JP2008225032A - Liquid crystal device, manufacturing method of liquid crystal device, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal device which has an alignment layer capable of aligning liquid crystal in a uniform direction on a pixel electrode without being influenced by steps, and to provide a manufacturing method of the liquid crystal device and an electronic apparatus. <P>SOLUTION: In the liquid crystal device which has liquid crystal with dielectric anisotropy between a pair of substrates, at least one of the pair of substrates have the pixel electrode and the inorganic alignment layer formed on the pixel electrode to align and restrict the liquid crystal; the inorganic alignment layer is formed of a first obliquely vapor-deposited film and a second obliquely vapor-deposited film formed by oblique vapor deposition on the substrate from mutually opposite directions, and the liquid crystal tilts of the liquid crystal developed by the first obliquely vapor-deposited film and second obliquely vapor-deposited film are mutually in the same direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal device in which a liquid crystal having negative dielectric anisotropy is sandwiched between a pair of substrates, a method for manufacturing the liquid crystal device, and an electronic apparatus.

As an alignment film for regulating alignment of liquid crystal molecules in a liquid crystal device which is an electro-optical device, an oblique deposition alignment film formed by depositing SiO ₂ or the like at a predetermined angle with respect to a substrate surface is known. A technique for forming this oblique vapor deposition alignment film on the substrate surface is disclosed, for example, in JP-A-5-203958 as an oblique vapor deposition method.

  By the way, in a vertical alignment type, so-called VA mode liquid crystal device, nematic liquid crystal having negative dielectric anisotropy is used, and liquid crystal molecules arranged substantially vertically on a substrate are tilted and aligned by a voltage to perform display. For this reason, if the tilt direction of the liquid crystal molecules is not constant at the time of driving, noticeable unevenness in brightness and darkness occurs. Therefore, in order to avoid this phenomenon, a slight pretilt angle is given during vertical alignment.

When a small pretilt angle is given, the liquid crystal molecules may fall in a direction different from the desired direction, which appears as uneven display. In order to improve this, for example, Japanese Examined Patent Publication No. 55-13338 discloses a method of forming an alignment film by performing oblique deposition twice from directions different from each other by 90 degrees, and setting the liquid crystal tilt direction constant. Has been.
JP-A-5-203958 Japanese Patent Publication No.55-13338

  By the way, a step is formed between the pixel electrodes adjacent to each other in the liquid crystal device by forming wirings, switching elements, and the like. In the case of forming an inorganic alignment film by the oblique deposition method described above, the oblique deposition alignment film is not formed in a region that is shadowed by this step when viewed from the deposition source, and display unevenness due to poor alignment of the liquid crystal is caused. As a result, the display quality deteriorates.

  The present invention has been made in view of the above problems, and a liquid crystal device and a liquid crystal device having an alignment film capable of aligning liquid crystal in a uniform orientation on a pixel electrode without being affected by a step. An object of the present invention is to provide an electronic device.

  A liquid crystal device according to the present invention is a liquid crystal device in which a liquid crystal having negative dielectric anisotropy is sandwiched between a pair of substrates, and at least one of the pair of substrates includes a pixel electrode and An inorganic alignment film that is formed on the pixel electrode and regulates alignment of the liquid crystal, and the inorganic alignment film is formed by oblique deposition on the substrate from opposite directions. And the tilt directions of the liquid crystals formed by the first oblique deposition film and the second oblique deposition film coincide with each other. It is characterized by.

  A method for manufacturing a liquid crystal device according to the present invention is a method for manufacturing a liquid crystal device in which a liquid crystal having negative dielectric anisotropy is sandwiched between a pair of substrates, and a predetermined amount is formed on a pixel electrode. Forming a first obliquely deposited film from an orientation by an oblique deposition method; and forming a second obliquely deposited method from an orientation opposite to the predetermined orientation on the first obliquely deposited film. Forming an oblique vapor deposition film, wherein in the step of forming the second oblique vapor deposition film, an inclination direction of the liquid crystal on the second oblique vapor deposition film is the first The deposition angle is determined so as to coincide with the tilt direction of the liquid crystal on the oblique deposition film.

  An electronic apparatus according to the present invention includes the liquid crystal device.

  According to such a configuration of the present invention, the inorganic alignment film formed by oblique deposition from opposite directions is formed on the entire display region without being affected by the step formed around the pixel electrode. The The inorganic alignment film formed over the entire display area regulates the alignment of the liquid crystal in all areas so as to be inclined in substantially the same direction.

  Therefore, according to the present invention, it is possible to align the liquid crystal in a uniform orientation in the entire display region without being affected by the step formed on the substrate. Therefore, it is possible to provide a high-quality display with high contrast without display abnormality such as light leakage due to alignment failure.

  According to the present invention, a plurality of pixels are arranged in a matrix, and the pixels have an opening region and a peripheral region surrounding the opening region, and the peripheral region is electrically connected to the pixel electrode. A switching element and a wiring electrically connected to the switching element are provided, and in the peripheral region, the inorganic alignment film is the first oblique deposition film or the second oblique deposition film. In the opening region, the inorganic alignment film preferably has a laminated structure of the first oblique vapor deposition film and the second oblique vapor deposition film.

  According to such a configuration, the alignment regulating force by the inorganic alignment film in the opening region and the alignment regulating force by the inorganic alignment film in the peripheral region can be set to predetermined values, respectively. Therefore, for example, by setting the alignment control force so as to suppress the occurrence of reverse tilt due to the lateral electric field due to the influence of adjacent pixels, the occurrence of uneven transmission in the disclination line caused by the occurrence of reverse tilt is suppressed. Therefore, it is possible to provide a display with higher contrast.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The liquid crystal device according to the present embodiment is a tilted vertical alignment type liquid crystal display device that controls liquid crystal having negative dielectric anisotropy so as to be aligned substantially vertically when no voltage is applied, so-called VA mode liquid crystal display device. It is. In each drawing used for the following description, the scale is different for each member in order to make each member a size that can be recognized on the drawing. Similarly, in each of the drawings used for the following description, the angle is emphasized and displayed in order to make the magnitude relation of the angle of each member recognizable on the drawing.

  First, the overall configuration of the liquid crystal device 100 of the present embodiment will be described with reference to FIGS. 1 and 2. Here, FIG. 1 is a plan view of the liquid crystal device when the TFT array substrate is viewed from the side of the counter substrate together with each component configured thereon. 2 is a cross-sectional view taken along the line H-H ′ of FIG. 1. In the present embodiment, as an example of the liquid crystal device, a transmissive liquid crystal display device of a TFT active matrix driving method with a built-in driving circuit is taken as an example.

  In the liquid crystal device 100, the liquid crystal 50 is sandwiched between the TFT array substrate 10 made of glass, quartz, or the like and the counter substrate 20, and the alignment state of the liquid crystal 50 is changed, whereby the counter substrate 20 is placed in the image display region 10a. The light incident from the side is modulated and emitted from the TFT array substrate 10 side, whereby an image is displayed in the image display region 10a.

  1 and 2, in the liquid crystal device 100 according to the present embodiment, the TFT array substrate 10 and the counter substrate 20 are arranged to face each other. The TFT array substrate 10 and the counter substrate 20 are bonded to each other by a seal material 52 provided in a seal region located around the image display region 10a. Between the TFT array substrate 10 and the counter substrate 20, A liquid crystal 50 is sandwiched. Further, in the sealing material 52, gap materials such as glass fibers or glass beads are arranged in a scattered manner so that the distance between the TFT array substrate 10 and the counter substrate 20 is set to a predetermined value.

  A light-shielding frame light-shielding film 53 that defines the frame area of the image display region 10a is provided on the counter substrate 20 side in parallel with the inside of the seal region where the seal material 52 is disposed. A part or all of the frame light shielding film 53 may be provided as a built-in light shielding film on the TFT array substrate 10 side.

  In the present embodiment, there is a non-display area located around the image display area 10a. In the non-display area, the data line driving circuit 101 and the mounting terminal 102 are provided along one side of the TFT array substrate 10 in an area located outside the seal area where the seal material 52 is disposed. Although not shown, by connecting a flexible printed circuit board or the like to the mounting terminals 102 exposed on the surface of the TFT array substrate 10, electrical connection between the liquid crystal device 100 and the outside such as a control device of an electronic device can be achieved. Done.

  The scanning line driving circuit 104 is provided along two sides adjacent to one side of the TFT array substrate 10 on which the data line driving circuit 101 and the mounting terminals 102 are provided, and is covered with the frame light shielding film 53. . Further, the TFT array substrate 10 is provided along the remaining side, that is, the side facing the one side of the TFT array substrate 10 on which the data line driving circuit 101 and the mounting terminal 102 are provided, and is provided so as to be covered with the frame light shielding film 53. The two scanning line driving circuits 104 are electrically connected to each other by the plurality of wirings 105.

  Further, at least one corner of the counter substrate 20 is provided with a vertical conductive material 106 that functions as a vertical conductive terminal for electrical connection between the TFT array substrate 10 and the counter substrate 20. On the other hand, the TFT array substrate 10 is provided with vertical conduction terminals in a region corresponding to these vertical conduction members 106. Electrical connection is made between the TFT array substrate 10 and the counter substrate 20 via the vertical conductive member 106 and the vertical conductive terminal.

In FIG. 2, an inorganic alignment film 16 is formed on the TFT array substrate 10 on the pixel electrode 9a after the formation of pixel switching TFTs, scanning lines, data lines, and the like. On the other hand, on the counter substrate 20, in addition to the counter electrode 21, a lattice-shaped or striped light-shielding film 23 and an inorganic alignment film 22 are formed on the uppermost layer. As will be described in detail later, the inorganic alignment films 16 and 22 formed on the surfaces of the TFT array substrate 10 and the counter substrate 20 that are in contact with the liquid crystal 50 are thin films made of a light-transmitting inorganic material such as SiO _2. is there. The inorganic alignment films 16 and 22 are films for regulating the alignment of the liquid crystal 50, and the liquid crystal 50 takes a predetermined alignment state between the pair of inorganic alignment films 16 and 22. Note that the liquid crystal device 100 of the present embodiment employs a tilted vertical alignment mode, a so-called VA mode.

An inorganic alignment film composed of an inorganic material such as SiO ₂ is excellent in light resistance and heat resistance with respect to an alignment film composed of an organic material such as polyimide, so that the display quality is not deteriorated over time. A liquid crystal device can be realized.

  In addition, a polarizing film, a retardation film, and a polarizing film are respectively provided on the side on which the incident light of the counter substrate 20 enters and on the side on which the outgoing light of the TFT array substrate 10 is emitted, depending on the normally white mode / normally black mode. A plate or the like is arranged in a predetermined direction.

  Next, the configuration of the pixel portion of the liquid crystal device described above will be described with reference to FIGS. FIG. 3 is an equivalent circuit of various elements, wirings, and the like in a plurality of pixels formed in a matrix that forms an image display area of the liquid crystal device. FIG. 4 is a schematic configuration diagram schematically showing an example of the configuration of the pixel portion in the TFT array substrate. FIG. 5 is a diagram illustrating the pretilt angle θp and the azimuth angle ψp. FIG. 6 is a diagram showing the relationship between the deposition angle and the pretilt angle of the inorganic vertical alignment film. 7 is a cross-sectional view taken along the line VII-VII in FIG.

  As shown in FIGS. 3 and 4, the liquid crystal device 100 according to the present embodiment includes a plurality of scanning lines 11 a and a plurality of data lines 6 a arranged so as to cross each other, and the plurality of scanning lines 11 a and the plurality of data lines. A pixel electrode 9a disposed corresponding to the intersection of the data lines 6a and a TFT 30 for switching control of the pixel electrode are provided.

  In other words, the TFT 30 that is a switching element, and the scanning line 11a, the data line 6a, and the capacitor line 400 that are electrically connected to the TFT 30 are formed in the peripheral region surrounding the pixel electrodes 9a arranged in a matrix. ing. A data line 6 a to which an image signal is supplied is electrically connected to the source of the TFT 30.

  The image signals S1, S2,..., Sn to be written to the data line 6a by the data drive circuit 101 may be supplied line-sequentially in this order, or for each group of data lines 6a adjacent to each other. You may make it supply.

  In addition, the scanning line 11a is electrically connected to the gate electrode 3a of the TFT 30, and the scanning line driving circuit 104 pulses the scanning signals G1, G2,... To the scanning line 11a and the gate electrode 3a at a predetermined timing. , Gm are applied in this order in a line sequential manner.

  The pixel electrode 9a is electrically connected to the drain of the TFT 30, and is supplied from the data line 6a by supplying the operation signal Gm to the TFT 30 at a predetermined timing and turning on the TFT 30 for a certain period. Image signals S1, S2,..., Sn are written to the pixel electrode 9a.

  Image signals S1, S2,..., Sn written to the pixel electrode 9a are held for a certain period with the counter electrode 21 formed on the counter substrate. The liquid crystal 50 having negative dielectric anisotropy modulates light by aligning liquid crystal molecules so as to fall from the normal direction of the TFT array substrate 10 to a predetermined direction according to the applied voltage level, Enables gradation display. In the normally white mode, the transmittance for incident light is reduced according to the voltage applied in units of each pixel, and in the normally black mode, the light is incident according to the voltage applied in units of each pixel. The light transmittance is increased, and light having a contrast corresponding to the image signal is emitted from the liquid crystal device 100 as a whole.

  In order to prevent the image signal held here from leaking, a storage capacitor 70 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 9a and the counter electrode. The storage capacitor 70 is provided side by side with the scanning line 11a, and the fixed potential side capacitor electrode is electrically connected to the capacitor wiring 400 fixed at a constant potential.

  In the present embodiment, when the liquid crystal device 100 is viewed in a plan view, that is, when the liquid crystal device 100 is viewed from the viewpoint of FIG. 1, the region where the light modulated by the liquid crystal 50 is emitted in the image display region 10a. It shall be called an opening area. A pixel electrode 9a, a counter electrode 21, and inorganic alignment films 16 and 22 are formed in the opening region. The TFT 30, the scanning line 11 a, the data line 6 a, the capacitor line 400, and the light shielding film 23 are formed in the peripheral area surrounding the opening area.

  Here, the definitions of the inclination angle θ and the azimuth angle ψ used in the following description will be described. In the present embodiment, first, two axes orthogonal to each other, the x axis and the y axis are defined on a plane parallel to the surface of the TFT array substrate 10 on the liquid crystal 50 side. In this embodiment, for example, the x axis is substantially parallel to the extending direction of the scanning line 11a, and the y axis is substantially parallel to the extending direction of the data line 6a. An axis perpendicular to the x-axis and y-axis, that is, an axis parallel to a normal line of a plane parallel to the surface of the TFT array substrate 10 on the liquid crystal 50 side is referred to as a z-axis. In addition, an inclination angle with respect to the z-axis is θ, and an azimuth angle on a plane parallel to the surface of the TFT array substrate 10 on the liquid crystal 50 side is ψ. The same applies to the surface of the counter substrate 20 on the liquid crystal 50 side.

  The liquid crystal device 100 of this embodiment is a vertical alignment mode liquid crystal display device using a liquid crystal 50 having negative dielectric anisotropy. Therefore, as shown in FIG. 6, the liquid crystal molecules 50a of the liquid crystal 50 are predetermined from the z-axis to the direction D1 of the predetermined azimuth angle ψp by the alignment regulating force by the inorganic alignment films 16 and 22 when no voltage is applied. Is oriented so as to be inclined by the angle θp. The tilt angle θp of the liquid crystal molecules 50a when no voltage is applied is referred to as a pretilt angle.

  The inorganic alignment films 16 and 22 that develop the pretilt angle θp in the predetermined azimuth angle ψp direction with respect to the liquid crystal 50 having such negative dielectric anisotropy are formed by a known oblique vapor deposition method. Is. In the oblique vapor deposition method, for example, as shown in FIG. 5, vapor deposition is performed at a position that forms a predetermined angle θ0 with respect to the TFT array substrate 10 from the direction D1 with respect to the z axis that is the normal line of the TFT array substrate 10. The source 60 is disposed to perform vapor deposition. This predetermined angle θ0 is referred to as a deposition angle.

In the present embodiment, the inorganic alignment films 16 and 22 are made of SiO ₂ , and are formed by performing the above oblique vapor deposition method using the vapor deposition source 60 as SiO ₂ . Microscopically, the inorganic alignment films 16 and 22 formed in this way are constituted by a large number of columnar structures made of SiO ₂ having a predetermined density.

This columnar structure is also called a column structure, and is a nanometer-order structure that grows by depositing SiO ₂ molecules by vapor deposition under a predetermined condition. This columnar structure is provided so as to be inclined in the D1 direction (azimuth angle ψp) by a predetermined vapor deposition angle θ0 with respect to a normal line (z axis) substantially parallel to the TFT array substrate 10.

  Here, FIG. 6 shows the relationship between the vapor deposition angle θ0 when forming the inorganic alignment film as the vertical alignment film and the pretilt angle of the liquid crystal molecules expressed by the inorganic alignment film formed at the vapor deposition angle θ0. In FIG. 6, the case where vapor deposition is performed from the direction orthogonal to the substrate surface when the vapor deposition angle θ0 is 0 degree is shown.

  That is, as shown in FIG. 6, the pretilt angle θp tends to increase with the vapor deposition angle θ0 until the vapor deposition angle θ0 reaches a certain value θ0a. However, if the deposition angle θ0 is further increased beyond θ0a, the value of the pretilt angle θp starts to decrease. When the vapor deposition angle θ0 reaches a predetermined value θ0b, the pretilt angle θp becomes 0 degree.

  As the deposition angle θ0 is further increased, the pretilt θp value becomes negative. That is, when the value of the pretilt angle θp is negative, unlike the state shown in FIG. 5, the liquid crystal molecules 50a are inclined by θp in the azimuth angle direction opposite to the D1 direction.

  In the present embodiment, a region where the pretilt angle θp takes a positive value, that is, a region where the value of the deposition angle θ0 in FIG. 6 is from 0 to less than θ0b is referred to as a forward tilt region. The inorganic alignment film formed by the oblique vapor deposition method with the vapor deposition angle θ0 in the forward tilt region exhibits a pretilt angle θp that is inclined in the same direction as the vapor deposition direction.

  On the other hand, in this embodiment, a region where the pretilt angle θp takes a negative value, that is, a region where the value of the deposition angle θ0 is larger than θ0b in FIG. 6 is referred to as a reverse tilt region. The inorganic alignment film formed by the oblique vapor deposition method with the vapor deposition angle θ0 in the reverse tilt region exhibits a pretilt angle θp that is inclined in a direction opposite to the vapor deposition direction.

Hereinafter, a schematic configuration of the display area 10a of the TFT array substrate 10 of the liquid crystal device 100 of the present embodiment will be described.
In the following description, it is assumed that the azimuth direction D1 of the pretilt of the liquid crystal molecules 50a expressed by the alignment regulating force of the inorganic alignment film 16 is substantially coincident with the cross-sectional direction of FIG. That is, the liquid crystal molecules 50a are inclined in a direction parallel to the paper surface of FIG. In FIG. 7, the upward direction is the normal direction of the TFT array substrate 10 as opposed to the paper surface.

  As shown in FIG. 7, the scanning line 11 a is formed in a region between adjacent pixel electrodes 9 a when the TFT array substrate 10 is viewed in plane, that is, a peripheral region of the opening region A <b> 0. The scanning line 11a is composed of a light-shielding metal film, and has a function of a light-shielding film that is provided so as to cover the TFT 30 in a plan view but prevents light from entering the TFT 30 (not shown).

  Further, the capacitor line 400 is also formed in a region between adjacent pixel electrodes 9a when the TFT array substrate 10 is viewed in plane, that is, in a peripheral region of the opening region A0. The capacitor line 400 is disposed above the scanning line 11a, and the interlayer insulating film 12 made of a silicon oxide film is formed between the capacitor line 400 and the scanning line 11a.

  In the upper layer of the capacitor line 400, the pixel electrode 9a is formed for each opening region A0 via the interlayer insulating film 12. In the present embodiment, the pixel electrode 9a is composed of an ITO film that is a transparent conductive film.

  The scanning line 11a, the capacitor line 400, the data line 6a, and the TFT 30 that is a switching element formed on the TFT array substrate 10 are all other than the opening area A0, that is, an area between adjacent pixel electrodes 9a. It is formed in the peripheral region. Therefore, as shown in FIG. 7, the laminated structure in the peripheral region of the opening region A0 tends to be thick, and as a result, the step 200 having the convex region as the peripheral region of the opening region A0 is formed on the surface where the pixel electrode 9a is formed. Occurs.

An inorganic alignment film 16 is formed on the pixel electrode 9a. In the present embodiment, the inorganic alignment film 16 is formed by oblique deposition of SiO ₂ , but the configuration is particularly different from that of the conventional inorganic alignment film.

Below, the structure of the inorganic alignment film 16 of the liquid crystal device 100 of this embodiment is demonstrated below.
As shown in FIG. 7, the inorganic alignment film 16 of the present embodiment has a two-layer laminated structure in the central portion of the opening region A0. The inorganic alignment film 16 includes a lower alignment film 41 that is a first oblique deposition film formed immediately above the pixel electrode 9 a and an upper layer that is a second oblique deposition film formed on the lower alignment film 41. The alignment film 42 is used.

The lower alignment film 41 is formed by obliquely depositing SiO ₂ from an azimuth angle direction 180 degrees opposite to the D1 direction when the deposition angle θ0 is a value that becomes a reverse tilt region, that is, a value θ01 larger than θ0b. It is a deposited film.

That is, as shown in FIG. 7, the lower alignment film 41 is configured such that the vapor deposition source 61 made of SiO ₂ is in a direction in which the azimuth angle ψ is ψp + 180 [°] with respect to the TFT array substrate 10. The tilt angle θ from the normal line of 10 is arranged at an angle satisfying θ01> θ0b [°] and oblique deposition is performed. Note that the lower alignment film 41 is not formed in the region A <b> 2 that is a shadow of the step 200 when viewed from the vapor deposition source 61.

  More specifically, the lower alignment film 41 is in a direction (azimuth angle ψp + 180 [°]) opposite to the D1 direction by a predetermined deposition angle θ01 with respect to a normal line (z axis) substantially parallel to the TFT array substrate 10. ) Is formed by a set of columnar structures protruding so as to be inclined.

On the other hand, the upper alignment film 42 formed on the lower alignment film 41 has an azimuth angle direction substantially the same as the D1 direction when the deposition angle θ0 is a value that becomes a forward tilt region, that is, a value θ02 that is less than θ0b. from a vapor deposition film formed by the SiO ₂ to oblique evaporation.

That is, the upper alignment film 42 tilts the evaporation source 62 made of SiO ₂ with respect to the TFT array substrate 10 in the direction in which the azimuth angle ψ is ψp [°] and from the normal line of the TFT array substrate 10. The angle θ is formed by performing oblique deposition with an angle θ satisfying θ01 <θ0b [°]. Note that the upper alignment film 42 is not formed in the region A1 that is a shadow of the step 200 when viewed from the vapor deposition source 62.

  More specifically, the upper alignment film 42 is inclined in the D1 direction (azimuth angle ψp [°]) by a predetermined deposition angle θ02 with respect to a normal line (z axis) substantially parallel to the TFT array substrate 10. It is comprised by the aggregate | assembly of the columnar structure convexly provided by.

  That is, in the opening region A0, the lower alignment film 41 and the upper alignment film 42 are formed so as to overlap in the region other than the regions A1 and A2 in the opening region A0. In the region A1, only the lower alignment film 41 is formed, while in the region A2, only the upper alignment film 42 is formed.

  The inorganic alignment film 16 composed of the lower alignment film 41 and the upper alignment film 42 formed by oblique vapor deposition from opposite directions is not affected by the step 200 and may be in the vicinity of the step 200. Thus, the inorganic alignment film 16 is formed over the entire display region 10a.

The liquid crystal 50 is aligned as follows by the inorganic alignment film 16 of the present embodiment having the above-described configuration.
First, in the region A1 in which the upper alignment film 42 is not formed and the lower alignment film 41 is in contact with the liquid crystal 50, a reverse tilt due only to the lower alignment film 41 is applied to the liquid crystal molecules 501 present in the region A1. By the orientation regulating force to be developed, a pretilt tilted by an angle θp1 in the direction D1 is given. The pretilt orientation of the liquid crystal molecules 501 present in the region A1 is substantially the same as the D1 direction.

  On the other hand, in the region A2 in which the lower alignment film 41 is not formed and the liquid crystal 50 is in contact with the upper alignment film 42, the forward tilt due to the upper alignment film 42 alone with respect to the liquid crystal molecules 502 existing in the region A2. The pre-tilt that is inclined by the angle θp2 in the direction D1 is given by the orientation regulating force that expresses. The pretilt orientation of the liquid crystal molecules 502 existing in the region A2 is substantially the same as the D1 direction.

  Further, in the region A3 in which the lower alignment film 41 and the upper alignment film 42 are formed so as to overlap each other, the pretilt angle θp1 defined by the lower alignment film 41 with respect to the liquid crystal molecules 503 existing in the region A3, and the upper layer A pretilt angle θp0 that is intermediate between the pretilt angle θp2 defined by the alignment film 42 is given.

  This is because when the inorganic alignment film formed by oblique vapor deposition is laminated in two layers, the alignment regulating force of the inorganic alignment film with respect to the liquid crystal is the alignment regulating force of both of the two inorganic alignment films. It is because it is determined by influence. In the present embodiment, the pretilt angle θp0 takes an intermediate value between θp1 and θp2, but the influence on the pretilt angle θp0 by the upper alignment film 30 on the side in contact with the liquid crystal is greater. Therefore, θp0 is closer to θp2.

  In the present embodiment, the deposition angles θ01 and θ02 when forming the lower alignment film 41 and the upper alignment film 42 so that the pretilt angle θp1 in the region A1 is larger than the pretilt angle θp0 in the region A3. Has been determined.

  Here, as described above, since the lower alignment film 41 and the upper alignment film 42 have a regulating force to align the liquid crystal in the same direction, similarly, the liquid crystal molecules 503 existing in the region A2 The pretilt azimuth is substantially the same as the D1 direction.

  In the liquid crystal device 100 of the present embodiment described above, the inorganic alignment film 16 composed of the lower alignment film 41 and the upper alignment film 42 formed by oblique deposition from opposite directions is formed in the opening region A0. The display area 10a is formed over the entire display area 10a without being affected by the step formed in the peripheral area. The inorganic alignment film 16 formed over the entire display area 10a regulates the alignment of the liquid crystal 50 in all areas so as to incline in the D1 direction, which is substantially the same direction, as described above.

  Therefore, the liquid crystal device 100 according to the present embodiment can align the liquid crystal in a uniform orientation in the entire display region 10a without being affected by the step formed on the substrate. Therefore, the liquid crystal device 100 of this embodiment can provide a high-quality display with high contrast without display abnormality such as light leakage due to alignment failure.

  In the liquid crystal device 100 of the present embodiment, the values of the pretilt angles θp1 and θp2 in the regions A1 and A2 that are the peripheral regions of the opening region A0 with respect to the pretilt angle θp0 in the region A3 that is the central region of the opening region A0. Can be different.

  For example, like the region A1 in FIG. 7, the liquid crystal molecules 501 existing in the region A1 that is easily affected by the lateral electric field generated between adjacent pixels by 1H inversion driving or the like are less susceptible to the influence of the lateral electric field. Can be oriented. In the case of this embodiment, the pretilt angle θp1 of the liquid crystal molecules 501 in the region A1 is made larger than the pretilt angle θp0 in the region A3 that is the central region of the opening region A0, thereby causing a lateral electric field due to the influence of adjacent pixels. The occurrence of reverse tilt can be suppressed.

  Therefore, according to the liquid crystal device 100 of the present embodiment, it is possible to suppress the occurrence of uneven transmittance in the disclination line caused by the occurrence of reverse tilt, and it is possible to provide a display with higher contrast. It becomes.

  In the counter substrate 20 as well, a lattice-shaped light shielding film generally called a black matrix is formed in the edge region of the opening region. Therefore, even in the counter substrate 20, a step is easily formed at the edge portion of the opening region, and liquid crystal alignment defects are easily caused by the effect of the step.

  However, the inorganic alignment film 22 of the counter substrate 20 is formed by obliquely depositing two layers of obliquely evaporated films from opposite directions in the same manner as the inorganic alignment film 16 of the present embodiment, and the orientation directions of both liquid crystals. By forming them so as to be in the same direction, it becomes possible to align the liquid crystal in a uniform direction without being affected by the step.

  Next, a method for manufacturing the liquid crystal device 100 having the above-described configuration, specifically, a method for forming the inorganic alignment films 16 and 26 in the liquid crystal device 100 will be described. In addition, since the formation method of the inorganic alignment film 26 is the same as that of the inorganic alignment film 16, only the formation method of the inorganic alignment film 16 is demonstrated below. Further, since the manufacturing method of the liquid crystal device other than the method of forming the inorganic alignment films 16 and 26 is well known, the description thereof is omitted.

  First, by laminating a known semiconductor thin film, insulating thin film or conductive thin film, on the pixel electrode 9a of the TFT array substrate 10 on which a laminated structure such as the scanning line 11a, the data line 6a, the capacitor line 400, and the TFT 30 is formed. In addition, the lower alignment film 41 is formed by oblique vapor deposition.

The lower alignment film 41 is formed by obliquely depositing SiO ₂ from an azimuth angle direction 180 degrees opposite to the D1 direction at a value θ01 where the deposition angle θ0 is a reverse tilt region, that is, a value θ01 that is equal to or greater than θ0b. Is done.

Next, on the lower alignment film 41, SiO ₂ is obliquely evaporated from the azimuth angle direction substantially the same as the D1 direction at a value at which the deposition angle θ0 is a forward tilt region, that is, a value θ02 that is less than θ0b. It is the vapor deposition film formed by.

  Here, the absolute value of the reverse pretilt angle θp1 expressed by the alignment regulating force of only the lower alignment film 41 is greater than the absolute value of the forward pretilt angle θp2 expressed by the alignment regulating force of only the upper alignment film 42. Also, the vapor deposition angles θ01 and θ02 are set so as to be a large value.

  Thus, the inorganic alignment film 16 of the present embodiment is formed.

  In the above-described embodiment, the two-layer oblique vapor deposition film forming the inorganic alignment film 16 is one in which the lower layer side develops a reverse pretilt and the upper layer side develops a forward pretilt. It goes without saying that the same effect can be obtained even if these are laminated in reverse.

  Next, an overall configuration, particularly an optical configuration, of an embodiment of a projection type color display device that is an electronic apparatus using the liquid crystal device described in detail above as a light valve will be described. FIG. 8 is a cross-sectional view illustrating a configuration example of a projection type color display device. In FIG. 8, a liquid crystal projector 1100, which is an example of an electronic apparatus in the present embodiment, uses the liquid crystal device 100 as RGB light valves 100R, 100G, and 100B, respectively. In the liquid crystal projector 1100, when projection light is emitted from a lamp unit 1102 of a white light source such as a metal halide lamp, light components R, G, and B corresponding to the three primary colors of RGB are obtained by three mirrors 1106 and two dichroic mirrors 1108. And are guided to the light valves 100R, 100G and 100B corresponding to the respective colors. At this time, in particular, the B light is guided through a relay lens system 1121 including an incident lens 1122, a relay lens 1123, and an exit lens 1124 in order to prevent light loss due to a long optical path. The light components corresponding to the three primary colors modulated by the light valves 100R, 100G, and 100B are synthesized again by the dichroic prism 1112 and then projected as a color image on the screen 1120 via the projection lens 1114.

  In addition to the electronic device described with reference to FIG. 8, the electronic device according to the present embodiment is a mobile computer, a liquid crystal television, a mobile phone, an electronic notebook, a word processor, a viewfinder type, or a monitor direct view type video. The present invention can be applied to various electronic devices such as a tape recorder, a workstation, a video phone, a POS terminal, or a touch panel.

  In the above-described embodiment, an active matrix drive type transmissive liquid crystal panel using TFTs has been described as a liquid crystal device. However, the present invention is not limited to this and has a negative dielectric anisotropy. The present invention can also be applied to other types of liquid crystal devices using liquid crystals.

  The liquid crystal device may be a display device that forms elements on a semiconductor substrate, for example, LCOS (Liquid Crystal On Silicon). In LCOS, a single crystal silicon substrate is used as an element substrate, and a transistor is formed on a single crystal silicon substrate as a switching element used for a pixel or a peripheral circuit. In addition, a reflective pixel electrode is used for the pixel, and each element of the pixel is formed below the pixel electrode.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit or idea of the invention that can be read from the claims and the entire specification, and a liquid crystal device with such a change, A method for manufacturing a liquid crystal device and electronic equipment are also included in the technical scope of the present invention.

FIG. 3 is a plan view of the electro-optical device when the TFT array substrate is viewed from the counter substrate side together with the components configured thereon. It is H-H 'sectional drawing of FIG. 3 is an equivalent circuit of various elements and wirings in a plurality of pixels formed in a matrix that forms an image display area of a liquid crystal device. It is a schematic block diagram which shows roughly an example of a structure of the pixel part in a TFT array substrate. It is a figure explaining the pretilt angle (theta) p and azimuth | direction angle (psi) p. It is a figure which shows the relationship between the vapor deposition angle of an inorganic vertical alignment film, and a pretilt angle. It is VII-VII sectional drawing of FIG. It is explanatory drawing which shows schematic structure of the optical system of a liquid crystal projector.

Explanation of symbols

  9a pixel electrode, 10 TFT array substrate, 11a scanning line, 16 inorganic alignment film, 41 lower alignment film, 42 upper alignment film, 61 deposition source, 62 deposition source, 200 step, 400 capacitance line, 501 to 503 liquid crystal molecules, θ01 Deposition angle, θ02 Deposition angle, θp0 pretilt angle, θp1 pretilt angle, θp2 pretilt angle, D1 orientation direction, A0 opening region

Claims (4)

A liquid crystal device in which a liquid crystal having negative dielectric anisotropy is sandwiched between a pair of substrates,
At least one of the pair of substrates includes a pixel electrode and an inorganic alignment film that is formed on the pixel electrode and regulates the alignment of the liquid crystal.
The inorganic alignment film includes a first oblique deposition film and a second oblique deposition film formed by oblique deposition on the substrate from opposite directions, and the first oblique deposition film. 2. A liquid crystal device according to claim 1, wherein tilt directions of the liquid crystal expressed by the oblique vapor deposition film and the second oblique vapor deposition film coincide with each other. A plurality of pixels are arranged in a matrix, and the pixels each include an opening region and a peripheral region surrounding the opening region, the switching element electrically connected to the pixel electrode in the peripheral region, and the switching Wiring electrically connected to the element is provided,
In the peripheral region, the inorganic alignment film is composed of one of the first oblique vapor deposition film or the second oblique vapor deposition film,
2. The liquid crystal device according to claim 1, wherein, in the opening region, the inorganic alignment film has a stacked structure of the first oblique vapor deposition film and the second oblique vapor deposition film. A method of manufacturing a liquid crystal device in which a liquid crystal having negative dielectric anisotropy is sandwiched between a pair of substrates,
Forming a first oblique vapor deposition film on the pixel electrode from a predetermined orientation by an oblique vapor deposition method;
Forming a second oblique deposition film on the first oblique deposition film by an oblique deposition method from an orientation opposite to the predetermined orientation;
In the step of forming the second oblique deposition film, the tilt direction of the liquid crystal on the second oblique deposition film matches the tilt direction of the liquid crystal on the first oblique deposition film. Thus, the vapor deposition angle is determined, and the manufacturing method of the liquid crystal device characterized by the above-mentioned.   An electronic apparatus comprising the liquid crystal device according to claim 1.

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