CN110418998B

CN110418998B - Liquid crystal display device, method of manufacturing liquid crystal display device, and projection display apparatus

Info

Publication number: CN110418998B
Application number: CN201880017379.3A
Authority: CN
Inventors: 八木宽雄
Original assignee: Sony Corp
Current assignee: Sony Corp
Priority date: 2017-03-17
Filing date: 2018-02-02
Publication date: 2022-06-28
Anticipated expiration: 2038-02-02
Also published as: WO2018168245A1; CN110418998A

Abstract

A liquid crystal display device according to one embodiment of the present disclosure is provided with: a pair of substrates arranged to face each other; a liquid crystal layer disposed between the pair of substrates; an inorganic oxide layer disposed between the liquid crystal layer and at least one of the pair of substrates; a silane coupling layer disposed between the liquid crystal layer and the inorganic oxide layer; and a metal oxide layer disposed between the inorganic oxide layer and the silane coupling layer.

Description

Liquid crystal display device, method of manufacturing liquid crystal display device, and projection display apparatus

Technical Field

The present disclosure relates to a liquid crystal display device used for, for example, a projection liquid crystal projector, a method of manufacturing the liquid crystal display device, and a projection display apparatus including the liquid crystal display device.

Background

Liquid crystal devices used for projection liquid crystal projectors require high reliability. In order to improve the reliability of the liquid crystal device, it is effective to improve light resistance by using an alignment film including an inorganic material (inorganic alignment film). However, for example, silicon oxide included in the inorganic alignment film has strong hygroscopicity, and the wet inorganic alignment film causes a leakage current among pixels.

To solve this problem, for example, patent document 1 discloses a liquid crystal cell including an inorganic alignment film subjected to a surface treatment using a silane coupling material.

Documents of the prior art

Patent document

Patent document 1: japanese unexamined patent application publication No. 2010-170036

Disclosure of Invention

Incidentally, from the viewpoint of reliability, it is required to improve the moisture resistance of a liquid crystal device (liquid crystal display device).

It is desirable to provide a liquid crystal display device, a method of manufacturing the liquid crystal display device, and a projection display apparatus that enable improvement of moisture resistance.

The liquid crystal display device according to an embodiment of the present disclosure includes: a pair of substrates facing each other; a liquid crystal layer interposed between the pair of substrates; an inorganic oxide layer interposed between the liquid crystal layer and at least one of the pair of substrates; a silane coupling layer interposed between the liquid crystal layer and the inorganic oxide layer; and a metal oxide layer interposed between the inorganic oxide layer and the silane coupling layer.

The method of manufacturing a liquid crystal display device according to an embodiment of the present disclosure includes: forming an inorganic oxide layer on at least one substrate of the pair of substrates; forming a metal oxide layer on the inorganic oxide layer; forming a silane coupling layer on the metal oxide layer; disposing one substrate and the other substrate to be opposed to each other with a gap therebetween; and a liquid crystal layer is formed in the gap.

The projection display device according to an embodiment of the present disclosure includes: a light source; the liquid crystal display device according to an embodiment includes a pixel region modulating light from a light source and emitting light corresponding to a picture; and a projection lens projecting a picture based on the light output from the liquid crystal display device.

In the liquid crystal display device according to the embodiment of the present disclosure, the method of manufacturing the liquid crystal display device according to the embodiment of the present disclosure, and the projection display apparatus according to the embodiment of the present disclosure, the metal oxide layer is disposed on the inorganic oxide layer, the inorganic oxide layer is disposed on at least one substrate of a pair of substrates opposite to each other with the liquid crystal layer interposed therebetween, and then the silane coupling layer is disposed on the metal oxide layer. This enables a stronger bond to be formed between the inorganic oxide layer and the silane coupling layer than if the silane coupling layer were provided directly on the surface of the inorganic oxide layer.

According to the liquid crystal display device of the embodiments of the present disclosure, the method of manufacturing the liquid crystal display device of the embodiments of the present disclosure, and the projection display apparatus of the embodiments of the present disclosure, the silane coupling layer is provided on the inorganic oxide layer through the metal oxide layer, the inorganic oxide layer is provided on at least one of the pair of substrates opposed to each other with the liquid crystal layer interposed therebetween. This enables the formation of a strong bond between the inorganic oxide layer and the silane coupling layer. Accordingly, a liquid crystal display device having improved moisture resistance and a projection display apparatus including the liquid crystal display device can be provided.

It should be noted that the above-described effects are not necessarily restrictive, and may include any of the effects described in the present disclosure.

Drawings

Fig. 1 is a schematic cross-sectional view of a configuration of a liquid crystal display device according to an embodiment of the present disclosure.

Fig. 2 is a flowchart showing a sequence of steps in the method of manufacturing the liquid crystal display device shown in fig. 1.

Fig. 3A is a schematic cross-sectional view describing a method of manufacturing a liquid crystal display device according to the present disclosure.

Fig. 3B is a schematic cross-sectional view of a step subsequent to fig. 3A.

Fig. 3C is a schematic cross-sectional view of a step subsequent to fig. 3B.

Fig. 3D is a schematic cross-sectional view of a step subsequent to fig. 3C.

Fig. 4 is an explanatory diagram of a stacked structure of the alignment film, the metal oxide layer, and the silane coupling layer shown in fig. 1.

Fig. 5 is a schematic cross-sectional view of the configuration of a liquid crystal display device according to a modification of the present disclosure.

Fig. 6 shows an example of the overall configuration of a projection display apparatus including a liquid crystal display device according to the present disclosure.

Fig. 7 shows another example of the overall configuration of a projection display apparatus including a liquid crystal display device according to the present disclosure.

Detailed Description

Hereinafter, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. The following description is merely specific examples of the present disclosure and the present disclosure should not be limited to the following implementations. Further, the present disclosure is not limited to the arrangement, the size, the spatial ratio, and the like of each component illustrated in the drawings. Note that the description is given in the following order.

1. Embodiment mode (example of liquid crystal display device in which a silane coupling layer is provided over an alignment film with a metal oxide layer therebetween)

1-1, arrangement of liquid crystal display device

1-2 method of manufacturing liquid crystal display device

1-3, operation and Effect

2. Modification (example of reflection type liquid crystal display device)

3. Application example

4. Example of operation

<1, embodiment >

(1-1, configuration of liquid Crystal display device)

Fig. 1 schematically shows a cross-sectional configuration of a liquid crystal display device (liquid crystal display device 1) according to an embodiment of the present disclosure. For example, the liquid crystal display device 1 is used as a liquid crystal light valve (e.g., the light modulation device 141R) of a projection display apparatus (projection display apparatus 3, see fig. 6) such as a projector described below. For example, the liquid crystal display device 1 has the following configuration: the pixel circuit substrate 11 and the counter substrate 21 are opposed to each other with the liquid crystal layer 30 therebetween, and the alignment films 12 and 22 (inorganic oxide layers), the metal oxide layers 13 and 23, and the silane coupling layers 14 and 24 are stacked in this order from the respective substrate sides (the pixel circuit substrate 11 and the counter substrate 21) between the pixel circuit substrate 11 and the liquid crystal layer 30 and between the counter substrate 21 and the liquid crystal layer 30.

For example, a pixel circuit layer including a transistor is provided on a surface side of the pixel circuit substrate 11 opposite to the liquid crystal layer 30 of the light-transmitting substrate, and for example, a pixel electrode is provided on the pixel circuit layer for each pixel (neither the pixel circuit layer nor the pixel electrode is shown). A pixel electrode is electrically coupled to the transistor, and an alignment film 12 is disposed on the pixel electrode. Although not shown, for example, a polarizing plate is attached to a surface of the substrate constituting the pixel circuit substrate 11 opposite to the surface opposite to the liquid crystal layer 30. Note that a peripheral circuit for driving the pixels is formed on the periphery of the pixel region of the pixel circuit substrate 11 (peripheral region (not shown)).

For example, although not shown, a counter electrode common to all pixels is provided on the surface side of the counter substrate 21 opposite to the liquid crystal layer 30 of the light-transmitting substrate. The alignment film 22 is provided on the counter electrode. Although not shown, for example, a polarizing plate is bonded to a surface of the substrate constituting the opposite substrate 21 opposite to the surface opposite to the liquid crystal layer 30.

For example, respective substrates constituting the pixel circuit substrate 11 and the counter substrate 21 are respectively configured by a light-transmitting transparent substrate including quartz, glass, or the like. Note that the pixel circuit substrate 11 may not necessarily be a transparent substrate. The pixel circuit substrate 11 may have such a configuration: the pixel circuit and the reflector are provided on a substrate including silicon or the like. For example, the pixel electrode and the counter electrode may include a light-transmitting conductive material. Specific examples of such materials include Indium Tin Oxide (ITO). For example, the polarizing plate includes polyvinyl alcohol (PVA) in which iodine (I) complex molecules are adsorbed and oriented.

For example, the

alignment films

12 and 22 each include an inorganic material such as silicon oxide (SiO)₂) Diamond-like carbon, and aluminum oxide (Al)₂O₃) And (3) a film. For example, the alignment film 12 and the alignment film 22 each preferably have a film thickness in the range of 50 μm to 250 μm.

The metal oxide layer 13 and the metal oxide layer 23 serve to form strong bonds (e.g., covalent bonds) between the alignment film 12 and the silane coupling layer 14 and between the alignment film 22 and the silane coupling layer 24, respectively. Specifically, the metal oxide layer 13 and the metal oxide layer 23 are bonded to hydroxyl groups (-OH) in the surfaces of the

respective alignment films

12 and 22, hydroxyl groups more active than the respective hydroxyl groups in the

alignment films

12 and 22 are generated on the surfaces, the hydroxyl groups are reacted with the silane coupling agent, and bonds are formed between the alignment film 12 and the silane coupling layer 14 and between the alignment film 22 and the silane coupling layer 24 with the respective metal oxide layers 13 and 23 therebetween. The metal oxide layer 13 and the metal oxide layer 23 each include a light-transmitting material. Specific examples of the light-transmitting material include metal oxides such as aluminum oxide (Al)₂O₃) Hafnium oxide (HfO)₂) Zirconium oxide (ZrO)₂) And tantalum oxide (Ta)₂O₅). The metal oxide layer 13 preferably has a film thickness of, for example, 5nm or less. More specifically, the film thickness preferably ranges from one atomic layer to ten atomic layers. One reason is to maintain the roughness of the surfaces of the alignment film 12 and the alignment film 22. For example, such metal oxides The compound layer 13 is preferably formed by an Atomic Layer Deposition (ALD) method. For the alignment film 12, for example, SiO₂Stacked on the pixel circuit substrate 11 in a columnar manner by oblique deposition, and exhibits liquid crystal tilt due to its surface shape, however, the details thereof are described below. The ALD method allows the metal oxide layer 13 to be formed with a very small film thickness, and thus it is easier to maintain the surface shape of the alignment film 12. Therefore, in the case where the orientation control is performed using another method, the metal oxide layer 13 may have a large film thickness. It is to be noted that the film quality of the metal oxide layer 13 and the metal oxide layer 23 is not particularly limited, and may have, for example, defects such as pin holes.

The silane coupling layer 14 and the silane coupling layer 24 serve to improve the moisture resistance of the alignment film 12 and the alignment film 22, respectively. The silane coupling layer 14 and the silane coupling layer 24 each comprise an oriented silane coupling material. Examples of the silane coupling material include compounds represented by the following general formula (1). The silane coupling layer 14 and the silane coupling layer 24 form covalent bonds with the alignment film 12 and the alignment film 22 through the metal oxide layer 13 and the metal oxide layer 23, respectively. The silane coupling layer 14 and the silane coupling layer 24 each include a film of one molecular layer, and for example, function effectively even in the case where the film of one molecular layer does not cover the entire surface of each of the metal oxide layer 13 and the metal oxide layer 23. In contrast, the silane coupling layer 14 and the silane coupling layer 24 tend to become uneven when formed thicker. Therefore, it is desirable that each of the silane coupling layer 14 and the silane coupling layer 24 is formed to a thickness of several molecular layers or less at most. Specifically, for example, the thickness is preferably 5nm or less.

X is methoxy (-OCH)₃) Ethoxy (-OC)₂H₅) Chlorine atom (Cl), and amino group (-NH)₂) Any one of (a); each of B and C is individually methoxy (-OCH)₃) Ethoxy (-OC)₂H₅) Chlorine atom (Cl), and amino group (-NH)₂) Any one of the above, or any one of an alkyl group, an alkenyl group, and an alkoxy group each having one to three carbon atoms; and A is any of an alkyl group, an alkenyl group, and an alkoxy group each having 6 to 20 carbon atoms, a group in which carbon atoms other than carbon atoms constituting both ends of a carbon chain of the alkyl group, the alkenyl group, and the alkoxy group are substituted with oxygen, or a group in which at least one or more hydrogen atoms constituting the alkyl group, the alkenyl group, and the alkoxy group are substituted with a halogen atom.

For example, the liquid crystal layer 30 may include various types of liquid crystals, such as a Vertical Alignment (VA) liquid crystal, a Twisted Nematic (TN) liquid crystal, or an in-plane switching (IPS) liquid crystal, and is displayed in a normally black mode or a Normally White (NW) mode, for example. For example, the liquid crystal layer 30 is sealed with a thermosetting sealing material or a UV-curable sealing material for bonding the side surface of the pixel circuit substrate 11 and the side surface of the counter substrate 21 together. The sealant for liquid crystal displays is commercially available for use in liquid crystal displays. As for the liquid crystal layer 30, the pixel circuit substrate 11 side and the counter substrate 21 side are bonded together using a sealing material, followed by injecting liquid crystal, and sealing the liquid crystal with, for example, a UV curing sealant. Alternatively, the liquid crystal layer 30 may be formed by a drop injection (ODF) process, for example.

(1-2, method of manufacturing liquid crystal display device)

For example, the liquid crystal display device 1 according to the present embodiment may be manufactured as follows. Fig. 2 shows a flow of steps in a method of manufacturing the liquid crystal display device 1. Fig. 3A to 3D schematically show a cross section of the liquid crystal display device 1 in each step.

First, as shown in fig. 3A, the alignment film 12 is formed over the pixel circuit substrate 11 by, for example, oblique deposition, for example, a transistor and a pixel electrode are provided for each pixel on the pixel circuit substrate 11 (step S101). Specifically, SiO having, for example, a film thickness of 100nm is formed₂A film inclined at an angle of, for example, 40 ° to 70 °, with the horizontal direction set at 0 °.

Next, as shown in fig. 3B, a metal oxide layer 13 is formed on the alignment film 12 (step S102). In particular, for example, by an ALD methodAl having, for example, five atomic layers is formed on the film 12₂O₃And (3) a membrane. Note that the metal oxide layer 13 is preferably formed by an ALD method. However, the metal oxide layer 13 may be formed using, for example, a Chemical Vapor Deposition (CVD) method or sputtering. In order to maintain the surface shape of the alignment film 12, the metal oxide layer 13 is preferably thin. However, the metal oxide layer 13 is not limited thereto as long as another orientation control method is prepared.

Next, as shown in fig. 3C, the surface of the metal oxide layer 13 is subjected to a silane coupling treatment (step S103). Specifically, for example, a silane coupling material including an alkyl chain having six or more carbon atoms is stacked as a vapor on the metal oxide layer 13 under normal pressure or reduced pressure. At this time, when the reactive group (for example, X in the general formula (1)) of the silane coupling material is a chlorine atom, an amino group, or the like, the reaction is completed. In the case where the reactive group is a methoxy group, an ethoxy group, or the like, water vapor is introduced to cause hydrolysis, followed by reaction with a hydroxyl group on the surface of the metal oxide layer 13. In this way, the silane coupling layer 14 is formed on the metal oxide layer 13.

Next, as shown in fig. 3D, the pixel circuit substrate 11 and the counter substrate 21 are bonded together with a gap therebetween (step S104). Specifically, the pixel circuit substrate 11 and the counter substrate 21 formed using a similar method are arranged so as to allow the silane coupling layer 14 and the silane coupling layer 24 to be opposed to each other, and the alignment film 12, the metal oxide layer 13, and the silane coupling layer 14 are stacked on the pixel circuit substrate 11 in this order. Subsequently, for example, a UV curing sealing material is applied to join the pixel circuit substrate 11 and the counter substrate 21 together except for the entrance around the pixel circuit substrate 11 and the counter substrate 21, and the sealing material is cured by irradiating the sealing material with UV.

Next, liquid crystal is injected into the gap between the pixel circuit substrate 11 and the counter substrate 21, and the liquid crystal layer 30 is formed. Finally, a sealant is applied to the inlet, and the sealant is cured by irradiating the sealant with UV. In this way, the liquid crystal display device 1 shown in fig. 1 is obtained.

(1-3, operation and Effect)

As described above, attempts have been made to improve the light resistance of liquid crystal devices used for projectors required to have high reliability. In order to improve light resistance, a commonly used alignment film comprising an organic polymer such as polyimide having a side chain alkyl group is replaced with a so-called inorganic alignment film comprising an inorganic material. However, for example, SiO included in the inorganic alignment film₂Has strong hygroscopicity, and the wet inorganic alignment film causes leakage current among pixels.

Therefore, in recent years, attempts have been made to achieve moisture resistance and orientation by subjecting an inorganic orientation film to surface treatment using a silane coupling material having liquid crystal orientation. However, the silane coupling material has low reactivity with hydroxyl groups on the surface of the inorganic alignment film, thus making it difficult to form strong bonds with the surface of the inorganic alignment film.

In order to solve this problem, as a method of forming a strong bond with the surface of the inorganic film, a method of adhering a silane coupling material to the inorganic film in a gas phase, subsequently hydrolyzing the silane coupling material, and further performing heating to subject the heated hydrolysate and hydroxyl groups on the inorganic film to dehydration condensation has been developed. However, the condensation reaction with the hydroxyl group on the inorganic film must be performed under high temperature conditions. There is a problem in that the high temperature causes the silane coupling material to be desorbed from the inorganic film before the reaction.

Therefore, the liquid crystal display device 1 according to the present embodiment has the following configuration: the pixel circuit substrate 11 and the counter substrate 21 are opposed to each other with the liquid crystal layer 30 therebetween, the alignment film 12 is disposed over the pixel circuit substrate 11, for example, the metal oxide layer 13 is disposed over the alignment film 12, and the silane coupling layer 14 is disposed through the metal oxide layer 13. Disposing the metal oxide layer 13 on the alignment film 12 improves the reactivity of the hydroxyl groups on the surface of the alignment film 12. As shown in fig. 4, a strong bond (e.g., covalent bond) is formed between the hydroxyl group of the alignment film 12 and the reactive group of the silane coupling material in the silane coupling layer 14 by the metal atom included in the metal oxide layer 13.

As described above, according to the present embodiment, the metal oxide layer 13 is provided between the alignment film 12 and the silane coupling layer 14 provided on the pixel circuit substrate 11, for example, among a pair of substrates (the pixel circuit substrate 11 and the counter substrate 21) opposed to each other with the liquid crystal layer 30 therebetween. Therefore, the hydroxyl groups on the surface of the alignment film 12 and the reactive groups of the silane coupling material included in the silane coupling layer 14 form covalent bonds through the metal atoms of the metal oxide layer 13. Therefore, the moisture resistance of the liquid crystal display device 1 can be improved. This makes it possible to suppress occurrence of a leakage current among the pixels of the alignment film 12.

Note that this embodiment mode gives the following examples: the metal oxide layer 13 and the metal oxide layer 23 are provided on the alignment film 12 and the alignment film 22 provided on the pixel circuit substrate 11 side and the counter substrate 21 side, respectively. However, providing the metal oxide layer only on one of the alignment films enables improvement in moisture resistance of the liquid crystal display device 1 as compared with a typical liquid crystal display device. In this case, the metal oxide layer is preferably provided on the pixel circuit substrate 11 side.

In addition, forming the metal oxide layer 13 and the metal oxide layer 23 using the ALD method makes it easier to maintain the respective inclinations of the alignment film 12 and the alignment film 22.

Next, modifications of the present disclosure are described. Note that components similar to those of the liquid crystal display device 1 according to the above-described embodiment are denoted by the same reference numerals, and descriptions thereof are omitted where appropriate.

<2, modification >

Fig. 5 schematically shows an example of a cross-sectional configuration of a liquid crystal display device (liquid crystal display device 2) according to a modification of the present disclosure. The liquid crystal display device 2 is used as a liquid crystal light valve of a projection display apparatus (projection display apparatus 4, see fig. 7) such as a projector described below, for example. The liquid crystal display device 2 includes, for example, a liquid crystal layer 30 between a reflector 41 and a counter substrate 21 opposed to each other. The dielectric layer 42, the metal oxide layer 43, and the silane coupling layer 14 are stacked in this order from the reflector 41 side between the reflector 41 and the liquid crystal layer 30. Similarly to the above embodiment, the alignment film 22, the metal oxide layer 23, and the silane coupling layer 24 are stacked in this order from the counter substrate 21 side between the counter substrate 21 and the liquid crystal layer 30.

For example, the reflector 41 includes a light reflective material such as aluminum (Al).

The dielectric layer 42 includes a dielectric material. Specific examples of dielectric materials include SiO₂。

For example, the metal oxide layer 43 serves to improve the reflectance of light incident on the liquid crystal display device 2 in the direction of the surface S1 by utilizing the difference in refractive index from the dielectric layer 42. The metal oxide layer 43 is formed by using a material having a larger refractive index than the dielectric layer 42. Similar to the metal oxide layer 13 and the metal oxide layer 23 according to the above-described embodiment, specific examples of the material having a larger refractive index include metal oxides such as aluminum oxide (Al)₂O₃) Hafnium oxide (HfO)₂) Zirconium oxide (ZrO)₂) And tantalum oxide (Ta)₂O₅). Note that the optimum value of the film thickness of each of the metal oxide layer 43 and the dielectric layer 42 varies depending on the wavelength. Therefore, the film thickness is set according to the purpose.

For example, the liquid crystal display device 2 according to the present modification may be manufactured as follows. First, for example, a CVD method is used for forming, for example, SiO with a thickness of 75nm on the reflector 41₂Film, thereby forming dielectric layer 42. Next, for example, a CVD method is used to form HfO, for example, having a thickness of 74nm, on the dielectric layer 42 ₂Film, thereby forming the metal oxide layer 43. Subsequently, similarly to the above-described embodiment, a silane coupling treatment is performed on the surface of the metal oxide layer 43 to form the silane coupling layer 14 on the metal oxide layer 43. Thereafter, the reflector 41 and the counter substrate 21 are arranged to allow the silane coupling layer 14 and the silane coupling layer 24 to oppose each other. An alignment film 22, a metal oxide layer 23, and a silane coupling layer 24 formed using a method similar to that of the above-described embodiment are stacked in this order on the counter substrate 21. After the silane coupling layer 14 and the silane coupling layer 24 are bonded together with a gap therebetween, liquid crystal is injected into the gap to form a liquid crystal layer. In this way, the liquid crystal display device 2 shown in fig. 5 is obtained.

As described above, the metal oxide layer 43 according to the present modification is arranged as an optical film together with the dielectric layer 42. Therefore, the liquid crystal display device 2 according to the present modification can improve (for example, 4%) the reflectance of light incident on the liquid crystal display device 2 in the direction of the surface S1 by utilizing the difference in refractive index between the dielectric layer 42 and the metal oxide layer 43. In addition, according to the present modification, the reflective liquid crystal display apparatus 2 can be more simply manufactured while maintaining the strength of the bond between the inorganic oxide layer (dielectric layer 42) and the silane coupling layer 14. Note that, according to the present modification, the counter substrate 21 side has a configuration similar to those of the above-described embodiment. Therefore, the liquid crystal on the counter substrate 21 side is aligned while maintaining its tilt.

<3, application example >

(application example 1)

Fig. 6 shows an example of the configuration of a projection display apparatus (projection display apparatus 3) including the liquid crystal display device 1 according to the embodiment of the present disclosure. For example, the projection display device 3 includes a light source 110 (light source), an illumination optical system 120, an image forming unit 140, and a projection optical system 150 in this order. The projection display device 3 generates image light by modulating and combining light (illumination light) output from the light source 110 of each of the RGB colors based on an image signal, and projects an image on a screen (not shown). The projection display apparatus 3 is a so-called three-chip transmissive projector that displays a color image using three transmissive

light modulation devices

141R, 141G, and 141B for respective colors of red, blue, and green. The

light modulation devices

141R, 141G, and 141B correspond to the liquid crystal display device 1.

The light source 110 emits white light including red (R), blue (B), and green (G) light required for displaying a color image. The light source 110 includes, for example, a halogen lamp, a metal halide lamp, a xenon lamp, or the like. Alternatively, for example, a solid-state light source such as a semiconductor Laser (LD) or a Light Emitting Diode (LED) may be used. In addition, the light source 110 is not limited to a single light source (white light source section) that emits white light as described above. For example, the light source 110 may include three types of light source sections: a green light source section emitting light in a green wavelength band, a blue light source section emitting light in a blue wavelength band, and a red light source section emitting light in a red wavelength band.

For example, the illumination optical system 120 includes an integrator device 121, a polarization conversion device 122, and a condenser lens 123. The integrator device 121 includes a first fly-eye lens 121A and a second fly-eye lens 121B. The first fly-eye lens 121A includes a plurality of two-dimensionally arranged microlenses. The second fly-eye lens 121B includes a plurality of microlenses arranged to correspond to the microlenses included in the first fly-eye lens 121A.

Light (parallel light) incident on the integrator device 121 from the light source 110 is split into a plurality of light fluxes by the microlenses of the first fly-eye lens 121A, allowing the respective microlenses included in the second fly-eye lens 121B to form an image. The respective microlenses in the second fly-eye lens 121B function as auxiliary light sources, and apply a plurality of parallel light beams having matching luminance to the polarization conversion device 122 as incident light.

The integrator device 121 has a function of arranging incident light applied to the polarization conversion device 122 from the light source 110 as a whole to have a uniform brightness distribution.

The polarization conversion device 122 has a function of equalizing the polarization state of light incident through the integrator device 121 or the like. The polarization conversion device 122 outputs the emitted light through, for example, a lens 65 or the like disposed on the light emitting side of the light source 110. The emitted light includes blue light B, green light G, and red light R.

The illumination optical system 120 further includes a dichroic mirror 124, a dichroic mirror 125, a reflecting mirror 126, a reflecting mirror 127, a reflecting mirror 128, a relay lens 129, a relay lens 130, a field lens 131R, a field lens 131G, a field lens 131B,

light modulation devices

141R, 141G, 141B, and a dichroic prism 142. The

light modulation devices

141R, 141G, 141B and the dichroic prism 142 function as an image forming section 140.

The dichroic mirrors 124 and 125 have properties of selectively reflecting color light of a predetermined wavelength range and transmitting light of other wavelength ranges. For example, the dichroic mirror 124 selectively reflects the red light R. The dichroic mirror 125 selectively reflects the green light G among the green light G and the blue light B that have been transmitted through the dichroic mirror 124. The remaining blue light B is transmitted through dichroic mirror 125. In this way, the light (white light Lw) emitted from the light source 110 is divided into a plurality of color light beams having different colors.

The divided red light R is reflected by the mirror 126, passes through the field lens 131R, thereby being collimated, and then enters the light modulation device 141R for modulating red light. The green light G passes through the field lens 131G so as to be collimated, and then enters the light modulation device 141G for modulating green light. Blue light B passes through relay lens 129, is reflected by mirror 127, and also passes through relay lens 130, and is reflected by mirror 128. The blue light B reflected by the mirror 128 passes through the field lens 131B so as to be collimated, and then enters the light modulation device 141B for modulating the blue light B.

The

light modulation devices

141R, 141G, and 141B are each electrically coupled to a signal source (e.g., a PC), not shown, that provides an image signal including image information. The

light modulation devices

141R, 141G, and 141B modulate incident light of the respective pixels based on the supplied image signals of the respective colors, and generate a red image, a green image, and a blue image, respectively. The modulated light beams of the respective colors (formed images) enter the dichroic prism 142 to be combined. The dichroic prism 142 overlaps and combines light beams of respective colors incident from three directions, and then outputs the combined light beam toward the projection optical system 150.

The projection optical system 150 includes a plurality of lenses 151 and the like, and applies the light combined by the dichroic prism 142 to a screen, not shown. This allows a full color image to be displayed.

(application example 2)

Fig. 7 shows an example of the configuration of a projection display apparatus (projection display apparatus 4) including a liquid crystal display device 2 according to a modification of the present disclosure. The projection display device 4 includes, for example, a light source 110, an illumination optical system 210, an image forming unit 220, and a projection optical system 230 in this order. The projection display device 4 modulates light (illumination light) output from the light sources 110 of the respective RGB colors based on an image signal and combines the modulated light beams, thereby generating image light, and projects an image on a screen section (not shown). The projection display apparatus 4 is a so-called three-plate reflective projector that displays a color image using three reflective light modulation devices 222R, 222G, and 222B of respective colors of red, blue, and green. The light modulation devices 222R, 222G, and 222B correspond to the liquid crystal display device 2.

Similar to the above application example 1, the light source 110 emits white light including red (R), blue (B), and green (G) light required for displaying a color image. The light source 110 includes, for example, a halogen lamp, a metal halide lamp, a xenon lamp, or the like. Alternatively, for example, a solid-state light source such as a semiconductor Laser (LD) or a Light Emitting Diode (LED) may be used. In addition, the light source 110 is not limited to a single light source (white light source section) that emits white light as described above. For example, the light source 110 may include three types of light source sections: a green light source section emitting light in a green wavelength band, a blue light source section emitting light in a blue wavelength band, and a red light source section emitting light in a red wavelength band.

The illumination optical system 210 includes, for example, fly-eye lenses 211(211A and 211B), a polarization conversion device 212, a lens 213,

dichroic mirrors

214A and 214B,

reflective mirrors

215A and 215B,

lenses

216A and 216B, a dichroic mirror 217, and polarizing plates 218A to 218C from a position close to the light source 110.

The fly-eye lenses 211(211A and 211B) make the luminance distribution of the white light from the light source 110 uniform. The polarization conversion device 212 is used to align the polarization axis of an incident light beam in a predetermined direction. For example, light other than p-polarized light is converted into p-polarized light. Lens 213 converges light from polarization conversion device 212 toward

dichroic mirrors

214A and 214B. Dichroic mirrors 214A and 214B each selectively reflect light of a predetermined wavelength range and selectively transmit light of other wavelength ranges. For example, the dichroic mirror 214A reflects red light mainly in the direction of the reflective mirror 215A. Further, the dichroic mirror 214B reflects blue light mainly in the direction of the reflective mirror 215B. Therefore, the green light mainly passes through the

dichroic mirrors

214A and 214B, and travels toward the reflective polarizing plate 221C of the image forming section 220. The reflective mirror 215A reflects light (mainly red light) from the dichroic mirror 214A toward the lens 216A, and the reflective mirror 215B reflects light (mainly blue light) from the dichroic mirror 214B toward the lens 216B. The lens 216A transmits light (mainly red light) from the reflective mirror 215A, and condenses the light to the dichroic mirror 217. The lens 216B transmits light (mainly blue light) from the mirror 215B, and condenses the light to the dichroic mirror 217. The dichroic mirror 217 selectively reflects green light and selectively transmits light of other wavelength ranges. In this example, the dichroic mirror 217 transmits a red light component among the light from the lens 216A. In the case where the light from the lens 216A includes a green light component, the green light component is reflected toward the polarizing plate 218C. The polarizing plates 218A to 218C each include a polarizer having a polarization axis in a predetermined direction. For example, in the case where light is converted into p-polarized light in the polarization conversion device 212, the polarizing plates 218A to 218C each transmit the p-polarized light and reflect the s-polarized light.

The image forming section 220 includes reflective polarizing plates 221A to 221C, reflective light modulation devices 222A to 222C, and a dichroic prism 223.

The reflective polarizing plates 221A to 221C respectively transmit light having the same polarization axis as that of the polarized light from the polarizing plates 218A to 218C (for example, p-polarized light), and reflect light having a polarization axis other than that of the p-polarized light (s-polarized light). Specifically, the reflective polarizing plate 221A transmits the p-polarized red light from the polarizing plate 218A in the direction of the reflective light modulation device 222A. The reflective polarizing plate 221B transmits the p-polarized blue light from the polarizing plate 218B in the direction of the reflective light modulation device 222C. The reflective polarizing plate 221C transmits the p-polarized green light from the polarizing plate 218C in the direction of the reflective light modulation device 222C. In addition, the p-polarized green light that has passed through

dichroic mirrors

214A and 214B and entered reflective polarizing plate 221C passes through reflective polarizing plate 221C as it is, and enters dichroic prism 223. In addition, the reflective polarizing plate 221A reflects the s-polarized red light from the reflective light modulation device 222A to enter the dichroic prism 223. The reflective polarizing plate 221B reflects the s-polarized blue light from the reflective light modulation device 222C to enter the s-polarized blue light into the dichroic prism 223. The reflective polarizing plate 221C reflects the s-polarized green light from the reflective light modulation device 222C to enter the s-polarized green light into the dichroic prism 223.

The reflective light modulation devices 222A to 222C perform spatial modulation on red light, blue light, and green light, respectively.

The dichroic prism 223 combines the incident red light, the incident blue light, and the incident green light together, and outputs the combined light toward the projection optical system 230.

The projection optical system 230 includes lenses L232 to L236 and a mirror M231. The projection optical system 230 enlarges the light output from the image forming part 220 to project the enlarged light on a screen or the like.

<4, working example >

As described below, various samples (for example, experimental examples 1 to 5) were manufactured as the liquid crystal display according to the present disclosure and comparative examples thereof, and the change of the contact angle on the substrate surface before and after the heat treatment, which was performed after the silane coupling treatment, was evaluated.

(Experimental example 1)

First, SiO₂Stacked on the substrate by oblique deposition to form an inorganic oxide layer (corresponding to the

alignment films

12 and 22 or the dielectric layer 42). Subsequently, the substrate was heated to 220 ℃ in the ALD unit, and trimethylaluminum (TMA; precursor 1) and water (H) were alternately introduced₂O; precursor 2) to form Al serving as a metal oxide layer on the inorganic oxide layer₂O₃And (3) a membrane. TMA and H₂One introduction of O was set as a single cycle, and the cycle was repeated five times, thus obtaining a film thickness of 0.6 nm. Next, the substrate was heated to 80 ℃, and thereafter a vapor of n-decyltrimethoxysilane was introduced as a silane coupling material at normal pressure. The substrate was exposed to steam for 30 minutes to attach the silane coupling material to the surface of the substrate. Subsequently, the substrate was exposed to water vapor for one hour to promote hydrolysis of the silane coupling material, and thereafter the substrate was heated and dried at 100 ℃ for 30 minutes, obtaining a sample of experimental example 1.

(Experimental example 2)

In Experimental example 2, except that the introduction of TMA and H was performed₂Circulation of O40 times to form Al with a film thickness of 5nm₂O₃Except for the film, a sample was produced using a method similar to that of experimental example 1.

(Experimental example 3)

In Experimental example 3, except that the introduction of TMA and H was performed₂O is cycled 160 times to form Al with a film thickness of 20nm₂O₃Except for the film, the film was produced by a method similar to that of Experimental example 1And (3) sampling.

(Experimental example 4)

In experimental example 4, except that tetrakis (ethylmethylamino) hafnium (IV) (TEMAH) was used as precursor 1, and introduction of TEMAH and H was performed₂Cycle of O7 times to form HfO with film thickness of 0.6nm₂Except for the film, a sample was produced using a method similar to that of experimental example 1.

(Experimental example 5)

Experimental example 5 is a comparative example of experimental examples 1 to 4. In experimental example 5, SiO was stacked on a substrate by oblique deposition₂To form an inorganic oxide layer. Subsequently, a sample was manufactured using a method similar to those of experimental example 1 and performing a silane coupling treatment on the surface of the inorganic oxide layer without providing a metal oxide layer.

For each of the above experimental examples 1 to 5, the contact angle of purified water on the substrate surface was measured, followed by heating at 200 ℃ for six hours, after which the contact angle of purified water on the substrate surface was measured again. Table 1 lists the production conditions and measurement results of the contact angle of purified water on the substrate surface before and after the heat treatment of experimental examples 1 to 5.

On the metal oxide layer (Al)₂O₃Film or HfO₂Film) on the inorganic oxide layer, the contact angles of purified water before the heat treatment were 77 ° (experimental example 1), 72 ° (experimental example 2), 82 ° (experimental example 3), and 81 ° (experimental example 4). Meanwhile, in experimental example 5 in which no metal oxide layer was provided, the contact angle was as small as 45 °. The contact angles after the heat treatment were 72 ° (experimental example 1), 74 ° (experimental example 2), 77 ° (experimental example 3), 75 ° (experimental example 4), and 4 ° (experimental example 4). In each of experimental examples 1 to 4, the change in contact angle before and after the heat treatment was very small regardless of the thickness of the metal oxide layer. Meanwhile, a large change was observed in experimental example 4. One conceivable reason is that the inorganic oxide layers in experimental examples 1 to 4 were coupled with silaneThe provision of the metal oxide layer between the layers results in a stronger bond between the inorganic oxide layer and the silane coupling layer, thereby obtaining a more stable surface.

In addition, substrates were manufactured through various processes similar to those of experimental examples 1 to 4, and were bonded to the corresponding substrates of experimental examples 1 to 5. Liquid crystal was injected into the gap between the substrates, and the image quality was observed. Therefore, in each of experimental examples 1, 2, and 4, the liquid crystal molecules exhibited a good vertical alignment. At TMA and H ₂In experimental example 3 in which the introduction cycle of O was performed 160 times, the liquid crystal molecules exhibited vertical alignment without any tilt. It is understood from the results that in the case of forming a thick metal oxide layer (in this embodiment, 20nm or more), it is necessary to use SiO removal₂The alignment control of the liquid crystal molecules is performed by a method other than the oblique deposition.

The present disclosure has been described above with reference to the embodiments, modifications, and operation examples. However, the present disclosure is not limited thereto, and may be modified in various ways. For example, the projection display device according to the present disclosure is not limited to the configuration described in the above embodiment, and is applicable to various types of display devices that modulate light from a light source by a liquid crystal display unit and display a picture using a projection lens.

In addition, the liquid crystal display device 1 according to the present disclosure can also be used as a liquid crystal light valve of the reflective projection display apparatus 4 described in the above-described application example 2 by adopting, for example, a configuration in which a light reflective material is used for the pixel circuit substrate 11 or the substrate included in the pixel electrode.

It should be noted that the content of the present disclosure can be configured as follows.

[1]

A liquid crystal display device, comprising:

a pair of substrates opposing each other;

A liquid crystal layer interposed between the pair of substrates;

an inorganic oxide layer interposed between the liquid crystal layer and at least one of the pair of substrates;

a silane coupling layer interposed between the liquid crystal layer and the inorganic oxide layer; and

and a metal oxide layer interposed between the inorganic oxide layer and the silane coupling layer.

[2]

The liquid crystal display device according to [1], wherein the silane coupling layer forms a covalent bond with the inorganic oxide layer through the metal oxide layer.

[3]

The liquid crystal display device according to [1] or [2], wherein in the metal oxide layer, metal oxide molecules each equivalent to one atomic layer to ten atomic layers are stacked.

[4]

The liquid crystal display device according to any one of [1] to [3], wherein the metal oxide layer has a film thickness of 5nm or less.

[5]

The liquid crystal display device according to any one of [1] to [4], wherein the metal oxide layer is formed using a light-transmitting material.

[6]

According to [5 ]]The liquid crystal display device, wherein the light transmissive material comprises aluminum oxide (Al)₂O₃) Hafnium oxide (HfO)₃) Zirconium oxide (ZrO)₂) And tantalum oxide (Ta)₂O₅) Any one of the above.

[7]

The liquid crystal display device according to any one of [1] to [6], wherein the silane coupling layer is formed using a silane coupling material represented by the following general formula (1):

[ solution 1]

(X represents methoxy (-OCH)₃) Ethoxy (-OC)₂H₅) Chlorine atom (Cl), and amino group (-NH)₂) Any one of the above-mentioned (B) and (C),

b and C each independently represent methoxy (-OCH)₃) Ethoxy (-OC)₂H₅) Chlorine atom (Cl), and amino group (-NH)₂) Any one of (1) to (2)Or any of an alkyl group, an alkenyl group, and an alkoxy group each having one to three carbon atoms, and

a represents any of an alkyl group, an alkenyl group, and an alkoxy group each having 6 to 20 carbon atoms, or a group in which carbon atoms other than carbon atoms at both ends of a carbon chain configuring the alkyl group, the alkenyl group, and the alkoxy group are substituted with oxygen, or a group in which at least one or more hydrogen atoms configuring the alkyl group, the alkenyl group, and the alkoxy group are substituted with a halogen atom. )

[8]

The liquid crystal display device according to any one of [1] to [7], wherein the inorganic oxide layer includes an alignment film.

[9]

The liquid crystal display device according to any one of [1] to [8], wherein

The pair of substrates includes a pixel circuit substrate provided with a plurality of pixel electrodes and a counter substrate opposed to the pixel circuit substrate, and

the metal oxide layer is provided at least on the pixel circuit substrate side.

[10]

A method of manufacturing a liquid crystal display device, the method comprising:

Forming an inorganic oxide layer on at least one of a pair of substrates;

forming a metal oxide layer on the inorganic oxide layer;

forming a silane coupling layer on the metal oxide layer;

arranging one substrate and the other substrate to face each other with a gap therebetween; and is

A liquid crystal layer is formed in the gap.

[11]

The method of manufacturing a liquid crystal display device according to [10], wherein the forming of the metal oxide layer comprises forming by an atomic layer deposition method.

[12]

A projection display device comprising:

a light source;

a liquid crystal display device including a pixel region modulating light from a light source and outputting light corresponding to a picture; and

a projection lens projecting a picture based on light output through the liquid crystal display device,

a liquid crystal display device comprising:

a pair of substrates opposed to each other,

a liquid crystal layer interposed between the pair of substrates,

an inorganic oxide layer interposed between the liquid crystal layer and at least one of the pair of substrates,

a silane coupling layer interposed between the liquid crystal layer and the inorganic oxide layer, and

This application claims the benefit of prior japanese patent application No. 2017-052515, filed on day 17/3/2017, to the japan patent office, the entire contents of which are incorporated herein by reference.

It should be understood by those skilled in the art that various changes, combinations, sub-combinations and alterations can be made according to design requirements and other factors insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. A liquid crystal display device comprising:

a pair of substrates facing each other;

a liquid crystal layer interposed between the pair of substrates;

a metal oxide layer interposed between the inorganic oxide layer and the silane coupling layer,

wherein the inorganic oxide layer includes an alignment film.

2. The liquid crystal display device according to claim 1, wherein the silane coupling layer forms a covalent bond with the inorganic oxide layer via the metal oxide layer.

3. The liquid crystal display device according to claim 1, wherein in the metal oxide layer, one atomic layer to ten atomic layers of metal oxide molecules are stacked.

4. The liquid crystal display device according to claim 1, wherein the metal oxide layer has a film thickness of 5nm or less.

5. The liquid crystal display device according to claim 1, wherein the metal oxide layer is formed using a light-transmitting material.

6. The liquid crystal display device according to claim 5, wherein the light-transmitting material comprises aluminum oxide (Al)₂O₃) Hafnium oxide (HfO)₃) Zirconium oxide (ZrO)₂) And tantalum oxide (Ta)₂O₅) Any one of the above.

7. The liquid crystal display device according to claim 1, wherein the silane coupling layer is formed using a silane coupling material represented by the following general formula (1):

wherein the content of the first and second substances,

x represents methoxy (-OCH)₃) Ethoxy (-OC)₂H₅) Chlorine atom (Cl), and amino group (-NH)₂) Any one of the above-mentioned (B) and (C),

b and C each independently represent methoxy (-OCH)₃) Ethoxy (-OC)₂H₅) Chlorine atom (Cl), and amino group (-NH)₂) Or each independently represents any of an alkyl group, an alkenyl group, and an alkoxy group each having one to three carbon atoms, and

a represents any of an alkyl group, an alkenyl group, and an alkoxy group each having 6 to 20 carbon atoms, or a group in which carbon atoms other than carbon atoms at both ends of a carbon chain configuring the alkyl group, the alkenyl group, and the alkoxy group are substituted with oxygen, or a group in which at least one or more hydrogen atoms of hydrogen atoms configuring the alkyl group, the alkenyl group, and the alkoxy group are substituted with a halogen atom.

8. The liquid crystal display device according to claim 1,

the metal oxide layer is provided at least on the pixel circuit substrate side.

9. A method of manufacturing a liquid crystal display device, the method comprising:

forming an inorganic oxide layer on at least one of a pair of substrates;

forming a metal oxide layer on the inorganic oxide layer;

forming a silane coupling layer on the metal oxide layer;

disposing the one substrate and the other substrate to face each other with a gap therebetween; and is provided with

A liquid crystal layer is formed in the gap,

wherein the inorganic oxide layer includes an alignment film.

10. The method of manufacturing a liquid crystal display device according to claim 9, wherein forming the metal oxide layer comprises forming by an atomic layer deposition method.

11. A projection display device comprising:

a light source;

a projection lens to project the picture based on the light output by the liquid crystal display device,

The liquid crystal display device includes:

a pair of substrates facing each other,

a liquid crystal layer interposed between the pair of substrates,

wherein the inorganic oxide layer includes an alignment film.