JP2007052050A - Liquid crystal device, method for manufacturing liquid crystal device, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal device and a method for manufacturing the device preventing degradation of the quality due to moisture absorption, and to provide an electronic apparatus using the device. <P>SOLUTION: The liquid crystal device comprises a liquid crystal held between a pair of substrates 10, 20 opposing to each other. An inorganic alignment layer 16 (22) is provided on the inner face of each substrate 10, 20, and the inorganic alignment layer 16 (22) is subjected to a treatment to impart water repellency with a plurality of water-repellent organic materials having different molecular weights. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal device, a method for manufacturing a liquid crystal device, and an electronic apparatus.

  2. Description of the Related Art A liquid crystal device used as a light modulation unit of a projection display device such as a liquid crystal projector has a configuration in which a sealing material is disposed at a peripheral portion between a pair of substrates, and liquid crystal is sealed at a central portion thereof. Electrodes for applying a voltage to the liquid crystal are formed on the inner surfaces of the pair of substrates, and an alignment film for controlling the alignment of liquid crystal molecules when a non-selective voltage is applied is formed on the inner surfaces of these electrodes. With such a configuration, the liquid crystal device modulates light source light based on a change in orientation of liquid crystal molecules between application of a non-selection voltage and application of a selection voltage, thereby producing image light.

  By the way, as the alignment film described above, a film obtained by rubbing the surface of a polymer film made of polyimide or the like to which a side chain alkyl group is added is generally used. The rubbing treatment is to orient the polymer in a predetermined direction by rubbing the surface of the polymer film in a predetermined direction with a roller made of a soft cloth. Due to the intermolecular interaction between the alignment polymer and the liquid crystal molecules, the liquid crystal molecules are arranged along the alignment polymer so that the liquid crystal molecules can be aligned in a predetermined direction when a non-selective voltage is applied. It has become. Further, the side chain alkyl group can give a pretilt to the liquid crystal molecules.

  However, when a liquid crystal device including such an organic alignment film is employed as a light modulation unit of a projector, the alignment film may be gradually decomposed by strong light or heat emitted from a light source. Then, after a long period of use, there is a risk that the liquid crystal molecule alignment control function will be degraded, such as the liquid crystal molecules being unable to align at the desired pretilt angle, and the display quality of the liquid crystal projector will be degraded.

Therefore, the use of an alignment film made of an inorganic material having excellent light resistance and heat resistance has been proposed. As a method for producing such an inorganic alignment film, for example, a silicon oxide (SiO ₂ ) film formed by oblique deposition is used. Film formation is known.
By the way, in general, in a liquid crystal device, moisture absorption and moisture permeation cause deterioration in quality. Therefore, it is conceivable that the surface of the alignment film is subjected to water repellent treatment to improve moisture resistance (see, for example, Patent Document 1). .
JP 2002-202509 A

  However, the inorganic alignment film formed by the oblique deposition method or the like has a structure in which many small gaps are formed in the surface layer portion thereof, and particularly when the water repellent treatment is performed with a water repellent treatment agent having a large molecular weight, This water repellent agent cannot penetrate into the small gaps or cannot be covered well, so that the effect of improving the moisture resistance of the alignment film cannot be obtained sufficiently.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal device that prevents deterioration in quality due to moisture absorption, a manufacturing method thereof, and an electronic device using the same. .

The liquid crystal device of the present invention is a liquid crystal device in which liquid crystal is sandwiched between a pair of substrates facing each other,
An inorganic alignment film is provided on each inner surface of the pair of substrates;
The inorganic alignment film is water repellent treated with a plurality of water repellent organic materials having different molecular weights.

  According to this liquid crystal device, since the inorganic alignment film is subjected to water repellency treatment with a plurality of water repellent organic materials having different molecular weights, the surface of the inorganic alignment film is mainly made water repellent with a large molecular weight water repellent organic material. The water repellent organic material having a small molecular weight mainly makes the inside of the gap between the surface layers of the inorganic alignment film water repellent. Therefore, almost all of the surface layer portion of the inorganic alignment film is made water-repellent, so that the moisture resistance is sufficiently improved, and the deterioration due to moisture absorption is surely prevented.

In the liquid crystal device, it is preferable that the inorganic alignment film is made of silicon oxide, and the plurality of water repellent organic materials are alcohols having different molecular weights.
If it does in this way, alcohol will react with the hydrophilic silanol group (Si-OH) formed in the surface layer part of an inorganic alignment film, and the alkyl group etc. in alcohol will substitute for hydrogen in a silanol group. As a result, the water-repellent alkyl group or the like is arranged on the surface layer portion of the inorganic alignment film, so that the inorganic alignment film exhibits water repellency.

A method for manufacturing a liquid crystal device according to the present invention is a method for manufacturing a liquid crystal device in which liquid crystal is sandwiched between a pair of substrates facing each other.
Forming an inorganic alignment film on each inner surface of the pair of substrates;
And a step of subjecting the inorganic alignment film to a water repellent treatment with a plurality of water repellent organic materials having different molecular weights.

  According to this method of manufacturing a liquid crystal device, the inorganic alignment film is subjected to a water repellency treatment with a plurality of water repellent organic materials having different molecular weights, so that the surface of the inorganic alignment film is mainly water repellent with a large molecular weight water repellent organic material. The water repellent organic material having a small molecular weight can make water repellent mainly in the gaps in the surface of the inorganic alignment film. Therefore, by making the entire surface portion of the inorganic alignment film water repellent, the resulting liquid crystal device is sufficiently improved in moisture resistance, and quality deterioration due to moisture absorption is reliably prevented. Can do.

Moreover, in the manufacturing method of the liquid crystal device, it is preferable that the inorganic alignment film is formed by an oblique deposition method.
In this way, the pre-tilt angle is favorably imparted to the liquid crystal molecules by the inorganic alignment film, and it is not necessary to perform a rubbing treatment or the like on the inorganic alignment film.

In the method for manufacturing a liquid crystal device, it is preferable that the inorganic alignment film is made of silicon oxide, and the plurality of water repellent organic materials are alcohols having different molecular weights.
If it does in this way, alcohol will react with the hydrophilic silanol group (Si-OH) formed in the surface layer part of an inorganic alignment film, and the alkyl group etc. in alcohol will substitute for hydrogen in a silanol group. As a result, the water-repellent alkyl group or the like is arranged on the surface layer portion of the inorganic alignment film, so that the inorganic alignment film exhibits water repellency.

In the liquid crystal device manufacturing method, in the water repellent treatment step, the water repellent treatment is first performed with a water repellent organic material having a large molecular weight, and then the water repellent treatment is performed with a water repellent organic material having a small molecular weight. It is preferable to carry out the treatment.
In this way, the surface of the inorganic alignment film can be made water repellent mainly by the water repellent organic material having a large molecular weight. At that time, because of the large molecular weight, it is difficult to make the water repellent within the gaps of the surface of the inorganic alignment film by this water repellent organic material, but then the water repellent by the water repellent organic material having a small molecular weight. It becomes possible to make the inside of the gap in the surface layer water repellent. Therefore, it becomes possible to make the entire surface layer portion of the inorganic alignment film water repellent satisfactorily.

An electronic apparatus according to the present invention includes the liquid crystal device or the liquid crystal device obtained by the manufacturing method.
According to this electronic apparatus, since the liquid crystal device in which the deterioration due to moisture absorption is reliably prevented is provided, the electronic apparatus itself is also prevented from being deteriorated in quality due to moisture absorption.

  The present invention will be described in detail below. First, an embodiment of a liquid crystal device according to the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a TFT array substrate for explaining a schematic configuration of a liquid crystal device 60 according to an embodiment of the present invention, FIG. 2 is an equivalent circuit diagram of the liquid crystal device 60, and FIG. FIG. 4 is an explanatory view of a planar structure, and FIG. 4 is an explanatory view of a cross-sectional structure of the liquid crystal device, and is a cross-sectional view taken along the line AA ′ in FIG.

  As shown in FIG. 4, the liquid crystal device 60 of the present embodiment has a liquid crystal 50 sandwiched between a pair of substrates 10 and 20 facing each other, and the inorganic alignment film 16 and the inner surfaces of the pair of substrates 10 and 20. 22 is provided. In particular, these inorganic alignment films 16 and 22 have been subjected to a water repellent treatment with a plurality of water repellent organic materials having different molecular weights.

  The schematic configuration of the liquid crystal device 60 will be described. As shown in FIG. 1, an image production region 101 is formed in the center of a TFT array substrate (substrate) 10 that is one of a pair of substrates 10 and 20. . A sealing material 19 is disposed on the peripheral edge of the image production region 101, and thereby the liquid crystal 50 (see FIG. 4) is sealed in the image production region 101. The liquid crystal 50 is formed by directly applying liquid crystal on the TFT array substrate 10, and has a so-called sealing-less structure in which the sealing material 19 is not provided with a liquid crystal inlet. A scanning line driving element 110 that supplies a scanning signal to a scanning line, which will be described later, and a data line driving element 120, which supplies an image signal to a data line, which will be described later, are mounted outside the sealing material 19. A wiring 76 is routed from the driving elements 110 and 120 to the connection terminal 79 at the end of the TFT array substrate 10.

On the other hand, a common electrode 21 (see FIG. 4) is formed on the counter substrate 20 (see FIG. 4) bonded to the TFT array substrate 10. The common electrode 21 is formed over almost the entire image forming region 101, and inter-substrate conducting portions 70 are provided at the four corners. A wiring 78 is routed from the inter-substrate conduction portion 70 to the connection terminal 79.
Then, various signals input from the outside are supplied to the image production region 101 via the connection terminals 79, so that the liquid crystal device is driven.

  In the image production area 101 of the liquid crystal device, as shown in the equivalent circuit diagram of FIG. 2, a plurality of dots are arranged in a matrix to constitute this, and each of these dots has a pixel electrode 9. Is formed. Further, on the side of the pixel electrode 9, a TFT element 30 which is a switching element for performing energization control to the pixel electrode 9 is formed. A data line 6 a is connected to the source of the TFT element 30. Image signals S1, S2,..., Sn are supplied to the data lines 6a from the data line driving elements described above.

  A scanning line 3 a is connected to the gate of the TFT element 30. Scanning signals G1, G2,..., Gm are supplied to the scanning line 3a in a pulsed manner from the scanning line driving element described above at a predetermined timing. On the other hand, the pixel electrode 9 is connected to the drain of the TFT element 30. When the TFT elements 30 serving as switching elements are turned on for a certain period by the scanning signals G1, G2,..., Gm supplied from the scanning line 3a, the image signals S1, S2,. Sn is written to the liquid crystal of each dot via the pixel electrode 9 at a predetermined timing.

  The predetermined level image signals S1, S2,..., Sn written in the liquid crystal are held for a certain period by a liquid crystal capacitor formed between the pixel electrode 9 and a common electrode described later. In order to prevent leakage of the held image signals S1, S2,..., Sn, a storage capacitor 17 is formed between the pixel electrode 9 and the capacitor line 3b, and is arranged in parallel with the liquid crystal capacitor. . Thus, when a voltage signal is applied to the liquid crystal, the alignment state of the liquid crystal molecules changes depending on the applied voltage level. Thereby, the light source light incident on the liquid crystal is modulated to produce image light.

  In the liquid crystal device of this embodiment, as shown in the plan view of FIG. 3, a rectangular array made of a transparent conductive material such as indium tin oxide (hereinafter referred to as ITO) is formed on the TFT array substrate. Shaped pixel electrodes 9 (the outlines of which are indicated by broken lines 9a) are arranged in a matrix. Further, data lines 6 a, scanning lines 3 a, and capacitor lines 3 b are provided along the vertical and horizontal boundaries of the pixel electrode 9. In the present embodiment, the rectangular area in which each pixel electrode 9 is formed is a dot, and the display can be performed for each dot arranged in a matrix.

  The TFT element 30 is formed around a semiconductor layer 1a made of a polysilicon film or the like. A data line 6 a is connected to a source region (described later) of the semiconductor layer 1 a through a contact hole 5. Further, a pixel electrode 9 is connected to a drain region (described later) of the semiconductor layer 1 a through a contact hole 8. On the other hand, a channel region 1a 'is formed in a portion of the semiconductor layer 1a facing the scanning line 3a.

  Further, as shown in the cross-sectional structure explanatory diagram of FIG. 4, this liquid crystal device is mainly composed of a TFT array substrate 10, a counter substrate 20 disposed opposite thereto, and a liquid crystal 50 sandwiched therebetween. Has been. The TFT array substrate 10 is mainly composed of a substrate body 10A made of a translucent material such as glass or quartz, a TFT element 30, a pixel electrode 9, an alignment film 16 and the like formed inside thereof. One counter substrate 20 is mainly composed of a substrate body 20A made of a light-transmitting material such as glass or quartz, and a common electrode 21 and an alignment film 22 formed inside thereof.

  A first light shielding film 11 a and a first interlayer insulating film 12 are formed on the surface of the TFT array substrate 10. A semiconductor layer 1a is formed on the surface of the first interlayer insulating film 12, and a TFT element 30 is formed around the semiconductor layer 1a. A channel region 1a 'is formed in a portion of the semiconductor layer 1a facing the scanning line 3a, and a source region and a drain region are formed on both sides thereof. Since the TFT element 30 employs an LDD (Lightly Doped Drain) structure, a high concentration region having a relatively high impurity concentration and a low concentration region (LDD region) having a relatively low impurity concentration in the source region and the drain region, respectively. And are formed. That is, a low concentration source region 1b and a high concentration source region 1d are formed in the source region, and a low concentration drain region 1c and a high concentration drain region 1e are formed in the drain region.

  A gate insulating film 2 is formed on the surface of the semiconductor layer 1a. A scanning line 3a is formed on the surface of the gate insulating film 2, and a portion facing the channel region 1a 'constitutes a gate electrode. A second interlayer insulating film 4 is formed on the surfaces of the gate insulating film 2 and the scanning line 3a. A data line 6a is formed on the surface of the second interlayer insulating film 4, and the data line 6a is connected to the high-concentration source region 1d through a contact hole 5 formed in the second interlayer insulating film 4. . Further, a third interlayer insulating film 7 is formed on the surfaces of the second interlayer insulating film 4 and the data line 6a. A pixel electrode 9 is formed on the surface of the third interlayer insulating film 7, and the pixel electrode 9 is a high-concentration drain through a contact hole 8 formed in the second interlayer insulating film 4 and the third interlayer insulating film 7. It is connected to the area 1e. Further, an inorganic alignment film 16 is formed so as to cover the pixel electrode 9, and the alignment of liquid crystal molecules when a non-selection voltage is applied is regulated.

In the present embodiment, the first storage capacitor electrode 1f is formed by extending the semiconductor layer 1a. Further, the gate insulating film 2 is extended to form a dielectric film, and the capacitor line 3b is disposed on the surface thereof to form a second storage capacitor electrode. Thus, the above-described storage capacitor 17 is configured.
A first light shielding film 11 a is formed on the surface of the substrate body 10 </ b> A corresponding to the formation region of the TFT element 30. The first light shielding film 11a prevents light incident on the liquid crystal device from entering the channel region 1a ′, the low concentration source region 1b, and the low concentration drain region 1c of the semiconductor layer 1a.

  On the other hand, a second light shielding film 23 is formed on the surface of the substrate body 20A in the counter substrate 20. The second light shielding film 23 prevents light incident on the liquid crystal device from entering the channel region 1a ′, the low concentration source region 1b, the low concentration drain region 1c, and the like of the semiconductor layer 1a. It is provided in a region overlapping with the layer 1a. A common electrode 21 made of a conductor such as ITO is formed on the surface of the counter substrate 20 over substantially the entire surface. Furthermore, an inorganic alignment film 22 is formed on the surface of the common electrode 21 so that the alignment of liquid crystal molecules when a non-selection voltage is applied is regulated.

  Here, both the inorganic alignment film 16 on the TFT array substrate 10 side and the inorganic alignment film 22 on the counter substrate 20 side are characteristic components of the present invention. That is, in the present invention, the inorganic alignment films 16 and 22 are subjected to a water repellent treatment with a plurality of water repellent organic materials having different molecular weights as described above.

These inorganic alignment films 16 and 22 are made of a silicon oxide such as SiO ₂ or SiO, or a metal oxide such as Al ₂ O ₃ , ZnO, MgO or ITO, and the like in a thickness of 0.02 to 0.3 μm (preferably , 0.02 to 0.08 μm). In addition, for the production of the inorganic alignment films 16 and 22, a sputtering method such as an ion beam sputtering method or a magnetron sputtering method, a vapor deposition method, a sol-gel method, or a self-organization method can be employed. In the present embodiment, the inorganic alignment films 16 and 22 are both made of silicon oxide mainly composed of SiO ₂ and formed by a conventionally known oblique deposition method.

  FIG. 5A illustrates a vapor deposition apparatus 503 as an example of a film formation apparatus that performs film formation by oblique vapor deposition. The vapor deposition apparatus 503 includes a vapor deposition source 512 that generates a vapor flow of the inorganic alignment film material, the TFT array substrate 10 before forming the inorganic alignment film, or the counter 20 (hereinafter simply referred to as the substrate 10) before forming the inorganic alignment film. And a holding mechanism 514 for holding (denoted (20)). In this vapor deposition apparatus 503, the substrate 10 (20) has a reference line X 1 connecting the vapor deposition source 512 and the position of the center of gravity of the substrate surface of the substrate 10 (20), and a straight line X 2 perpendicular to the film formation surface of the substrate 10 (20). Is held by the holding mechanism 514 so that the angle θ0 formed by Therefore, an alignment film is formed on the substrate 10 (20) and the traveling direction of the inorganic material generated by the vapor deposition source 512, that is, the direction in which the inorganic material flies, as indicated by the arrow Y1 in FIGS. The angle θ1 formed with the substrate surface (deposition surface) to be adjusted can be adjusted by changing the angle θ0. The angle θ1 is set to a predetermined value for arranging columnar structures to be described later on the substrate surface so as to obtain a surface shape effect for performing alignment control in the alignment film 16 (22). . However, in this embodiment, since oblique deposition is performed, the angle θ1 is less than 90 °.

  When oblique vapor deposition is performed by such a vapor deposition apparatus, as shown by an arrow in FIG. 5B, the alignment film material sublimated from the vapor deposition source 512 has a substantially constant incident angle (inclination) with respect to the substrate 10 (20). Angle). Then, as shown in FIG. 6A, the alignment film material is deposited in an oblique column shape on the substrate 10 (20), thereby forming a columnar structure 16a (22a) of an inorganic material (silicon oxide). The columnar structures 16a (22a) are formed innumerably on the surface of the substrate 10 (20), whereby the inorganic alignment film 16 (22) is formed. Thus, when the columnar structure 16a (22a) is formed at a predetermined inclination angle, and thereby the inorganic alignment film 16 (22) is formed, in the liquid crystal device 60, the liquid crystal along the columnar structure 16a (22a) is formed. By aligning the molecules, a pretilt angle is imparted to the liquid crystal molecules. That is, as described above, the alignment of liquid crystal molecules is regulated in a predetermined direction by the inorganic alignment films 16 and 22 when a non-selection voltage is applied.

In addition, as described above, the inorganic alignment films 16 and 22 formed by such an oblique vapor deposition method are subjected to water repellent treatment with a plurality of water repellent organic materials having different molecular weights. The number (type) of the water-repellent organic material to be used may be 3 or more, but considering the effect obtained by the treatment, it is sufficient to use two types of organic materials having different molecular weights. The water-repellent organic material to be used is not particularly limited, but various organic solvents having water repellency, for example, organic solvents having an alkyl group or a benzene ring are preferably used, and plural kinds (two kinds) of organic solvents are used. As materials, materials having high affinity with each other, for example, materials having the same functional group are used. In particular, in the present embodiment in which the inorganic alignment films 16 and 22 are made of silicon oxide mainly composed of SiO ₂ , it is preferable that all of the plurality of water repellent organic materials be alcohol.

When two types of alcohol are used as the water-repellent organic material, particularly those having an alkyl group having a relatively high carbon number that exhibits water repellency and those having a smaller carbon number and therefore a smaller molecular weight are used. Is preferred. For example, it is preferable to perform a water repellency treatment using octyl alcohol having 8 carbon atoms (octanol; C ₈ H ₁₇ OH) and isopropyl alcohol having 3 carbon atoms (isopropanol; (CH ₃ ) ₂ CHOH).
In addition, when water repellent treatment is performed using two types of water repellent organic materials having different molecular weights, the water repellent treatment is performed first with a water repellent organic material having a large molecular weight, and then a water repellent treatment with a small molecular weight is performed. It is preferable to perform a water repellent treatment with an aqueous organic material.

  That is, first, as the water repellent organic material having a large molecular weight, the inorganic alignment film 16 (22) made of silicon oxide is subjected to a water repellent treatment using, for example, octyl alcohol. The water repellent treatment is not particularly limited, but a gas phase treatment is preferably employed. In the gas phase treatment, for example, the substrate 10 (20) on which the inorganic alignment film 16 (22) is formed and the octyl alcohol in the container are placed in a sealed container, and the vapor of octyl alcohol is supplied to the inorganic alignment film. 16 (22) for a predetermined time. At that time, heating may be performed as necessary to increase the concentration of octanol vapor in the sealed container.

When the octyl alcohol vapor is brought into contact with the inorganic alignment film 16 (22) in this way, the hydrophilic silanol group (Si—OH) formed on the surface layer portion of the inorganic alignment film 16 (22) made of silicon oxide is formed. The octyl alcohol reacts to replace the octyl group (C ₈ H ₁₇ —) in the octyl alcohol with the hydrogen in the silanol group to give (Si—OC ₈ H ₁₇ ). As a result, as shown in FIG. 6B, a large number of water-repellent octyl groups (alkyl groups) A are arranged on the surface layer portion of the inorganic alignment film 16 (22), so that the inorganic alignment film 16 (22) is repellent. It becomes water-based. However, since the octyl group A has a relatively large molecular weight and is also sterically large, the water-repellent organic material (octyl alcohol) having a large molecular weight causes a gap in the surface layer portion of the inorganic alignment film 16 (22), That is, it is difficult to make the water repellent even in the gap formed between the columnar structures 16a (22a).

  Therefore, in the present invention, the inorganic alignment film 16 (22) is again subjected to water repellency treatment using a material having a molecular weight different from that of the water-repellent organic material, particularly a water-repellent organic material having a small molecular weight. That is, for example, isopropyl alcohol is used as a water repellent organic material having a small molecular weight, and the inorganic alignment film 16 (22) in which a large number of octyl groups A are arranged is subjected to a water repellent treatment again. As this water repellency treatment, the treatment in the gas phase as described above can be adopted, and the treatment in the liquid phase can also be adopted. In the liquid phase treatment, the substrate 10 (20) is immersed in liquid isopropyl alcohol, and the surface layer portion of the inorganic alignment film 16 (22) is brought into contact with liquid isopropyl alcohol. In this state, ultrasonic waves are applied to the substrate 10 (20) and isopropyl alcohol, or the inside of the processing chamber is decompressed.

By performing ultrasonic treatment and pressure reduction treatment in this manner, isopropyl alcohol enters the gap in the surface layer portion of the inorganic alignment film 16 (22) more favorably and reacts with silanol groups (Si—OH) in the gap. Then, the isopropyl group ((CH ₃ ) ₂ CH—) in isopropyl alcohol is replaced with hydrogen in the silanol group to form (Si—O (CH ₃ ) ₂ CH). As a result, as shown in FIG. 6C, a large number of water-repellent isopropyl groups (alkyl groups) B are mainly arranged in the gaps of the surface of the inorganic alignment film 16 (22), whereby the inorganic alignment film 16 (22) comes to exhibit stronger water repellency.

Therefore, the inorganic alignment film 16 (22) subjected to the water repellent treatment in this way has the surface layer portion made water repellent by the octyl group A and the inorganic alignment film 16 (22 by the isopropyl group B). ) Since the water-repellent property is formed even in the gap of the surface layer portion, the moisture resistance of the entire film is further improved.
That is, in the inorganic alignment film 16 (22) in the state shown in FIG. 6A before the water repellent treatment is performed, the presence of the hydrophilic silanol group causes the two in FIG. Water (humidity) is likely to exist in the region W indicated by the dotted line. Therefore, when the substrates 10 and 20 are assembled without performing the water repellency treatment on the inorganic alignment films 16 and 22 and the liquid crystal device is formed, when the water or moisture enters from the outside, the inorganic alignment films 16 and 22 are formed. , 22 enters the surface layer portion and comes into direct contact with the liquid crystal, thereby deteriorating the liquid crystal and degrading its characteristics.

  Further, water repellent treatment is performed with a water-repellent organic material having a large molecular weight, and mainly the surface layer portion of the inorganic alignment film 16 (22) is made water repellent, so that water (moisture) is formed in the surface layer portions of the inorganic alignment films 16 and 22. ) Can easily be narrowed to a region where the octyl group A is not arranged, as indicated by a two-dot chain line in FIG. 6B. However, even in this case, since the octyl group A is not arranged especially in the gap of the inorganic alignment film 16 (22), the region W in which water (humidity) still exists remains relatively wide. Therefore, when the substrates 10 and 20 are assembled in this state and the liquid crystal device is formed, when water or moisture enters from the outside, it also enters the surface layers of the inorganic alignment films 16 and 22 and directly contacts the liquid crystal. There is a risk of deteriorating the properties of the liquid crystal.

Therefore, the water repellent treatment is again performed with a water repellent organic material having a small molecular weight, and the surface layer portion of the inorganic alignment films 16 and 22 is mainly made water repellent in the gap portion of the surface layer portion of the inorganic alignment film 16 (22). The region W where water (humidity) tends to exist can be further narrowed to a region where the isopropyl group B is not arranged as shown by a two-dot chain line in FIG.
After the water repellent treatment is performed a plurality of times with the water repellent organic materials having different molecular weights, the substrates 10 and 20 are assembled to form the liquid crystal device of the present invention. Even if moisture or moisture tries to enter, it is difficult for the water to enter the surface layer portions of the inorganic alignment films 16 and 22 that have been made water-repellent. As a result, water and moisture hardly enter the surface layer portions of the inorganic alignment films 16 and 22. Become.

  As shown in FIG. 4, in the liquid crystal device 60 of the present embodiment, between the TFT array substrate 10 having the inorganic alignment film 16 (22) subjected to the water repellent treatment as described above and the counter substrate 20, A liquid crystal 50 made of nematic liquid crystal or the like is sandwiched and sealed with a sealing material 19 (see FIG. 1). Nematic liquid crystal molecules have a positive dielectric anisotropy, and are horizontally aligned along the substrate when a non-selection voltage is applied, and vertically aligned along the electric field direction when a selection voltage is applied. The nematic liquid crystal molecules have positive refractive index anisotropy, and the product (retardation) Δnd of the birefringence and the liquid crystal thickness is, for example, about 0.40 μm (60 ° C.). Note that the alignment regulation direction by the alignment film 16 of the TFT array substrate 10 and the alignment regulation direction by the alignment film 22 of the counter substrate 20 are set to be twisted by about 90 °. Thereby, the liquid crystal device 60 of the present embodiment operates in the twisted nematic mode.

  In addition, polarizing plates 18 and 28 made of a material obtained by doping polyvinyl alcohol (PVA) with iodine or the like are disposed outside the substrates 10 and 20. The polarizing plates 18 and 28 are preferably mounted on a support substrate made of a high thermal conductivity material such as sapphire glass or quartz, and are separated from the liquid crystal device 60. Each of the polarizing plates 18 and 28 has a function of absorbing linearly polarized light in the absorption axis direction and transmitting linearly polarized light in the transmission axis direction. The polarizing plate 18 on the TFT array substrate 10 side is arranged so that its transmission axis substantially coincides with the alignment regulating direction of the alignment film 16. The polarizing plate 28 on the counter substrate 20 side has its transmission axis aligned with the alignment film 22. It arrange | positions so that it may correspond with a regulation direction substantially.

The liquid crystal device 60 is disposed with the counter substrate 20 facing the light source. Of the light source light, only linearly polarized light that matches the transmission axis of the polarizing plate 28 passes through the polarizing plate 28 and enters the liquid crystal device 60.
In the liquid crystal device 60 when the non-selection voltage is applied, the liquid crystal molecules horizontally aligned with respect to the substrate are arranged in a spiral manner by twisting about 90 ° in the thickness direction of the liquid crystal 50. Therefore, the linearly polarized light incident on the liquid crystal device 60 is rotated about 90 ° and emitted from the liquid crystal device 60. Since this linearly polarized light coincides with the transmission axis of the polarizing plate 18, it passes through the polarizing plate 18. Accordingly, white display is performed in the liquid crystal device 60 when the non-selection voltage is applied (normally white mode).

  Further, in the liquid crystal device 60 when the selection voltage is applied, the liquid crystal molecules are vertically aligned with respect to the substrate. Therefore, the linearly polarized light incident on the liquid crystal device 60 is emitted from the liquid crystal device 60 without being rotated. Since this linearly polarized light is orthogonal to the transmission axis of the polarizing plate 18, it does not pass through the polarizing plate 18. Accordingly, black display is performed in the liquid crystal device 60 when the selection voltage is applied.

  In the liquid crystal device 60 having such a configuration, the inorganic alignment films 16 and 22 are subjected to water repellency treatment a plurality of times (twice) with water repellent organic materials having different molecular weights. Even if water or moisture tries to enter, it becomes difficult for the water or moisture to enter the surface layer portions of the inorganic alignment films 16 and 22 that have been made water-repellent, so that water and moisture hardly enter the surface layer portions of the inorganic alignment films 16 and 22. . Therefore, the moisture resistance is sufficiently improved, and quality deterioration due to moisture absorption is surely prevented.

Also in such a method of manufacturing the liquid crystal device 60, the inorganic alignment films 16 and 22 are subjected to water repellency treatment using a plurality of water repellent organic materials having different molecular weights. In addition, the surface of the inorganic alignment film can be made water-repellent, and the inside of the surface of the inorganic alignment film can be made water-repellent mainly by a water-repellent organic material having a small molecular weight. Therefore, by making the entire surface layer portion of the inorganic alignment films 16 and 22 water-repellent, the obtained liquid crystal device 60 is sufficiently improved in moisture resistance as described above, and quality deterioration due to moisture absorption is surely achieved. Can be prevented.
Further, since the water repellent treatment is performed with the water repellent organic material in this way, for example, organic components as impurities are attached to the inorganic alignment films 16 and 22 before the water repellent treatment by a cleaning treatment or the like as a pretreatment. However, the organic component can be removed and cleaned by this water repellent treatment.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, although octyl alcohol and isopropyl alcohol are used as the water-repellent organic material in the above embodiment, other alcohols may be used, and water-repellent organic materials other than alcohol may be used.
In addition, in the water repellent treatment, the treatment was first performed with the water repellent organic material having a large molecular weight, and then the treatment was performed with the water repellent organic material having a small molecular weight. May be performed.
Further, the water repellent treatment with a water-repellent organic material having a large molecular weight is performed by the vapor phase method, but it is needless to say that the treatment may be performed by the liquid phase method. However, as the molecular weight increases, the boiling point thereof becomes higher and the vapor pressure becomes lower. Therefore, it is necessary to sufficiently dry compared with the case of processing by a gas phase method.

(projector)
Next, a projector as an embodiment of the electronic apparatus of the invention will be described with reference to FIG. FIG. 7 is a schematic configuration diagram showing a main part of the projector. This projector includes the liquid crystal device according to the above-described embodiment as light modulation means.

  7, 810 is a light source, 813 and 814 are dichroic mirrors, 815, 816 and 817 are reflection mirrors, 818 is an entrance lens, 819 is a relay lens, 820 is an exit lens, and 822, 823 and 824 are liquid crystal devices of the present invention. 825 is a cross dichroic prism, and 826 is a projection lens. The light source 810 includes a lamp 811 such as a metal halide and a reflector 812 that reflects the light of the lamp.

  The dichroic mirror 813 transmits red light contained in white light from the light source 810 and reflects blue light and green light. The transmitted red light is reflected by the reflection mirror 817 and is incident on the light modulation means 822 for red light. The green light reflected by the dichroic mirror 813 is reflected by the dichroic mirror 814 and is incident on the light modulating means 823 for green light. Further, the blue light reflected by the dichroic mirror 813 passes through the dichroic mirror 814. For blue light, in order to prevent light loss due to a long optical path, a light guide means 821 including a relay lens system including an incident lens 818, a relay lens 819, and an exit lens 820 is provided. Blue light is incident on the light modulating means 824 for blue light through the light guiding means 821.

  The three color lights modulated by the respective light modulation means 822, 823, and 824 are incident on the cross dichroic prism 825. The cross dichroic prism 825 is formed by bonding four right-angle prisms. A dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in an X shape at the interface. Yes. These dielectric multilayer films combine the three color lights to form light representing a color image. The synthesized light is projected onto the screen 827 by the projection lens 826 which is a projection optical system, and the image is enlarged and displayed.

  The projector having such a configuration includes the liquid crystal device as a light modulation unit. Since the liquid crystal device includes the inorganic alignment film having excellent light resistance and heat resistance as described above, the alignment film is not deteriorated by strong light or heat irradiated from the light source. In addition, since the projector includes the liquid crystal device in which quality deterioration due to moisture absorption is reliably prevented, the electronic device itself is also prevented from being deteriorated in quality due to moisture absorption.

  It should be noted that the technical scope of the present invention is not limited to the above-described embodiment, and includes those in which various modifications are made to the above-described embodiment without departing from the gist of the present invention. For example, in the above embodiment, a liquid crystal device including a TFT as a switching element has been described as an example. However, the present invention is applied to a liquid crystal device including a two-terminal element such as a thin film diode as a switching element. It is also possible. In the above embodiment, the transmissive liquid crystal device has been described as an example. However, the present invention can also be applied to a reflective liquid crystal device. In the above embodiment, the liquid crystal device functioning in the TN (Twisted Nematic) mode has been described as an example. However, the present invention can be applied to a liquid crystal device functioning in the VA (Vertical Alignment) mode. Further, in the embodiment, the description has been given by taking a three-plate projection display device (projector) as an example, but the present invention can also be applied to a single-plate projection display device or a direct-view display device.

  The liquid crystal device of the present invention can also be applied to electronic devices other than projectors. A specific example is a mobile phone. This mobile phone includes the liquid crystal device according to each of the above-described embodiments or modifications thereof in a display unit. Other electronic devices include, for example, IC cards, video cameras, personal computers, head-mounted displays, fax machines with display functions, digital camera finders, portable TVs, DSP devices, PDAs, electronic notebooks, and electronic bulletin boards. And advertising announcement displays.

It is a top view of the TFT array substrate of a liquid crystal device. It is an equivalent circuit diagram of a liquid crystal device. It is explanatory drawing of the planar structure of a liquid crystal device. It is explanatory drawing of the cross-section of a liquid crystal device. (A) is a schematic diagram of a vapor deposition apparatus, (b) is explanatory drawing of oblique vapor deposition. (A)-(c) is explanatory drawing of the water-repellent process to an inorganic alignment film. It is a schematic block diagram which shows the principal part of a projector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Substrate (TFT array substrate), 16 ... Inorganic alignment film, 20 ... Substrate (counter substrate), 22 ... Inorganic alignment film, 50 ... Liquid crystal, 60 ... Liquid crystal device, A ... Octyl group, B ... Isopropyl group

Claims (7)

A liquid crystal device having a liquid crystal sandwiched between a pair of substrates facing each other,
An inorganic alignment film is provided on each inner surface of the pair of substrates;
The liquid crystal device, wherein the inorganic alignment film is subjected to a water repellent treatment with a plurality of water repellent organic materials having different molecular weights.   The liquid crystal device according to claim 1, wherein the inorganic alignment film is made of silicon oxide, and the plurality of water repellent organic materials are alcohols having different molecular weights. A method of manufacturing a liquid crystal device in which a liquid crystal is sandwiched between a pair of substrates facing each other,
Forming an inorganic alignment film on each inner surface of the pair of substrates;
And a step of subjecting the inorganic alignment film to a water repellent treatment with a plurality of water repellent organic materials having different molecular weights.   4. The method of manufacturing a liquid crystal device according to claim 3, wherein the inorganic alignment film is formed by an oblique deposition method.   5. The liquid crystal device according to claim 3, wherein the inorganic alignment film is made of silicon oxide, and the plurality of water repellent organic materials are alcohols having different molecular weights.   4. The water repellent treatment is performed by first performing a water repellent treatment with a water repellent organic material having a large molecular weight, and then performing a water repellent treatment with a water repellent organic material having a low molecular weight. The liquid crystal device according to claim 1. An electronic apparatus comprising the liquid crystal device according to claim 1 or 2, or the liquid crystal device obtained by the manufacturing method according to any one of claims 3 to 6.

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