JP2010066645A - Liquid crystal device and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accelerate a response speed without increasing a drive voltage too much in a liquid crystal device which adopts an in-plane switching driving system and uses a liquid crystal molecule having negative permittivity anisotropy. <P>SOLUTION: The liquid crystal device (100) includes a first substrate (10), a second substrate (20), a first electrode (9a-1) and a second electrode (11-1) formed on the first substrate, a third electrode (9a-2) and a fourth electrode (11-2) formed on the second substrate, and a liquid crystal layer (50) including the liquid crystal molecule (50a) held between the first substrate and the second substrate and driven by electric fields generated between the first electrode and the second electrode and between the third electrode and the fourth electrode. The liquid crystal molecule has the negative dielectric anisotropy. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technical field of, for example, a liquid crystal device and an electronic apparatus including such a liquid crystal device.

  There is a liquid crystal device in which a liquid crystal is sandwiched between a pair of substrates as an electro-optical material. In a liquid crystal device, for example, liquid crystal molecules are placed in a predetermined alignment state between a pair of substrates, for example, by applying a predetermined voltage to the liquid crystal molecules for each pixel portion formed in the image display region, The gradation display is performed by changing the order and modulating the light. As a liquid crystal device, an IPS (In Plane Switching) method or FFS (Fringe Field Switching), in which a pixel electrode and a common electrode are provided on the TFT array substrate side and the direction of the electric field applied to the liquid crystal molecules is substantially parallel to the substrate. A liquid crystal device adopting a horizontal electric field driving method such as a method is known (see, for example, Patent Document 1). The horizontal electric field driving method is a vertical electric field driving method such as a TN (Twisted Nematic) driving method in which a vertical electric field is applied to liquid crystal molecules interposed between a pixel electrode and a counter electrode formed on each of a pair of opposing substrates. It is attracting attention because of its superior viewing angle characteristics.

  In a liquid crystal device that employs a horizontal electric field driving method, since no electrode is formed on the counter substrate side, charges are likely to be accumulated on the counter substrate side. As a result, an electric field (particularly, a vertical electric field in a direction perpendicular to the substrate) resulting from the accumulated charge may be applied to the liquid crystal molecules. That is, a horizontal electric field should be generated in a direction substantially parallel to the substrate, but a vertical electric field in a direction perpendicular to the substrate may be generated. In this case, liquid crystal molecules that should be driven in a direction substantially parallel to the substrate (in other words, should rotate in a plane substantially horizontal to the substrate) are driven in a direction perpendicular to the substrate (in other words, the substrate Stand up in a direction perpendicular to For this reason, the alignment control of the liquid crystal in the originally intended mode cannot be performed, and as a result, the display quality of the liquid crystal device is deteriorated. In the liquid crystal device adopting the IPS method, for example, a region where no lateral electric field is generated may be generated immediately above the electrode. This also leads to deterioration of the display quality of the liquid crystal device.

  In order to solve such a technical problem, for example, as disclosed in Patent Document 1, liquid crystal molecules having negative dielectric anisotropy Δε (that is, liquid crystal molecules satisfying Δε <0) are used. Liquid crystal devices are known. Since liquid crystal molecules having a negative dielectric anisotropy Δε rotate in a direction perpendicular to the direction of the applied electric field, even if a vertical electric field is applied to the liquid crystal molecules, the liquid crystal molecules Driven to rotate in a substantially horizontal plane.

JP 2003-322869 A

  Here, as a liquid crystal molecule having a positive dielectric anisotropy Δε (that is, a liquid crystal molecule satisfying Δε> 0), the absolute value of the dielectric anisotropy Δε (that is, | Δε |) is relatively large. In addition, liquid crystal molecules having a relatively small rotational viscosity coefficient γ1 are generally used. On the other hand, in the liquid crystal molecules having a negative dielectric anisotropy Δε, the absolute value of the dielectric anisotropy Δε is relatively small compared to the liquid crystal molecules having a positive dielectric anisotropy Δε and At present, liquid crystal molecules having a relatively large rotational viscosity coefficient γ1 are used. Therefore, a liquid crystal device using liquid crystal molecules having a negative dielectric anisotropy Δε has a larger rotational viscosity coefficient γ1 than a liquid crystal device using liquid crystal molecules having a positive dielectric anisotropy Δε. Therefore, a new technical problem that the response speed becomes slow occurs. In order to solve this technical problem, it can be considered as one solution to reduce the rotational viscosity coefficient γ1 of the liquid crystal molecules. Here, in order to reduce the rotational viscosity coefficient γ1 of the liquid crystal molecules, it is necessary to reduce the absolute value of the dielectric anisotropy Δε of the liquid crystal molecules. However, if the absolute value of the dielectric anisotropy Δε of the liquid crystal molecule is simply reduced in order to reduce the rotational viscosity coefficient γ1 of the liquid crystal molecule, the absolute value of the dielectric anisotropy Δε is reduced. A high drive voltage is required.

  In addition, in the liquid crystal device employing the lateral electric field driving method, there is no electrode on the counter substrate side (that is, it is necessary to apply an electric field to the entire liquid crystal layer from the TFT array substrate side), so the liquid crystal near the counter substrate is used. In order to drive the molecules reliably, a higher driving voltage is required as compared with a liquid crystal device employing a vertical electric field driving method. For this reason, in a liquid crystal device that employs a lateral electric field driving method and uses liquid crystal molecules having negative dielectric anisotropy Δε, the driving is relatively high in order to reliably drive the liquid crystal molecules near the counter substrate. A technical problem arises that the voltage needs to be higher in order to increase the response speed. However, since a high drive voltage is not preferable from the viewpoint of low power consumption, there arises a technical problem that the response speed cannot be increased.

  The present invention has been made in view of, for example, the conventional problems described above. For example, in a liquid crystal device that employs a horizontal electric field driving method and uses liquid crystal molecules having negative dielectric anisotropy Δε, the driving voltage is excessively increased. It is an object of the present invention to provide a liquid crystal device capable of improving the response speed without increasing the frequency and an electronic apparatus including such a liquid crystal device.

(Liquid crystal device)
In order to solve the above problems, a liquid crystal device according to the present invention includes a first substrate (for example, a TFT array substrate described later) and a second substrate (for example, an opposite surface described later) disposed so as to face the first substrate. Substrate), a first electrode (for example, a TFT side pixel electrode described later) and a second electrode (for example, a TFT side common electrode described later) formed on the second substrate side of the first substrate, and the second A third electrode (for example, a counter-side pixel electrode to be described later) and a fourth electrode (for example, a counter-side common electrode to be described later) formed on the first substrate side of the substrate, the first substrate and the second substrate; And a liquid crystal layer including liquid crystal molecules that are driven by an electric field generated between the first electrode and the second electrode and between the third electrode and the fourth electrode. The liquid crystal molecules have negative dielectric anisotropy.

  According to the liquid crystal device of the present invention, the first electrode and the second electrode are formed on the first substrate. In addition, a third electrode and a fourth electrode are formed on the second substrate. That is, the liquid crystal device according to the present invention employs a lateral electric field driving method such as an FFS (Fringe Field Switching) method or an IPS (In Plane Switching) method.

  For this reason, the alignment state of the liquid crystal molecules (particularly, liquid crystal molecules having negative dielectric anisotropy) contained in or constituting the liquid crystal layer is changed to the first electrode formed on the first substrate and It can be changed by the electric field generated by the potential difference between the second electrodes and the electric field generated by the potential difference between the third electrode and the fourth electrode formed on the second substrate. As a result, the liquid crystal device can be used as, for example, various types of display devices such as direct-view type or projection type that perform transmissive display, reflective display, or transflective display, for example. In the present invention, the electric field is, for example, a transverse electric field. The “lateral electric field” means an electric field in a direction along the surface of the first substrate or the second substrate (typically, it is regarded as parallel to or substantially parallel to the surface of the first substrate or the second substrate. The electric field to be obtained).

  Here, since the liquid crystal molecules have negative dielectric anisotropy, the liquid crystal molecules are arranged so that the major axis direction of the liquid crystal molecules is orthogonal to the direction of the applied electric field (in other words, the liquid crystal molecules ) So that the minor axis direction is along the direction of the applied electric field. For this reason, when a lateral electric field that is an electric field in a direction along the surface of the first substrate or the second substrate is applied, the liquid crystal molecules are in a plane parallel to the surface of the first substrate or the second substrate. Rotate at. On the other hand, a vertical electric field (typically, an electric field that is perpendicular to or approximately the same as the perpendicular to the surface of the first substrate or the second substrate) in the direction intersecting the surface of the first substrate or the second substrate. Even when the electric field is unintentionally applied to the liquid crystal layer, the minor axes of the liquid crystal molecules are aligned in the direction along the longitudinal electric field (that is, the major axis direction of the liquid crystal molecules is orthogonal to the longitudinal electric field). Therefore, the state where the major axis direction of the liquid crystal molecules is horizontal to the surface of the first substrate or the second substrate is maintained. In other words, the liquid crystal molecules do not rise or rise in a direction perpendicular to the surface of the first substrate or the second substrate. That is, not only the lateral electric field that should be originally applied to the liquid crystal layer but also the longitudinal electric field is unintentionally applied to the liquid crystal layer, the major axis direction of the liquid crystal molecules corresponds to the longitudinal electric field in the first substrate. Alternatively, the liquid crystal molecules are aligned horizontally with respect to the surface of the second substrate, and the liquid crystal molecules rotate in a plane parallel to the surface of the first substrate or the second substrate in response to a lateral electric field. For this reason, even if a vertical electric field is applied as well as a horizontal electric field, the liquid crystal molecules rotate while maintaining a state in which the major axis direction is substantially parallel to the surface of the first substrate or the second substrate. Accordingly, the driving of the liquid crystal molecules contained in the liquid crystal layer can be suitably controlled. As a result, it is possible to suitably suppress a decrease in display quality of the liquid crystal device.

  In addition, in the present invention, not only the first electrode and the second electrode are formed on the first substrate side, but also the third electrode and the fourth electrode are formed on the second substrate side. Thus, both the electric field applied from the first substrate side and the electric field applied from the second substrate side are applied. On the other hand, in the liquid crystal device according to the first comparative example in which the first electrode and the second electrode are formed only on the first substrate side and the electrode is not formed on the second substrate side, the first substrate side Only the electric field applied from is applied. Therefore, a state where an electric field is not sufficiently applied may occur in the vicinity of the second substrate. For this reason, a state in which the liquid crystal molecules near the second substrate cannot be suitably driven may occur. Further, as in the liquid crystal device according to the second comparative example disclosed in Patent Document 1, a lateral electric field caused by a potential difference between the electrode on the first substrate and the electrode on the second substrate is applied. However, since the lateral electric field is concentrated near the first substrate, the same problem occurs. Therefore, in the liquid crystal devices according to the first comparative example and the second comparative example, in order to prevent the occurrence of a state where the electric field is not sufficiently applied to the liquid crystal molecules located in the vicinity of the second substrate, the drive voltage (that is, the first electrode) The electric field resulting from the potential difference between the first electrode and the second electrode needs to be relatively high. However, in the liquid crystal device of the present invention, an electric field can be reliably applied to the entire liquid crystal layer without relatively increasing the driving voltage as compared with the liquid crystal device according to the comparative example. That is, if the liquid crystal device of the present invention and the liquid crystal devices of the first comparative example and the second comparative example each use liquid crystal molecules having the same absolute value of dielectric anisotropy, Compared with the liquid crystal device of the example, not only the liquid crystal molecules located near the first substrate but also the liquid crystal molecules located near the second substrate can be reliably driven without increasing the driving voltage.

  In other words, such a technical effect can be achieved by reducing the absolute value of the dielectric anisotropy of the liquid crystal molecules contained in the liquid crystal layer of the liquid crystal device of the present invention without excessively increasing the driving voltage. This leads to a technical effect that the liquid crystal device of the present invention can be driven. In other words, even if the absolute value of the dielectric anisotropy of the liquid crystal molecules contained in the liquid crystal layer of the liquid crystal device of the present invention is relatively small, it is about the same as the drive voltage used by the liquid crystal device of the comparative example. This leads to a technical effect that the liquid crystal device of the present invention can be driven using the driving voltage. That is, in the liquid crystal device of the present invention, even if the absolute value of the dielectric anisotropy of the liquid crystal molecules is reduced, there is no inconvenience that the driving voltage becomes excessively high. Therefore, in the liquid crystal device of the present invention, the rotational viscosity coefficient of the liquid crystal molecules can be reduced by reducing the absolute value of the dielectric anisotropy. Thereby, in the liquid crystal device of the present invention, the response speed can be increased. That is, in the liquid crystal device of the present invention, it is possible to increase the response speed while using a driving voltage comparable to that of the liquid crystal device according to the comparative example (that is, without excessively increasing the driving voltage).

  Note that by forming electrodes not only on the first substrate side but also on the second substrate side, it is possible to effectively prevent the disadvantage that static electricity or the like is accumulated on the second substrate side. For this reason, the effect that generation | occurrence | production of the vertical electric field itself can be suppressed appropriately also arises. As a result, it is possible to more suitably suppress deterioration in display quality of the liquid crystal device. In other words, in the present invention, if an electrode is formed not only on the first substrate side but also on the second substrate side, only the effect that the response speed can be increased without excessively increasing the driving voltage is obtained. In addition, the deterioration of display quality itself can be suitably suppressed. It should be noted that the suppression of the deterioration in display quality is also realized by liquid crystal molecules having negative dielectric anisotropy. For this reason, in the liquid crystal device of the present invention, display quality is improved by using liquid crystal molecules having negative dielectric anisotropy and forming electrodes not only on the first substrate side but also on the second substrate side. The decrease is further suppressed.

  In one aspect of the liquid crystal device of the present invention, the liquid crystal device includes a plurality of pixel portions provided at intersections of a plurality of scanning lines and a plurality of data lines, and one pixel portion of the plurality of pixel portions. The direction of the electric field generated between the first electrode and the second electrode is substantially the same as the direction of the electric field generated between the third electrode and the fourth electrode in the one pixel portion.

  According to this aspect, the directions of the electric field applied from the first substrate side and the electric field applied from the second substrate side are aligned for each pixel unit. For this reason, even when both the electric field applied from the first substrate side and the electric field applied from the second substrate side are applied to the liquid crystal layer, it is as if either the first substrate or the second substrate. A state equivalent to a state where an electric field is applied from the side (particularly, a state where an electric field generated using a relatively high driving voltage is applied) is realized. Accordingly, by forming the electrodes not only on the first substrate side but also on the second substrate side, the first electrode and the second electrode can be formed only on the first substrate side while suitably enjoying the various effects described above. Similarly to the liquid crystal device according to the comparative example in which no electrode is formed on the two substrates, an electric field can be suitably applied to each pixel portion.

  In another aspect of the liquid crystal device of the present invention, the liquid crystal device includes a plurality of pixel portions provided at intersections of the plurality of scanning lines and the plurality of data lines, and one pixel portion of the plurality of pixel portions. An absolute value of a voltage applied between the first electrode and the second electrode in the first pixel portion, and an absolute value of a voltage applied between the third electrode and the fourth electrode in the one pixel portion, Are substantially the same.

  According to this aspect, the absolute values of the electric field applied from the first substrate side and the voltage applied from the second substrate side are uniform for each pixel unit. For this reason, even when both the electric field applied from the first substrate side and the electric field applied from the second substrate side are applied to the liquid crystal layer, it is as if either the first substrate or the second substrate. A state equivalent to a state where an electric field is applied from the side (particularly, a state where an electric field generated using a relatively high driving voltage is applied) is realized. Accordingly, by forming the electrodes not only on the first substrate side but also on the second substrate side, the first electrode and the second electrode can be formed only on the first substrate side while suitably enjoying the various effects described above. Similarly to the liquid crystal device according to the comparative example in which no electrode is formed on the two substrates, an electric field can be suitably applied to each pixel portion.

  In another aspect of the liquid crystal device of the present invention, the first electrode sandwiches a first insulating layer between the second electrode and the third electrode sandwiches the fourth electrode with a second insulation. An electrode disposed on the liquid crystal layer side of the first electrode and the second electrode, and an electrode disposed on the liquid crystal layer side of the third electrode and the fourth electrode, respectively, sandwiching the layers Includes a slit extending in a predetermined direction, and the slits of the electrodes disposed on the liquid crystal layer side of the first electrode and the second electrode, the third electrode, and the fourth electrode The slits included in the electrode disposed on the liquid crystal layer side are disposed at substantially the same position as viewed from the normal direction of the first substrate or the second substrate.

  According to this aspect, the electrode configuration on the first substrate side and the electrode configuration on the second substrate side can be matched.

  In another aspect of the liquid crystal device of the present invention, the first electrode sandwiches a first insulating layer between the second electrode and the third electrode sandwiches the fourth electrode with a second insulation. An electrode disposed on the liquid crystal layer side of the first electrode and the second electrode, and an electrode disposed on the liquid crystal layer side of the third electrode and the fourth electrode, respectively, sandwiching the layers Includes a slit extending in a predetermined direction, and the slits of the electrodes disposed on the liquid crystal layer side of the first electrode and the second electrode, the third electrode, and the fourth electrode The slits included in the electrodes disposed on the liquid crystal layer side are alternately disposed as viewed from the normal direction of the first substrate or the second substrate.

  According to this aspect, the slit provided in the electrode arranged on the liquid crystal layer side of the first electrode and the second electrode, and the slit provided in the electrode arranged on the liquid crystal layer side of the third electrode and the fourth electrode Does not overlap when viewed from the normal direction of the first substrate or the second substrate. For this reason, a slit provided in an electrode disposed on the liquid crystal layer side of the first electrode and the second electrode, and an electrode portion of the electrode disposed on the liquid crystal layer side of the third electrode and the fourth electrode, They can be overlapped when viewed from the normal direction of the first substrate or the second substrate. Similarly, the slit provided in the electrode disposed on the liquid crystal layer side of the third electrode and the fourth electrode, and the electrode portion of the electrode disposed on the liquid crystal layer side of the first electrode and the second electrode, They can be overlapped when viewed from the normal direction of the first substrate or the second substrate.

  In another aspect of the liquid crystal device of the present invention, the first electrode is disposed closer to the liquid crystal layer than the second electrode, and the third electrode is closer to the liquid crystal layer than the fourth electrode. The first electrode and the third electrode are each a pixel electrode, and each of the second electrode and the fourth electrode is a common electrode.

  According to this aspect, in both the first substrate and the second substrate, the pixel electrode can be an upper electrode and the common electrode can be a lower electrode.

  In another aspect of the liquid crystal device of the present invention, the first electrode is disposed closer to the liquid crystal layer than the second electrode, and the fourth electrode is the liquid crystal layer than the third electrode. The first electrode and the third electrode are each a pixel electrode, and each of the second electrode and the fourth electrode is a common electrode.

  According to this aspect, on the first substrate side, the pixel electrode is an upper layer electrode and the common electrode is a lower layer electrode, while on the second substrate side, the common electrode is an upper layer electrode and the pixel electrode is a lower layer electrode. Can do.

(Electronics)
In order to solve the above problems, an electronic apparatus of the present invention includes the above-described liquid crystal device of the present invention (including various aspects thereof).

  According to the electronic apparatus of the present invention, since the above-described liquid crystal device (or various aspects thereof) of the present invention is provided, the occurrence of image sticking can be suitably suppressed. For this reason, projection-type display devices in which the occurrence of burn-in is suppressed, televisions, mobile phones, electronic notebooks, portable audio players, word processors, digital cameras, viewfinder type or monitor direct-view type video recorders, workstations, video phones, POSs Various electronic devices such as terminals and touch panels can be realized.

  The operation and other advantages of the present invention will become more apparent from the embodiments described below.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(1) Basic Configuration of Liquid Crystal Device First, the configuration of the liquid crystal device according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan view showing the configuration of the liquid crystal device according to this embodiment, and FIG. 2 is a cross-sectional view taken along the line HH ′ of FIG.

  1 and 2, in the liquid crystal device 100 according to the present embodiment, the TFT array substrate 10 as an example of the “first substrate” according to the present invention and the counter substrate 20 as an example of the “second substrate” according to the present invention. Are arranged opposite to each other. A liquid crystal layer 50 is sealed between the TFT array substrate 10 and the counter substrate 20, and the TFT array substrate 10 and the counter substrate 20 are in a frame-shaped or frame-shaped seal region located around the image display region 10a. The sealing material 52 provided is bonded to each other.

  The sealing material 52 is made of, for example, an ultraviolet curable resin, a thermosetting resin, or the like for bonding the two substrates, and is applied on the TFT array substrate 10 in the manufacturing process and then cured by ultraviolet irradiation, heating, or the like. It is. In the sealing material 52, spacers such as glass fibers or glass beads for dispersing the distance between the TFT array substrate 10 and the counter substrate 20 (inter-substrate gap) to a predetermined value are dispersed.

  In FIG. 1, a light-shielding frame light-shielding film 53 that defines the frame area of the image display region 10a is provided on the counter substrate 20 side in parallel with the inside of the seal region where the sealing material 52 is disposed. A data line driving circuit 101 and an external circuit connection terminal 102 are provided along one side of the TFT array substrate 10 in a region located outside the sealing region in which the sealing material 52 is disposed in the peripheral region. However, the data line driving circuit 10 may be provided inside the seal region so that the data line driving circuit 101 is covered by the frame light shielding film 53. The sampling circuit 7 is provided so as to be covered with the frame light shielding film 53 on the inner side of the seal region along the one side. Further, the scanning line driving circuit 104 is provided so as to be covered with the frame light-shielding film 53 inside the seal region along two sides adjacent to the one side. On the TFT array substrate 10, vertical conduction terminals 106 for connecting the two substrates with the vertical conduction material 107 are arranged in regions facing the four corner portions of the counter substrate 20. Thus, electrical conduction can be established between the TFT array substrate 10 and the counter substrate 20.

  On the TFT array substrate 10, a lead wiring 90 is formed for electrically connecting the external circuit connection terminal 102 to the data line driving circuit 101, the scanning line driving circuit 104, the vertical conduction terminal 106, and the like. .

  In FIG. 2, on the TFT array substrate 10, a pixel switching TFT (Thin Film Transistor) 116 which is a driving element, scanning lines Y1 to Yn (where n is an integer equal to or greater than 1), and a data line X1 A laminated structure in which wiring such as Xm (where m is an integer of 1 or more) is formed is formed. Further, in the image display area 10a, the common electrode 11-1, the insulating layer 12-1, and the pixel electrode 9a are provided on the upper layer of wiring such as the pixel switching TFT 116, the scanning lines Y1 to Yn, and the data lines X1 to Xm. -1 is formed in this order.

  On the other hand, a color filter and a black matrix (not shown) are formed on the surface of the counter substrate 20 facing the TFT array substrate 10. The black matrix is formed of, for example, a light-shielding metal film such as chromium or chromium oxide, a resinous light-shielding film, or the like, and is patterned, for example, in a lattice shape in the image display region 10a on the counter substrate 20. On the black matrix 23, similarly to the TFT array substrate 10, a pixel switching TFT 116 that is a driving element, and a laminated structure in which wirings such as scanning lines Y1 to Yn and data lines X1 to Xm are formed. Is formed. Further, in the image display area 10a, the common electrode 11-2, the insulating layer 12-2, and the pixel electrode 9a are provided on the upper layer of the TFT 116 for pixel switching, the scanning lines Y1 to Yn, the data lines X1 to Xm, and the like. -2 are formed in this order.

  Thus, in the liquid crystal device 100 according to the present embodiment, the pixel electrode 9a-1 and the common electrode 11-1 are formed on the TFT array substrate 10 side, and the pixel electrode 9a- is also formed on the counter substrate 20 side. 2 and the common electrode 11-2. That is, the liquid crystal device 100 according to the present embodiment generates an electric field (lateral electric field) generated between the pixel electrode 9a-1 and the common electrode 11-1 and between the pixel electrode 9a-2 and the common electrode 11-2. A lateral electric field driving method (in particular, an FFS method) is employed in which the alignment state of the liquid crystal layer 50 is controlled by each electric field (lateral electric field).

  Here, the pixel electrode 9a-1 that constitutes a specific example of the “first electrode” of the present invention is provided in a matrix in plan view so as to form each pixel portion 70 that constitutes the image display region 10a. . Further, the pixel electrode 9a-1 has a slit 9b-1 extending in the longitudinal direction as will be described in detail later (see FIG. 4). On the other hand, the common electrode 11-1 that constitutes a specific example of the “second electrode” of the present invention may be provided in a matrix in a plan view like the pixel electrode 9a-1, or a plurality of pixel electrodes. It may be provided in a planar shape so as to be common to 9a-1.

  Further, the pixel electrodes 9a-2 that constitute one specific example of the “third electrode” of the present invention are provided in a matrix in a plan view so as to form each pixel portion 70 that constitutes the image display region 10a. In particular, the pixel electrode 9a-2 is provided in an opening portion of the black matrix (that is, a portion where a light shielding metal film or a resin light shielding film is not formed). Further, the pixel electrode 9a-2 has a slit 9b-2 extending in the longitudinal direction, as will be described in detail later (see FIG. 4). On the other hand, the common electrode 11-2 constituting one specific example of the “fourth electrode” of the present invention may be provided in a matrix in a plan view like the pixel electrode 9a-2, or a plurality of pixel electrodes It may be provided in a planar shape so as to be common to 9a-2.

  On the pixel electrode 9a-1 (in other words, on the TFT array substrate 10 on which the components such as the pixel electrode 9a-1 are formed) and on the pixel electrode 9a-2 (in other words, the components such as the pixel electrode 9a-2 are On the counter substrate 20 formed), an alignment film 8 is laminated. At this time, a rubbing process is performed on the alignment film 8 formed on each of the TFT array substrate 10 and the counter substrate 20.

  The liquid crystal layer 50 includes, for example, liquid crystal molecules 50a in which one kind or several kinds of nematic liquid crystals are mixed, and takes a predetermined alignment state between the pair of alignment films 8. Particularly in the present embodiment, the liquid crystal molecules 50a included in the liquid crystal layer 50 have a negative dielectric anisotropy Δε. That is, the dielectric anisotropy Δε of the liquid crystal molecules 50 a included in the liquid crystal layer 50 according to the present embodiment satisfies Δε <0. As an example, the dielectric anisotropy Δε of the liquid crystal molecules 50 a included in the liquid crystal layer 50 according to this embodiment is −2.5.

  Although not shown here, in addition to the data line driving circuit 101 and the scanning line driving circuit 104, the TFT array substrate 10 is used for inspecting the quality, defects, and the like of the liquid crystal device during manufacturing or at the time of shipment. An inspection circuit, an inspection pattern, or the like may be formed.

(2) Detailed Configuration of Liquid Crystal Device Next, with reference to FIGS. 3 and 4, an electrical configuration of a main part of the liquid crystal device 100 according to the present embodiment will be described. FIG. 3 is a block diagram conceptually showing the electrical configuration of the main part of the liquid crystal device 100 according to the present embodiment. FIG. 4 is a cross-sectional view conceptually showing the configuration of the pixel unit 70. FIG. 3 is a perspective view conceptually showing each of a pixel electrode 9a-1 and a pixel electrode 9a-2.

  In FIG. 3, the liquid crystal device 100 according to the present embodiment includes a scanning line driving circuit 104 and a data line driving circuit 101 in the peripheral region located around the image display region 10a on the TFT array substrate 10 and a not-shown image. A drive circuit such as a driver IC circuit is formed.

  The scanning line driving circuit 104 sequentially supplies scanning signals to the scanning lines Y1 to Yn formed on the TFT array substrate 10 and the scanning lines Y1 to Yn formed on the counter substrate 20, respectively. In particular, since the scanning line driving circuit 104 is formed on the TFT array substrate 10, the scanning line driving circuit 104 sends a scanning signal to the scanning line Y 1 formed on the counter substrate 20 via the vertical conductive material 107. To Yn sequentially. For example, when a high level scanning signal is supplied to a certain scanning line Yj (where j is an integer satisfying 1 ≦ j ≦ n), all the TFTs 116 connected to the scanning line Yj are turned on, and this scanning is performed. All the pixel portions 70 corresponding to the line Yj are selected.

  The data line driving circuit 101 sequentially supplies the image signal to the data lines X1 to Xm formed on the TFT array substrate 10, and the write voltage based on the image signal is supplied to the pixel electrode 9a− via the TFT 116 in the ON state. Write to 1. In addition, the data line driving circuit 101 sequentially supplies image signals to the data lines X1 to Xm formed on the counter substrate 20 through the vertical conductive material 107, and supplies the image signals to the image signals through the on-state TFTs 116. The write voltage based on it is written to the pixel electrode 9a-2.

  The liquid crystal device 100 according to the present embodiment is further provided with a plurality of pixel units 70 arranged in a matrix in the image display region 10 a occupying the centers of the TFT array substrate 10 and the counter substrate 20.

  As shown in FIGS. 3, 4A, and 4B, the pixel unit 70 has a substantially rectangular outer shape in plan view on the TFT array substrate 10 side, and a plurality of slits formed on the inside thereof. The pixel electrode 9a-1 including the pixel electrode 9b-1, the common electrode 11-1 having a solid shape in plan view including the pixel electrode 9a-1, and the long side end of the pixel electrode 9a-1. Data line Xk (where k is an integer satisfying 1 ≦ k ≦ m) and scanning line Yj extending along the short side edge of the pixel electrode 9a-1 (where j is an integer satisfying 1 ≦ j ≦ n) ), A TFT 116 for switching pixels formed in the vicinity of the intersection of the data line Xk and the scanning line Yj, and a storage capacitor 119 (not shown in FIGS. 4A and 4B). Similarly, the pixel unit 70 has a substantially rectangular outer shape in plan view on the counter substrate 20 side, and includes a plurality of slits 9b-2 formed inside thereof, and a pixel electrode 9a-2. The common electrode 11-2 having a solid shape in plan view including the data line Xk and the data line Xk extending along the long side end of the pixel electrode 9a-2 (where k is an integer satisfying 1 ≦ k ≦ m) And the scanning line Yj extending along the short side edge of the pixel electrode 9a-2 (where j is an integer satisfying 1 ≦ j ≦ n) and the vicinity of the intersection of the data line Xk and the scanning line Yj. A pixel switching TFT 116 and a storage capacitor 119 (not shown in FIGS. 4A and 4B) are provided.

  Here, in this invention, as shown in FIG.4 (b), the slit 9b-1 and the slit 9b-2 are arrange | positioned in the same position seeing from the normal line direction of the TFT array board | substrate 10 or the opposing board | substrate 20. As shown in FIG. It is preferable.

  The slit 9b-1 is not limited to a rectangular opening provided in the pixel electrode 9a-1, and may be an opening having an arbitrary shape, for example. Further, the slit 9b-1 is not limited to the opening provided in the pixel electrode 9a-1, and is, for example, a shape in which one side is opened (that is, the pixel electrode 9a-1 has a comb-tooth shape). The shape). Similarly, the slit 9b-2 is not limited to the rectangular opening provided in the pixel electrode 9a-2, and may be an opening having an arbitrary shape, for example. Further, the slit 9b-2 is not limited to the opening provided in the pixel electrode 9a-2. For example, the slit 9b-2 has a shape in which one side is opened (that is, the pixel electrode 9a-2 has a comb-tooth shape). The shape).

  The TFT 116 has a source terminal electrically connected to one of the data lines X1 to Xm, a gate terminal electrically connected to one of the scanning lines Y1 to Yn, and a drain terminal electrically connected to the pixel electrode 9a. Has been. The pixel switching TFT 116 is switched between an on state and an off state by a scanning signal supplied from the scanning line driving circuit 104.

  The liquid crystal element 118 includes a pixel electrode 9a-1, a common electrode 11-1, a pixel electrode 9a-2, a common electrode 11-2, and a liquid crystal layer 50. The pixel electrode 9a-1 and the pixel electrode 9a-2 are electrically connected to any one of the data lines X1 to Xm via the TFT 116. The common electrode 11-1 and the common electrode 11-2 are electrically connected to the common wiring COM. During the operation of the liquid crystal device 100, the pixel electrode 9a-1 having the potential (writing potential) of the image signal supplied from the data lines X1 to Xm and the TFT 116 and the common potential supplied via the common wiring COM are used. An electric field is generated between the common electrode 11-1 and the common electrode 11-1. Similarly, the pixel electrode 9a-2 having the potential (write potential) of the image signal supplied from the data lines X1 to Xm and the TFT 116, and the common electrode 11 having the common potential supplied via the common wiring COM. An electric field is generated between -2. The liquid crystal is driven according to the electric field, that is, the orientation or order of the molecular assembly is changed according to the electric field, thereby modulating light and enabling gradation display.

  At this time, the direction and intensity of the electric field generated between the pixel electrode 9a-1 and the common electrode 11-1 of a certain pixel unit 70 are the same as the pixel electrode 9a-2 and the common electrode 11-2 of the same pixel unit 70. It is preferable that the direction and strength of the electric field generated therebetween are the same or substantially the same. For this reason, it is preferable that an image signal having the same polarity and potential is supplied to each of the pixel electrode 9a-1 and the pixel electrode 9a-2 included in each of the plurality of pixel portions 70. Furthermore, it is preferable that a common voltage signal having the same polarity and potential is supplied to each of the common electrode 11-1 and the common electrode 11-2 included in each of the plurality of pixel portions 70.

  The storage capacitor 119 is added in parallel with the liquid crystal element 118 in order to prevent the held image signal from leaking. In particular, the storage capacitor 119 is preferably formed on each of the TFT array substrate 10 and the counter substrate 20. One electrode constituting the storage capacitor 119 formed on the TFT array substrate 10 is electrically connected to the pixel electrode 9a-1, and the other electrode is electrically connected to the common electrode 11-1. . Similarly, one electrode constituting the storage capacitor 119 formed on the counter substrate 20 is electrically connected to the pixel electrode 9a-2, and the other electrode is electrically connected to the common electrode 11-2. ing.

  The liquid crystal device 100 of this embodiment having such a configuration operates as follows. First, by supplying a high-level scanning signal from the scanning line driving circuit 104 to the scanning line Yj, all the TFTs 116 connected to the scanning line Yj are turned on, and all the pixel units 70 related to the scanning line Yj are turned on. select. In addition, an image signal is supplied from the data line driving circuit 101 to the data lines X1 to Xm in synchronization with the selection of the pixel unit 70 related to the scanning line Yj. As a result, image signals are supplied from the data line driving circuit 101 to the pixel portions 70 selected by the scanning line driving circuit 104 via the data lines X1 to Xm and the TFTs 116, and the writing voltage based on this image signal is applied to the pixels. Data is written to each of the electrode 9a-1 and the pixel electrode 9a-2. As a result, as shown in FIG. 4A, a potential difference is generated between the pixel electrode 9a-1 and the common electrode 11-1, and between the pixel electrode 9a-2 and the common electrode 11-2. (In other words, the electric field caused by the potential difference between the pixel electrode 9a-1 and the common electrode 11-1 and the electric field caused by the potential difference between the pixel electrode 9a-2 and the common electrode 11-2) are the liquid crystal layer 50. To be applied.

  Here, since the liquid crystal molecules 50a have a negative dielectric anisotropy Δε, the liquid crystal molecules 50a are orthogonal to the direction of the electric field in which the major axis direction of the liquid crystal molecules 50a is applied by applying an electric field. Rotate as you do. In other words, the liquid crystal molecules 50a rotate so that the minor axis direction of the liquid crystal molecules 50a is along the direction of the applied electric field. Therefore, when a lateral electric field that is an electric field in the direction along the surface of each of the TFT array substrate 10 and the counter substrate 20 is applied, the major axis direction of the liquid crystal molecules 50a is the same as that of the TFT array substrate 10 and the counter substrate 20. Rotate in a plane horizontal to each of the surfaces. On the other hand, an electric field in a direction intersecting with the surface of the TFT array substrate 10 (typically, an electric field that can be regarded as being perpendicular to or approximately perpendicular to the respective surfaces of the TFT array substrate 10 and the counter substrate 20, Even when a longitudinal electric field, which is an electric field indicated by a dotted arrow in 4 (a), is applied to the liquid crystal layer 50 unintentionally, the minor axis of the liquid crystal molecules 50a is in a direction along the longitudinal electric field. Since the liquid crystal molecules 50a are arranged (that is, the long axis direction of the liquid crystal molecules 50a is orthogonal to the vertical electric field), the long axis direction of the liquid crystal molecules 50a is the surface of the TFT array substrate 10 and the counter substrate 20, respectively. Oriented to ensure horizontal. That is, not only the horizontal electric field that should be originally applied to the liquid crystal layer 50 but also the case where the vertical electric field is unintentionally applied to the liquid crystal layer 50, the major axis direction of the liquid crystal molecules 50a depends on the vertical electric field. The liquid crystal molecules 50a are horizontally aligned with respect to the respective surfaces of the TFT array substrate 10 and the counter substrate 20 according to a lateral electric field, while being aligned horizontally with respect to the respective surfaces of the TFT array substrate 10 and the counter substrate 20. Rotate in a smooth plane. For this reason, even if a vertical electric field is applied as well as a horizontal electric field, the liquid crystal molecules 50a maintain the state in which the major axis direction thereof is substantially parallel to the surfaces of the TFT array substrate 10 and the counter substrate 20, respectively. Rotate.

  On the other hand, in the case of the liquid crystal device 101 according to the comparative example including a liquid crystal layer including liquid crystal molecules having positive dielectric anisotropy Δε (where Δε> 0), each of the TFT array substrate 10 and the counter substrate 20 is provided. When a longitudinal electric field that is an electric field intersecting the surface is unintentionally applied to the liquid crystal layer, the major axis direction of the liquid crystal molecules rises with respect to each of the TFT array substrate 10 and the counter substrate 20. Will rotate. In other words, the liquid crystal molecules rotate so that the major axis direction is inclined in the direction perpendicular to the respective surfaces of the TFT array substrate 10 and the counter substrate 20. For this reason, the alignment control of the liquid crystal molecules in the originally intended mode cannot be performed, and as a result, the display quality of the liquid crystal device may be deteriorated.

  However, in this embodiment, even if a vertical electric field as well as a horizontal electric field is applied, the liquid crystal molecules 50a are in a state in which the major axis direction is substantially parallel to the surfaces of the TFT array substrate 10 and the counter substrate 20, respectively. Rotate while maintaining That is, even if a vertical electric field is applied as well as a horizontal electric field, the major axis direction of the liquid crystal molecules 50a rises with respect to the TFT array substrate 10 and the counter substrate 20 or on the surface of the TFT array substrate 10. On the other hand, the liquid crystal molecules 50a are hardly or completely rotated so as to be inclined in a direction perpendicular to the vertical direction. Accordingly, the driving of the liquid crystal molecules 50a included in the liquid crystal layer 50 can be suitably controlled. For this reason, since it is possible to suitably suppress inconvenience that the black display is blurred or the white display is dull, the contrast can be relatively increased. Thereby, it is possible to suitably suppress the deterioration of the display quality of the liquid crystal device 100.

  In addition, in the liquid crystal device 100 according to the present embodiment, in addition to forming the pixel electrode 9a-1 and the common electrode 11-1 on the TFT array substrate 10, the pixel electrode 9a-2 and the common electrode 11-1 are also formed on the counter substrate 20 side. A common electrode 11-2 is formed. Therefore, both the electric field applied from the TFT array substrate 10 side and the electric field applied from the counter substrate 20 side are applied to the liquid crystal layer 50. For this reason, an electric field can be suitably applied to the entire liquid crystal layer 50 or the entire liquid crystal layer 50 or the entire region of the liquid crystal layer 50 where the liquid crystal molecules 50a that should contribute to image display are located.

  Here, a liquid crystal device according to a comparative example will be described with reference to FIG. FIG. 5 is a cross-sectional view conceptually showing the structure of the liquid crystal device according to the comparative example.

  As shown in FIG. 5A, the liquid crystal device 101 according to the first comparative example includes the pixel electrode 9a and the common electrode 11 only on the TFT array substrate 10 side, and the pixel electrode 9a and the common electrode on the counter substrate 20 side. The electrode 11 is not provided. In this case, as shown in FIG. 5A, only the electric field applied from the TFT array substrate 10 side is applied to the liquid crystal layer 50. Therefore, a state where an electric field is not sufficiently applied may occur in the vicinity of the counter substrate 20. For this reason, a state where the liquid crystal molecules 50a in the vicinity of the counter substrate 20 cannot be suitably driven may occur. Accordingly, in the liquid crystal device 101 according to the first comparative example, the electric field is not sufficiently applied to the liquid crystal molecules 50a located near the counter substrate 20 (that is, the liquid crystal molecules 50a located near the counter substrate 20 are sufficiently driven). In order to prevent the occurrence of such a state, it is necessary to relatively increase the drive voltage (that is, the electric field due to the potential difference between the pixel electrode 9a and the common electrode 11).

  As shown in FIG. 5B, the liquid crystal device 102 according to the second comparative example includes only the pixel electrode 9a having a slit on the TFT array substrate 10 side and only the solid common electrode 11 on the counter substrate 20 side. I have. In this case, as shown in FIG. 5B, an electric field generated between the pixel electrode 9a and the common electrode 11 is applied to the liquid crystal layer 50, but the lateral electric field is concentrated on the TFT array substrate 10 side. It is difficult to generate on the counter substrate 20 side. That is, in the vicinity of the counter substrate 20, a state in which the lateral electric field is not sufficiently applied may occur. For this reason, a state where the liquid crystal molecules 50a in the vicinity of the counter substrate 20 cannot be suitably driven may occur. Therefore, in the liquid crystal device 102 according to the second comparative example, a state where a sufficient electric field is not applied to the liquid crystal molecules 50a located near the counter substrate 20 (that is, the liquid crystal molecules 50a located near the counter substrate 20 are sufficiently driven). In order to prevent the occurrence of such a state, it is necessary to relatively increase the drive voltage (that is, the electric field due to the potential difference between the pixel electrode 9a and the common electrode 11).

  As shown in FIG. 5C, the liquid crystal device 102 according to the third comparative example includes only the pixel electrode 9a having a slit on the TFT array substrate 10 side and faces the slit of the pixel electrode 9a on the counter substrate 20 side. Only the common electrode 11 is provided. In this case, as shown in FIG. 5C, an electric field generated between the pixel electrode 9a and the common electrode 11 is applied to the liquid crystal layer 50, but the lateral electric field is concentrated on the TFT array substrate 10 side. It is difficult to generate on the counter substrate 20 side. That is, in the vicinity of the counter substrate 20, a state in which the lateral electric field is not sufficiently applied may occur. For this reason, a state where the liquid crystal molecules 50a in the vicinity of the counter substrate 20 cannot be suitably driven may occur. Accordingly, in the liquid crystal device 103 according to the third comparative example, the electric field is not sufficiently applied to the liquid crystal molecules 50a located near the counter substrate 20 (that is, the liquid crystal molecules 50a located near the counter substrate 20 are sufficiently driven). In order to prevent the occurrence of such a state, it is necessary to relatively increase the drive voltage (that is, the electric field due to the potential difference between the pixel electrode 9a and the common electrode 11).

  However, in the liquid crystal device 100 of the present embodiment, the entire liquid crystal layer 50 can be obtained without relatively increasing the driving voltage as compared with the liquid crystal devices 101, 102, and 103 according to the first to third comparative examples. It is possible to reliably apply an electric field. In other words, in the liquid crystal device 100 of the present embodiment, the entire liquid crystal layer 50 is used by using a relatively low driving voltage as compared with the liquid crystal devices 101, 102, and 103 according to the first to third comparative examples. It is possible to reliably apply an electric field. That is, if the liquid crystal device 100 of this embodiment and the liquid crystal devices 101, 102, and 103 of the first to third comparative examples each use the liquid crystal molecules 50a having the same absolute value of the dielectric anisotropy Δε. In the liquid crystal device 100 of the present embodiment, the liquid crystal molecules located in the vicinity of the TFT array substrate 10 without increasing the driving voltage as compared with the liquid crystal devices 101, 102, and 103 of the first to third comparative examples. Not only 50a but also the liquid crystal molecules 50a located in the vicinity of the counter substrate 20 can be reliably driven.

  Here, a decrease in drive voltage will be described with reference to FIG. FIG. 6 is a graph conceptually showing an aspect of the drive voltage decrease. In FIG. 6, the liquid crystal device 100 of the present embodiment and the liquid crystal devices 101, 102, and 103 of the first to third comparative examples each have liquid crystal molecules 50 a having the same absolute value of dielectric anisotropy Δε. An example of use will be described.

  As indicated by a circle mark and a thick line in FIG. 6, in the liquid crystal device 100 according to the present embodiment, black display (that is, a state where the transmittance is 0%) to white display (that is, a state where the transmittance is 100%). The drive voltage required for changing to approximately 3V. On the other hand, as indicated by the square marks and the dotted lines in FIG. 6, in the liquid crystal devices 101, 102, and 103 according to the first comparative example to the third comparative example, the drive necessary for changing from black display to white display is shown. The voltage is approximately 5.5V. Thus, in the liquid crystal device 100 of the present embodiment, a relatively low driving voltage is used (in other words, driving is performed) compared to the liquid crystal devices 101, 102, and 103 according to the first to third comparative examples. Even if the voltage is not increased excessively, the electric field can be reliably applied to the entire liquid crystal layer 50.

  Here, the technical effect of “decrease in driving voltage” is reversed. In other words, the absolute value of the dielectric anisotropy Δε of the liquid crystal molecules 50 a included in the liquid crystal layer 50 of the liquid crystal device 100 of the present embodiment is relatively compared. Even if it is made smaller, the liquid crystal device 100 can be driven without excessively increasing the drive voltage. In other words, even if the absolute value of the dielectric anisotropy Δε of the liquid crystal molecules 50a included in the liquid crystal layer 50 of the liquid crystal device 100 of the present embodiment is relatively small, the liquid crystal of the first comparative example to the third comparative example. The liquid crystal device 100 of the present embodiment can be driven using a drive voltage that is comparable to the drive voltage normally used by the devices 101, 102, and 103. That is, in the liquid crystal device 100 of this embodiment, even if the absolute value of the dielectric anisotropy Δε of the liquid crystal molecules 50a is reduced, there is no inconvenience that the drive voltage becomes excessively high. Therefore, in the liquid crystal device 100 of the present embodiment, the rotational viscosity coefficient γ1 of the liquid crystal molecules 50a can be reduced by reducing the absolute value of the dielectric anisotropy Δε of the liquid crystal molecules 50a. Here, the response speed is substantially proportional to the rotational viscosity coefficient γ1 of the liquid crystal molecules 50a. For this reason, in the liquid crystal device 100 of the present embodiment, the rotational viscosity coefficient γ1 of the liquid crystal molecules 50a can be reduced (in other words, even if the rotational viscosity coefficient γ1 of the liquid crystal molecules 50a is reduced, the driving voltage is excessively increased. Because there is no inconvenience such as high), the response speed can be increased. That is, in the liquid crystal device 100 of the present embodiment, the response speed can be increased while using drive voltages comparable to those of the liquid crystal devices 101, 102, and 103 according to the first to third comparative examples. In other words, in the liquid crystal device 100 of the present embodiment, the response speed is increased without excessively increasing the drive voltage, as compared with the liquid crystal devices 101, 102, and 103 according to the first to third comparative examples. be able to.

  Here, with reference to FIG. 7, a mode in which the response speed is increased will be described. FIG. 7 is a graph conceptually showing an aspect in which the response speed is increased. FIG. 7 illustrates an example in which the liquid crystal device 100 of the present embodiment and the liquid crystal devices 101, 102, and 103 of the first to third comparative examples use the same drive voltage.

  As shown in FIG. 7, the response speed of the liquid crystal device 100 according to the present embodiment is faster than the response speeds of the liquid crystal devices 101, 102, and 103 of the first comparative example to the third comparative example. In the present embodiment, when the “response speed of the liquid crystal device” is changed from black display (that is, the state where the transmittance is 0%) to white display (that is, the state where the transmittance is 100%), the transmission is performed. The time required until the transmittance becomes 90% from the state where the rate becomes 10% is used.

  FIG. 7 illustrates the response speed when changing from black display (that is, a state where the transmittance is 0%) to white display (that is, a state where the transmittance is 100%). However, the response speed when changing from black display to intermediate gradation (that is, the state where the transmittance is greater than 0% and less than 100), the response speed when changing from white display to intermediate gradation, and white Similarly, the response speed when changing from display to black display, the conversion speed when changing from intermediate gradation to intermediate gradation, and the like are similarly applied to the liquid crystal devices 101, 102, and 103 of the first comparative example to the third comparative example. The response speed of each is faster.

  Thus, according to the liquid crystal device 100 according to the present embodiment, the response speed can be increased without excessively increasing the drive voltage necessary for driving the liquid crystal molecules 50a.

  In the liquid crystal device 100 according to the present embodiment, the direction and intensity of the electric field generated between the pixel electrode 9a-1 of the certain pixel unit 70 and the common electrode 11-1 are set to the pixel electrode 9a- of the same pixel unit 70. 2 and the direction and intensity of the electric field generated between the common electrode 11-2 and the common electrode 11-2. Therefore, an electric field applied from the TFT array substrate 10 side (that is, an electric field caused by a potential difference between the pixel electrode 9a-1 and the common electrode 11-1) and an electric field applied from the counter substrate 20 side (that is, the electric field difference). Even when both of the electric field due to the potential difference between the pixel electrode 9a-2 and the common electrode 11-2 are applied to the liquid crystal layer 50, the electric field is applied as if only from the TFT array substrate 10 side. A state equivalent to the state can be realized. Therefore, an electric field can be suitably applied to each pixel unit 70 while preferably enjoying the various effects described above, so that there is no adverse effect on image display.

  In addition to forming the pixel electrode 9a-1 and the common electrode 11-1 on the TFT array substrate 10 side, the pixel electrode 9a-2 and the common electrode 11-2 are also formed on the counter substrate 20 side. It is possible to effectively prevent the inconvenience of unintentionally accumulating such charges on the counter substrate 20 side. For this reason, the effect that generation | occurrence | production of the vertical electric field itself can be suppressed appropriately also arises. As a result, the deterioration of the display quality of the liquid crystal device 100 can be more suitably suppressed. That is, in the liquid crystal device 100 according to the present embodiment, in addition to forming the pixel electrode 9a-1 and the common electrode 11-1 on the TFT array substrate 10, the pixel electrode 9a-2 and the common electrode are also formed on the counter substrate 20 side. By forming 11-2, in addition to the effect that the response speed can be increased without excessively increasing the drive voltage, there is also the effect that the display quality itself can be suitably suppressed. You can enjoy it at the same time.

(3) First Modification Next, a liquid crystal device 100a according to a first modification will be described with reference to FIG. FIG. 8 is a cross-sectional view conceptually showing the configuration of the pixel unit 70 of the liquid crystal device 100a according to the first modification, and a perspective view conceptually showing each of the pixel electrode 9a-1 and the pixel electrode 9a-2. It is. In addition, about the same structure as the liquid crystal device 100 mentioned above, the detailed description is abbreviate | omitted by attaching | subjecting the same referential mark.

  As shown in FIGS. 8A and 8B, the liquid crystal device 100a according to the first modification is the liquid crystal device 100 described above except for the positional relationship between the slit 9b-1 and the slit 9b-2. It has the same configuration. In the liquid crystal device 100a according to the first modified example, as shown in FIG. 8B, the slit 9b-1 and the slit 9b-2 are complementary to each other along the normal direction of the TFT array substrate 10 or the counter substrate 20. It is arranged at the position. That is, in the liquid crystal device 100a according to the first modification, the slits 9b-1 and 9b-2 are arranged so as not to overlap with each other along the normal direction of the TFT array substrate 10 or the counter substrate 20. Therefore, the slit 9b-1 of the pixel electrode 9a-1 formed on the TFT array substrate 10 and the electrode portion of the pixel electrode 9a-2 formed on the counter substrate 20 are connected to the TFT array substrate 10 or the counter substrate. It is possible to overlap along 20 normal directions. Similarly, the electrode portion of the pixel electrode 9a-1 formed on the TFT array substrate 10 and the slit 9b-2 of the pixel electrode 9a-2 formed on the counter substrate 20 are connected to the TFT array substrate 10 or the counter substrate. It is possible to overlap along 20 normal directions.

  Even if comprised in this way, the various effects mentioned above can be enjoyed suitably.

  In the above description, the slit 9b-1 and the slit 9b-2 are arranged at the same position along the normal direction of the TFT array substrate 10 or the counter substrate 20, and the slit 9b-1 and the slit 9b- 2 are arranged at complementary positions along the normal direction of the TFT array substrate 10 or the counter substrate 20. However, these are merely examples of the arrangement positions of the slit 9b-1 and the slit 9b-2, and needless to say, they may be arranged at other positions.

(4) Second Modification Next, with reference to FIG. 9, a liquid crystal device 100b according to a second modification will be described. FIG. 9 is a cross-sectional view conceptually showing the structure of the pixel portion 70 of the liquid crystal device 100b according to the second modification. In addition, about the same structure as the liquid crystal device 100 mentioned above, the detailed description is abbreviate | omitted by attaching | subjecting the same referential mark.

  As shown in FIG. 9, the liquid crystal device 100b according to the second modification has the same configuration as the liquid crystal device 100 described above except for the pixel electrode 9a-2 and the common electrode 11-2. In the liquid crystal device 100b according to the second modification, as shown in FIG. 9, the pixel electrode 9a-2, the insulating layer 12-2, and the common electrode 11-2 are formed in this order on the counter substrate 20. That is, in the liquid crystal device 100b according to the second modification, the vertical relationship between the pixel electrode 9a-2 and the common electrode 11-2 is reversed as compared with the liquid crystal device 100 described above. For this reason, in the liquid crystal device 100b according to the second modification, the pixel electrodes 9a-2 are provided in a matrix in a plan view so as to form the respective pixel portions 70 constituting the image display region 10a. Each pixel electrode 9a-2 is a solid electrode in plan view. The common electrode 11-2 has a slit 11b-1 extending in the longitudinal direction.

  In the liquid crystal device 100 according to the second modified example, on the TFT array substrate 10 side, an electric field is applied in the direction from the pixel electrode 9a-1 that is the upper layer electrode to the common electrode 11-1 that is the lower layer electrode. Thus, on the counter substrate 20 side, an electric field is applied in a direction from the pixel electrode 9a-2 that is the lower layer electrode to the common electrode 11-2 that is the upper layer electrode. Even if comprised in this way, the various effects mentioned above can be enjoyed suitably.

  In the above description, the vertical relationship between the pixel electrode 9a-2 and the common electrode 11-2 on the counter substrate 20 side is reversed. However, it goes without saying that the vertical relationship between the pixel electrode 9a-1 and the common electrode 11-1 on the TFT array substrate 10 side may be reversed.

(5) Electronic Device Next, an example of an electronic device including the liquid crystal device 100 described above will be described with reference to FIGS. 10 and 11.

  FIG. 10 is a perspective view of a mobile personal computer to which the above-described liquid crystal device is applied. 10, a computer 1200 includes a main body 1204 provided with a keyboard 1202 and a liquid crystal display unit 1206 including the liquid crystal device 100 described above. The liquid crystal display unit 1206 is configured by adding a backlight to the back surface of the liquid crystal device 100.

  Next, an example in which the above-described liquid crystal device 100 is applied to a mobile phone will be described. FIG. 11 is a perspective view of a mobile phone which is an example of an electronic apparatus. In FIG. 11, a cellular phone 1300 includes a liquid crystal device 1005 that adopts a reflective display format and has the same configuration as the liquid crystal device 100 described above, together with a plurality of operation buttons 1302.

  Since these electronic devices also include the liquid crystal device 100 described above, the various effects described above can be suitably enjoyed.

  In addition to the electronic devices described with reference to FIGS. 10 and 11, a liquid crystal television, a viewfinder type or a monitor direct-view type video tape recorder, a car navigation device, a pager, an electronic notebook, a calculator, a word processor, a workstation A video phone, a POS terminal, a device provided with a touch panel, a projection display device such as a liquid crystal projector, and the like. Needless to say, the present invention can be applied to these various electronic devices.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit or concept of the invention that can be read from the claims and the entire specification, and the liquid crystal device accompanying such a change In addition, electronic devices are also included in the technical scope of the present invention.

It is a top view which shows the structure of the liquid crystal device which concerns on this embodiment. It is H-H 'sectional drawing of FIG. It is a block diagram which shows notionally the electrical structure of the principal part of the liquid crystal device which concerns on this embodiment. FIG. 2 is a plan view conceptually showing a more detailed configuration of a pixel portion and a perspective view conceptually showing each of a pixel electrode and a pixel electrode. It is sectional drawing which shows notionally the structure of the liquid crystal device which concerns on a comparative example. It is a graph which shows notionally the mode of reduction of drive voltage. It is a graph which shows notionally the mode that response speed becomes quick. It is sectional drawing which shows notionally the structure of the pixel part of the liquid crystal device which concerns on a 1st modification, and a perspective view which shows each of a pixel electrode and a pixel electrode notionally. It is sectional drawing which shows notionally the structure of the pixel part of the liquid crystal device which concerns on a 2nd modification. It is a perspective view of a mobile personal computer to which a liquid crystal device is applied. 1 is a perspective view of a mobile phone to which a liquid crystal device is applied.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 8 ... Alignment film, 9a-1 ... Pixel electrode, 9a-2 ... Pixel electrode, 9b-1 ... Slit, 9b-2 ... Slit, 10 ... TFT array substrate, 11-1 ... Common electrode, 11-2 ... Common electrode , 12-1 ... insulating film, 12-2 ... insulating layer, 20 ... counter substrate, 50 ... liquid crystal layer, 50 a ... liquid crystal molecules, 70 ... pixel portion, 100 ... liquid crystal device, 116 ... TFT

Claims (8)

A first substrate;
A second substrate disposed to face the first substrate;
A first electrode and a second electrode formed on the second substrate side of the first substrate;
A third electrode and a fourth electrode formed on the first substrate side of the second substrate;
It is sandwiched between the first substrate and the second substrate and is driven by an electric field generated between the first electrode and the second electrode and between the third electrode and the fourth electrode. A liquid crystal layer containing liquid crystal molecules
The liquid crystal device, wherein the liquid crystal molecules have negative dielectric anisotropy. The liquid crystal device includes a plurality of pixel portions provided at intersections of a plurality of scanning lines and a plurality of data lines,
A direction of an electric field generated between the first electrode and the second electrode in one pixel portion of the plurality of pixel portions, and between the third electrode and the fourth electrode in the one pixel portion. The liquid crystal device according to claim 1, wherein the direction of the electric field generated in is substantially the same. The liquid crystal device includes a plurality of pixel portions provided at intersections of a plurality of scanning lines and a plurality of data lines,
The absolute value of the voltage applied between the first electrode and the second electrode in one pixel portion of the plurality of pixel portions, and the third electrode and the fourth electrode in the one pixel portion. The liquid crystal device according to claim 1, wherein an absolute value of a voltage applied between the first and second voltages is substantially the same. The first electrode sandwiches a first insulating layer between the second electrode,
The third electrode sandwiches a second insulating film between the fourth electrode and the fourth electrode;
The electrodes arranged on the liquid crystal layer side of the first electrode and the second electrode and the electrodes arranged on the liquid crystal layer side of the third electrode and the fourth electrode are respectively in a predetermined direction. It has a slit that extends,
The slit provided in the electrode disposed on the liquid crystal layer side of the first electrode and the second electrode, and the electrode disposed on the liquid crystal layer side of the third electrode and the fourth electrode are provided. 4. The liquid crystal device according to claim 1, wherein the slits are disposed at substantially the same position when viewed from the normal direction of the first substrate or the second substrate. 5. . The first electrode sandwiches a first insulating layer between the second electrode,
The third electrode sandwiches a second insulating film between the fourth electrode and the fourth electrode;
The electrodes arranged on the liquid crystal layer side of the first electrode and the second electrode and the electrodes arranged on the liquid crystal layer side of the third electrode and the fourth electrode are respectively in a predetermined direction. It has a slit that extends,
The slit provided in the electrode disposed on the liquid crystal layer side of the first electrode and the second electrode, and the electrode disposed on the liquid crystal layer side of the third electrode and the fourth electrode are provided. 4. The liquid crystal device according to claim 1, wherein the slits are alternately arranged when viewed from a normal direction of the first substrate or the second substrate. 5. The first electrode is disposed closer to the liquid crystal layer than the second electrode,
The third electrode is disposed closer to the liquid crystal layer than the fourth electrode,
Each of the first electrode and the third electrode is a pixel electrode,
The liquid crystal device according to claim 1, wherein each of the second electrode and the fourth electrode is a common electrode. The first electrode is disposed closer to the liquid crystal layer than the second electrode,
The fourth electrode is disposed closer to the liquid crystal layer than the third electrode,
Each of the first electrode and the third electrode is a pixel electrode,
The liquid crystal device according to claim 1, wherein each of the second electrode and the fourth electrode is a common electrode.   An electronic apparatus comprising the liquid crystal device according to claim 1.

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