JP2007155949A - Liquid crystal device, manufacturing method of liquid crystal device, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal device which is free of disclination and provides bright display and has a high contrast based upon vertical alignment at low cost. <P>SOLUTION: The liquid crystal device of the present invention has a liquid crystal layer 50, formed of liquid crystal which is vertically aligned in an initial state and has negative dielectric anisotropy, sandwitched between a pair of substrates 10 and 20 is equipped with a plurality of pixel parts X and has alignment films 40 and 60 formed on the substrates 10 and 20 on sides of the liquid crystal layer 50. The alignment films 40 and 60 comprise vertical alignment films 41 and 61 which align liquid crystal in the pixel parts X and horizontal alignment films 42 and 62 which align liquid crystal at peripheries of the pixel parts X and have a pretilt at a specified azimuth angle. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

  There is a liquid crystal projector as a device for displaying an image on a large screen using a liquid crystal device. Projectors are required to have high brightness and high contrast, and in that respect, vertical alignment type liquid crystal devices are capable of high-contrast display, and have recently been adopted as liquid crystal alignment methods for projector liquid crystal devices.

  However, in the vertical alignment method, the liquid crystal molecules stand perpendicular to the substrate surface, and the interaction in the azimuth direction that falls when a voltage is applied is weak. Therefore, when a voltage is applied, liquid crystal molecules fall in various directions due to a lateral electric field generated from the electrode end, and liquid crystal molecules parallel to the transmission axis of any polarizing plate under crossed Nicols do not cause a phase difference. Depending on the case, there is a case where it does not contribute to the display and the transmittance becomes lower than that of the horizontal alignment.

Therefore, for example, Patent Document 1 discloses a method for providing a pretilt angle to an alignment film for the purpose of aligning alignment directions in one direction.
JP 2004-163921 A

  However, according to the technique disclosed in Patent Document 1, when the pretilt angle is increased, a phase difference is generated in the liquid crystal molecules in a state in which no voltage is applied, and light leakage may occur even in black display, resulting in low contrast. Therefore, the present invention eliminates the influence of the horizontal electric field generated from the electrode end when a voltage is applied, and makes the liquid crystal molecules fall in a uniform direction without forming a tilt in the vertical alignment portion in the pixel region. An object of the present invention is to provide a low-contrast liquid crystal device that is low in generation, bright in display, and based on vertical alignment. It is another object of the present invention to provide a method for manufacturing such a liquid crystal device, and further to provide an electronic device including the liquid crystal device.

  In order to solve the above problems, a liquid crystal device of the present invention is a liquid crystal device in which a liquid crystal layer composed of a liquid crystal having an initial alignment state of vertical alignment and a negative dielectric anisotropy is sandwiched between a pair of substrates. A plurality of pixel portions, and an alignment film is formed on the liquid crystal layer side of the substrate, the alignment film comprising a vertical alignment film for aligning liquid crystals of the pixel portion, and a peripheral portion of the pixel portion And a horizontal alignment film having a pretilt having a predetermined azimuth angle.

  According to such a liquid crystal device, even if no pretilt is formed in the alignment film in the pixel portion, the influence of the transverse electric field generated from the electrode end when voltage is applied is eliminated, and the direction in which the liquid crystal molecules are tilted is uniformly regulated. Is possible. In other words, even if no pretilt is formed in the alignment film in the pixel portion, the pretilt having a predetermined azimuth angle is formed in the alignment film in the peripheral portion of the pixel portion (pixel peripheral portion). Therefore, the orientation of the liquid crystal can be regulated so that it falls in the azimuth direction of the pretilt of the alignment film in the peripheral portion. As a result, light leakage hardly occurs and a high contrast display can be realized. For example, when the polarizing plate is designed on the outside of the substrate under crossed Nicols, the liquid crystal in the pixel portion is aligned vertically with a pretilt of approximately 0 ° when no voltage is applied, so that dark display with almost no light leakage can be realized. On the other hand, as described above, the liquid crystal molecules in the pixel portion are uniformly tilted in the azimuth direction set in the peripheral alignment film when a voltage is applied, thereby realizing a bright display with excellent visibility without causing disclination. Can do. As described above, according to the liquid crystal device of the present invention, it is possible to provide a high-contrast and bright display uniformly and with high quality over the entire screen. Note that the pixel peripheral portion includes not only the non-pixel portion that forms the boundary of each pixel portion, but also the pixel peripheral portion region as well as within the pixel portion.

  In the liquid crystal device of the present invention, the vertical alignment film is selectively disposed in the pixel portion, and the horizontal alignment film is selectively disposed in a non-pixel portion that forms a boundary between the pixel portions. can do. With such a configuration, the above-described orientation mode can be suitably realized.

  In particular, in the present invention, the vertical alignment film may not be rubbed. By not performing the rubbing treatment, it is possible to suitably realize vertical alignment with a pretilt angle of 0 ° in a state in which no voltage is applied (initial alignment state). Meanwhile, the horizontal alignment film may be rubbed. By subjecting the horizontal alignment film to a rubbing treatment, it is possible to suitably impart a pretilt having a predetermined azimuth angle.

  Next, in order to solve the above-described problem, a method for manufacturing a liquid crystal device according to the present invention includes sandwiching a liquid crystal layer composed of liquid crystal having an initial alignment state of vertical alignment and a negative dielectric anisotropy between a pair of substrates. A first step of performing a rubbing process by forming a horizontal alignment film in a region corresponding to a peripheral portion of the pixel portion on a substrate, and a method for manufacturing a liquid crystal device including a plurality of pixel portions; And a second step of forming a vertical alignment film in a region corresponding to the pixel portion on the substrate.

  With such a method, the above-described liquid crystal device can be easily and reliably manufactured. That is, if the horizontal alignment film is selectively formed in the region corresponding to the peripheral portion of the pixel portion and the rubbing process is performed, the vertical alignment film is selectively formed in the region corresponding to the pixel portion. The liquid crystal in the pixel portion can be vertically aligned when no voltage is applied, and the liquid crystal in the pixel portion can be tilted along the azimuth direction of the alignment film formed in the peripheral portion of the pixel when a voltage is applied.

  Here, the first step includes a step of selectively disposing the horizontal alignment film on a peripheral portion of the pixel portion by a droplet discharge method and a step of performing a rubbing process on the disposed horizontal alignment film. Can do. Further, the second step may include a step of selectively disposing the vertical alignment film on the pixel portion by a droplet discharge method. If a horizontal alignment film or a vertical alignment film is arranged by such a droplet discharge method, selective formation of each alignment film on the periphery of the pixel portion or the pixel portion can be realized more easily and reliably. It becomes.

  The liquid crystal device of the present invention can be used as a light modulation device for a display screen of an electronic device such as a liquid crystal television or a mobile phone, a monitor of a personal computer, or a liquid crystal projector. By using it for such an application, it is possible to provide an electronic device having excellent display characteristics. Further, by manufacturing the liquid crystal device by the above manufacturing method, the above-described electronic device can be provided at low cost.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In addition, in each figure, in order to make each layer and each member the size which can be recognized on drawing, the scale is varied for every layer and each member.

[Liquid Crystal Device]
The liquid crystal device of the present embodiment described below is an active matrix transmissive liquid crystal device using a TFT (Thin-Film Transistor) element as a switching element.

  FIG. 1 is an equivalent circuit diagram of switching elements, signal lines, and the like in a plurality of pixels arranged in a matrix that constitutes an image display region of the transmissive liquid crystal device of this embodiment. FIG. 2 is a plan view showing the structure of a plurality of pixel groups adjacent to each other on a TFT array substrate on which data lines, scanning lines, pixel electrodes and the like are formed. FIG. 3 is a cross-sectional view of the element region of the transmissive liquid crystal device of this embodiment, and is a cross-sectional view taken along the line A-A ′ of FIG. 2. FIG. 4 is a cross-sectional view schematically showing a plurality of pixel regions in the transmissive liquid crystal device of this embodiment. 3 and 4, the upper side in the drawing is the light incident side, and the lower side in the drawing is the viewing side (observer side).

  In the transmissive liquid crystal device according to the present embodiment, as shown in FIG. 1, a plurality of pixels arranged in a matrix that constitutes an image display region are subjected to energization control for the pixel electrode 9 and the pixel electrode 9. TFT elements 30 as the switching elements are formed, and the data line 6 a to which an image signal is supplied is electrically connected to the source of the TFT element 30. Image signals S1, S2,..., Sn to be written to the data line 6a are supplied line-sequentially in this order, or are supplied for each group to a plurality of adjacent data lines 6a.

  In addition, the scanning line 3a is electrically connected to the gate of the TFT element 30, and scanning signals G1, G2,..., Gm are applied to the plurality of scanning lines 3a in a pulse-sequential manner at predetermined timing. The Further, the pixel electrode 9 is electrically connected to the drain of the TFT element 30, and the image signal S1, S2,... Supplied from the data line 6a is turned on by turning on the TFT element 30 as a switching element for a certain period. , Sn is written at a predetermined timing.

  A predetermined level of image signals S1, S2,..., Sn written to the liquid crystal via the pixel electrode 9 is held for a certain period with the common electrode described later. The liquid crystal modulates light by changing the orientation and order of the molecular assembly according to the applied voltage level, thereby enabling gradation display. Here, in order to prevent the held image signal from leaking, a storage capacitor 70 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 9 and the common electrode.

  Next, the planar structure of the transmissive liquid crystal device of this embodiment will be described with reference to FIG. As shown in FIG. 2, a rectangular pixel electrode 9 (outlined by a dotted line portion 9A) made of a transparent conductive material such as indium tin oxide (hereinafter abbreviated as “ITO”) is formed on the TFT array substrate. A plurality of pixels are provided in a matrix, and data lines 6 a, scanning lines 3 a, and capacitor lines 3 b are provided along the vertical and horizontal boundaries of the pixel electrode 9. In the present embodiment, each pixel electrode 9 and the area where the data line 6a, the scanning line 3a, the capacitor line 3b, etc. are arranged so as to surround each pixel electrode 9 are pixels, and are arranged in a matrix. The display can be displayed for each pixel.

  The data line 6a is electrically connected to a source region (described later) through a contact hole 5 in the semiconductor layer 1a made of, for example, a polysilicon film constituting the TFT element 30, and the pixel electrode 9 is connected to the semiconductor layer 1a. Among these, it is electrically connected to a drain region described later via a contact hole 8. In addition, the scanning line 3a is disposed so as to face a channel region (a region with a diagonal line rising to the left in the figure), which will be described later, in the semiconductor layer 1a, and the scanning line 3a serves as a gate electrode at a portion facing the channel region. Function.

  The capacitor line 3b is formed from a main line portion extending in a substantially straight line along the scanning line 3a (that is, a first region formed along the scanning line 3a in a plan view) and a portion intersecting 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 previous stage (upward in the drawing) along the data line 6 a. In FIG. 2, a plurality of first light shielding films 11 a are provided in a region indicated by a diagonal line rising to the right.

  Next, a cross-sectional structure of the transmissive liquid crystal device of this embodiment will be described with reference to FIGS. In FIG. 4, some components such as switching elements are omitted in view of the visibility of the drawing. As shown in FIGS. 3 and 4, in the transmissive liquid crystal device of the present embodiment, a TFT array substrate (liquid crystal device substrate) 10 and a counter substrate (liquid crystal device substrate) 20 disposed opposite thereto are provided. A liquid crystal layer 50 is sandwiched therebetween. The liquid crystal layer 50 is made of a liquid crystal having an initial alignment state of vertical alignment and a negative dielectric anisotropy, and the transmissive liquid crystal device is a display device of a vertical alignment mode.

  The TFT array substrate 10 is mainly composed of a substrate body 10A made of a light-transmitting material such as quartz, a pixel electrode 9 formed on the surface of the liquid crystal layer 50, and an alignment film 40. The counter substrate 20 is made of glass or The substrate main body 20A made of a translucent material such as quartz, the common electrode 21 formed on the liquid crystal layer 50 side surface, and the alignment film 60 are mainly configured. As shown in FIG. 3, in the TFT array substrate 10, pixel electrodes 9 are provided on the surface of the substrate body 10 </ b> A on the liquid crystal layer 50 side, and each pixel electrode 9 is controlled to be switched to a position adjacent to each pixel electrode 9. A pixel switching TFT element 30 is provided.

  The pixel switching TFT element 30 has an LDD (Lightly Doped Drain) structure, and includes a scanning line 3a, a channel region 1a ′ of the semiconductor layer 1a in which a channel is formed by an electric field from the scanning line 3a, and the scanning line 3a. A gate insulating film 2 that insulates the semiconductor layer 1a, a data line 6a, a low concentration source region 1b and a low concentration drain region 1c of the semiconductor layer 1a, and a high concentration source region 1d and a high concentration drain region 1e of the semiconductor layer 1a. ing.

  Further, a second contact hole 5 leading to the high concentration source region 1d and a contact hole 8 leading to the high concentration drain region 1e are formed on the substrate main body 10A including the scanning line 3a and the gate insulating film 2. An interlayer insulating film 4 is formed. That is, the data line 6 a is electrically connected to the high concentration source region 1 d through the contact hole 5 that penetrates the second interlayer insulating film 4. Further, on the data line 6a and the second interlayer insulating film 4, a third interlayer insulating film 7 having a contact hole 8 leading to the high concentration drain region 1e is formed. That is, the high concentration drain region 1 e is electrically connected to the pixel electrode 9 through the contact hole 8 that penetrates the second interlayer insulating film 4 and the third interlayer insulating film 7.

  Further, in this embodiment, the gate insulating film 2 is extended from a position facing the scanning line 3a and used as a dielectric film, the semiconductor film 1a is extended to form the first storage capacitor electrode 1f, and further opposed thereto. The storage capacitor 70 is configured by using a part of the capacitor line 3b to be a second storage capacitor electrode.

  On the surface of the TFT array substrate 10 on the liquid crystal layer 50 side of the substrate body 10A, the TFT switching substrate 30 is transmitted through the region where the pixel switching TFT elements 30 are formed. The return light reflected at the interface 10 and air and returning to the liquid crystal layer 50 side is prevented from entering at least the channel region 1a ′ and the low concentration source / drain regions 1b and 1c of the semiconductor layer 1a. A first light shielding film 11a is provided. Further, a first interlayer insulation for electrically insulating the semiconductor layer 1a constituting the pixel switching TFT element 30 from the first light shielding film 11a is provided between the first light shielding film 11a and the pixel switching TFT element 30. A film 12 is formed. Further, as shown in FIG. 2, in addition to providing the first light-shielding film 11a on the TFT array substrate 10, the first light-shielding film 11a is electrically connected to the capacitor line 3b at the preceding stage or the subsequent stage through the contact hole 13. Configured to connect to.

  An alignment film 40 is formed on the TFT array substrate 10 on the liquid crystal layer 50 side, that is, on the pixel electrode 9 and the third interlayer insulating film 7. The alignment film 40 controls the alignment of the liquid crystal molecules in the liquid crystal layer 50 when no voltage is applied. Here, as shown in FIG. 4, the alignment film 40 has a different alignment function for each predetermined region. Yes.

  Specifically, the alignment film 40 is mainly used for the vertical alignment film 41 mainly disposed in the pixel portion X that is the region where the pixel electrode 9 is formed, and the non-pixel portion Y that forms the boundary between the pixel portions X. And a horizontal alignment film 42 disposed on the substrate. More specifically, the horizontal alignment film 42 is formed on a pixel peripheral portion including a non-pixel portion Y (a region where the pixel electrode 9 is not formed) and a part of the periphery of the pixel portion X. The vertical alignment film 41 is formed in a region surrounded by the pixel peripheral portion where the horizontal alignment film 42 is formed.

  With such a configuration, the liquid crystal of the pixel portion X is aligned vertically to the substrate 10 mainly based on the vertical alignment film 41, while the liquid crystal of the non-pixel portion Y is mainly based on the horizontal alignment film 42. Orient horizontally. The horizontal alignment film 42 has a pretilt with a predetermined azimuth and is made of a polyimide film that is rubbed. The vertical alignment film 41 is composed of a material in which a basic skeleton is polyimide, which is a material for forming a horizontal alignment film, and a long chain alkyl group or a functional group having a rigid planar structure is introduced into its side chain. The rubbing process is not applied. Therefore, the liquid crystal molecules constituting the liquid crystal layer 50 in the pixel peripheral portion have a pretilt in a predetermined azimuth angle direction in the absence of voltage application, while the liquid crystal molecules constituting the liquid crystal layer 50 in the inner region from the pixel peripheral portion are When the voltage is not applied, the pretilt angle is approximately 0 °.

  On the other hand, the counter substrate 20 has a surface on the liquid crystal layer 50 side of the substrate body 20A, which is a region facing the formation region of the data line 6a, the scanning line 3a, and the pixel switching TFT element 30, that is, an opening region of each pixel unit. The second light-shielding film 23 for preventing incident light from entering the channel region 1a ′, the low-concentration source region 1b, and the low-concentration drain region 1c of the semiconductor layer 1a of the pixel switching TFT element 30 in the other regions. Is provided.

  Furthermore, the common electrode 21 made of ITO or the like is formed over the substantially entire surface of the substrate body 20A on which the second light shielding film 23 is formed, and the alignment film 60 is formed on the liquid crystal layer 50 side. Is formed. Similar to the alignment film 40 formed on the TFT array substrate 10 side, the alignment film 60 includes a vertical alignment film 61 and a horizontal alignment film 62.

  Specifically, similar to the alignment film 40, the vertical alignment film 61 mainly disposed in the pixel portion X that is the region where the pixel electrode 9 is formed and the non-pixel portion Y that forms the boundary of the pixel portion X The horizontal alignment film 62 is mainly disposed. More specifically, the horizontal alignment film 62 is formed on a pixel peripheral portion composed of a non-pixel portion Y (a region where the pixel electrode 9 is not formed) and a part of the periphery of the pixel portion X. The vertical alignment film 61 is formed in a region surrounded by the pixel peripheral portion where the horizontal alignment film 62 is formed.

  In the liquid crystal device according to the present embodiment having the alignment films 40 and 60 having such a configuration, the inner region of the pixel peripheral portion (the inner region excluding the peripheral portion of the pixel portion X (for example, the peripheral portion of the pixel portion X is 0% to 10%). % (Preferably a region excluding 1% to 10%))) is in a non-rubbing state, but when a voltage is applied, the periphery of the pixel (the periphery of the non-pixel portion Y and the pixel portion X (for example, the periphery of the pixel portion X is 0%) 10% (preferably 1% to 10%))), and the liquid crystal molecules can be tilted along the azimuthal direction formed by the horizontal alignment film 42. Become. Therefore, high contrast due to the pretilt angle being substantially 0 ° in the initial state (no voltage applied state), high transmittance due to alignment of liquid crystal molecules in the voltage applied state, and prevention of disclination. High-quality display can be realized.

  That is, as shown in FIG. 5, the liquid crystal molecules are aligned with the application of voltage. First, in the initial alignment state (voltage non-application state), as shown in FIG. 5A, in the pixel portion X where the pixel electrode 9 is mainly formed, the liquid crystal molecules 51b are aligned perpendicular to the substrate 10A. In the non-pixel portion Y, the liquid crystal molecules 51a are aligned horizontally with respect to the substrate 10A with a pretilt in a predetermined azimuth angle direction.

  When a voltage is applied from this state, as shown in FIG. 5B, the liquid crystal molecules 51b of the pixel portion X are tilted. In this case, the liquid crystal molecules 51a of the non-pixel portion Y are affected by the azimuth angle direction, It will tilt along the azimuth direction. Therefore, the tilt direction of the liquid crystal molecules 51b is uniform in the pixel portion X, and no disclination line is formed as shown in FIG.

  When the vertical alignment film is formed on the entire inner surface of the substrates 10 and 20 as in the conventional case, the liquid crystal molecules exhibit an alignment behavior as shown in FIG. That is, while no voltage is applied, the liquid crystal molecules 51 are aligned perpendicular to the substrate 10A in all regions (FIG. 6A), while the liquid crystal molecules 51 tilt when a voltage is applied, but the tilt direction is uniform. The disclination D is generated (FIG. 6B).

  Further, in the present embodiment, the pixel portion X that contributes to the display is mainly composed of the vertical alignment films 42 and 62 that are not subjected to the rubbing process. Therefore, when the rubbing process is performed as in the conventional case, the pixel surface X is formed on the film surface. The display quality of the liquid crystal device is improved without any deterioration of the display quality due to the formed lines.

Next, a method for manufacturing the liquid crystal device of this embodiment will be described.
First, the TFT array substrate 10 is created.
Here, a light-transmitting substrate 10A made of glass or the like is prepared. The pixel electrode 9 and the like are formed by a known method. Subsequently, an alignment film 40 is formed on the third interlayer insulating film 7 including the pixel electrode 9.

  Specifically, the alignment film 40 is formed through a process as shown in FIG. In FIG. 7, the description of the insulating film 7 and the like formed between the substrate 10A and the pixel electrode 9 is omitted. Although both the substrate 10A and the substrate 20A are shown in FIG. 7, each substrate is created in a separate process, and here, the description will be made focusing on the substrate 10A.

  First, the horizontal alignment film 42 is formed on the pixel peripheral portion including the non-pixel portion Y and the periphery of the pixel portion X with respect to the substrate 10A on which the pixel electrode 9 is formed (FIG. 7A). Specifically, a liquid composition is prepared by dissolving or dispersing a material constituting the horizontal alignment film 42 (horizontal alignment film forming material) in a predetermined solvent, and using a liquid droplet ejection apparatus such as an inkjet apparatus. A fixed point is arranged around the pixel periphery by a droplet discharge method (FIG. 7B). Then, the liquid composition arranged at a fixed point is dried to obtain the intended horizontal alignment film 42. In this embodiment, polyimide is used as the horizontal alignment film forming material.

Next, as shown in FIG. 7C, a rubbing process is performed on the horizontal alignment film 42 by a rubbing apparatus in which a rubbing cloth 58 is wound around a roller. Thereafter, the vertical alignment film 41 is formed in a region surrounded by the horizontal alignment film 42, that is, a region excluding the peripheral portion of the pixel portion X (FIG. 7D). Here, as in the case where the horizontal alignment film 42 is formed, a liquid composition is prepared by dissolving or dispersing a material (vertical alignment film forming material) constituting the vertical alignment film 41 in a predetermined solvent, and this is formed into an ink jet apparatus. A fixed point is placed in a region surrounded by the horizontal alignment film 42 by a droplet discharge method using a droplet discharge device such as the one shown in FIG. Then, the target vertical alignment film 41 is obtained by drying the liquid composition arranged at fixed points. In this embodiment, polyimide is used as the material for forming the vertical alignment film, and a long-chain alkyl group or a functional group having a rigid planar structure is introduced into the side chain. The vertical alignment film 41 is not rubbed.
The TFT array substrate 10 is formed through the alignment film forming process as described above.

  On the other hand, a counter substrate 20 is also formed separately from the TFT array substrate 10 described above. Here, after preparing the substrate 20A, the light-shielding film 23 and the counter electrode 21 are formed on the substrate 20A by using the same method as that for forming the TFT array substrate 10, and further described above with reference to FIG. The counter substrate 20 is obtained by forming the alignment film 60 including the horizontal alignment film 62 and the vertical alignment film 61 by using the method.

Thereafter, the TFT array substrate 10 and the counter substrate 20 are bonded together via a sealing agent, and liquid crystal having a negative dielectric anisotropy (negative liquid crystal material) is injected from a liquid crystal injection port formed in the sealing agent, thereby producing a liquid crystal panel. And Further, the liquid crystal device of this embodiment is manufactured by bonding polarizing plates to both sides of the panel in a crossed Nicol state and connecting predetermined wiring.
As described above, in the method of manufacturing the liquid crystal device according to this embodiment, the horizontal alignment film 42 and the vertical alignment film 41 are fixedly arranged in a predetermined region by the droplet discharge method in the alignment film forming step. It is possible to manufacture the device simply and reliably.

  In this embodiment, the horizontal alignment film 42 (62) and the vertical alignment film 41 (61) are formed separately. For example, a step is provided in a portion where the horizontal alignment film 42 (62) is formed. Thereafter, the horizontal alignment film 42 (62) and the vertical alignment film 41 (61) may be formed at the same time, and a rubbing process may be applied to both the films. In this case, since the step is formed in the portion where the horizontal alignment film 42 (62) is formed, the horizontal alignment film 42 (62) is formed at a position higher than the vertical alignment film 41 (61). That is, the rubbing process for the vertical alignment film 41 (61) is relatively weak, and the tilt angle is hardly given.

Further, in this embodiment, in order to provide a pretilt having an azimuth angle with respect to the horizontal alignment film 42 (62), a polyimide film that has been rubbed is used as the horizontal alignment film 42 (62). For example, an obliquely deposited film formed by oblique deposition of an inorganic material (inorganic oxide) typified by SiO ₂ , or an IBS film formed by forming an inorganic material (inorganic oxide) by ion beam sputtering (IBS) is used horizontally. The alignment film 42 (62) can also be used. In this case, a rubbing-less alignment film is formed not only in the pixel portion X but also in the non-pixel portion Y.

As described above, the liquid crystal device and the manufacturing method thereof as one embodiment of the present invention have been described. However, the present invention is not limited to this, and the description of each claim is made without departing from the scope described in each claim. The present invention is not limited to the wording, and the range can be easily replaced by those skilled in the art, and improvements based on the knowledge normally possessed by those skilled in the art can be appropriately added.
For example, in the present embodiment, only an active matrix type liquid crystal device using a TFT element has been described, but the present invention is not limited to this, and an active matrix type liquid crystal using a TFD (Thin-Film Diode) element is used. The present invention can also be applied to a device, a passive matrix liquid crystal device, and the like. In the present embodiment, only the transmissive liquid crystal device has been described. However, the present invention is not limited to this, and can be applied to a reflective or transflective liquid crystal device. Thus, the present invention can be applied to a liquid crystal device having any structure.

[Electronics]
Examples of electronic devices including the liquid crystal device of the above embodiment will be described.
FIG. 8A is a perspective view showing an example of a mobile phone. In FIG. 8A, reference numeral 500 denotes a mobile phone body, and reference numeral 501 denotes a liquid crystal display unit using the liquid crystal device of the above embodiment.

  FIG. 8B is a perspective view illustrating an example of a portable information processing apparatus such as a word processor or a personal computer. In FIG. 8B, reference numeral 600 denotes an information processing apparatus, reference numeral 601 denotes an input unit such as a keyboard, reference numeral 603 denotes an information processing apparatus body, and reference numeral 602 denotes a liquid crystal display unit using the liquid crystal device of the above embodiment. .

  FIG. 8C is a perspective view showing an example of a wristwatch type electronic device. In FIG. 8C, reference numeral 700 denotes a watch body, and reference numeral 701 denotes a liquid crystal display unit using the liquid crystal device of the above embodiment.

  As described above, since the electronic apparatus shown in FIG. 8 uses the above-described liquid crystal device as an example of the present invention for the display unit, there is no problem that rubbing streaks are displayed, for example, when a rubbing process is performed. Thus, a display device capable of maintaining a high-contrast and high-quality display for a long time is obtained.

[Projection type display device]
Next, a configuration of a projection display device (projector) including the liquid crystal device according to the above embodiment as a light modulation unit will be described with reference to FIG. FIG. 9 is a schematic configuration diagram showing a main part of a projection display device using the liquid crystal device of the above embodiment as a light modulation device. 9, 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, 822, 823 and 824 are liquid crystal light modulators, Reference numeral 825 denotes a cross dichroic prism, and reference numeral 826 denotes a projection lens.

  The light source 810 includes a lamp 811 such as a metal halide and a reflector 812 that reflects the light of the lamp. The dichroic mirror 813 that reflects blue light and green light transmits red light out of the light flux 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 red light liquid crystal light modulation device 822 including the liquid crystal device as an example of the present invention.

  On the other hand, of the color light reflected by the dichroic mirror 813, the green light is reflected by the dichroic mirror 814 that reflects green light, and enters the liquid crystal light modulator 823 for green light that includes the above-described liquid crystal device according to the present invention. . Note that the blue light also passes through the second dichroic mirror 814. For blue light, light guide means 821 comprising a relay lens system including an incident lens 818, a relay lens 819, and an exit lens 820 is provided in order to compensate for the difference in optical path length from green light and red light. Through this, the blue light is incident on the liquid crystal light modulation device 824 for blue light provided with the liquid crystal device as an example of the present invention.

  The three color lights modulated by the respective light modulation devices are incident on the cross dichroic prism 825. In this prism, four right-angle prisms are bonded together, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in a cross shape on the inner surface. 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.

  Since the projection display device having the above-described structure includes the liquid crystal device as an example of the present invention described above, for example, there is no problem that a rubbing streak is displayed as in the case of performing a rubbing process, and the contrast is high. A display device capable of maintaining a high-quality display over a long period of time.

1 is an equivalent circuit diagram of switching elements, signal lines, etc. in a liquid crystal device according to an embodiment of the present invention. FIG. 2 is a plan view showing a structure of a plurality of pixel groups adjacent to each other on a TFT array substrate in the liquid crystal device of FIG. 1. Sectional drawing which shows the element structure about the liquid crystal device of FIG. FIG. 2 is a cross-sectional view schematically showing a configuration of a pixel region of the liquid crystal device of FIG. FIG. 4 is an explanatory diagram schematically showing a change in alignment of liquid crystal accompanying voltage application in the liquid crystal device of the present embodiment. Explanatory drawing which shows typically the orientation change of the liquid crystal accompanying a voltage application in the conventional liquid crystal device. Explanatory drawing shown about the formation process of alignment film. FIG. 14 is a perspective view illustrating some examples of the electronic apparatus according to the invention. The figure which shows an example about the projection type display apparatus which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... TFT array substrate, 20 ... Counter substrate, 10A, 20A ... Substrate body, 40, 60 ... Alignment film, 41, 61 ... Vertical alignment film, 42, 62 ... Horizontal alignment film, 50 ... Liquid crystal layer

Claims (10)

A liquid crystal device in which a liquid crystal layer composed of a liquid crystal having an initial alignment state of vertical alignment and a negative dielectric anisotropy is sandwiched between a pair of substrates,
A plurality of pixel portions,
An alignment film is formed on the liquid crystal layer side of the substrate,
The alignment film is composed of a vertical alignment film for aligning the liquid crystal in the pixel portion and a horizontal alignment film for aligning the liquid crystal in the peripheral portion of the pixel portion and having a pretilt with a predetermined azimuth angle. A liquid crystal device.   The horizontal alignment film is disposed on a non-pixel portion that forms a boundary between the pixel portions and a part of the periphery of the pixel portion, while the vertical alignment film is surrounded by the horizontal alignment film. The liquid crystal device according to claim 1, wherein the liquid crystal device is disposed in a region.   The liquid crystal device according to claim 1, wherein the vertical alignment film is not rubbed.   The liquid crystal device according to claim 1, wherein the horizontal alignment film is rubbed.   5. The liquid crystal device according to claim 1, wherein in the pixel portion, the liquid crystal molecules constituting the liquid crystal layer have a pretilt angle of 0 ° when no voltage is applied. A liquid crystal device comprising a plurality of pixel portions, in which a liquid crystal layer composed of a liquid crystal having an initial alignment state of vertical alignment and negative dielectric anisotropy is sandwiched between a pair of substrates,
A first step of performing a rubbing process by forming a horizontal alignment film in a region corresponding to a peripheral portion of the pixel portion on the substrate;
And a second step of forming a vertical alignment film in a region corresponding to the pixel portion on the substrate.   The first step includes a step of selectively disposing the horizontal alignment film on a peripheral portion of the pixel portion by a droplet discharge method, and a step of performing a rubbing process on the disposed horizontal alignment film. A method for manufacturing a liquid crystal device according to claim 6.   8. The method of manufacturing a liquid crystal device according to claim 6, wherein the second step includes a step of selectively disposing the vertical alignment film on the pixel portion by a droplet discharge method.   9. The liquid crystal according to claim 6, wherein the second step includes a step of disposing the vertical alignment film in a region surrounded by the horizontal alignment film by a droplet discharge method. Device manufacturing method. An electronic apparatus comprising the liquid crystal device according to claim 1.

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