JP2008083485A - Liquid crystal display device and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device that can perform initial transition operation, more surely at low voltage and at a high speed, and to provide an electronic apparatus with the same. <P>SOLUTION: At least one spacer 61, that retains the spacing between an element substrate 11 and an opposing substrate 12 is arranged, corresponding to each of a plurality of pixel regions, wherein the spacer 61 is subjected to an alignment processing for aligning liquid crystal molecules 13A that constitute a liquid crystal layer 13 so that the liquid crystal molecules are oriented from one side of the element substrate 11 and the opposing substrate 12, to the other side thereof along the surface. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device and an electronic apparatus that employ an OCB (Optical Compensated Bend) mode.

  In recent years, particularly in the field of liquid crystal display devices typified by liquid crystal television receivers, an OCB (Optical Compensated Bend) mode liquid crystal display device with a high response speed has been spotlighted for the purpose of improving the quality of moving images. In the OCB mode, in the initial state, the liquid crystal molecules have a splay alignment that opens in a splayed manner between a pair of substrates, and the liquid crystal molecules need to have a bend alignment bent in a bow shape during a display operation. That is, in the OCB mode, high-speed response is realized by modulating the transmittance with the degree of bending of the bend orientation during the display operation.

  As described above, in the case of the OCB mode liquid crystal display device, since the liquid crystal molecules are in the splay alignment when the power is shut off, the bend at the time of the display operation is changed from the initial splay alignment by applying a voltage higher than a certain threshold value when the power is turned on. A so-called initial transition operation is required to transfer the alignment state of the liquid crystal molecules to the alignment. Here, if the initial transition is not sufficient, display failure may occur or desired high-speed response may not be obtained.

Therefore, a liquid crystal display device in which fine particles are dispersed in an alignment film that regulates the initial alignment state of liquid crystal molecules constituting the liquid crystal layer has been proposed (for example, see Patent Document 1). In this liquid crystal display device, the voltage of the initial transition operation is reduced by partially reducing the alignment regulating force of the alignment film in the vicinity where fine particles are present.
Further, there is provided a liquid crystal display device in which fine particles having a diameter smaller than a distance between a pair of substrates sandwiching a liquid crystal layer are subjected to an alignment treatment for aligning liquid crystal molecules in a direction perpendicular to the surface and dispersed on the substrate surface. It has been proposed (see, for example, Patent Document 2). In this liquid crystal display device, liquid crystal molecules are aligned in a direction perpendicular to a pair of substrates and used as initial transition nuclei, thereby speeding up the initial transition operation.
JP 2002-131754 A JP 2004-310139 A

However, the following problems remain in the conventional liquid crystal display device adopting the OCB mode. That is, in the former liquid crystal display device, it is necessary to disperse the fine particles in the alignment film, thereby complicating the manufacturing process. If the amount of fine particles dispersed is excessively large, scattering or the like may occur due to aggregation or sedimentation. .
In the latter liquid crystal display device, since the liquid crystal molecules are aligned perpendicularly to the surface of the fine particles, there are liquid crystal molecules aligned horizontally with respect to the substrate. Accordingly, there is a problem that the liquid crystal molecules are horizontally aligned in the vicinity of the horizontally aligned liquid crystal molecules, and the initial transition operation cannot be smoothly performed.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a liquid crystal display device and an electronic apparatus including the liquid crystal display device that can perform the initial transition operation more reliably at a low voltage and at high speed.

  The present invention employs the following configuration in order to solve the above problems. That is, the liquid crystal display device according to the present invention is driven in the OCB mode by being sandwiched between the first substrate provided with the first electrode, the second substrate provided with the second electrode, and the first and second substrates. A liquid crystal display device comprising a plurality of pixel regions arranged in a plane and having a liquid crystal layer that holds a distance between the first and second substrates corresponding to each of the plurality of pixel regions At least one spacer is disposed, and the spacer is subjected to an alignment treatment for aligning liquid crystal molecules constituting the liquid crystal layer so as to be directed from one of the first and second substrates to the other along the surface. It is characterized by.

In the present invention, the liquid crystal molecules are aligned perpendicularly to the first and second substrates at and near the surface of the spacer, so that the initial transition operation can be more reliably performed at a low voltage.
That is, since the alignment treatment is performed on the spacer from one of the first and second substrates to the other, the liquid crystal molecules aligned along the spacer are in an alignment state similar to the bend alignment. Thereby, when a voltage is applied between the first and second electrodes, the bend alignment state propagates to other liquid crystal molecules using the liquid crystal molecules aligned on the surface of the spacer as transition nuclei. At this time, a spacer is provided corresponding to each pixel region, and this bend orientation is propagated for each pixel region. In addition, since the spacers are in contact with the surfaces of the first and second substrates, the spacers prevent the liquid crystal molecules from being aligned horizontally with respect to the first and second substrates. Therefore, the initial transition operation can be more reliably performed at a high speed with a low voltage.

In the liquid crystal display device according to the present invention, it is preferable that the spacer is disposed in a region overlapping with a region where the first electrode is not formed in a plan view.
In the present invention, by providing the spacer on the non-formation region of the first electrode, it is possible to reduce the influence such as scattering that the spacer has on the display by the pixel region.

In the liquid crystal display device according to the present invention, a switching element for driving the first electrode and a signal electrode connected to the switching element are provided on a first substrate, and the spacer has the signal electrode in a plan view. It is preferable that it is arrange | positioned in the area | region which overlaps.
In this invention, by arranging the spacer in the vicinity of the signal electrode where a strong electric field is formed, the bend alignment can be propagated at a higher speed using the liquid crystal molecules aligned on the surface of the spacer as the transition nucleus. .

In the liquid crystal display device according to the present invention, the switching element may constitute a transistor, and the signal electrode may be connected to the gate of the switching element.
In the present invention, since a high voltage is supplied to the signal electrode by connecting the signal electrode to the gate of the switching element, the bend alignment can be propagated at a higher speed. Further, the initial transition operation can be performed at a high speed by supplying a high voltage to the signal electrode to easily cause disclination in the liquid crystal layer.

Further, the liquid crystal display device according to the present invention is preferably provided with an initial alignment transition means for promoting the initial alignment transition of the liquid crystal molecules corresponding to each of the plurality of pixel regions.
In the present invention, by providing the initial transition alignment means, the initial transition operation in each pixel region can be further speeded up.

In the liquid crystal display device according to the present invention, the initial alignment transition means may be configured by an opening formed in the first electrode.
In the present invention, an electric field can be generated near the opening of the first electrode in a direction different from the initial alignment direction of the liquid crystal molecules according to the shape of the opening. Thereby, the liquid crystal molecules are reoriented while rotating along the direction of the electric field by applying a voltage, and thus disclination is likely to occur. The initial transition operation can be speeded up by propagating the orientation transition using the disclination as an initial transition nucleus.

In the liquid crystal display device according to the present invention, it is preferable that the spacer is disposed in a region overlapping the opening in a plan view.
According to the present invention, the display by the pixel region is less affected by the scattering by the spacer.

In the liquid crystal display device according to the present invention, the initial alignment transition means may be constituted by a convex portion provided on at least one of the first and second substrates.
In the present invention, an electric field is generated in a direction different from the initial alignment direction of the liquid crystal molecules with respect to the liquid crystal molecules arranged on the convex portion. Thereby, the direction in the planar direction of the liquid crystal molecules is shifted from the initial alignment direction, and a region in which the liquid crystal molecules are twisted (twisted) in the region where the electric field acts is formed. Here, in the OCB mode liquid crystal molecules, the twist alignment energy (Gibbs energy) state is located between the splay alignment and the bend alignment, and the alignment transition from the twist alignment to the bend alignment propagates very easily. To do. Therefore, the initial transfer operation can be performed at high speed.

In the liquid crystal display device according to the present invention, the initial alignment transition means may be constituted by a recess provided in at least one of the first and second substrates.
In the present invention, a twist-aligned region is formed by shifting the alignment state of the liquid crystal molecules arranged on the recess from the initial alignment direction when a voltage is applied. Therefore, the initial transfer operation can be performed at high speed.

An electronic apparatus according to the present invention includes the above-described liquid crystal display device.
According to the present invention, the liquid crystal molecules that are aligned in the same manner as the bend alignment by the spacers provided corresponding to each pixel region are used as transition nuclei, so that the voltage and speed of the initial transition operation can be more reliably reduced. I can plan.

[First Embodiment]
Hereinafter, a liquid crystal display device according to a first embodiment of the present invention will be described with reference to the drawings. In each drawing used in the following description, the scale is appropriately changed to make each member a recognizable size. Here, FIG. 1 is a plan view showing the liquid crystal display device, FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, FIG. 3 is an equivalent circuit diagram showing the liquid crystal display device, and FIG. FIG. 4B is a cross-sectional view taken along the line B-B in FIG.

[Liquid Crystal Display]
First, a schematic configuration of the liquid crystal display device 1 will be described. The liquid crystal display device 1 in this embodiment is an active matrix type transflective liquid crystal display device, and includes three sub-pixels that output light of each color of R (red), G (green), and B (blue). This is a liquid crystal display device constituting one pixel. Here, the display area which is the minimum unit constituting the display is referred to as a “sub-pixel area (pixel area)”.

As shown in FIGS. 1 and 2, the liquid crystal display device 1 includes an element substrate (first substrate) 11, a counter substrate (second substrate) 12 arranged to face the element substrate 11, the element substrate 11, and the counter substrate. And a liquid crystal layer 13 sandwiched between the two. In the liquid crystal display device 1, the element substrate 11 and the counter substrate 12 are bonded together with a sealing material 14, and the liquid crystal layer 13 is sealed in an area partitioned by the sealing material 14. The liquid crystal display device 1 is provided with a peripheral parting 15 provided along the inner periphery of the sealing material 14. The liquid crystal display device 1 is viewed in plan view (the element substrate 11 is viewed from the counter substrate 12 side) surrounded by the peripheral parting 15. In the state), a rectangular area is set as an image display area 16.
In addition, the liquid crystal display device 1 includes a data line driving circuit 21 and a scanning line driving circuit 22 provided in an outer region of the sealing material 14, a connection terminal 23 that is electrically connected to the data line driving circuit 21, and the scanning line driving circuit 22. Wiring 24 to be connected is provided.

In the liquid crystal display device 1, as shown in FIG. 3, a plurality of sub-pixel areas constituting the image display area 16 are arranged in a matrix.
In each of the plurality of sub-pixel regions, a pixel electrode (first electrode) 31 and a TFT (Thin Film Transistor) element (driving element) 32 for switching control of the pixel electrode 31 are provided. In the image display area 16, a plurality of data lines 33 and scanning lines (signal electrodes) 34 are arranged in a grid pattern.

  The TFT element 32 has a source connected to the data line 33, a gate connected to the scanning line 34, and a drain connected to the pixel electrode 31. The data line 33 is connected to the data line driving circuit 21 and is configured to supply the image signals S1, S2,..., Sn supplied from the data line driving circuit 21 to each sub-pixel region. Further, the scanning line 34 is connected to the scanning line driving circuit 22 and is configured to supply the scanning signals G1, G2,..., Gm supplied from the scanning line driving circuit 22 to each sub-pixel region. Here, the data line driving circuit 21 may supply the image signals S <b> 1 to Sn in this order in a line sequential manner, or may supply each of the data lines 33 adjacent to each other for each group. The scanning line driving circuit 22 supplies the scanning signals G1 to Gm in a pulse-sequential manner at predetermined timing.

  In the liquid crystal display device 1, the TFT elements 32, which are switching elements, are turned on for a certain period by the input of scanning signals G1 to Gm, so that the image signals S1 to Sn supplied from the data line 33 are at a predetermined timing. The pixel electrode 31 is written. A predetermined level of the image signals S1 to Sn written to the liquid crystal via the pixel electrode 31 is between the pixel electrode 31 and a counter electrode (second electrode) 55 (described later) disposed so as to face the liquid crystal layer 13. Is held for a certain period. Here, in order to prevent the retained image signals S1 to Sn from leaking, a storage capacitor 35 is provided so as to be connected in parallel with a liquid crystal capacitor formed between the pixel electrode 31 and the counter electrode 55. Yes. The storage capacitor 35 is provided between the drain of the TFT element 32 and the capacitor line 36.

Next, a detailed configuration of the liquid crystal display device 1 will be described with reference to FIG. In FIG. 4A, the major axis direction of the substantially rectangular sub-pixel region in plan view, the major axis direction of the pixel electrode 31, the extending direction of the data line 33 are the X-axis direction, and the minor axis of the sub-pixel region. The direction, the short axis direction of the pixel electrode 31, and the extending direction of the scanning line 34 and the capacitor line 36 are defined as the Y axis direction.
As shown in FIG. 4B, the liquid crystal display device 1 includes a polarizing plate 37 provided on the outside of the element substrate 11 (on the side opposite to the liquid crystal layer 13), and the outside of the counter substrate 12 (on the side opposite to the liquid crystal layer 13). ) And a lighting device (not shown) that is provided outside the polarizing plate 37 and emits illumination light from the outer surface side of the element substrate 11.

The element substrate 11 includes, for example, a substrate body 41 made of a light-transmitting material such as glass, quartz, and plastic, a gate insulating film 42 sequentially stacked on the inner surface (the liquid crystal layer 13 side) of the substrate body 41, and an interlayer An insulating film 43 and an alignment film 44 are provided.
Further, the element substrate 11 includes a scanning line 34 and a capacitor line 36 disposed on the inner surface of the substrate body 41, and a data line 33 (shown in FIG. 4A) disposed on the inner surface of the gate insulating film 42. ), The semiconductor layer 45, the source electrode 46 and the drain electrode 47, and the resin layer 48 and the pixel electrode 31 disposed on the inner surface of the interlayer insulating film 43.

The gate insulating film 42 is made of a translucent material such as SiO ₂ (silicon oxide), for example, and is provided so as to cover the scanning lines 34 and the capacitor lines 36 formed on the substrate body 41.
Similar to the gate insulating film 42, the interlayer insulating film 43 is made of a light-transmitting material such as SiO ₂ (silicon oxide), and the data line 33, the semiconductor layer 45, and the like formed on the gate insulating film 42. It is provided so as to cover the source electrode 46 and the drain electrode 47. The interlayer insulating film 43 is provided with a contact hole 43A that secures conduction between a transparent electrode 31B (described later) of the pixel electrode 31 and a drain electrode 47 and connects the pixel electrode 31 and the TFT 32.
The alignment film 44 is made of a translucent resin material such as polyimide, and is provided so as to cover the pixel electrode 31 formed on the inner surface of the interlayer insulating film 43. The surface of the alignment film 44 is subjected to a rubbing process in the major axis direction (arrow R direction shown in FIG. 4A) of the sub-pixel region.

  As shown in FIG. 4A, the data line 33 is arranged along the major axis direction (X-axis direction) of the sub-pixel region. The scanning line 34 is arranged along the minor axis direction (Y-axis direction) of the sub-pixel region. The capacitor line 36 is disposed adjacent to the scanning electrode 34 on the pixel electrode 31 side so as to extend in parallel with the scanning line 34. Therefore, the data line 33, the scanning line 34, and the capacitor line 36 are wired in a substantially lattice shape in plan view.

  As shown in FIGS. 4A and 4B, the semiconductor layer 45 is made of a semiconductor such as amorphous silicon partially formed in a region overlapping with the scanning line 34 in plan view via the gate insulating film 42. ing. The source electrode 46 is branched from the data line 33, and a part thereof is formed so as to cover a part of the semiconductor layer 45. The drain electrode 47 is formed so as to partially cover the semiconductor layer 45, and the storage capacitor 35 is formed by the capacitor line 36 and a portion that overlaps the capacitor line 36 in plan view through the gate insulating film 42. Is configured. These semiconductor layer 45, source electrode 46 and drain electrode 47 constitute a TFT element 32. Therefore, the TFT element 32 is provided near the intersection of the data line 33 and the scanning line 34.

  The resin layer 48 corresponds to one end of the surface of the interlayer insulating film 43 in the major axis direction (X-axis direction) of the sub-pixel region (of the sub-pixel region divided into two in the major axis direction). Are provided on a portion corresponding to the side separated from the scanning line 34 and the capacitor line 36 provided on the surface, and unevenness is formed on the surface.

The pixel electrode 31 has a substantially rectangular shape in plan view. The reflective electrode 31A covers the resin layer 48, and the other end portion in the major axis direction (X-axis direction) of the sub-pixel region of the surface of the interlayer insulating film 43 ( A transparent electrode 31B provided in a portion corresponding to a scanning line 34 and a capacitive line 36 provided corresponding to the sub-pixel region in the sub-pixel region divided into two in the major axis direction; It has.
The reflective electrode 31A is made of a highly reflective metal material such as Al or Ag. The transparent electrode 31B is made of a light-transmitting conductive material such as ITO (Indium Tin Oxide), and is electrically connected to the reflective electrode 31A. The transparent electrode 31B is connected to the TFT element 32 through a contact hole 43A formed in the interlayer insulating film 43.
The reflective electrode 31A formation region constitutes the reflective display region R, and the transparent electrode 31B formation region constitutes the transmissive display region T.

On the other hand, as shown in FIG. 4B, the counter substrate 12 is made of a light-transmitting material such as glass, quartz, or plastic, for example, and a surface of the substrate body 51 and the inside of the substrate body 51 (the liquid crystal layer 13 side). A light shielding film 52, a color filter layer 53, a liquid crystal layer thickness adjusting layer 54, a counter electrode 55, and an alignment film 56, which are sequentially stacked.
The light shielding film 52 is formed in a region of the surface of the substrate body 51 that overlaps the edge of the sub pixel region in plan view, and borders the sub pixel region.
The color filter layer 53 is disposed corresponding to each sub-pixel region, and is made of, for example, acrylic and contains a color material corresponding to the color displayed in each sub-pixel region.

The liquid crystal layer thickness adjusting layer 54 is made of a light-transmitting insulating material such as acrylic resin, and is formed in a region overlapping the reflective electrode 31A in plan view through the liquid crystal layer 13 or the like. The liquid crystal layer thickness adjusting layer 54 has a thickness different from the thickness of the liquid crystal layer 13 in the reflective display region R and the thickness of the liquid crystal layer 13 in the transmissive display region T, and is applied to the light transmitted through the liquid crystal layer 13. The phase difference is optimized in each of the reflective display region R and the transmissive display region T. The thickness of the liquid crystal layer thickness adjusting layer 54 is such that the phase difference of the liquid crystal layer 13 in the reflective display region R is ¼ wavelength. Note that the phase difference of the liquid crystal layer 13 in the transmissive display region T is ½ wavelength.
The counter electrode 55 is made of a light-transmitting conductive material such as ITO, and is provided so as to cover the liquid crystal layer thickness adjusting layer 54.
The alignment film 56 is made of a light-transmitting resin material such as polyimide, and is provided so as to cover the counter electrode 55. The surface of the alignment film 56 is subjected to a rubbing process in the same direction as the alignment direction of the alignment film 44 (the arrow R direction shown in FIG. 4A).

Between the element substrate 11 and the counter substrate 12, a spacer 61 that maintains a distance between the element substrate 11 and the counter substrate 12 is provided via the interlayer insulating film 43 and the color filter layer 53 in a plan view. The light shielding film 52 is disposed so as to overlap.
The spacer 61 is made of, for example, a resin material such as polyimide, and has a spherical shape whose diameter is equal to the distance between the element substrate 11 and the counter substrate 12. An alignment process is performed on the surface of the spacer 61 so as to go from the element substrate 11 toward the counter substrate 12 along the surface.
Here, as the alignment treatment applied to the spacer 61, for example, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, 4-aminophenylpropyltrimethoxysilane, N- (trimethoxysilylpropyl)- Examples thereof include a method of forming a film of a silane coupling agent having _two polar functional groups (—NH ₂ , —CONH, etc.) bonded to the surface of the spacer 61 such as ethylenediamine on the surface of the spacer 61.
The spacer 61 is arranged corresponding to each sub-pixel region. Here, as a method for arranging the spacer 61, the surface of the alignment film 44 is charged with a region that overlaps the scanning line 34 in plan view via the interlayer insulating film 43 and the like, and the surface of the spacer 61 is also charged. And a method of arranging the spacer 61 by electrostatic attraction and a method of arranging the spacer 61 using an ink jet method.

  The liquid crystal layer 13 is configured to operate in the OCB mode, and the liquid crystal molecules 13A are in bend alignment as shown in FIG. Here, the liquid crystal molecules 13 </ b> A in the vicinity of the spacer 61 are aligned so as to be directed from the element substrate 11 toward the counter substrate 12 along the surface of the spherical spacer 61 by performing an alignment process on the surface of the spacer 61. . For this reason, the liquid crystal molecules 13A in the vicinity of the spacer 61 are in the alignment state equivalent to the bend alignment. Further, since the spacer 61 is in contact with the inner side surfaces of the element substrate 11 and the counter substrate 12, the liquid crystal molecules 13 </ b> A are prevented from being horizontally aligned with respect to the element substrate 11 and the counter substrate 12 by the spacer 61. ing.

The polarizing plates 37 and 38 are provided so that their transmission axes are substantially orthogonal to each other. A quarter-wave plate 65 and a half-wave plate 66 are stacked on the inner surface side of the polarizing plate 37, and a quarter-wave plate 67 and a half-wave plate 68 are disposed on the inner surface side of the polarizing plate 38. Are stacked.
Here, an optical compensation film (not shown) may be disposed inside one or both of the polarizing plates 37 and 38. By disposing the optical compensation film, it is possible to compensate for the phase difference of the liquid crystal layer 13 when the liquid crystal display device 1 is viewed from the front or perspective, and it is possible to reduce light leakage and increase contrast. As an optical compensation film, a negative uniaxial medium in which a discotic liquid crystal having a negative refractive index anisotropy is hybrid-oriented or a nematic liquid crystal having a positive refractive index anisotropy in a hybrid orientation is positive uniaxial. Medium. Further, a combination of a negative uniaxial medium and a positive uniaxial medium, or a biaxial medium in which the refractive index in each direction is nx>ny> nz may be used.

[Initial transfer operation]
Next, an initial transition operation of the OCB mode liquid crystal display device 1 will be described with reference to the drawings. Here, FIG. 5 is an explanatory diagram showing the alignment state of the liquid crystal molecules in the OCB mode.
In the OCB mode liquid crystal display device, in the initial state (non-operation), the liquid crystal molecules 13A are in an alignment state (splay alignment) in which the liquid crystal molecules 13A are open as shown in FIG. As shown in FIG. 5B, the liquid crystal molecules 13A are in an alignment state (bend alignment) bent like a bow. The liquid crystal display device 1 is configured to realize high-speed response of the display operation by modulating the transmittance with the degree of bending of the bend orientation during the display operation.

  As described above, in the case of the OCB mode liquid crystal display device 1, since the alignment state of the liquid crystal molecules is the splay alignment when the power is shut off, by applying a voltage higher than a certain threshold value to the liquid crystal molecules 13A when the power is turned on, FIG. A so-called initial transition operation is required in which the alignment state of the liquid crystal molecules is transferred from the initial splay alignment shown in FIG. 5A to the bend alignment during the display operation shown in FIG. Here, when the initial transition is not sufficiently performed, display failure and desired high-speed response may not be obtained.

As an initial transition operation of the liquid crystal layer 13, a method in which a pulse voltage is applied between the pixel electrode 31 and the counter electrode 55 while the scanning lines 34 are turned on line-sequentially can be used.
Here, the alignment treatment is performed on the spacer 61 so as to go from the element substrate 11 toward the counter substrate 12 along the surface. For this reason, the liquid crystal molecules 13 </ b> A in the vicinity of the spacer 61 are horizontally aligned along the surface of the spacer 61 from the element substrate 11 toward the counter substrate 12. Thereby, the liquid crystal molecules 13A in the vicinity of the spacer 61 are in an alignment state equivalent to the bend alignment.

  Then, by applying this initial transition voltage (for example, 5V), the liquid crystal molecules 13A bend-aligned by the spacers 61 become initial transition nuclei, and the initial transition propagates to the periphery. In addition, disclination occurs in the sub-pixel region by applying the initial transition voltage, and the initial transition propagates to the periphery by using this disclination as an initial transition nucleus. Here, the spacer 61 is arranged in a region overlapping with the scanning line 34 connected to the gate of the TFT element 32 via the interlayer insulating film 43 and the like in plan view, and a high voltage is applied to the scanning line 34. The propagation of the initial transition using the liquid crystal molecules 13A bend-aligned by the spacer 61 as the initial transition nuclei is performed at a higher speed (for example, within 1 second). Furthermore, since the spacers 61 are arranged corresponding to the respective sub-pixel regions and are prevented from being horizontally oriented with respect to the element substrate 11 and the counter substrate 12 by the spacers 61, the initial transfer operation is smooth. To be done.

  Note that the spacer 61 is disposed in a region that overlaps the scanning line 34 in plan view through the interlayer insulating film 43 and the like and is not formed in the pixel electrode 31, so that light transmitted through the liquid crystal layer 13 is transmitted by the spacer 61. It is avoided that the display of the image by the sub pixel region is deteriorated due to the influence of scattering or the like.

〔Electronics〕
The liquid crystal display device 1 having the above configuration is applied as a display unit 101 of a mobile phone 100 as shown in FIG. 6, for example. The cellular phone 100 includes a main body 105 having a plurality of operation buttons 102, a mouthpiece 103, a mouthpiece 104, and the display unit 101.

As described above, according to the liquid crystal display device 1 and the mobile phone 100 in the present embodiment, the liquid crystal molecules 13A that are aligned along the surface of the spacer 61 and are in the alignment state similar to the bend alignment function as initial transition nuclei. By doing so, the initial transition operation can be more reliably performed at a high speed with a low voltage. Here, since the spacer 61 is disposed in a region overlapping the scanning line 34 connected to the gate of the TFT element 32 and the interlayer insulating film 43 in a plan view, a high voltage is applied to the scanning line 34. Since the initial transition is propagated at high speed by the liquid crystal molecules 13A aligned on the surface of the spacer 61, the initial transition operation can be performed in a shorter time.
In addition, since the spacer 61 is disposed in a region where the pixel electrode 31 is not formed and overlaps the scanning line 34 in plan view via the interlayer insulating film 43 and the like, it is possible to avoid display deterioration due to the sub-pixel region. it can.

[Second Embodiment]
Next, a liquid crystal display device according to a second embodiment of the present invention will be described with reference to the drawings. Here, FIG. 7 is a schematic plan view showing the sub-pixel region. In this embodiment, since the configuration of the sub-pixel region is different from that of the first embodiment, this point will be mainly described, and the same reference numerals are given to the components described in the above embodiment, and the description will be given. Omitted.

In the liquid crystal display device 110 according to the present embodiment, slits (initial alignment transition means, openings) 112A are formed in the transparent electrode 111B among the reflective electrode 111A and the transparent electrode 111B constituting the pixel electrode 111 provided in each sub-pixel region. Is formed.
The slit 112A has a shape bent in a crank shape in plan view, and is formed in a region of the transparent electrode 111B that overlaps the capacitor line 36.

In the liquid crystal display device 110 having such a configuration, when an initial transition voltage is applied in the initial transition operation, the liquid crystal molecules 13A bend-aligned by the spacers 61 become initial transition nuclei and the initial transition propagates to the periphery as described above. To do.
Further, in the region where the slit 112A is formed, as indicated by arrows R3 and R4 shown in FIG. 7, the direction along the major axis direction (X-axis direction) of the sub-pixel region parallel to the initial alignment direction or the initial alignment direction Electric fields are generated in various directions such as a direction along the short axis direction (Y-axis direction) of the sub-pixel region orthogonal to the vertical direction. Thereby, the liquid crystal molecules 13A try to realign while rotating along the electric field direction by an electric field in a direction different from the initial alignment direction. For this reason, disclination occurs in the liquid crystal layer 13, and the initial transition propagates using the disclination as an initial transition nucleus.

As described above, the liquid crystal display device 110 according to the present embodiment has the same operations and effects as those described above. However, by generating electric fields in various directions in the region where the slits 112A are formed, the liquid crystal layer 13 has a disk. Since it becomes easy to generate a line, the initial transfer operation can be performed in a shorter time.
In the present embodiment, the shape of the slit 112A formed in the pixel electrode 111 is not limited to the shape bent in a crank shape in plan view, and it is possible to generate electric fields in various directions by applying an initial transition voltage. Other shapes such as a slit 112B bent in a bellows shape in a plan view as shown in FIG. 8A and a spiral slit 112C in a plan view as shown in FIG. 8B may be used. A plurality of the slits 112 </ b> A to 111 </ b> C may be formed in the pixel electrode 111. Further, the position where the slit is formed is not limited to the region overlapping the capacitance line 36, and may be another region.
Further, the spacer 61 may be arranged in a region overlapping with the slits 112A to 111C in plan view. Thereby, it can avoid that the display by a sub-pixel area | region deteriorates.

[Third Embodiment]
Next, a liquid crystal display device according to a third embodiment of the present invention will be described with reference to the drawings. Here, FIG. 9 is a schematic sectional view showing the sub-pixel region. In this embodiment, since the configuration of the sub-pixel region is different from that of the first embodiment, this point will be mainly described, and the same reference numerals are given to the components described in the above embodiment, and the description will be given. Omitted.

In the liquid crystal display device 120 according to the present embodiment, a plurality of island-shaped convex portions (initial alignment transition means) 121 are formed on the pixel electrodes 31 provided in each sub-pixel region. The convex portion 121 is provided in a region of the transparent electrode 31 </ b> B constituting the pixel electrode 31 that overlaps the inclined portion of the liquid crystal layer thickness adjusting layer 54 in plan view via the liquid crystal layer 13 and the like. The alignment film 44 is provided so as to cover the pixel electrode 31 and the convex portion 121.
The liquid crystal molecules 13A arranged in the region where the convex portions 121 are formed are aligned in a direction different from the initial alignment state of the other liquid crystal molecules 13A by the convex portions 121.

In the liquid crystal display device 120 having such a configuration, when an initial transition voltage is applied in the initial transition operation, the liquid crystal molecules 13A bend-aligned by the spacers 61 become initial transition nuclei and the initial transition propagates to the periphery as described above. To do.
Further, since the alignment state of the liquid crystal molecules 13A in the formation region of the convex portion 121 is different from the initial alignment direction, the direction of the generated electric field is different from the alignment direction. Thereby, the direction in the plane direction of the liquid crystal molecules 13A is shifted from the initial alignment direction, and a twisted alignment (twist alignment) region is formed in the convex portion 121. As a result, disclination occurs in the liquid crystal layer 13, and the initial transition propagates using the disclination as an initial transition nucleus.

As described above, the liquid crystal display device 120 according to the present embodiment has the same operations and effects as described above. However, a twist-aligned region is formed in the region where the convex portion 121 is formed, and thus the liquid crystal layer 13 is formed. Since disclination is likely to occur, the initial transfer operation can be performed in a shorter time.
In the present embodiment, the island-shaped protrusions 121 are formed on the pixel electrode. However, if the twisted alignment region can be formed by shifting the orientation in the plane direction of the liquid crystal molecules 13A from the initial alignment direction, The shape is not limited and may be other shapes such as a line shape. In addition to the convex portion 121, a twist-oriented region may be formed by forming a concave portion (not shown) formed in the alignment film 44, for example. And if the area | region by which the twist orientation was formed is formed, the convex part 121 may be provided not only in the area | region which overlaps with the liquid-crystal layer thickness adjustment layer 54 by planar view through the liquid-crystal layer 13, etc., but in another area | region. Further, although the convex portion 121 or the concave portion is formed on the element substrate 11, it may be formed on at least one of the element substrate 11 and the counter substrate 12. Also good.

In addition, this invention is not limited to the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.
For example, although the spacer is spherical in the above-described embodiment, it may have other shapes as long as the liquid crystal molecules aligned on the surface of the spacer are in the same alignment state as the bend alignment.
Further, it is sufficient that at least one spacer is disposed corresponding to the sub-pixel region, and a plurality of spacers may be disposed.
In addition, although the spacer is arranged in a region overlapping with the scanning line connected to the gate of the TFT element, if the initial transition can be performed in a short time using the liquid crystal molecules aligned on the surface of the spacer as the initial transition nucleus, the data You may arrange | position in the area | region which overlaps with a line or a capacity | capacitance line. For example, by disposing a spacer on the data line adjacent to the convex portion, the disclination generated at the convex portion is easily affected by the spacer and bends easily. If the influence of the spacer on the display by the sub-pixel area is small, the spacer may be arranged in the transmissive display area or the reflective display area. Here, when the spacer is arranged in the reflective display region, the diameter thereof is made equal to the distance between the element substrate and the counter substrate in the reflective display region.

In addition, the liquid crystal display device uses a TFT element as a drive element for switching the pixel electrode. However, the present invention is not limited to the TFT element, and other drive elements such as a TFD (Thin Film Diode) element may be used. Good.
The liquid crystal display device employs a normally black mode, but may employ a normally white mode.
The liquid crystal display device is a transflective liquid crystal display device, but may be a transmissive or reflective liquid crystal display device.
The liquid crystal display device is a color liquid crystal display device that performs color display of three colors of R, G, and B. However, the liquid crystal display device may include a sub-pixel region that performs other color display, and performs monochromatic color display. It is good also as a structure. Here, the color filter layer may be provided on the element substrate without providing the color filter layer on the counter substrate.

  In addition, the electronic device provided with the liquid crystal display device is not limited to a mobile phone, but a PDA (Personal Digital Assistant), a personal computer, a notebook personal computer, a workstation, a digital still camera, an in-vehicle monitor, a car Navigation device, head-up display, digital video camera, television receiver, viewfinder type or monitor direct-view type video tape recorder, pager, electronic notebook, calculator, electronic book or projector, word processor, video phone, POS terminal, touch panel It may be another electronic device such as a device provided, a lighting device, or the like.

It is a schematic plan view which shows the liquid crystal display device in 1st Embodiment. It is AA arrow sectional drawing of FIG. FIG. 2 is an equivalent circuit diagram of FIG. 1. FIG. 4A is a plan view showing a sub-pixel region, and FIG. It is explanatory drawing which shows the orientation state of the liquid crystal molecule of OCB mode. It is a schematic perspective view which shows a mobile telephone provided with a liquid crystal display device. It is a schematic plan view which shows the sub pixel area | region in 2nd Embodiment. It is a top view which shows the other opening shape which can apply this invention. It is a schematic sectional drawing of the sub pixel area | region in 3rd Embodiment.

Explanation of symbols

1, 110, 120 Liquid crystal display device, 11 Element substrate (first substrate), 12 Counter substrate (second substrate), 13 Liquid crystal layer, 13A Liquid crystal molecule, 31, 111 Pixel electrode (first electrode), 32 TFT element ( (Driving element), 34 scanning line (signal electrode), 55 counter electrode (second electrode), 61 spacer, 100 mobile phone (electronic device), 112A to 112C slit (initial alignment transition means, opening), 121 convex portion ( Initial orientation transition means)

Claims (10)

A first substrate provided with a first electrode; a second substrate provided with a second electrode; and a liquid crystal layer sandwiched between the first and second substrates and driven in an OCB mode, and arranged in a plane A liquid crystal display device comprising a plurality of pixel regions,
Corresponding to each of the plurality of pixel regions, at least one spacer for maintaining a distance between the first and second substrates is disposed,
The spacer is subjected to an alignment treatment for aligning liquid crystal molecules constituting the liquid crystal layer so as to be directed from one of the first and second substrates to the other along the surface. apparatus.   2. The liquid crystal display device according to claim 1, wherein the spacer is disposed in a region overlapping with a region where the first electrode is not formed in a plan view. A switching element for driving the first electrode and a signal electrode connected to the switching element are provided on the first substrate,
The liquid crystal display device according to claim 1, wherein the spacer is disposed in a region overlapping the signal electrode in plan view. The switching element constitutes a transistor;
The liquid crystal display device according to claim 3, wherein the signal electrode is connected to a gate of the switching element.   2. The liquid crystal display device according to claim 1, wherein initial alignment transition means for promoting initial alignment transition of the liquid crystal molecules is provided corresponding to each of the plurality of pixel regions.   6. The liquid crystal display device according to claim 5, wherein the initial alignment transition means is constituted by an opening formed in the first electrode.   The liquid crystal display device according to claim 6, wherein the spacer is disposed in a region overlapping the opening in plan view.   6. The liquid crystal display device according to claim 5, wherein the initial alignment transition means is constituted by a convex portion provided on at least one of the first and second substrates.   6. The liquid crystal display device according to claim 5, wherein the initial alignment transfer means is constituted by a recess provided in at least one of the first and second substrates.   An electronic apparatus comprising the liquid crystal display device according to claim 1.

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