JP2005010480A - Alignment substrate, method for manufacturing alignment substrate, liquid crystal device and electronic device - Google Patents

Abstract

An alignment substrate and a liquid crystal device capable of reducing the occurrence rate of a short circuit between electrodes and reducing the occurrence rate of image sticking are provided.
An alignment substrate of the present invention includes an electrode for applying a voltage to liquid crystal molecules, and an insulating film formed on a part of the surface of the electrode. On the surface of the electrode 9 and / or the insulating film 41, grooves 16, ridges 17 and irregularities 10a capable of aligning liquid crystal molecules are formed. The insulating film 41 is formed at least on the upper end portion of the electrode 9 and is smaller than the exposed area of the electrode 9. The liquid crystal device of the present invention includes such an alignment substrate 10.
[Selection] Figure 4

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an alignment substrate, a method for manufacturing the alignment substrate, a liquid crystal device, and an electronic apparatus.
[0002]
[Prior art]
A liquid crystal device is used as a light modulation device in a projection display device such as a liquid crystal projector. A liquid crystal device is configured by sandwiching a liquid crystal layer between a pair of opposed substrates. Electrodes for applying a voltage to the liquid crystal layer are formed inside the pair of substrates. In addition, an alignment film that controls the alignment of liquid crystal molecules when no voltage is applied is formed inside the electrode. As this alignment film, a polymer film whose surface has been rubbed is used. An image display is performed on the liquid crystal device based on a change in the arrangement of liquid crystal molecules between when no voltage is applied and when the voltage is applied.
[0003]
However, when a liquid crystal device provided with such an alignment film is employed in a light modulation device of a liquid crystal 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, the liquid crystal molecule alignment control function may be degraded, such as the liquid crystal molecules being unable to align at the desired pretilt angle when no voltage is applied, and the display quality of the liquid crystal projector may deteriorate. .
[0004]
Therefore, instead of the alignment film, a configuration in which unevenness is formed on the surface of the electrode to control the alignment of liquid crystal molecules is disclosed in claim 13 of Patent Document 1. In this configuration, a large number of parallel grooves are formed on the surface of the electrode. A large number of serrated convex portions are repeatedly formed along the groove. The liquid crystal molecules are aligned in a uniaxial direction along each groove, and have a pretilt angle along each serrated convex portion. As described above, the surface of the electrode is formed into a shape capable of aligning the liquid crystal molecules, so that the alignment film is not formed.
[0005]
[Patent Document 1]
JP-A-9-152612
[0006]
[Problems to be solved by the invention]
However, in the configuration described above, the electrodes formed inside the pair of substrates are exposed to the liquid crystal layer. Therefore, when a conductive foreign material is mixed in the liquid crystal layer, there is a problem that the foreign material may be disposed between the pair of electrodes to short-circuit both electrodes.
[0007]
In order to avoid a short circuit between the electrodes, it is conceivable to form an electrical insulating film on the entire surface of each electrode. However, when the electrode is energized with the electrical insulating film formed, induced charges are generated on the surface of the electrical insulating film. Then, after a long period of use, the induced charge is constantly generated, and the liquid crystal molecules may not move while being attracted to the electric insulating film, so that a so-called burn-in phenomenon may occur. When this burn-in phenomenon occurs, there is a problem that the orientation of the liquid crystal molecules cannot be controlled and image display becomes impossible.
[0008]
The present invention has been made in order to solve the above-described problems, and is an alignment substrate capable of reducing the occurrence rate of short circuits between conductors and reducing the occurrence rate of image sticking. And it aims at provision of the manufacturing method.
Another object is to provide a highly reliable liquid crystal device and electronic device.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, an alignment substrate of the present invention is a substrate capable of aligning liquid crystal molecules, and is formed above the substrate and applies a voltage to the liquid crystal molecules, and the surface of the conductor And an electrical insulator formed on a part of the substrate.
According to this configuration, since the electrical insulator is formed on the surface of the conductor, the occurrence rate of the short circuit between the conductors can be reduced. Further, since the electrical insulator is formed only on a part of the surface of the conductor, the occurrence rate of image sticking can be reduced. As a result, it is possible to suppress both the occurrence rate of short circuit and burn-in between conductors within an allowable range.
[0010]
The electrical insulator is preferably formed at least at the upper end of the conductor.
The short circuit between the conductors occurs when a foreign substance having conductivity is disposed between the upper ends of the conductors. Therefore, by forming an electrical insulator at least at the upper end of the conductor, the occurrence rate of a short circuit between the conductors can be efficiently reduced.
[0011]
The area of the electrical insulator is preferably smaller than the exposed area of the conductor.
According to this configuration, the occurrence rate of image sticking can be reduced. However, since the exposed area of the conductor is increased, the occurrence rate of a short circuit between the conductors is increased. However, a short circuit between conductors often occurs immediately after assembly of the liquid crystal device, and if defective products are eliminated by inspection before product shipment, the possibility of a failure occurring under the user is low. On the other hand, burn-in occurs after long-term use by the user. Therefore, if the area of the electrical insulator is reduced to reduce the occurrence rate of burn-in, a highly reliable liquid crystal device can be provided to the user.
[0012]
The electrical insulator is preferably made of a material having visible light permeability.
According to this configuration, the liquid crystal device including the alignment substrate of the present invention can transmit visible light, and the liquid crystal device can function as a light modulation unit.
[0013]
The electrical insulator is preferably made of a light-resistant material.
According to this configuration, even when the liquid crystal device including the alignment substrate of the present invention is employed as the light modulation unit of the projection display device, the electrical insulator is not easily decomposed by strong light or heat emitted from the light source. Therefore, a short circuit between the conductors can be prevented over a long period of time.
[0014]
Moreover, it is desirable that the surface of the electrical insulator and / or the conductor is formed into a shape capable of aligning the liquid crystal molecules.
According to this configuration, it is not necessary to separately form an alignment film in order to align the liquid crystal molecules. Therefore, the manufacturing cost can be reduced. Further, the alignment film is not decomposed by strong light or heat, and the display quality of the liquid crystal device does not deteriorate. Further, the rubbing treatment of the alignment film is not necessary, and the occurrence of problems due to the rubbing cloth or the dust of the alignment film material can be avoided. Therefore, a highly reliable liquid crystal device can be provided.
[0015]
A plurality of grooves capable of aligning the liquid crystal molecules and a plurality of protrusions separating the grooves are formed in parallel on the surface of the conductor, and the liquid crystal is formed at the bottom of each groove. A plurality of irregularities capable of orienting molecules are periodically formed along the extending direction of each groove, and the electrical insulator is formed on all or part of the surface of each protrusion. Is desirable.
According to this configuration, liquid crystal molecules can be aligned by the grooves, protrusions, and irregularities, and there is no need to form an alignment film. Therefore, a highly reliable liquid crystal device can be provided. Further, it is possible to form grooves, ridges, and irregularities on the surface of the conductor with a short etching, and the manufacturing cost can be reduced. Furthermore, since the electrical insulator is formed on the surface of the ridge which is the upper end portion of the conductor, the occurrence rate of a short circuit between the conductors can be reduced.
[0016]
Further, a plurality of grooves capable of aligning the liquid crystal molecules and a plurality of ridges separating each of the grooves are formed in parallel to each other on the surface of the conductor. A plurality of irregularities capable of aligning liquid crystal molecules are periodically formed along the direction in which each protrusion extends, and the electrical insulator is formed on all or a part of the surface of each irregularity. May be.
Also with this configuration, the liquid crystal molecules can be aligned by the grooves, protrusions, and irregularities, and there is no need to form an alignment film. Therefore, a highly reliable liquid crystal device can be provided. In addition, since the electrical insulator is formed on the uneven surface that is the upper end portion of the conductor, the occurrence rate of a short circuit between the conductors can be reduced.
[0017]
Also, a plurality of grooves capable of aligning the liquid crystal molecules and a plurality of protrusions separating the grooves are formed in parallel on the surface of the conductor, and the liquid crystal is formed at the bottom of each groove. A plurality of irregularities capable of orienting molecules are periodically formed along the extending direction of the grooves, and a plurality of irregularities capable of orienting the liquid crystal molecules are formed on the top of the protrusions. The electrical insulator may be formed on all or part of the surface of each of the irregularities formed periodically along the direction in which the ridges extend and formed on the top of the ridges. .
According to this configuration, the liquid crystal molecules can be favorably aligned by a large number of irregularities, and there is no need to form an alignment film. Therefore, a highly reliable liquid crystal device can be provided. Furthermore, since the electrical insulator is formed on the upper end portion of the conductor by forming the electrical insulator on the uneven surface formed on the top of the ridge, the occurrence rate of the short circuit between the conductors can be reduced. Can do.
[0018]
On the other hand, the method for manufacturing an alignment substrate according to the present invention includes a step of forming a conductor on the surface of the substrate body, a step of forming an electrical insulator on the surface of the conductor, and a mask material on the surface of the electrical insulator. Forming the mask material into a shape capable of aligning liquid crystal molecules, and etching the electrical insulator and / or the conductor via the molded mask material, Forming a surface of the electrical insulator and / or the conductor into a shape capable of aligning liquid crystal molecules.
According to this configuration, since a shape capable of aligning liquid crystal molecules is formed on the surface of the electrical insulator and / or conductor, it is not necessary to form an alignment film. Therefore, a highly reliable liquid crystal device can be provided. In addition, the electrical insulator and the conductor can be formed at a time, and the manufacturing cost can be reduced.
[0019]
Further, another method for producing an alignment substrate of the present invention includes a step of forming a mask material on a surface of a substrate body, a step of forming the mask material into a shape capable of aligning liquid crystal molecules, and the formed mask. Etching the surface of the substrate body through a material to form the surface of the substrate body into a shape capable of aligning the liquid crystal molecules; and forming a conductor on the surface of the substrate body; And a step of forming an electrical insulator on a part of the surface of the conductor.
According to this configuration, since a shape capable of aligning liquid crystal molecules is formed on the surface of the electrical insulator and / or conductor, it is not necessary to form an alignment film. In addition, since the conductor and the electrical insulator can be formed to have a uniform thickness, a stable voltage can be applied to the liquid crystal molecules. Therefore, a highly reliable liquid crystal device can be provided.
[0020]
On the other hand, a liquid crystal device according to the present invention includes the above-described alignment substrate. Moreover, it manufactured using the manufacturing method of the alignment substrate mentioned above, It is characterized by the above-mentioned. Thereby, a highly reliable liquid crystal device can be provided.
[0021]
A pair of substrates disposed opposite to each other; a liquid crystal layer sandwiched between the pair of substrates; a conductor formed on a surface of each substrate on the liquid crystal layer side to apply a voltage to the liquid crystal layer; And an electrical insulator formed on a part of the surface of the body.
According to this configuration, since the electrical insulator is formed on the surface of the conductor, the occurrence rate of the short circuit between the conductors can be reduced. Further, since the electrical insulator is formed only on a part of the surface of the conductor, the occurrence rate of image sticking can be reduced. As a result, it is possible to suppress both the occurrence rate of short circuit and burn-in between conductors within an allowable range, and it is possible to provide a highly reliable liquid crystal device.
[0022]
On the other hand, an electronic apparatus according to the present invention includes the above-described liquid crystal device. According to this configuration, a highly reliable electronic device can be provided.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.
[0024]
[First Embodiment]
A liquid crystal device and an alignment substrate according to a first embodiment of the present invention will be described with reference to FIGS. In the embodiment, an active matrix transmissive liquid crystal device using a thin film transistor (hereinafter referred to as TFT) element as a switching element will be described as an example. FIG. 1 is an equivalent circuit diagram of a plurality of pixels arranged in a matrix so as to constitute an image display region of a transmissive liquid crystal device. 2 is a plan view of a plurality of pixels formed on the TFT array substrate, and FIG. 3 is a side cross-sectional view taken along line AA ′ of FIG.
[0025]
[Liquid Crystal Device]
As shown in FIG. 1, pixel electrodes 9 that are conductors are formed on a plurality of pixels arranged in a matrix so as to form an image display region of a transmissive liquid crystal device. Further, a TFT element 30 which is a switching element for performing energization control to the pixel electrode 9 is formed on the side of the pixel electrode 9. A data line 6 a is electrically connected to the source of the TFT element 30. Image signals S1, S2,..., Sn are supplied to each data line 6a. The image signals S1, S2,..., Sn may be supplied to each data line 6a in this order, or may be supplied for each group to a plurality of adjacent data lines 6a.
[0026]
The scanning line 3 a is electrically connected to the gate of the TFT element 30. Scan signals G1, G2,..., Gm are supplied to the scanning line 3a in pulses at a predetermined timing. The scanning signals G1, G2,..., Gm are applied sequentially to the respective scanning lines 3a in this order. Further, the pixel electrode 9 is electrically connected to the drain of the TFT element 30. When the TFT element 30 serving as a switching element is turned on for a certain period by the scanning signals G1, G2,..., Gm supplied from the scanning line 3a, the pixel signals S1, S2,. , Sn are written into the liquid crystal of each pixel at a predetermined timing.
[0027]
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 pixel signals S1, S2,..., Sn, a storage capacitor 70 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. As a result, the light incident on the liquid crystal is modulated to enable gradation display.
[0028]
[Plane structure]
Next, the planar structure of the liquid crystal device of the embodiment will be described with reference to FIG. In the liquid crystal device of the embodiment, a rectangular pixel electrode 9 (the outline of which is indicated by a broken line 9a) made of a transparent conductive material such as indium tin oxide (hereinafter referred to as ITO) is formed on the TFT array substrate. Are arranged in a matrix. A data line 6 a, a scanning line 3 a, and a capacitor line 3 b are provided along the vertical and horizontal boundaries of the pixel electrode 9. In the embodiment, the region in which each pixel electrode 9 is formed is a pixel, and has a structure capable of performing display for each pixel arranged in a matrix.
[0029]
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 electrically connected to a source region (described later) of the semiconductor layer 1 a through a contact hole 5. Further, the pixel electrode 9 is electrically connected to the drain region (described later) of the semiconductor layer 1 a through the contact hole 8. On the other hand, a channel region 1a ′ is formed in a portion facing the scanning line 3a in the semiconductor layer 1a. The scanning line 3a functions as a gate electrode in a portion facing the channel region 1a ′.
[0030]
The capacitance line 3b is a data line from the intersection of the main line portion (that is, the first region formed along the scanning line 3a in plan view) extending in a substantially straight line along the scanning line 3a and the data line 6a. And a protruding portion (that is, a second region extending along the data line 6 a when viewed in a plan view) protruding toward the front side (upward in the drawing) along 6 a. In addition, a first light shielding film 11a is formed in a region indicated by a diagonal line rising to the right in FIG. Then, the protruding portion of the capacitor line 3b and the first light shielding film 11a are electrically connected through the contact hole 13 to form a storage capacitor to be described later.
[0031]
[Cross-section structure]
Next, the cross-sectional structure of the liquid crystal device of the embodiment will be described with reference to FIG. FIG. 3 is a side sectional view taken along line AA ′ of FIG. As shown in FIG. 3, the liquid crystal device according to the embodiment mainly includes a TFT array substrate 10, a counter substrate 20 disposed so as to face the TFT array substrate 10, and a liquid crystal layer 50 sandwiched therebetween.
[0032]
The TFT array substrate 10 is mainly composed of a substrate main body 10A made of a translucent material such as quartz, a TFT element 30 formed inside thereof, a pixel electrode 9 as a conductor, and the like. One counter substrate 20 is mainly composed of a substrate body 20A made of a translucent material such as glass or quartz, a common electrode 21 which is a conductor formed inside the substrate body 20A, and the like. Further, the liquid crystal layer 50 is composed of TN liquid crystal or the like.
[0033]
On the surface of the TFT array substrate 10, a first light shielding film 11a and a first interlayer insulating film 12, which will be described later, are formed. 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 having a relatively low concentration) are respectively provided in the source region and the drain region. Region). 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.
[0034]
A gate insulating film 2 is formed on the surface of the semiconductor layer 1a. Then, a scanning line 3a is formed on the surface of the gate insulating film 2, and a part thereof 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 electrically connected to the high-concentration source region 1d through a contact hole 5 formed in the second interlayer insulating film 4. ing. Further, a third interlayer insulating film 7 is formed on the surfaces of the second interlayer insulating film 4 and the data line 6a. Then, a pixel electrode 9 is formed on the surface of the third interlayer insulating film 7, and the pixel electrode 9 becomes a high-concentration drain region through a contact hole 8 formed in the second interlayer insulating film 4 and the third interlayer insulating film 7. 1e is electrically connected.
[0035]
In the embodiment, the first storage capacitor electrode 1f is formed by extending the semiconductor film 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 70 is configured.
[0036]
The first light shielding film 11 a is formed on the surface of the TFT array substrate 10 corresponding to the formation region of the TFT element 30. The first light-shielding film 11a is incident from the counter substrate 20 side, is reflected by the outer surface of the TFT array substrate 10 (interface between the TFT array substrate 10 and air), and returns to the liquid crystal layer 50 at least in the semiconductor layer 1a. This prevents the light from entering the channel region 1a ′, the low concentration source region 1b, and the low concentration drain region 1c. The first light-shielding film 11a is electrically connected to the previous-stage or subsequent-stage capacitor line 3b through a contact hole 13 formed in the first interlayer insulating film 12. Accordingly, the first light shielding film 11a functions as a third storage capacitor electrode, and a new storage capacitor is formed between the first storage capacitor electrode 1f and the first interlayer insulating film 12 as a dielectric film.
[0037]
On the other hand, a second light shielding film 23 is formed on the surface of the counter substrate 20 corresponding to the formation region of the data lines 6 a, the scanning lines 3 a, and the TFT elements 30. The second light shielding film 23 prevents incident light from the counter substrate 20 side from entering the channel region 1a ′, the low concentration source region 1b, and the low concentration drain region 1c of the semiconductor layer 1a. Further, a common electrode 21 made of a conductor such as ITO is formed on almost the entire surface of the counter substrate 20 and the second light shielding film 23.
[0038]
[Alignment substrate]
The surfaces of the TFT array substrate 10 and the counter substrate 20 described above are formed in a shape capable of aligning liquid crystal molecules as described below. Therefore, the TFT array substrate 10 and the counter substrate 20 constitute the alignment substrate of the first embodiment. In the embodiment, the surface shapes of the TFT array substrate 10 and the counter substrate 20 and the electrical insulator formed on these surfaces are characteristic structures. Since this characteristic configuration is common to the TFT array substrate 10 and the counter substrate 20, the TFT array substrate 10 will be described below as an example.
[0039]
FIG. 4 is a perspective view of the alignment substrate of the first embodiment. A plurality of grooves 16 and protrusions 17 are alternately formed in parallel on the surface of the pixel electrode of the TFT array substrate (hereinafter simply referred to as a substrate) 10. That is, the groove | channel 16 is arrange | positioned between each protrusion 17, Each groove | channel 16 is formed in linear form with the predetermined width. Moreover, the protrusion 17 is arrange | positioned so that each groove | channel 16 may be separated, and each protrusion 17 is formed in linear form with the predetermined width. In addition, the groove | channel 16 and the protrusion 17 are extended along the direction which should orientate a liquid crystal molecule. Then, liquid crystal molecules near the surface of the substrate 10 enter the inside of the groove 16 and are arranged along the side wall, thereby being aligned along the extending direction of the groove 16. When the liquid crystal molecules are twisted in the liquid crystal layer, the extending direction of the grooves 16 and the protrusions 17 in the TFT array substrate 10 and the extending direction of the grooves 16 and the protrusions 17 in the counter substrate 20 are mutually Are arranged in a state twisted by a predetermined angle.
[0040]
On the other hand, a plurality of irregularities 10 a are formed at the bottom of each groove 16. The irregularities 10 a are formed to have the same width as the grooves 16 and are periodically arranged along the extending direction of the grooves 16. A step G is provided between the top of the projections and depressions 10 a and the surface of the protrusion 17. The height of the step G is 30 to 500 nm, and more preferably 100 to 250 nm. This makes it possible to align the liquid crystal molecules inside the groove 16 and to prevent display quality from being deteriorated due to the difference in retardation between the groove 16 and the protrusion 17. Furthermore, the cross section of the unevenness 10a along the extending direction of the groove 16 is a triangular shape (sawtooth shape) having a gentle slope and a steep slope. The inclination of the gentle slope is set to be equal to the pretilt angle to be given to the liquid crystal molecules. The liquid crystal molecules that have entered the groove 16 are arranged along the gentle slope, so that a pretilt angle is given to the liquid crystal molecules.
[0041]
On the other hand, an insulating film 41 that is an electrical insulator is formed on the surface of each protrusion 17. The insulating film 41 is made of an organic material such as a resin having visible light permeability or an inorganic material. Accordingly, the liquid crystal device including the substrate 10 can transmit visible light, and the liquid crystal device can function as a light modulation unit. However, since the insulating film 41 is formed only on a part of the pixel electrode, it can be made of a material having a slightly lower visible light transmission property such as silicon nitride (SiN). The insulating film 41 is made of a light resistant material. Thereby, even when the liquid crystal device including the substrate 10 is used as the light modulation unit of the projection display device, the insulating film 41 is not easily decomposed by strong light or heat irradiated from the light source. Therefore, even when the projection display device is used for a long time, it is possible to prevent a short circuit between the electrodes in the liquid crystal device. Specifically, silicon oxide (SiO 2), magnesium oxide (MgO), or the like can be used as the electrically insulating material having visible light transmittance and light resistance.
[0042]
The insulating film 41 is formed on a part of the surface of the substrate 10. That is, the insulating film 41 is formed so as to cover about 5 to 95% of the surface of the pixel electrode. Note that the insulating film 41 is preferably formed so that the area of the insulating film 41 is smaller than the exposed area of the pixel electrode. Specifically, the insulating film 41 is formed on about 10 to 30% of the entire surface of the pixel electrode. Thus, by reducing the area of the insulating film 41, the occurrence rate of image sticking can be reduced. But since the exposed area of an electrode becomes large, the incidence rate of the short circuit between electrodes becomes high. However, the short circuit between the electrodes occurs immediately after the assembly of the liquid crystal device, and if defective products are eliminated by inspection before product shipment, the possibility of failure occurring under the user is low. On the other hand, burn-in occurs after long-term use by the user. Therefore, on the assumption that the presence or absence of a short circuit between the electrodes is confirmed by a pre-shipment inspection, if the area of the insulating film 41 is reduced to reduce the occurrence rate of image sticking, a highly reliable liquid crystal device for the user Can be provided.
[0043]
The insulating film 41 prevents a short circuit between the pixel electrode of the TFT array substrate 10 and the common electrode of the counter substrate 20. In particular, the conductive foreign matter mixed in the liquid crystal layer is sandwiched between the electrodes, thereby preventing a short circuit between the electrodes. Therefore, the insulating film 41 is formed at least on the upper end portion of the substrate 10. Specifically, the insulating film 41 is formed on the surface of the protrusion 17 that is the upper end portion of the substrate 10. When the protrusions 17 are formed on about 10 to 30% of the entire surface of the pixel electrode, the insulating film 41 may be formed on the entire surface of the protrusions 17. Further, when the protrusions 17 are formed on 30% or more of the entire surface of the pixel electrode, the insulating film 41 is formed on a part of the surface of the protrusions 17. Thereby, as described above, a highly reliable liquid crystal device can be provided.
[0044]
FIG. 5 is a side sectional view taken along line BB in FIG. 5 and the subsequent drawings omit illustrations of TFT elements and various wirings formed between the substrate body 10A and the pixel electrode 9 for easy understanding. As shown in FIG. 5, the surface of the substrate body 10 </ b> A in the first embodiment is a substantially flat surface, and the pixel electrode 9 is formed thereon. The protrusions 17, the grooves 16, and the irregularities 10 a described above are formed on the surface of the pixel electrode 9. Furthermore, the insulating film 41 described above is formed on the surface of the protrusion 17. Note that the liquid crystal molecules 49 are arranged above the gentle slope of the unevenness 10a, and a pretilt angle is given to the liquid crystal molecules 49. Thus, since the surface of the pixel electrode 9 is formed in a shape capable of aligning liquid crystal molecules, no alignment film is formed on the surface of the pixel electrode 9. That is, the pixel electrode 9 and the insulating film 41 are exposed from the liquid crystal layer. In addition, a TFT element etc. can be formed easily by making the surface of 10 A of board | substrates into a substantially flat surface. Further, since the protrusions 17, the grooves 16, and the unevenness 10 a are formed only on the surface of the pixel electrode 9, the region other than the region where the pixel electrode 9 is formed becomes a substantially flat surface. Thereby, the obstacle at the time of liquid crystal injection is reduced, and the injection time can be shortened.
[0045]
[Production method]
Next, the manufacturing method of the alignment substrate of 1st Embodiment is demonstrated. 6 and 7 are explanatory diagrams of the method for manufacturing the alignment substrate according to the first embodiment.
[0046]
First, as shown in FIG. 6A, an electrode conductive film 9a is formed on the substrate body 10A by sputtering or the like. Note that the conductive film 9a is formed as a flat film at this stage. Next, an insulating film 41 is formed on the surface of the conductive film 9a by a CVD method or the like. Note that the insulating film 41 is formed on the entire surface of the conductive film 9a at this stage. Next, for example, a resist 60 is applied as a mask material to the surface of the insulating film 41. The resist 60 is applied to the surface of the insulating film 41 with a uniform thickness by a spin coating method or the like. Then, the entire substrate 10 is put into an exposure apparatus, and the resist 60 is exposed. For exposure of the resist 60, a gray scale mask (hereinafter simply referred to as GSM) 52 is used. GSM is a photomask whose density changes stepwise or continuously, and the light transmittance increases from the dark part to the light part so that exposure to a deep position of the resist is possible. In the GSM of the first embodiment, a portion corresponding to the protrusion is a dark portion, and a portion corresponding to the groove is a light portion. Further, in the portion corresponding to the groove, the shade is changed stepwise or continuously from the portion corresponding to the top of the unevenness to the portion corresponding to the bottom. The resist 60 is exposed by irradiating light 53 such as ultraviolet rays through the GSM 52 thus formed.
[0047]
Next, as shown in FIG. 6B, the resist 60 is developed. Thereby, in the case of a positive resist, the exposed part is removed. In the first embodiment, the portion corresponding to the ridge is not exposed and is exposed to a deep position from the top to the bottom of the unevenness, so that the shape corresponding to the protrusion, groove and unevenness is patterned on the top of the resist 60. The Note that the upper portion of the resist 60 may be patterned by pressing the transfer mold without using dry etching using GSM. As this transfer mold, a pattern in which ridges, grooves, and inverted shapes of irregularities to be formed in the resist 60 are patterned is used. The transfer mold is composed of a substrate such as quartz, and patterning on the substrate can be performed by a focused ion beam processing method (FIB) or the like.
[0048]
Next, as shown in FIG. 7A, the insulating film 41 and the conductive film 9a are dry-etched through the patterned resist 60. Next, as shown in FIG. For dry etching, an ion etching method or the like can be used. In order to etch the resist 60, oxygen gas or the like is suitable as the etchant 54, and in order to etch the insulating film 41 made of silicon oxide or the like and the conductive film 9a made of ITO or the like, the etchant 54 is made of a fluorine-based material. The gas is preferred. However, when only one of the gases is used, the selection ratio becomes a problem. Therefore, both gases are mixed and used at an appropriate ratio. By performing etching with the mixed gas in this way, the selection ratio between the resist 60, the insulating film 41, and the conductive film 9a can be adjusted to an appropriate value. On the other hand, when both gases are used, process management becomes complicated. Therefore, an inert gas such as argon can be used as the etchant 54. In this way, the process management is simplified by performing etching only with the plasma-ized inert gas. Further, the selectivity is reduced, and the insulating film 41 and the conductive film 9a can be accurately patterned in the same shape as the resist 60.
[0049]
When dry etching is performed as described above, the insulating film 41 and the conductive film 9a are sequentially etched following the resist 60 in the thin portion of the resist 60. In the thick portion of the resist 60, only the resist 60 is etched, and the insulating film 41 and the conductive film 9a are not etched. Thereby, the insulating film 41 and the conductive film 9 a are patterned in the same shape as the resist 60. As described above, as shown in FIG. 7B, the above-described protrusion 17, groove 16, and unevenness 10 a are formed on the upper portion of the pixel electrode 9. Further, the above-described insulating film 41 is disposed only on the surface of the ridge 17.
[0050]
As described above, in the method of manufacturing the alignment substrate according to the first embodiment, the electrical insulating film and the electrode can be formed at a stretch, and the manufacturing cost can be reduced. Note that the contour of the pixel electrode 9 may be formed simultaneously with the formation of the surface of the pixel electrode 9. In this case, the manufacturing cost can be further reduced. Further, since the alignment substrate of the first embodiment forms the unevenness 10a from the bottom to the top of the groove 16, the groove 16, the protrusion 17 and the unevenness 10a are formed on the surface of the pixel electrode 9 by etching in a short time. be able to. Therefore, the manufacturing cost can be further reduced.
[0051]
Then, a liquid crystal device is formed using the alignment substrate described above. Specifically, a sealing material is applied to the peripheral portion of one of the TFT array substrate and the counter substrate formed as described above, and spacers for realizing a predetermined cell gap are dispersed. Then, both the substrates are bonded to each other through the sealing material in a state where the extending directions of the grooves and the protrusions on both the substrates are shifted by a predetermined angle. Further, TN liquid crystal or the like is injected from a liquid crystal injection hole formed in a part of the sealing material, and the liquid crystal injection hole is sealed with a sealing material. Thus, a liquid crystal device is formed.
[0052]
[Modification]
FIG. 8 is a side sectional view of a modification of the alignment substrate according to the first embodiment. In the alignment substrate 110 shown in FIG. 8, shapes corresponding to the protrusions 117, the grooves 116, and the unevenness 110a are formed on the surface of the substrate body 110A. The pixel electrode 109 is formed with a uniform thickness above the substrate body 110A, and the ridge 117, the groove 116, and the unevenness 110a are formed on the surface of the pixel electrode 109. Further, an insulating film 141 is formed on the surface of the protrusion 117. In addition, on the surface of the substrate body 110A, it is preferable that the shape corresponding to the protrusion 117, the groove 116, and the unevenness 110a is selectively formed only in the formation region of the pixel electrode 109, and the other region is a substantially flat surface. . Thereby, a TFT element or the like can be easily formed in a region other than the region where the pixel electrode 109 is formed. Further, as described above, the liquid crystal injection time can be shortened.
[0053]
Next, a manufacturing method of the above-described modification will be described. 9 and 10 are explanatory diagrams of the manufacturing method of the above-described modification.
As shown in FIG. 9A, the surface of the substrate body 110A is initially formed to be a substantially flat surface. Then, a resist 160 is applied to the surface of the substrate body 110A. Next, as in the first embodiment, the resist 160 is exposed through the GSM 162, and the exposed resist 160 is developed. Then, as shown in FIG. 9B, the shape corresponding to the protrusions, grooves and irregularities is patterned on the top of the resist 160.
[0054]
Next, the substrate body 110A is dry-etched using the patterned resist 160 as a mask. Note that an inert gas such as argon can be used for the etchant 164 as described above. As a result, as shown in FIG. 10A, the upper portion of the substrate body 110A is patterned in the same shape as the resist, and shapes corresponding to protrusions, grooves, and irregularities are formed on the upper portion of the substrate body 110A.
[0055]
Next, as shown in FIG. 10B, pixel electrodes 109 are formed with a uniform thickness above the substrate body 110A. Thus, the protrusion 117, the groove 116, and the unevenness 110a are formed on the surface of the pixel electrode 109. Further, as in the first embodiment, the insulating film 141 is formed only on the surface of the protrusion 117. Thereby, an insulating film 141 is formed on a part of the surface of the pixel electrode 109.
[0056]
In the above-described modification, the pixel electrode 109 and the insulating film 141 can be formed to have a uniform thickness, so that a stable voltage can be applied to the liquid crystal molecules. Therefore, a highly reliable liquid crystal device can be provided. In the above-described modification, the shape corresponding to the protrusion 117, the groove 116, and the unevenness 110a is formed on the surface of the substrate body 110A. However, it is formed between the substrate body 110A and the pixel electrode 109 shown in FIG. On the surface of the first interlayer insulating film 12, the second interlayer insulating film 4, or the third interlayer insulating film 7, shapes corresponding to protrusions, grooves, and irregularities may be formed. In particular, if the above shape is formed on the outermost third interlayer insulating film 7, the shape can be faithfully reproduced on the surface of the pixel electrode 9, and the alignment regulating force of liquid crystal molecules can be improved.
[0057]
In each of the alignment substrate of the first embodiment described above and the modifications thereof, the upper portion of the electrode is formed in a shape capable of aligning liquid crystal molecules. According to this configuration, it is not necessary to separately form an alignment film in order to align the liquid crystal molecules. Therefore, the manufacturing cost can be reduced. Further, the alignment film is not decomposed by strong light or heat, and the display quality of the liquid crystal device does not deteriorate. Further, the rubbing treatment of the alignment film is not necessary, and the occurrence of problems due to the rubbing cloth or the dust of the alignment film material can be avoided. Therefore, a highly reliable liquid crystal device can be provided.
[0058]
FIG. 17 is a performance table of the alignment substrate according to the first embodiment and its modifications. In both the alignment substrate of the first embodiment and the modification thereof, since the insulating film is formed on a part of the surface of the electrode, the short circuit between the electrodes is compared with the case where the entire surface of the electrode is exposed to the liquid crystal layer. Can be reduced. Further, since the insulating film is formed only on a part of the surface of the electrode, the occurrence rate of image sticking can be reduced as compared with the case where the insulating film is formed on the entire surface of the electrode. As a result, it is possible to suppress both the occurrence rate of short circuit and seizure between the electrodes within an allowable range. Therefore, a highly reliable liquid crystal device can be provided, and the yield of the liquid crystal device can be improved.
[0059]
[Second Embodiment]
Next, an alignment substrate according to a second embodiment of the present invention will be described with reference to FIGS. The alignment substrate of the second embodiment is different from the first embodiment in that unevenness capable of aligning liquid crystal molecules is formed on the top of each protrusion, and an electrical insulator is formed on the upper end of the protrusion. . Since other points are the same as those of the first embodiment, detailed description thereof is omitted. Further, since the above configuration is common to the TFT array substrate and the counter substrate, the following description will be given by taking a TFT array substrate (hereinafter simply referred to as a substrate) as an example.
[0060]
FIG. 11 is a perspective view of the alignment substrate of the second embodiment. A plurality of grooves 216 and protrusions 217 are alternately formed in parallel on the surface of the pixel electrode 209 of the substrate 210. A plurality of projections and depressions 210b are formed on the top of each protrusion. The irregularities 210b are formed to have the same width as the protrusions 217, and are periodically arranged along the extending direction of the protrusions 217. A step G is provided between the apex of the unevenness 210b and the bottom surface of the groove 216. As in the first embodiment, the height of the step G is 30 to 500 nm, and more preferably 100 to 250 nm. Moreover, the uneven | corrugated 210b cross section along the extending direction of the protrusion 217 is made into the triangular shape (sawtooth shape) which has a gentle slope and a steep slope. By disposing the liquid crystal molecules along the gentle slope, a pretilt angle is given to the liquid crystal molecules.
[0061]
On the other hand, an insulating film 241 that is an electrical insulator is formed on the upper end portion of the surface of each unevenness 210 b that is the upper end portion of the pixel electrode 209. This insulating film 241 is formed on a part of the surface of the substrate 210, specifically, about 10 to 30% of the entire surface of the pixel electrode 209. Note that when the protrusion 217 is formed on about 10 to 30% of the entire surface of the pixel electrode 209, an insulating film may be formed on the entire surface of the unevenness 210b. In addition, when the protrusions 217 are formed on 30% or more of the entire surface of the pixel electrode 209, the insulating film 241 is formed on a part of the surface of the unevenness 210b. In this case, the insulating film 241 is formed at least on the upper end portion of the unevenness 210b that is the upper end portion of the pixel electrode 209. As a result, it is possible to efficiently reduce the occurrence rate of a short circuit between the electrodes, and to provide a highly reliable liquid crystal device.
[0062]
12 is a side cross-sectional view taken along the line CC of FIG. As shown in FIG. 12, the surface of the substrate body 210A in the second embodiment is a substantially flat surface, and the pixel electrode 209 is formed on the upper surface. Further, an insulating film 241 is formed on the surface of the pixel electrode 209. The protrusions 217, the grooves 216, and the unevenness 210 b described above are formed on the pixel electrodes 209 and the insulating film 241 that are stacked. Note that the trench 216 is formed through the insulating film 241 to the middle layer of the pixel electrode, and the pixel electrode 209 is exposed on the bottom surface of the trench 216. The unevenness 210b is formed from the insulating film 241 to the upper layer portion of the pixel electrode 209, and the insulating film 241 and / or the pixel electrode 209 are exposed on the surface of the unevenness 210b.
[0063]
The alignment substrate 210 of the second embodiment is manufactured by the same method as that of the first embodiment. That is, first, similarly to FIG. 6A, a conductive film, an insulating film, and a resist are sequentially formed above the substrate. Then, the resist is exposed using GSM. At that time, GSM different from the first embodiment is used. In the GSM used in the first embodiment, a pattern whose density is changed stepwise or continuously from the top to the bottom of the unevenness is formed on the pattern corresponding to the groove. However, in the second embodiment, since the projections and depressions are formed on the top of the ridges, GSM is used in which the pattern corresponding to the projections and depressions is formed on the pattern corresponding to the ridges. Next, the exposed resist is developed using the GSM. Thereby, like FIG.6 (b), the shape corresponded to a protrusion, a groove | channel, and an unevenness | corrugation is patterned to a resist. Then, as in FIG. 6B, the insulating film and the conductive film are dry-etched using the patterned resist as a mask. Then, as shown in FIG. 12, the alignment substrate 210 of the second embodiment is formed. In the manufacturing method of the alignment substrate described above, the insulating film 241 and the pixel electrode 209 can be formed at a stretch. Therefore, the manufacturing cost can be reduced.
[0064]
[Modification]
FIG. 13 is a side sectional view of a modified example of the alignment substrate according to the second embodiment. In the modification shown in FIG. 13, shapes corresponding to the protrusions 317, the grooves 316, and the unevenness 310b are formed on the surface of the substrate body 310A. However, unlike the modification of the alignment substrate of the first embodiment, a shape corresponding to the unevenness 310b is formed on the upper portion corresponding to the protrusion 317. A pixel electrode 309 is formed with a uniform thickness above the substrate body 310A, and protrusions 317, grooves 316, and irregularities 310b similar to those of the second embodiment are formed on the surface of the pixel electrode 309. Furthermore, an insulating film 341 is formed on the surface of the upper end portion of the unevenness 310b. Note that, on the surface of the substrate body 310A, it is preferable that the shapes corresponding to the protrusions 317, the grooves 316, and the unevenness 310b are selectively formed only in the formation region of the pixel electrode 309 and the other regions are substantially flat surfaces. .
[0065]
The alignment substrate according to the modification of the second embodiment is manufactured by the same method as that of the modification of the first embodiment. First, as in FIG. 9A, a resist is formed on the substantially flat surface of the substrate body. Next, the resist is exposed using the same GSM as in the second embodiment. Next, as in FIG. 9B, the exposed resist is developed, and shapes corresponding to the protrusions, grooves, and irregularities are patterned into the resist. Further, the substrate body is dry etched using the patterned resist as a mask. As a result, similar to FIG. 10A, shapes corresponding to the protrusions, grooves and irregularities are patterned on the upper portion of the substrate body. Next, as shown in FIG. 13, pixel electrodes 309 are formed with a uniform thickness above the substrate body. Thereby, the protrusion 317, the groove 316, and the unevenness 310b are formed on the surface of the pixel electrode 309. Further, an insulating film 341 is formed on the upper end portion of the unevenness 310b. Thus, the insulating film 341 is formed on part of the surface of the pixel electrode 309.
[0066]
Both the alignment substrate of the second embodiment described above and the modifications thereof can achieve the same effects as those of the first embodiment. That is, since the surface of the electrode is formed in a shape capable of aligning liquid crystal molecules, it is not necessary to separately form an alignment film, and the occurrence of problems due to the alignment film can be avoided. In addition, as shown in FIG. 17, since the insulating film is formed on a part of the surface of the electrode, the occurrence rate of the short circuit between the electrodes can be reduced. Further, since the insulating film is formed only on part of the electrode, the occurrence rate of image sticking can be reduced. Therefore, it is possible to suppress both the occurrence rate of short circuit and seizure between the electrodes within an allowable range. Thus, a highly reliable liquid crystal device can be provided, and the yield of the liquid crystal device can be improved.
[0067]
[Third Embodiment]
Next, an alignment substrate according to a third embodiment of the present invention will be described with reference to FIGS. In the alignment substrate of the third embodiment, unevenness capable of aligning liquid crystal molecules is formed at the top of each protrusion and the bottom of each groove, and an electrical insulator is formed at the top of the protrusion formed at the top of each protrusion. This is different from the first embodiment and the second embodiment. Since other points are the same as those of the first embodiment and the second embodiment, detailed description thereof is omitted. Further, since the above configuration is common to the TFT array substrate and the counter substrate, the following description will be given by taking a TFT array substrate (hereinafter simply referred to as a substrate) as an example.
[0068]
FIG. 14 is a perspective view of the alignment substrate of the third embodiment. A plurality of grooves 416 and protrusions 417 are alternately formed in parallel on the surface of the pixel electrode 409 of the substrate 410. A plurality of irregularities 410 a are periodically formed along the extending direction of the grooves 416 at the bottom of each groove 416. A plurality of projections and depressions 410b are formed on the top of each protrusion 417 periodically along the extending direction of the protrusion 417. In addition, the level | step difference G is provided between the top part of the unevenness | corrugation 410a, and the bottom part of the unevenness | corrugation 410b. Similar to the first and second embodiments, the height of the step G is 30 to 500 nm, more preferably 100 to 250 nm. Furthermore, the cross sections of the unevenness 410a and the unevenness 410b are triangular (sawtooth shape) having a gentle slope and a steep slope. By disposing the liquid crystal molecules along the gentle slope, a pretilt angle is given to the liquid crystal molecules.
[0069]
On the other hand, an insulating film 441 that is an electrical insulator is formed on the upper end portion of each of the projections and depressions 410b that is the upper end portion of the pixel electrode 409, as in the second embodiment. The insulating film 441 is formed on a part of the surface of the substrate 410, specifically, about 10 to 30% of the entire surface of the pixel electrode 409. Note that in the case where the protrusions 417 are formed on about 10 to 30% of the entire surface of the pixel electrode 409, an insulating film may be formed on the entire surface of the unevenness 410b. In addition, when the protrusion 417 is formed on 30% or more of the entire surface of the pixel electrode 409, the insulating film 441 is formed on a part of the surface of the protrusion 417. Thereby, a highly reliable liquid crystal device can be provided.
[0070]
15 is a side cross-sectional view taken along the line DD of FIG. As shown in FIG. 15, the surface of the substrate body 410A in the third embodiment is a substantially flat surface, and the pixel electrode 409 is formed thereabove. Further, an insulating film 441 is formed on the surface of the pixel electrode 409. The protrusions 417 and unevenness 410b, and the grooves 416 and unevenness 410a are formed above the pixel electrode 409 and / or the insulating film 441 that are stacked. Note that the pixel electrode 409 is exposed on the surface of the unevenness 410a, and the insulating film 441 and / or the pixel electrode 409 is exposed on the surface of the unevenness 410b.
[0071]
The alignment substrate 410 of the third embodiment is manufactured by the same method as that of the first and second embodiments. That is, first, similarly to FIG. 6A, a conductive film, an insulating film, and a resist are sequentially formed above the substrate. Then, the resist is exposed using GSM. In the third embodiment, since the unevenness is formed on the bottom of the groove and the top of the protrusion, the pattern corresponding to the unevenness is formed both on the pattern corresponding to the groove and on the pattern corresponding to the protrusion. Use GSM. Next, the exposed resist is developed using the GSM. Thereby, like FIG.6 (b), the shape corresponded to a protrusion, a groove | channel, and an unevenness | corrugation is patterned to a resist. Then, as in FIG. 6B, the insulating film and the conductive film are dry-etched using the patterned resist as a mask. Then, as shown in FIG. 15, the alignment substrate 410 of the third embodiment is formed. In the manufacturing method of the alignment substrate described above, the insulating film 441 and the pixel electrode 409 can be formed at a stretch. Therefore, the manufacturing cost can be reduced.
[0072]
[Modification]
FIG. 16 is a side sectional view of a modified example of the alignment substrate according to the third embodiment. In the modification shown in FIG. 16, shapes corresponding to the grooves 516 and the unevenness 510a, and the protrusions 517 and the unevenness 510b are formed on the surface of the substrate body 510A. Then, the pixel electrode 509 is formed on the upper surface of the substrate body 510A with a uniform thickness. On the surface of the pixel electrode 509, the groove 516, the unevenness 510a, the protrusion 517, and the unevenness 510b are formed as in the third embodiment. Yes. Further, an insulating film 541 is formed on the surface of the upper end portion of the unevenness 510b. Note that on the surface of the substrate body 510A, the shapes corresponding to the grooves 516 and the projections and depressions 510a and the protrusions 517 and the projections and depressions 510b are selectively formed only in the formation region of the pixel electrode 509, and the other regions are substantially flat surfaces. Is preferred.
[0073]
The alignment substrate according to the modification of the third embodiment is manufactured by the same method as that of the modification of the first embodiment and the second embodiment. First, as in FIG. 9A, a resist is formed on the substantially flat surface of the substrate body. Next, the resist is exposed using the same GSM as in the third embodiment. Next, as in FIG. 9B, the exposed resist is developed, and shapes corresponding to the protrusions, grooves, and irregularities are patterned into the resist. Further, the substrate body is dry etched using the patterned resist as a mask. As a result, similar to FIG. 10A, shapes corresponding to the protrusions, grooves and irregularities are patterned on the upper portion of the substrate body. Next, as shown in FIG. 16, pixel electrodes 509 are formed with a uniform thickness above the substrate body. Thereby, the groove 516 and the unevenness 510a, the protrusion 517 and the unevenness 510b are formed on the surface of the pixel electrode 509. Further, an insulating film 541 is formed on the upper end portion of the unevenness 510b. As described above, the alignment substrate according to the modification of the third embodiment is formed.
[0074]
Both the alignment substrate of the third embodiment described above and the modifications thereof can achieve the same effects as those of the first embodiment and the second embodiment. In particular, since liquid crystal molecules can be favorably aligned by a large number of irregularities, it is not necessary to separately form an alignment film, and the occurrence of problems due to the alignment film can be avoided. In addition, as shown in FIG. 17, since the insulating film is formed on a part of the surface of the electrode, the occurrence rate of the short circuit between the electrodes can be reduced. Further, since the insulating film is formed only on part of the electrode, the occurrence rate of image sticking can be reduced. Therefore, it is possible to suppress both the occurrence rate of short circuit and seizure between the electrodes within an allowable range. Thus, a highly reliable liquid crystal device can be provided, and the yield of the liquid crystal device can be improved.
[0075]
[Projection type display device]
Next, a projection display device which is a specific example of the electronic apparatus of the invention will be described with reference to FIG. FIG. 18 is a schematic configuration diagram illustrating a main part of the projection display device. This projection type display device includes the transmissive liquid crystal device according to any one of the first to third embodiments as a liquid crystal light modulation device.
[0076]
In FIG. 18, 810 is a light source, 813 and 814 are dichroic mirrors, 815, 816 and 817 are reflection mirrors, 818 is an incident 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, 826 is a projection lens, 831, 832, and 833 are polarizing plates on the incident side, and 834, 835, and 836 are polarizing plates on the outgoing side. The light source 810 includes a lamp 811 such as a metal halide and a reflector 812 that reflects the light of the lamp.
[0077]
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 liquid crystal light modulation device 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 liquid crystal light modulator 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. The blue light is incident on the blue light liquid crystal light modulation device 824 via the light guide unit 821.
[0078]
The three color lights modulated by the respective light modulation devices 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.
[0079]
As described above, when the transmissive liquid crystal device according to any of the first to third embodiments is used as the liquid crystal light modulators 822, 823, and 824 of the projection display device, strong light or heat emitted from the light source 810 is used. Thus, the alignment film is not decomposed. Further, the liquid crystal alignment control function does not deteriorate even after long-term use, and the display quality of the projection display device does not deteriorate.
[0080]
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 spirit of the present invention. For example, in the embodiment, the TN mode liquid crystal device has been described as an example. However, the present invention can be applied to the ECB mode, the vertical alignment mode, the STN (Super Twisted Nematic) mode, the ferroelectric mode, the antiferroelectric mode, and the like when no voltage is applied. The alignment state of the liquid crystal molecules can be applied to any liquid crystal device. In the embodiment, a liquid crystal device including a TFT as a switching element has been described as an example. However, a two-terminal element such as a thin film diode may be employed as the switching element. In the embodiment, the transmissive liquid crystal device has been described as an example. However, the liquid crystal device of the present invention can be applied to a reflective or transflective liquid crystal device. Furthermore, although the three-plate projection display device has been described as an example of the electronic apparatus, the liquid crystal device of the present invention can be applied to a single-plate projection display device or a direct-view display device.
[0081]
Another specific example of the electronic device of the present invention is a mobile phone. This mobile phone includes the transmissive liquid crystal device according to any one of the first to third embodiments in a display unit. Other electronic devices include, for example, an IC card, a video camera, a personal computer, a head mounted display, a fax machine with a display function, a digital camera finder, a portable TV, a DSP device, a PDA, an electronic notebook, and an electric bulletin board. And advertising announcement displays.
[Brief description of the drawings]
FIG. 1 is an equivalent circuit diagram of a plurality of pixels in a liquid crystal device.
FIG. 2 is a plan view of a plurality of pixels formed on a TFT array substrate.
FIG. 3 is a side cross-sectional view taken along line AA ′ of FIG.
FIG. 4 is a perspective view of an alignment substrate according to the first embodiment.
5 is a side cross-sectional view taken along line BB in FIG. 4. FIG.
FIG. 6 is a first explanatory view of a method for manufacturing an alignment substrate.
FIG. 7 is a second explanatory view of the method of manufacturing the alignment substrate.
FIG. 8 is a side sectional view of a modified example of the alignment substrate of the first embodiment.
FIG. 9 is a first explanatory view of a manufacturing method of a modified example of an alignment substrate.
FIG. 10 is a second explanatory diagram of the manufacturing method of the modified example of the alignment substrate.
FIG. 11 is a perspective view of an alignment substrate according to a second embodiment.
12 is a side cross-sectional view taken along line CC in FIG. 11. FIG.
FIG. 13 is a side sectional view of a modified example of the alignment substrate of the second embodiment.
FIG. 14 is a perspective view of an alignment substrate according to a third embodiment.
15 is a side sectional view taken along line DD of FIG.
FIG. 16 is a side cross-sectional view of a modified example of the alignment substrate of the third embodiment.
FIG. 17 is a performance table of an alignment substrate according to an embodiment and variations thereof.
FIG. 18 is a configuration diagram showing a main part of a projection display device.
[Explanation of symbols]
9 electrodes 10 substrates 10a irregularities 16 grooves 17 ridges 41 insulating films

Claims (15)

A substrate capable of aligning liquid crystal molecules,
A conductor formed above the substrate and applying a voltage to the liquid crystal molecules;
An electrical insulator formed on a part of the surface of the conductor;
An alignment substrate comprising: The alignment substrate according to claim 1, wherein the electrical insulator is formed at least on an upper end portion of the conductor. The alignment substrate according to claim 1, wherein an area of the electrical insulator is smaller than an exposed area of the conductor. 4. The alignment substrate according to claim 1, wherein the electrical insulator is made of a material having visible light permeability. The alignment substrate according to claim 1, wherein the electrical insulator is made of a light-resistant material. 6. The alignment substrate according to claim 1, wherein a surface of the electrical insulator and / or the conductor is formed into a shape capable of aligning the liquid crystal molecules. On the surface of the conductor, a plurality of grooves capable of aligning the liquid crystal molecules and a plurality of protrusions separating the grooves are formed in parallel to each other,
A plurality of irregularities capable of aligning the liquid crystal molecules are periodically formed at the bottom of each groove along the extending direction of each groove,
The alignment substrate according to claim 1, wherein the electrical insulator is formed on all or a part of the surface of each protrusion. On the surface of the conductor, a plurality of grooves capable of aligning the liquid crystal molecules and a plurality of protrusions separating the grooves are formed in parallel to each other,
A plurality of protrusions and recesses capable of orienting the liquid crystal molecules are periodically formed on the top of each protrusion along the extending direction of each protrusion,
The alignment substrate according to claim 1, wherein the electrical insulator is formed on all or a part of the surface of each of the irregularities. On the surface of the conductor, a plurality of grooves capable of aligning the liquid crystal molecules and a plurality of protrusions separating the grooves are formed in parallel to each other,
A plurality of irregularities capable of aligning the liquid crystal molecules are periodically formed at the bottom of each groove along the extending direction of each groove,
A plurality of protrusions and recesses capable of orienting the liquid crystal molecules are periodically formed on the top of each protrusion along the extending direction of each protrusion,
The orientation according to any one of claims 1 to 6, wherein the electrical insulator is formed on all or a part of a surface of each of the irregularities formed on the top of each protrusion. substrate. Forming a conductor above the substrate body;
Forming an electrical insulator on the surface of the conductor;
Forming a mask material on the surface of the electrical insulator;
Forming the mask material into a shape capable of aligning liquid crystal molecules;
By etching the electrical insulator and / or the conductor through the molded mask material, the surface of the electrical insulator and / or the conductor is formed into a shape capable of aligning the liquid crystal molecules. And a process of
A method for producing an alignment substrate, comprising: Forming a mask material on the surface of the substrate body;
Forming the mask material into a shape capable of aligning liquid crystal molecules;
Etching the surface of the substrate body through the molded mask material, forming the surface of the substrate body into a shape capable of aligning the liquid crystal molecules;
Forming a conductor above the substrate body;
Forming an electrical insulator on a portion of the surface of the conductor;
A method for producing an alignment substrate, comprising: A liquid crystal device comprising the alignment substrate according to claim 1. A liquid crystal device manufactured using the method for manufacturing an alignment substrate according to claim 10. A pair of substrates disposed opposite to each other, a liquid crystal layer sandwiched between the pair of substrates, a conductor formed on a surface of each substrate on the liquid crystal layer side, and applying a voltage to the liquid crystal layer; And an electric insulator formed on a part of the surface. An electronic apparatus comprising the liquid crystal device according to claim 12.

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