrode 14 and a common electrode 15, a color filter substrate 20 disposed to face the element substrate 10, and a liquid crystal layer 30 sandwiched between these substrates. Here, an image is displayed toward the color filter substrate 20 (Z positive direction).

The element substrate 10 uses a transparent substrate 10A made of glass, quartz, plastic, or the like as a base. The scanning line 11 and the common electrode 15 are provided on the inner side (the liquid crystal layer 30 side) of the transparent substrate 10A, and an insulating film 16 is provided so as to cover them. On the insulating film 16, the data line 12, the semiconductor layer 131 of the TFT 13, the source electrode 135, and the like are provided.
A part of 2 is branched and is in electrical contact with the source region of the semiconductor layer 131. Semiconductor layer 131
Is made of, for example, polycrystalline silicon, and the drain region of the semiconductor layer 131 is in contact with the source electrode 135. A part of the source electrode 135 is disposed so as to overlap the common electrode 15, and this part constitutes a capacitor for holding an image signal when energized.

An interlayer insulating film 17 is provided so as to cover the data line 12, the TFT 13, and the source electrode 135. The interlayer insulating film 17 is provided with a through hole that exposes the source electrode 135.
A pixel electrode 14 is provided across the inside of the through hole and a predetermined region on the interlayer insulating film 17.
The pixel electrode 14 is in contact with the source electrode 135 inside the through hole. An alignment film 18 is provided so as to cover the pixel electrode 14, and the alignment film 18 controls the alignment direction of the liquid crystal molecules of the liquid crystal layer 30 together with the alignment film 22 described later. A polarizing plate 19 is provided outside the transparent substrate 10A, and an illumination device (not shown) such as a backlight for illuminating the polarizing plate 19 side of the liquid crystal device 1 is provided.

The color filter substrate 20 of this embodiment uses a glass substrate 20A as a base. A color filter layer 21 is formed on the inner side (the liquid crystal layer 30 side) of the glass substrate 20A. The color filter layer 21 has a color material portion corresponding to each of the sub-pixels Pr, Pg, and Pb, although a detailed configuration thereof is not illustrated. For example, the sub-pixel Pr is provided with a color material portion that absorbs light in a wavelength band other than red light, and the light passing therethrough is emitted as red light. Between these color material portions, a light shielding portion corresponding to the light shielding region D (see FIG. 1A) is provided. An alignment film 22 is provided inside the color filter layer 21. Glass substrate 2
An electrostatic shield film 23 is provided in contact with the outer side of 0A, and a low refractive index film 24 is provided in contact with the outer side of the electrostatic shield 23 film. The electrostatic shield film 23 and the low refractive index film 24 constitute a laminated film 40, and a polarizing plate 25 is provided outside the laminated film 40.

The electrostatic shield film 23 is made of a conductive material having translucency such as tin oxide (SnO ₂ ) or indium tin oxide (ITO). The electrostatic shield film 23 releases the static electricity on the color filter substrate 20 side through a conductive portion (not shown). This prevents the color filter substrate 20 from being charged and prevents an unexpected vertical electric field from being generated between the color filter substrate 20 and the element substrate 10. The low refractive index film 24 is made of a light-transmitting forming material such as silicon oxide (SiO ₂ ), magnesium fluoride (MgF ₂ ), or fluorine resin. Further, by selecting the forming material, the refractive index is lower than both the electrostatic shield film 23 and the glass substrate 20A. Such a laminated film 40 attenuates light reflected on the surface of the glass substrate 20A on the Z positive direction side (outside) out of light (external light) incident on the liquid crystal device 1 from the viewing side (Z positive direction side). To work. Details thereof will be described later.

In the liquid crystal device 1 configured as described above, the image signal supplied from the data line driving circuit is supplied to the source region of the TFT 13 via the data line. The scanning signal supplied from the scanning line driving circuit turns on and off the channel of the TFT 13 at a predetermined timing via the scanning line. Thereby, the pixel electrode 14 in which the image signal is electrically connected to the drain region of the TFT 13.
And an electric field corresponding to the image signal is generated between the pixel electrode 14 and the common electrode 15. The azimuth angle of the liquid crystal molecules of the liquid crystal layer 30 is controlled by a component parallel to the XY plane of this electric field, that is, a lateral electric field.

On the other hand, the light from the illuminating device is incident on the liquid crystal layer 30 with the polarization direction aligned by the polarizing plate 19, and the polarization state changes according to the azimuth angle of the liquid crystal molecules and is emitted to the color filter substrate 20 side. The light incident on the color filter substrate 20 passes through the color filter layer 21 to become a predetermined color light and enters the polarizing plate 25. The light incident on the polarizing plate 25 is absorbed by the polarizing plate 25 according to the polarization state, and is emitted as colored light having a predetermined gradation. In this way, the sub-pixel P
Light emitted from each of r, Pg, and Pb is mixed and visually recognized, thereby constituting the minimum unit of full color display. Such light is emitted from each of a large number of pixels, so that a desired image can be displayed.

[Production example]
Such a liquid crystal device 1 is manufactured, for example, by the following method.
First, two glass wafers are prepared. One of the two sheets is for forming the transparent substrate 10A, and the other is for forming the glass substrate 20A. In this example, after processing each glass wafer, these are bonded together. Therefore, a glass wafer having a predetermined thickness or more is selected and its strength is ensured. Thereby, it is prevented that damage, such as a crack, arises in a glass wafer by the press at the time of bonding.

Next, various wirings, elements, and the like constituting the element substrate 10 are formed in a predetermined region of one glass wafer. Further, the color filter layer 21 and the alignment film 22 are formed in a predetermined region of the other glass wafer. And the glass wafer used as the element substrate 10 and the glass wafer used as the color filter substrate 20 are bonded together via a spacer. Then, the glass wafer is thinned by chemical etching or the like from the outside with the bonded side as the inside. Thus, one glass wafer becomes the transparent substrate 10A, and the other glass wafer becomes the glass substrate 20A. Note that minute pits and scratches such as crystal defects may occur on the glass wafer surface. Since this portion is more easily etched than other portions by etching, the portion may become visible in size as the thickness is reduced.

Next, the polarizing plate 19 is formed on the outside of the transparent substrate 10A, and the electrostatic shield film 23, the low refractive index film 24, and the polarizing plate 25 are sequentially formed on the outside of the glass substrate 20A. In this example, an ITO film is formed on the glass wafer 20A to a thickness of about 10 to 20 nm, and the electrostatic shield film 23 is formed.
Subsequently, SiO ₂ is formed to a thickness of about 14 to 26 nm to form a low refractive index film 24.

If SiO ₂ or MgF ₂ is selected as the material for forming the low refractive index film, these can be formed by the same film forming method as ITO, and the electrostatic shield film and the low refractive index film can be formed by continuous film formation. Can be formed. When the film is continuously formed, the probability that foreign matter enters between the electrostatic shield film 23 and the low refractive index film 24 is reduced, and deterioration of display quality due to scattering of external light and internal light is prevented. .

In the field of electronic equipment, a technique of forming an insulating portion made of SiO _{2 on a} pixel electrode made of ITO or the like is often used. Therefore, if SiO ₂ is selected as a material for forming the low refractive index film and such a technique is used, the adhesion between the electrostatic shield film 23 and the low refractive index film 24 becomes good, and a highly reliable laminated film Can be formed.

Moreover, if ITO is formed to a thickness of 10 nm or more, the glass substrate 20A is formed due to defective film formation or the like.
Is prevented from being partially exposed. If the film is formed to a thickness of 20 nm or less, the thermal load on the components of the liquid crystal device 1 is reduced to a level that does not damage the components. For example, the semiconductor layer 131 made of polycrystalline silicon is formed containing hydrogen in order to prevent the crystal defects. When the semiconductor layer 131 is heated to a high temperature (for example, 300 ° C.), hydrogen is desorbed and the characteristics are deteriorated. However, since the thermal load is reduced as described above, the characteristic deterioration is prevented. Further, since the thermal load is reduced, it is possible to prevent the atmospheric gas from thermally expanding between the substrate to be the element substrate 10 and the substrate to be the color filter substrate 20 to deform these substrates.

Examples of the ITO or SiO ₂ film forming method include sputtering, vapor deposition, and plasma C.
A known technique such as the VD method can be used. Further, when a low refractive index film is formed with a resin material, a spin coat method or the like may be used. In this example, the electrostatic shield film 23 and the low refractive index film 24 are formed by using an atmospheric pressure plasma CVD method. According to the atmospheric pressure plasma CVD method, a film can be formed in a non-depressurized atmosphere, so that the following inconveniences when forming a film in a depressurized atmosphere can be avoided.
In the case of forming a film in a reduced pressure atmosphere, in the process of lowering the atmospheric pressure, the space between the substrate serving as the element substrate 10 and the substrate serving as the color filter substrate 20 (inner side) is less likely to be exhausted than the outer side. The pressure is higher than the outside. Then, the two substrates are deformed outward,
In extreme cases, damage such as cracking will occur. However, if the film is formed in a non-depressurized atmosphere as in this example, there is almost no pressure difference between the inside and the outside, so damage to these substrates can be avoided.

After forming the laminated film 40 including the electrostatic shield film 23 and the low refractive index film 24 as described above, the color filter substrate 20 is obtained by forming the polarizing plate 25 thereon. Moreover, the element substrate 10 is obtained by forming the polarizing plate 19 outside the transparent substrate 10A.
The liquid crystal device 1 is obtained by injecting and sealing a liquid crystal material between the element substrate 10 and the color filter substrate 20.

According to such a manufacturing method, since the thinning is performed after the substrate to be the element substrate 10 and the substrate to be the color filter substrate 20 are bonded together, damage due to the bonding can be prevented,
The thin liquid crystal device 1 can be manufactured with a good yield. If such a liquid crystal device is to be manufactured without reducing the thickness, the base material of the element substrate or the color filter substrate is selected from a material that is thinner than the glass wafer used in this example and can ensure strength. Because it is necessary, it becomes expensive. That is, by reducing the thickness, a low-cost base material (glass wafer) can be used, and the cost can be reduced. On the other hand, when the thickness is reduced, pits and scratches that are manifested may be generated on the surface of the glass substrate 20A facing outward.
In the liquid crystal device 1 of the present invention, such pits and the like are hardly visible. The mechanism will be described below with reference to FIG.

As shown in FIG. 3, external light incident from the outside of the liquid crystal device 1 becomes light L that passes through the polarizing plate 25 and passes through the low refractive index film 24. A part of the light L is incident on the electrostatic shield film 23 and the glass substrate 2
The light is reflected at the interface between 0A and the electrostatic shield film 23 and enters the low refractive index film 24 again. This light becomes light L <b> 1 that goes to the outside of the liquid crystal device 1. A part of the light L is reflected at the interface between the low refractive index film 24 and the electrostatic shield film 23, and becomes light L <b> 2 that goes to the outside of the liquid crystal device 1. The light L1 and the light L2 interfere with each other, and the superimposed light is emitted to the outside of the liquid crystal device 1.

If the phases of the light L1 and the light L2 are shifted by a half wavelength, the light L1 and the light L2 cancel each other, so that the reflectance of the external light on the surface of the glass substrate 20A is theoretically zero. Thereby, even if there is a pit or the like on the surface of the glass substrate 20 </ b> A facing outward, this is not visible from the outside of the liquid crystal device 1. Specifically, such an effect can be obtained by satisfying both the following expressions (1) and (2). In Formula (1) and Formula (2), n ₀ , n ₁ , and n ₂ are the refractive index of the polarizing plate 25, the refractive index of the low refractive index film 24, and the refractive index of the electrostatic shield film 23, respectively. d is the thickness of the electrostatic shield film 23, and λ is the wavelength of light traveling in the polarizing plate 25.
n ₁ ² = n ₁ × n ₂ ... Formula (1)
n ₁ × d = λ / 4 (2)

Thus, λ is included in the expression (2), and the reflectance of the external light on the surface of the glass substrate 20A is a function of the wavelength of the light traveling in the polarizing plate 25. This wavelength includes the wavelength of external light and the laminated film 40.
The low-refractive index film 24 and the electrostatic shield film 23 of this embodiment are
It is optimized so that the reflectance on the surface of the glass substrate 20A of visible light (for example, the wavelength is 450 nm to 700 nm) is minimized. In the present invention, since the laminated film 40 and the glass substrate 20A are in direct contact with each other, it is not necessary to consider the reflection on the surface of the member as compared with the case where a member is interposed between them. Optimization can be performed from the viewpoint of minimizing the reflectance on the surface of the substrate 20A.

[Example]
Next, the difference in reflectance between the comparative example and the example will be described with reference to FIGS. FIG. 4A shows the refractive indexes of various members used in the comparative examples or examples [Table 1] and FIG.
(B) shows the configurations of Comparative Examples 1 and 2 and the reflectance of external light [Table 2], and FIG. 4C shows the configurations of Examples 1 to 4 to which the present invention is applied and the reflectance of external light. It is shown [Table 3]. The reflectances of Comparative Examples 1 and 2 shown in [Table 1] of FIG. 4B and the reflectances of Examples 1 to 4 shown in [Table 2] of FIG. Based on the results. This simulation is performed by performing multiple reflection calculation in consideration of reflection at the interface between each layer, and calculating the reflectance of the entire visible light using a matrix method.

As shown in Table 1 of FIG. 4A, the refractive index of the polarizing plate in the simulation is 1.
60, the refractive index of ITO (electrostatic shield film) is 2.00, the refractive index of MgF ₂ (low refractive index film) is 1.60, the refractive index of SiO ₂ (low refractive index film) is 1.46, glass The refractive index of the substrate is 1.5
2. The refractive index of TiO ₂ (high refractive index film) is 2.52. The high refractive index film is an example of a film having a higher refractive index than the electrostatic shield film. The refractive index of ITO varies depending on the film forming method, and the range is approximately 1.80 to 2.00.

As shown in Table 2 of FIG. 4 (b), Comparative Example 1 has a configuration similar to that in the prior art in which ITO and a polarizing plate are sequentially provided on a glass substrate, and the reflectance is 0.27%. there were. Comparative Example 2 has a configuration in which ITO, TiO ₂ , and a polarizing plate are sequentially provided on a glass substrate, and the reflectance thereof is 1.76%, which is higher than that of Comparative Example 1. Thus, it is considered that when a film having a refractive index higher than that of the electrostatic shield film is used, the reflectance becomes high, and pits and the like on the surface of the glass substrate are easily visually recognized.

As shown in Table 3 of FIG. 4C, Example 1 has a configuration in which ITO, MgF ₂ , and a polarizing plate are sequentially provided on a glass substrate, and the reflectance is 0.21%. Yes. Example 2 has a configuration in which ITO, SiO ₂ , and a polarizing plate are sequentially provided on a glass substrate, and the reflectance thereof is 0.24%. Example 3 has a configuration in which MgF ₂ , ITO, and a polarizing plate are sequentially provided on a glass substrate, and the reflectance thereof is 0.12%. Example 3 has a configuration in which SiO ₂ , ITO, and a polarizing plate are sequentially provided on a glass substrate, and the reflectance thereof is 0.15%.

Thus, Examples 1-4 which applied this invention are all considered that the reflectance is lower than the comparative example 1, and it is thought that the pit etc. on the surface of a glass substrate are difficult to visually recognize. Also,
In Examples 3 and 4, the refractive index is lower than in Examples 1 and 2, and it can be seen that if a low refractive index film is arranged on the glass substrate side, the visibility of pits and the like is remarkably reduced. In addition, the refractive index of Examples 1 and 3 is lower than that of Examples 2 and 4. If MgF ₂ is selected as the material for forming the low refractive index film, it can be seen that the visibility of pits and the like is reduced. .

As described above, in the liquid crystal device of the present invention, the laminated film 40 is formed on the second substrate (glass substrate 20A).
), The design of the laminated film 40 is facilitated and the laminated film 40 is optimized and the surface of the glass substrate 20A is compared with the case where a member is interposed between them. It is possible to significantly reduce the reflectance at. Therefore, when pits and scratches are generated on the surface layer of the glass substrate 20A, they are difficult to be visually recognized, and display quality is prevented from being deteriorated due to visual recognition of the pits. As described in [Production Example], if a thin liquid crystal device is manufactured at low cost, pits may be formed on the surface of the glass substrate. However, according to the present invention, deterioration of display quality due to pits is prevented. Therefore, the liquid crystal device can be manufactured at a low cost and with a thin shape and a high quality image can be obtained.

(A) is an enlarged plan view of a pixel, and (b) is a schematic configuration plan view of a sub-pixel. It is sectional drawing which follows the A-A 'line of FIG.1 (b). It is explanatory drawing which shows the mechanism in which the reflectance in the transparent substrate surface becomes low. (A)-(c) is [Table 1]-[Table 3] which shows a comparative example and an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Element substrate (first substrate), 14 ... Pixel electrode (first electrode), 15 ... Common electrode (second electrode), 20 ... Color filter substrate (second substrate), 20A ... Glass substrate (transparent substrate), 23 ... Electrostatic shield film, 24 ... Low refractive index film, 25 ... Polarizing plate, 30 ... Liquid crystal layer, 40 ... Multilayer film

Claims (6)

A first substrate having a first electrode and a second electrode;
A second substrate disposed opposite the first substrate;
A liquid crystal layer containing liquid crystal molecules sandwiched between the first substrate and the second substrate and driven by an electric field generated between the first electrode and the second electrode,
The second substrate includes a transparent substrate, a polarizing plate provided on the opposite side of the liquid crystal layer in the transparent substrate, and a laminate provided in contact with the transparent substrate between the transparent substrate and the polarizing plate. And having a membrane,
The laminated film is provided in contact with the electrostatic shielding film having translucency, and has a translucency and a refractive index lower than that of the electrostatic shielding film and the transparent substrate. A refractive index film,
The liquid crystal device, wherein the electrostatic shield film or the low refractive index film is disposed in contact with the transparent substrate. The liquid crystal device according to claim 1, wherein the low refractive index film is in contact with the transparent substrate. The liquid crystal device according to claim 1, wherein the electrostatic shield film is in contact with the transparent substrate. The electrostatic shield film is made of indium tin oxide and has a thickness of 10 nm to 20 nm.
The liquid crystal device according to claim 1, wherein the liquid crystal device is as follows. The liquid crystal device according to claim 4, wherein the low refractive index film is made of silicon oxide and has a thickness of 14 nm to 26 nm. The liquid crystal device according to claim 4, wherein the low refractive index film is made of magnesium fluoride and has a thickness of 15 nm to 34 nm.

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