JP2008197203A - Liquid crystal device, method for manufacturing the same, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal device in which the initial transition operation for transferring a liquid crystal layer from spray alignment to bend alignment can be performed at a high speed and display quality is excellent. <P>SOLUTION: The liquid crystal device is provided with a pair of substrates 10, 20 holding a liquid crystal layer 50 in-between and performs display by transferring the alignment state of the liquid crystal layer 50 from the spray alignment to the bend alignment. The liquid crystal layer 50 includes a nano carbon substance 54. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

An OCB (Optical Compensated Bend) mode liquid crystal device is known as a liquid crystal device suitable for moving image display with a high-speed response. In the OCB mode liquid crystal device, an alignment transition from the splay alignment to the bend alignment, which is an initial state, is necessary at the start of operation, and it is desired to increase the speed of the initial alignment transition. For example, in Patent Document 1, initial transition nuclei are easily generated by aligning liquid crystal on the spacer surface in the liquid crystal layer.
Japanese Patent Laid-Open No. 10-142638

  However, when the spacer in the liquid crystal layer is used as the initial transition means as in the liquid crystal device described in Patent Document 1, the alignment of the liquid crystal is disturbed around the spacer which is the initial transition means, and the image quality is deteriorated. There is a problem of end.

  The present invention has been made in view of the above-described problems of the prior art, and can perform an initial transition operation for transitioning a liquid crystal layer from a splay alignment to a bend alignment at high speed, and is excellent in display quality. The purpose is to provide.

In order to solve the above-described problems, the liquid crystal device of the present invention is a liquid crystal device that includes a pair of substrates that sandwich a liquid crystal layer and performs display by changing the alignment state of the liquid crystal layer from splay alignment to bend alignment. The liquid crystal layer includes a nanocarbon material.
According to this configuration, initial transition nuclei can be generated around the nanocarbon material contained in the liquid crystal layer during the initial transition operation. Thereby, the initial transfer operation can be performed at high speed without providing an initial transfer means such as a spacer. In addition, since a fine nanocarbon material is used as an initial transition means, it is possible to suppress a decrease in transmittance due to the provision of the initial transition means and a decrease in contrast ratio due to liquid crystal orientation disorder around the initial transition means. A liquid crystal device capable of high-quality display can be realized.

  The nanocarbon substance may be dispersed in the liquid crystal layer. With such a configuration, it is possible to obtain a liquid crystal device capable of high-speed initial transition operation only by adding a nanocarbon substance to the liquid crystal material.

  The nanocarbon material may be provided on a contact surface of at least one of the pair of substrates with the liquid crystal layer. Even in such a configuration, the same effect as that obtained by dispersing the nanocarbon substance in the liquid crystal layer can be obtained.

  The nanocarbon material is preferably a carbon nanohorn or a carbon nanotube. By using these nanocarbon materials, a liquid crystal device having both a high-speed initial transition operation and excellent display quality has been obtained.

  The nanocarbon material content is preferably 0.00001 wt% or more and 0.1 wt% or less with respect to the liquid crystal layer. By making the addition amount of the nanocarbon material within the above range, the initial transfer operation can be speeded up without greatly degrading the display quality.

  Furthermore, the content of the nanocarbon material is preferably 0.0002 wt% or more and 0.02 wt% or less with respect to the liquid crystal layer. By setting the addition amount of the nanocarbon material in the above range, a liquid crystal device capable of obtaining excellent display quality and performing a high-speed initial transfer operation can be realized.

The liquid crystal device of the present invention is a liquid crystal device that includes a pair of substrates sandwiching a liquid crystal layer and performs display by changing the alignment state of the liquid crystal layer from splay alignment to bend alignment. An alignment film containing a nanocarbon material is formed on at least one of the substrates on the liquid crystal layer side.
Even in such a configuration, initial transition nuclei can be generated around the nanocarbon material located in the surface layer portion of the alignment film, so that the initial transition operation can be speeded up. In addition, since the nanocarbon material is minute, the influence on display quality can be minimized.

Next, a method for manufacturing a liquid crystal device according to the present invention is a method for manufacturing a liquid crystal device that includes a pair of substrates sandwiching a liquid crystal layer and performs display by changing the alignment state of the liquid crystal layer from splay alignment to bend alignment. And it has the process of apply | coating the liquid body containing a nanocarbon substance on at least one board | substrate among a pair of said board | substrates, and the process of drying the said liquid body on the said board | substrate.
According to this manufacturing method, it is possible to easily manufacture a liquid crystal device in which the nanocarbon material is disposed at a position in contact with the substrate of the liquid crystal layer.

The method for manufacturing a liquid crystal device according to the present invention is a method for manufacturing a liquid crystal device comprising a pair of substrates sandwiching a liquid crystal layer and performing display by changing the alignment state of the liquid crystal layer from splay alignment to bend alignment. The liquid material including the alignment film forming material and the nanocarbon material is applied to the surface of the substrate on at least one of the pair of substrates, and the liquid material is solidified to include the nanocarbon material. The alignment film is formed.
According to this manufacturing method, a liquid crystal device including an alignment film in which a nanocarbon substance is dispersed in the alignment film can be easily manufactured.

  An electronic apparatus according to the present invention includes the liquid crystal device according to the present invention described above. According to this configuration, it is possible to effectively prevent display failure due to the initial transfer operation, and to provide an electronic device including a display unit capable of displaying a high-quality and high-speed response.

Embodiments of the present invention will be described below 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.

(First embodiment)
FIG. 1A is a plan view showing the liquid crystal device of the present embodiment, and FIG. 1B is a cross-sectional view taken along the line HH ′ of FIG. 2 is an equivalent circuit diagram showing the liquid crystal device, FIG. 3 is a plan view of the subpixel region, and FIG. 4 is a cross-sectional view of the liquid crystal device along the line AA ′ in FIG. FIG. 5 is a schematic view showing the alignment state of liquid crystal molecules.

The liquid crystal device 100 according to the present embodiment is an active matrix type transmissive liquid crystal device, and includes three sub-pixels corresponding to each color light of R (red), G (green), and B (blue). It constitutes a pixel. Here, a display area which is a minimum unit constituting the display is referred to as a “sub-pixel area”, and a display area formed by three sub-pixels is referred to as a “pixel area”.
In the following embodiments, a case where a transmissive liquid crystal device is configured will be described. However, the present invention can also be applied to a reflective or transflective liquid crystal device without any problem.

  As shown in FIG. 1, the liquid crystal device 100 includes an element substrate (first substrate) 10, a counter substrate (second substrate) 20 disposed to face the element substrate 10, and the element substrate 10 and the counter substrate 20. And a sandwiched liquid crystal layer 50. In the liquid crystal device 100, the element substrate 10 and the counter substrate 20 are bonded together with a sealing material 52, and the liquid crystal layer 50 is sealed in an area partitioned by the sealing material 52. A peripheral parting line 53 is formed along the inner periphery of the sealing material 52, and a rectangular area is shown as an image display area in a plan view (a state in which the element substrate 10 is viewed from the counter substrate 20 side) surrounded by the peripheral parting part 53. 10a. Further, the liquid crystal device 100 includes a data line driving circuit 101 and a scanning line driving circuit 104 provided in an outer region of the sealant 52, a connection terminal 102 that is electrically connected to the data line driving circuit 101 and the scanning line driving circuit 104, and a scanning line. Wiring 105 for connecting the drive circuits 104 to each other is provided.

  In the image display area 10a of the liquid crystal device 100, as shown in FIG. 2, a plurality of sub-pixel areas are arranged in a matrix in plan view. Corresponding to each sub-pixel region, a pixel electrode 9 and a TFT (Thin Film Transistor) 30 that controls switching of the pixel electrode 9 are provided. In the image display area 10a, a plurality of data lines 6a and scanning lines 3a are formed extending in a grid pattern.

The data line 6a is electrically connected to the source of the TFT 30, and the scanning line 3a is electrically connected to the gate. The drain of the TFT 30 is electrically connected to the pixel electrode 9. The data line 6a is connected to the data line driving circuit 101 shown in FIG. 1, and supplies image signals S1, S2,..., Sn supplied from the data line driving circuit 101 to each sub-pixel region. The scanning line 3a is connected to the scanning line driving circuit 104 shown in FIG. 1, and supplies scanning signals G1, G2,..., Gm supplied from the scanning line driving circuit 104 to each sub-pixel region.
The image signals S1 to Sn supplied from the data line driving circuit 101 to the data line 6a may be supplied line-sequentially in this order, or may be supplied for each of a plurality of adjacent data lines 6a for each group. Good. The scanning line driving circuit 104 supplies the scanning signals G1 to Gm to the scanning line 3a in a pulse-sequential manner in a pulse-sequential manner at a predetermined timing.

In the liquid crystal device 100, the image signals S1 to Sn supplied from the data line 6a are supplied to the pixel electrode at a predetermined timing by turning on the TFT 30 as a switching element for a predetermined period by the input of the scanning signals G1 to Gm. 9 is written. Then, image signals S1 to Sn of a predetermined level written to the liquid crystal through the pixel electrode 9 are held for a certain period between the pixel electrode 9 and a common electrode (described later) arranged to face each other through the liquid crystal layer 50. .
Here, in order to prevent the held image signals S1 to Sn from leaking, a storage capacitor 17 is connected in parallel with a liquid crystal capacitor formed between the pixel electrode 9 and the common electrode. The storage capacitor 17 is provided between the drain of the TFT 30 and the capacitor line 3b.

  Next, a detailed configuration of the liquid crystal device 100 will be described with reference to FIGS. 3 and 4. In FIG. 3, the major axis direction of the sub-pixel region substantially rectangular in plan view, the major axis direction of the pixel electrode 9, and the extending direction of the data line 6a are the X-axis direction, the minor axis direction of the sub-pixel region, and the pixel electrode. The minor axis direction 9 and the extending direction of the scanning line 3a and the capacitance line 3b are defined as the Y-axis direction.

  As shown in FIG. 4, the liquid crystal device 100 includes an element substrate 10 and an opposite substrate 20 that are opposed to each other with the liquid crystal layer 50 interposed therebetween, and a retardation plate disposed outside the element substrate 10 (on the opposite side to the liquid crystal layer 50). 33 and the polarizing plate 36, the retardation plate 34 and the polarizing plate 37 disposed on the outer side of the counter substrate 20 (on the side opposite to the liquid crystal layer 50), and the outer side of the polarizing plate 36. And an illumination device 60 that emits illumination light.

  As shown in FIG. 3, a pixel electrode 9 having a rectangular shape in plan view is formed in each subpixel region. Of the side edges of the pixel electrode 9, the data line 6a extends along the long side edge, and the scanning line 3a extends along the short side edge. On the pixel electrode 9 side of the scanning line 3a, a capacitor line 3b extending in parallel with the scanning line 3a is formed.

  A TFT 30 as a switching element is formed on the scanning line 3a. The TFT 30 includes a semiconductor layer 35 made of an island-shaped amorphous silicon film, and a source electrode 6b and a drain electrode 32 disposed so as to partially overlap the semiconductor layer 35 in a planar manner. The scanning line 3 a functions as a gate electrode of the TFT 30 at a position overlapping the semiconductor layer 35 in plan view.

  The source electrode 6 b is electrically connected to the data line 6 a at the end opposite to the semiconductor layer 35. The drain electrode 32 forms a capacitive electrode 31 at the end opposite to the semiconductor layer 35. The capacitor electrode 31 is arranged in the plane area of the capacitor line 3b, and the storage capacitor 17 having the capacitor electrode 31 and the capacitor line 3b as electrodes is formed at this position. The pixel electrode 9 and the capacitor electrode 31 are electrically connected via the pixel contact hole 14 formed in the planar region of the capacitor electrode 31, whereby the drain of the TFT 30 and the pixel electrode 9 are electrically connected. ing.

  4, the liquid crystal layer 50 sealed between the element substrate 10 and the counter substrate 20 is configured to operate in the OCB mode. When the liquid crystal device 100 is in operation, FIG. As shown in FIG. 5A, the liquid crystal molecules 51 exhibit a bend alignment in which the liquid crystal molecules 51 are aligned in a generally arcuate shape. In the liquid crystal device of this embodiment, the nanocarbon material 54 is dispersed in the liquid crystal layer 50 as shown in FIG.

  As the nanocarbon material 54, carbon nanohorns, carbon nanotubes, carbon fibers, fullerenes, or those containing a plurality of these can be used. Carbon nanotubes may be either single-walled or multi-walled. Among these, it is preferable to use carbon nanohorns having a conical microstructure or carbon nanotubes having a tubular or fibrous microstructure.

  The element substrate 10 includes a substrate body 11 made of a translucent material such as glass, quartz, or plastic as a base. Inside the substrate body 11 (on the liquid crystal layer 50 side), the scanning lines 3a and the capacitor lines 3b, a gate insulating film 12 covering the scanning lines 3a and the capacitor lines 3b, and the scanning lines 3a are opposed to each other through the gate insulating film 12. A semiconductor layer 35 to be connected, a source electrode 6b (data line 6a) connected to the semiconductor layer 35, a drain electrode 32, and a capacitor connected to the drain electrode 32 and facing the capacitor line 3b through the gate insulating film 12. Electrode 31 is formed. That is, the TFT 30 and the storage capacitor 17 connected thereto are formed on the substrate body 11.

  A flattening film 13 is formed to cover the TFT 30 and flatten unevenness on the substrate caused by the TFT 30 or the like. A pixel contact hole 14 penetrating the planarizing film 13 and reaching the capacitor electrode 31 is formed, and the pixel electrode 9 and the capacitor electrode 31 formed on the planarizing film 13 via the pixel contact hole 14 are electrically connected. It is connected to the. An alignment film 18 is formed so as to cover the pixel electrode 9. The alignment film 18 is made of polyimide, for example, and is rubbed in the major axis direction (X-axis direction) of the sub-pixel region. With such an alignment film 18, the liquid crystal molecules 51 are aligned along the alignment direction 18 a indicated by the dashed arrows in FIG. 3.

  The counter substrate 20 is made of a translucent material such as glass, quartz, or plastic, and includes a substrate body 21 as a base. On the inner side of the substrate body 21 (on the liquid crystal layer 50 side), a color filter 22 made of a color material layer corresponding to each sub-pixel region, a common electrode 25, and an alignment film 29 are stacked.

  The common electrode 25 is made of a transparent conductive material such as ITO and has a planar shape that covers a plurality of subpixel regions. A flattening film may be formed between the common electrode 25 and the color filter 22 to flatten the unevenness on the color filter 22. The alignment film 29 is made of polyimide, for example, and is formed so as to cover the common electrode 25. The surface of the alignment film 29 is rubbed in the major axis direction (X-axis direction) of the sub-pixel region as indicated by a solid arrow 29a in FIG. With the alignment film 29, the liquid crystal molecules 51 are aligned along the alignment direction 29a indicated by the solid line arrow in FIG.

The polarizing plates 36 and 37 are arranged so that their transmission axes are substantially orthogonal to each other. A retardation plate 33 provided on the inner surface side of the polarizing plate 36 and a retardation plate 34 provided on the inner surface side of the polarizing plate 37 provide a phase difference of approximately ¼ wavelength to transmitted light. It is a four phase difference plate, and a λ / 4 phase difference plate and a λ / 2 phase difference plate may be laminated.
Further, an optical compensation film may be additionally arranged inside one or both of the polarizing plates 36 and 37. By arranging the optical compensation film, the contrast can be further improved. 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.

  In the liquid crystal device 100 of the present embodiment having the above configuration, the nanocarbon material 54 is dispersed in the liquid crystal layer 50, and the nanocarbon material 54 undergoes initial alignment transition in the OCB mode liquid crystal layer 50. It functions as an initial transfer means to promote. Hereinafter, the operation and effect of the liquid crystal device 100 due to the nanocarbon material 54 functioning as an initial transition means will be described.

First, an initial transition operation of the OCB mode liquid crystal device 100 will be described with reference to FIG. FIG. 5 is an explanatory diagram showing the alignment state of liquid crystal molecules in the OCB mode.
In the OCB mode liquid crystal device, in its initial state (non-operation), the liquid crystal molecules 51 are in an alignment state (splay alignment) that is open in a splay shape as shown in FIG. As shown in FIG. 5A, the liquid crystal molecules 51 are in an alignment state bent in a bow shape (bend alignment). The liquid crystal device 100 is configured to realize high-speed response of the display operation by modulating the transmittance with the degree of bending of the bend alignment during the display operation.

  In the case of the liquid crystal device 100 in the OCB mode, since the alignment state of the liquid crystal molecules at the time of power-off is the splay alignment shown in FIG. 5B, by applying a voltage higher than a certain threshold at the time of power-on to the liquid crystal molecules 51, 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. 5B to the bend alignment during the display operation shown in FIG. If the initial transition is not sufficiently performed, display failure may occur or desired high-speed response cannot be obtained.

As an initial transition operation of the liquid crystal layer 50 in the liquid crystal device 100, a method of applying a pulse voltage between the pixel electrode 9 and the common electrode 25 while the scanning lines 3a are turned on line-sequentially can be used.
Here, FIG. 6 is a diagram for explaining the action of the nanocarbon material 54 as the initial transfer means in the initial transfer operation, and is a plan view of the sub-pixel region for the sub-pixel region.

As shown in FIG. 4, in the present embodiment, the nanocarbon material 54 that functions as an initial transition means is dispersed in the liquid crystal layer 50. When the initial transition operation is performed in the liquid crystal device 100, initial transition nuclei (bend nuclei) 54b serving as starting points of orientation transition are locally formed in the liquid crystal layer 50, as shown in FIG. 6A. . The generation position of the initial transition nucleus 54 b corresponds to the position where the nanocarbon material 54 exists in the liquid crystal layer 50, and the number of generation of the initial transition nucleus 54 b increases as the addition amount of the nanocarbon material 54 increases. Therefore, the nanocarbon material 54 functions as an initial transition means for promoting the generation of initial transition nuclei in the liquid crystal layer 50.
From the initial transition nuclei 54b generated around the nanocarbon material 54, as shown in FIG. 6B, the bend alignment region 50b in which the liquid crystal molecules are bend aligned propagates radially to the periphery, and eventually the liquid crystal in the sub-pixel region. The entire layer becomes bend orientation and the initial transition operation is completed.

  In addition, since the nanocarbon material 54 is a carbon material having a microstructure, the addition of a small amount hardly affects the display quality. That is, if the nanocarbon material 54 is opaque, the display light is shielded, and it is also assumed that the alignment of the liquid crystal is disturbed around the nanocarbon material 54. However, the size of the nanocarbon material 54 is the initial transfer means. Since it is extremely small as compared with spacers and electrode slits that can be made to function, it is possible to suppress a loss of display light and a decrease in contrast ratio due to disorder of alignment of liquid crystal molecules. Therefore, according to the present invention, it is possible to speed up the initial transfer operation while ensuring display quality. In addition, since the nanocarbon material 54 can be uniformly dispersed in the liquid crystal layer 50, initial transition nuclei can be generated in the liquid crystal layer 50 evenly, and the entire liquid crystal layer 50 can be uniformly initially transitioned. it can.

Note that the nanocarbon material 54 functions as an initial transfer means for the following reason.
Since each of the nanocarbon materials 54 such as carbon nanotubes and carbon nanohorns is a minute structure, several to several tens of carbon nanohorns are aggregated when dispersed in the liquid crystal layer 50. . When the aggregated structure and the liquid crystal molecules 51 are in contact with each other, the liquid crystal molecules 51 are taken into the structure or the alignment of the liquid crystal molecules 51 is disturbed around the structure. When a voltage is applied to the liquid crystal layer 50 for initial transition, most of the liquid crystal molecules 51 are aligned in the direction in which the pixel electrode 9 and the common electrode 25 face each other (the thickness direction of the liquid crystal layer). However, since the liquid crystal molecules 51 taken into the nanocarbon material 54 composed of a structure in which carbon nanohorns and the like are aggregated are inhibited by the nanocarbon material 54 and hardly move, the alignment with the surrounding liquid crystal molecules 51 is disturbed. As a result, it is considered that initial transition nuclei 54 b are generated around the nanocarbon material 54. If the liquid crystal molecules 51 around the nanocarbon material 54 are randomly oriented, initial transition nuclei 54b are generated in the randomly oriented portions.

[Example]
The inventor actually manufactured a liquid crystal device for the configuration of the first embodiment, and verified that the addition of the nanocarbon material 54 speeds up the initial transfer operation. In addition, the relationship between the initial transition time and the display quality with respect to the added amount of the nanocarbon material 54 was also investigated.

  The liquid crystal device 100 of the present embodiment shown in FIGS. 1 to 4 is the same as a conventionally known OCB mode liquid crystal device except for the configuration of the liquid crystal layer 50, and can be easily obtained by using a conventionally known manufacturing method. Can be manufactured. That is, when liquid crystal is injected inside the sealing material 52 that bonds the element substrate 10 and the counter substrate 20, a material in which a nanocarbon material 54 such as a carbon nanotube or carbon nanohorn is dispersed is injected into the liquid crystal. Thus, the liquid crystal device 100 can be manufactured.

In this example, the element substrate 10 on which the alignment film 18 is formed and the counter substrate 20 on which the alignment film 29 is formed are prepared, and the element substrate 10 and the counter substrate 20 are attached to the alignment films 18 and 29. The rubbing process was performed so that the rubbing directions were the same when they were combined. Thereafter, the element substrate 10 and the counter substrate 20 were bonded to each other through a sealing material 52 to produce an empty cell. The cell gap was set to 5.3 μm.
Next, a liquid crystal material having positive dielectric anisotropy prepared by dispersing 0.002% by weight of carbon nanohorns was prepared and injected into the above empty cell to obtain a liquid crystal device 100.
In the liquid crystal device 100 manufactured in this example, the liquid crystal layer 50 is in the splay alignment in the initial state, and a voltage of 5 V is applied between the pixel electrode 9 and the common electrode 25, which is shown in FIG. As described above, initial transition nuclei (bend nuclei) 54 b are generated from the periphery of the carbon nanohorn (nanocarbon material 54) dispersed in the liquid crystal layer 50. Thereafter, when the liquid crystal device 100 was observed with the voltage applied, as shown in FIG. 6B, the initial transition propagated from the initial transition nucleus 54b to the periphery, and all the subpixels transitioned to bend alignment. did. The time required for the above initial transfer operation was 5.4 seconds.

  Next, in order to verify the relationship between the initial transition time depending on the addition amount of the nanocarbon material 54 and the display quality, as shown in Table 1, the addition amount of the carbon nanohorn ranges from 0 wt% to 0.2 wt%. The eight types of liquid crystal devices changed in the above were prepared, and the time required for the initial transition operation and the contrast ratio were measured for each of the liquid crystal devices.

As shown in Table 1, by adding 0.00001% by weight of carbon nanohorns to the liquid crystal layer 50, compared to a liquid crystal device having a conventional configuration (concentration 0%) in which no carbon nanohorns are added, The transition time can be shortened by 10 seconds or more.
In addition, the initial transition time is shortened as the amount of carbon nanohorn added is increased, but the contrast ratio is lowered. On the other hand, when 0.2% by weight of carbon nanohorn is added, the contrast ratio is lower than 350. . Thus, the contrast ratio decreases because the carbon nanohorn is more easily aggregated as the amount of carbon nanohorn added is increased, and light leakage caused by disordered liquid crystal alignment around the aggregate and transmission due to opaque aggregates. This is thought to be due to a decrease in rate.
Therefore, the preferred amount of carbon nanohorn added is 0.00001 wt% or more and 0.1 wt% or less from Table 1.

Further, if the amount of carbon nanohorn added is 0.0002 wt% or more and 0.02 wt% or less, the initial transition operation time can be set to about 10 seconds or less, and a contrast ratio of 400 or more can be obtained. preferable.
Furthermore, when carbon nanohorn was added in an amount of 0.002% by weight, good results were obtained in both initial transition time and contrast ratio.

  In addition, although the case where carbon nanohorn was used as the nanocarbon material 54 was described in this example, a liquid crystal device in which carbon nanotubes are dispersed in the liquid crystal layer 50 instead of the carbon nanohorn was manufactured by a method according to this example. As in this example, initial transition nuclei were generated from the periphery of the carbon nanotubes, which propagated to the periphery, and the initial transition operation could be performed quickly.

Further, a plurality of liquid crystal devices were produced by changing the amount of carbon nanotubes added in the range of 0.00001 wt% to 0.2 wt%, and the initial transition time and contrast ratio of these liquid crystal devices were measured. Results similar to those shown in 1 were obtained. That is, by adding 0.00001% by weight of carbon nanotubes to the liquid crystal layer, the initial transition time could be increased by about 10 seconds.
The initial transition time was shortened as the amount of carbon nanotubes added was increased, but the contrast ratio was lowered. On the other hand, when the amount of carbon nanotubes added was 0.2% by weight, a contrast ratio of 350 or more could not be obtained.
The range of the carbon nanotube addition amount with which the initial transition time is about 10 seconds or less and a contrast ratio of 400 or more is obtained is 0.0002 wt% or more and 0.02 wt% or less, as in the case of carbon nanohorn. It was.

  As described above in detail, according to the liquid crystal device 100 of the present embodiment, the nanocarbon material 54 is dispersed in the liquid crystal layer 50, whereby a high-speed and uniform initial transition operation is possible, and the rising operation is quick. Can realize a high-quality liquid crystal device. In addition, since the initial transition nucleus can be easily formed at a low voltage, it is not necessary to change the breakdown voltage and power supply configuration of the TFT 30, and the power consumption can be reduced. Moreover, since a conventionally well-known structure can be used except the liquid crystal layer 50, it can manufacture very easily.

Further, since it is not necessary to provide an initial transfer means for speeding up the initial transfer operation on the element substrate 10 or the counter substrate 20, the aperture ratio is not lowered by providing the initial transfer means, and a bright display can be obtained. it can.
However, it goes without saying that other initial transfer means may be provided in the present invention. As such an initial transition means, a spacer disposed in the liquid crystal layer 50, an electrode slit formed in the pixel electrode 9 or the like, an electrode for initial transition nucleus generation, a sub-pixel region, or a periphery thereof are selectively formed. A liquid crystal region having a different alignment direction can be used.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS.
FIG. 7 is a schematic cross-sectional view of the liquid crystal device 200 of the present embodiment. FIG. 8 is a process diagram for explaining a method of manufacturing the liquid crystal device 200.
The liquid crystal device of the present embodiment has the same configuration as that of the first embodiment except that the position of the nanocarbon material 54 in the liquid crystal layer 50 is different. Therefore, in FIG. 7 and FIG. 8, the same reference numerals are given to the same components as those in the first embodiment, and detailed description thereof will be omitted.

  As shown in FIG. 7, the liquid crystal device 200 of this embodiment includes a configuration in which a liquid crystal layer 50 is sandwiched between an element substrate 10 and a counter substrate 20. In the liquid crystal device 200 of this embodiment, the nanocarbon material 54 included in the liquid crystal layer 50 is attached to the surfaces of the alignment films 18 and 29 that are in contact with the liquid crystal layer 50.

As described above, the nanocarbon material 54 may be attached to the alignment films 18 and 29. Even in such a configuration, when a voltage of, for example, 5 V is applied between the pixel electrode 9 and the common electrode 25, initial transition nuclei are generated around the nanocarbon material 54, and the initial transition starts around the initial transition nuclei. Propagate and perform the initial transition operation.
Therefore, also in the liquid crystal device 200 of the present embodiment, the same operational effects as those of the first embodiment can be obtained.

  When manufacturing the liquid crystal device 200 of the present embodiment, first, as shown in FIG. 8A, the nanocarbon material 54 is dispersed in a dispersion medium such as water or alcohol on the element substrate 10 on which the alignment film 18 is formed. The dispersed liquid 140 is applied. The coating method of the liquid 140 is not particularly limited, and a spin coating method, a printing method, an ink jet method, or the like can be used. Further, as a dispersion medium for dispersing the nanocarbon material 54, a surface treatment agent for the alignment film (a silane coupling agent solution or the like) can also be used.

  Then, as shown in FIG. 8B, the dispersion medium is removed from the liquid material 140 by vacuum drying or heat treatment, and the nanocarbon material 54 is adhered onto the alignment film 18. Further, the nanocarbon material 54 is deposited on the alignment film 29 in the same process for the counter substrate 20.

  7 is manufactured by bonding the element substrate 10 and the counter substrate 20 obtained in this way through a sealing material 52 and injecting liquid crystal inside the sealing material 52. Can do. In the case of the present embodiment, since the nanocarbon material 54 is disposed on the alignment films 18 and 29 in advance, a normal liquid crystal can be used for injection.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS.
FIG. 9 is a schematic cross-sectional view of the liquid crystal device 300 of the present embodiment. FIG. 10 is a process diagram for explaining the manufacturing method of the liquid crystal device 300.
The liquid crystal device of the present embodiment is the same as that of the first embodiment except that the configurations of the liquid crystal layer 50 and the alignment film are different. Therefore, in FIG. 9 and FIG. 10, the same reference numerals are given to the same components as those in the first embodiment, and detailed description thereof will be omitted.

  As shown in FIG. 9, the liquid crystal device 300 of this embodiment includes a configuration in which a liquid crystal layer 50 is sandwiched between an element substrate 10 and a counter substrate 20. In the liquid crystal device 300 of this embodiment, the alignment film 18A and the alignment film 29A to which the nanocarbon material 54 is added are formed on the element substrate 10 and the counter substrate 20 as alignment films in contact with the liquid crystal layer 50, respectively. Yes. The nanocarbon material 54 is not added to the liquid crystal constituting the liquid crystal layer 50.

As described above, the nanocarbon material 54 may be dispersed in the alignment films 18A and 29A. Even in such a configuration, by applying a voltage of, for example, 5 V between the pixel electrode 9 and the common electrode 25, initial transition nuclei are formed around the nanocarbon material 54 exposed or close to the surfaces of the alignment films 18A and 29A. The initial transition operation can be performed by propagating the initial transition around the initial transition nucleus.
Therefore, also in the liquid crystal device 300 of the present embodiment, the same operational effects as those of the first embodiment can be obtained.

  When manufacturing the liquid crystal device 300 of the present embodiment, first, as shown in FIG. 10A, on the element substrate 10 on which the pixel electrodes 9 are formed, the nanocarbon substance 54 is used as a liquid material for forming an alignment film. The dispersed liquid 180 is applied. The coating method of the liquid 180 is not particularly limited, and a spin coating method, a printing method, an ink jet method, or the like can be used.

  Then, as shown in FIG. 10B, the alignment film 18A in which the nanocarbon material 54 is dispersed can be formed on the element substrate 10 by solidifying the liquid 180 by vacuum drying or heat treatment. . Also, the alignment film 29A in which the nanocarbon material 54 is dispersed can be formed on the counter substrate 20 in the same process.

  7 is manufactured by bonding the element substrate 10 and the counter substrate 20 obtained in this way through a sealing material 52 and injecting liquid crystal inside the sealing material 52. Can do. In the case of the present embodiment, since the nanocarbon material 54 is dispersed in advance in the alignment films 18A and 29A, a normal liquid crystal can be used.

  In this embodiment, since the nanocarbon material 54 located on the surface layer portion of the alignment films 18A and 29A functions as the initial transfer means, the amount of the nanocarbon material 54 added to the alignment films 18A and 29A is the alignment amount. It is preferable to adjust according to the proportion of the nanocarbon material 54 disposed on the surface layer portion during film formation.

(Electronics)
The liquid crystal device according to the present invention having the above configuration can be used as a display unit 1301 of a mobile phone 1300 as shown in FIG. A cellular phone 1300 includes a plurality of operation buttons 1302, a mouthpiece 1303, a mouthpiece 1304, and the display portion 1301 in a housing.
According to the mobile phone 1300, since the initial transfer operation is reliably performed in a short time, it is possible to obtain a high-speed response display without display defects.
Further, the electronic device including the liquid crystal device of the present invention 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, Car navigation system, head-up display, digital video camera, television receiver, viewfinder type or monitor direct-view type video tape recorder, pager, electronic organizer, calculator, electronic book or projector, word processor, video phone, POS terminal, touch panel It may be another electronic device such as a device including a lighting device or a lighting device.

FIG. 1 is an overall configuration diagram of a liquid crystal device according to a first embodiment. FIG. 2 is an equivalent circuit diagram. FIG. 3 is a plan view of one sub-pixel region. 4 is a cross-sectional view of the liquid crystal device taken along the line A-A ′ of FIG. 3. FIG. 5 is an explanatory diagram of the initial transfer operation. FIG. 6 is an operation explanatory view of the liquid crystal device of the first embodiment. FIG. 7 is a schematic cross-sectional view of the liquid crystal device of the second embodiment. FIG. 8 is an explanatory diagram related to the manufacturing method. FIG. 9 is a schematic cross-sectional view of a liquid crystal device according to a third embodiment. FIG. 10 is an explanatory diagram related to the manufacturing method. FIG. 11 is a perspective view illustrating an example of an electronic device.

Explanation of symbols

  100, 200, 300 liquid crystal device, 10 element substrate, 20 counter substrate, 18, 18A, 29, 29A alignment film, 50 liquid crystal layer, 50b bend alignment region, 51 liquid crystal molecule, 54 nanocarbon material, 54b initial transition nucleus (bend) Nuclear)

Claims (10)

A liquid crystal device comprising a pair of substrates sandwiching a liquid crystal layer, and performing display by changing the alignment state of the liquid crystal layer from splay alignment to bend alignment,
The liquid crystal device, wherein the liquid crystal layer contains a nanocarbon material.   The liquid crystal device according to claim 1, wherein the nanocarbon material is dispersed in the liquid crystal layer.   The liquid crystal device according to claim 1, wherein the nanocarbon material is provided on a contact surface of at least one of the pair of substrates with the liquid crystal layer.   The liquid crystal device according to claim 1, wherein the nanocarbon substance is a carbon nanohorn or a carbon nanotube.   5. The liquid crystal device according to claim 1, wherein a content of the nanocarbon material is 0.00001 wt% or more and 0.1 wt% or less with respect to the liquid crystal layer.   5. The liquid crystal device according to claim 1, wherein a content of the nanocarbon material is 0.0002 wt% or more and 0.02 wt% or less with respect to the liquid crystal layer. A liquid crystal device comprising a pair of substrates sandwiching a liquid crystal layer, and performing display by changing the alignment state of the liquid crystal layer from splay alignment to bend alignment,
An alignment film containing a nanocarbon material is formed on at least one of the pair of substrates on the liquid crystal layer side. A manufacturing method of a liquid crystal device comprising a pair of substrates sandwiching a liquid crystal layer, and performing display by changing the alignment state of the liquid crystal layer from splay alignment to bend alignment,
A method of manufacturing a liquid crystal device, comprising: applying a liquid material containing a nanocarbon material on at least one of the pair of substrates; and drying the liquid material on the substrate. . A manufacturing method of a liquid crystal device comprising a pair of substrates sandwiching a liquid crystal layer, and performing display by changing the alignment state of the liquid crystal layer from splay alignment to bend alignment,
A liquid material containing an alignment film forming material and a nanocarbon material is applied on at least one of the pair of substrates, and the liquid material is solidified to form the alignment film containing the nanocarbon material. A method of manufacturing a liquid crystal device.   An electronic apparatus comprising the liquid crystal device according to claim 1.

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