JP2005241831A - Liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display element with a novel structure, in which liquid crystal molecules perform a switching motion in substrate surfaces. <P>SOLUTION: The liquid crystal display element, which has a first substrate equipped with a first electrode including a voltage supplying part and a part for display, a second substrate equipped with a second electrode including a voltage supplying part and a part for display and disposed nearly in parallel with the first substrate and a liquid crystal layer interposed between the first and second substrates and displays in a display region, wherein seen from a direction normal to the first and second substrates, in the display region the part for display of the first electrode and that of the second electrode are placed alternately with each other, and further, a distance between the part for display of the first electrode and that of the adjacent second electrode is longer than a distance between the first and second substrates, is provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display element (Liquid Crystal Display, LCD), and more particularly to a liquid crystal display element that performs an in-plane switching drive operation.

  2. Description of the Related Art A so-called character (segment) display liquid crystal display element that displays numbers and pictures by electrode shapes is known. As the liquid crystal operation mode, a twisted nematic (TN) mode in which the orientation of liquid crystal molecules is twisted between the upper and lower substrates is widely used. In a TN mode liquid crystal display element, a very good transmittance can be obtained by selecting an appropriate design condition. A TN mode liquid crystal display element has a simple structure and can be manufactured at low cost.

  However, the TN mode liquid crystal display element has a significant viewing angle dependency because the liquid crystal molecules are switched from the horizontal direction to the vertical direction with respect to the substrate. In particular, in a general TN mode liquid crystal display element in which a uniform alignment process is applied to the substrate surface, the viewing angle region in which display is visible is remarkably limited, and color change with respect to the viewing angle change is particularly significant when voltage is applied. It is.

  In order to improve the viewing angle dependency, an in-plane switching mode that switches the alignment state of the liquid crystal by applying an electric field in the horizontal direction is effective. The in-plane switching mode has excellent viewing angle characteristics not found in other liquid crystal display modes because the liquid crystal molecules are switched in the horizontal direction with respect to the substrate and the liquid crystal molecules are not aligned in the vertical direction with respect to the substrate.

  The in-plane switching mode has not been used for a liquid crystal display element for character (segment) display. One of the causes is that in the in-plane switching mode liquid crystal display element, electrode pairs for driving and display are arranged only on one side of the substrate, so characters (segments) that directly display numbers and pictures with electrode patterns In the display electrode, the originally non-simple shape would be more complicated.

  FIGS. 16A and 16B are schematic plan views showing a display pattern and an electrode pattern in a segment type liquid crystal display element, respectively.

  FIG. 16A shows an example of a display pattern for displaying the character “T”.

  Reference is made to FIG. The display of “T” in FIG. 16A is performed using, for example, electrode shapes arranged on the upper and lower substrates. For example, the segment electrode (lower electrode) 39 and the common electrode (upper electrode) 38 are formed in a pattern as shown in the figure, and “T” can be displayed by overlapping them with a predetermined distance.

  In addition, a liquid crystal display element has been proposed in which electrodes on the upper and lower substrates are formed in a plurality of stripes or checkers, and an oblique electric field is applied to the liquid crystal layer to control liquid crystal alignment. (For example, refer to Patent Document 1 and Patent Document 2.) These liquid crystal display elements have a high scattering property, a low driving voltage, a bright display with a high contrast ratio, and an excellent gradation.

JP 07-333611 A Japanese Patent Laid-Open No. 08-136941

  An object of the present invention is to provide a liquid crystal display element having a novel structure in which liquid crystal molecules perform in-plane switching operation.

  According to one aspect of the present invention, a first substrate including a first electrode including a voltage supply portion and a display portion, a second electrode including a voltage supply portion and a display portion, A liquid crystal display element having a second substrate disposed substantially parallel to one substrate and a liquid crystal layer sandwiched between the first substrate and the second substrate and performing display in a display region And when viewed from the normal direction of the first and second substrates, the display portion of the first electrode and the display portion of the second electrode are staggered in the display region. The distance between the display portion of the first electrode and the display portion of the second electrode that are disposed adjacent to each other is equal to or greater than the distance between the first substrate and the second substrate. A liquid crystal display element can be provided.

  This liquid crystal display element is a liquid crystal display element in which the liquid crystal molecules generally switch in the substrate plane when a voltage (potential difference) sufficient to switch the liquid crystal molecules is applied between the upper and lower electrodes.

  According to the present invention, it is possible to provide a liquid crystal display element having a novel structure in which liquid crystal molecules perform in-plane switching operation.

  FIG. 1 is a schematic cross-sectional view illustrating a liquid crystal display device according to an embodiment.

  A liquid crystal layer 37 is sandwiched between the upper substrate 30 and the lower substrate 31 that are arranged substantially in parallel. The thickness of the liquid crystal layer 37 is, for example, 5 μm. The liquid crystal of the liquid crystal layer 37 has a negative dielectric anisotropy (Δε <0), for example, and the liquid crystal is horizontally aligned with respect to both substrates. Although the liquid crystal layer 37 with TN orientation is shown in the figure, it may be uniaxial parallel orientation.

  The upper substrate 30 is formed on a glass substrate 32 including a transparent glass substrate 32, a common electrode 38 having a comb-shaped portion formed of, for example, ITO (Indium Tin Oxide) on the glass substrate 32, and the common electrode 38. The alignment film 34 is included.

  The lower substrate 31 includes a transparent glass substrate 33, a segment electrode 39 having a comb-shaped portion formed of, for example, ITO on the glass substrate 33, and an alignment film formed on the glass substrate 33 including the segment electrode 39. 35. Uniform liquid crystal alignment processing such as rubbing processing is performed on the alignment films 34 and 35 of both substrates.

  The common electrode 38 and the segment electrode 39 are formed so that the respective comb-tooth shaped portions constitute a staggered arrangement when viewed from the normal direction of the upper substrate 30 and the lower substrate 31. A voltage is applied between the common electrode 38 and the segment electrode 39 by a voltage applying means, and the liquid crystal alignment state of the liquid crystal layer 37 can be changed. The shape and arrangement of the common electrode 38 and the segment electrode 39 will be described in detail later using a plan view.

  In addition, even when the common electrode 38 and the segment electrode 39 have a region that partially overlaps other than the display portion, the electrode may be formed of a metal material that can block light, or negative dielectric anisotropy By using a liquid crystal material having (Δε <0), adverse effects on display such as erroneous lighting can be prevented.

  Further, as a material for forming the common electrode 38 and the segment electrode 39, when the dielectric anisotropy of the liquid crystal of the liquid crystal layer 37 is positive (Δε> 0), a light-shielding metal or conductive material is used. It is valid. This is because the use of an opaque electrode prevents light penetration even when liquid crystal molecules rise on the electrode.

  When the dielectric anisotropy is negative (Δε <0), in addition to these, a translucent or transparent metal or conductive material can be used. When a liquid crystal material with a negative dielectric anisotropy (Δε <0) is used, the liquid crystal on the electrode responds to the substrate in the horizontal direction when a voltage is applied. It is possible to prevent the occurrence of false lighting. The response of the liquid crystal will be described in detail later.

  The polarizing plates 40 and 41 are disposed opposite to the glass substrates 32 and 33. The two polarizing plates are arranged, for example, in crossed Nicols, and each transmit polarized light in a specific direction (absorption axis direction). The two polarizing plates may be arranged in parallel Nicols. In either case, it is preferable that the direction of the rubbing treatment applied to the substrate on the light introduction side coincides with the absorption axis or transmission axis direction of the polarizing plate disposed to face the substrate.

  2A is a plan view showing an example of the shape and arrangement of electrodes (common electrode 38 and segment electrode 39) formed on both substrates, and FIG. 2B is a plan view of FIG. It is sectional drawing along the 2B-2B line.

  Reference is made to FIG. The common electrode 38 and the segment electrode 39 are, for example, partly formed in a comb-teeth shape and arranged so that the parts corresponding to the comb teeth are alternately meshed (interdigital) when viewed from the normal direction of the substrate. Is done.

  Reference is made to FIG. Since the common electrode 38 and the segment electrode 39 are formed as described above, the comb-shaped portions of both electrodes constitute an alternate arrangement.

  With reference to FIG. 3 and FIG. 4 to FIG. 6, the display using the electrode having the comb-shaped portion will be described in detail.

  FIG. 3A is a schematic plan view showing an example of the display area of the liquid crystal display element, and FIGS. 3B and 3C are schematic plan views showing examples of the common electrode 38 and the segment electrode 39, respectively. FIG. (D) is a schematic plan view showing an example of the arrangement of the common electrode 38 and the segment electrode 39 in the display region.

  Reference is made to FIG. The liquid crystal display element includes a display area 45 that can display characters, graphics, and the like. In FIG. 3A, the display area 45 is, for example, five separated areas for displaying each character of the character string “TITLE”.

  Reference is made to FIG. The common electrode 38 is formed so that a part thereof has a comb-teeth shape.

  Reference is made to FIG. The segment electrode 39 is also formed so that a part thereof has a comb-teeth shape. The positions where the comb teeth portions of both electrodes are formed, the length of the comb teeth, and the like are appropriately determined depending on the characters to be displayed. Using the common electrode 38 shown in FIG. 3B and the segment electrode 39 shown in FIG. 3C, “T”, “I”, “T” are displayed in the five display areas shown in FIG. Each character of “L” and “E” can be displayed.

  Reference is made to FIG. The arrangement of the common electrode 38 and the segment electrode 39 in the display region 45 for displaying the letter “I” when viewed from the normal direction of the substrate is shown.

  With respect to each of the common electrode 38 and the segment electrode 39, portions that generate an electric field for display are referred to as display portions 38a and 39a, and other portions are referred to as voltage supply portions 38b and 39b. In FIG. 3D, the portions within the display region 45 are display portions 38 and 39a, and the portions outside the display region 45 are voltage supply portions 38b and 39b.

  In the display area 45, the display portions 38a of the common electrode 38 and the display portions 39a of the segment electrode 39 are alternately arranged. When viewed from the normal direction of the substrate, the distance between the display portion 38a of the adjacent common electrode 38 and the display portion 39a of the segment electrode 39 is, for example, 20 μm. Further, the voltage supply portion 38b of the common electrode 38 and the voltage supply portion 39b of the segment electrode 39 are arranged so as not to be close to each other.

  As will be described later, in order to switch the liquid crystal molecules of the liquid crystal layer 37 substantially only in the horizontal direction, when viewed from the normal direction of the upper substrate 30 and the lower substrate 31, the display portion and the segment of the adjacent common electrode 38 are segmented. The distance from the display portion of the electrode 39 is not less than the distance between the upper substrate 30 and the lower substrate 31. In order to enhance the certainty of switching the liquid crystal molecules only in the substantially horizontal direction, when viewed from the normal direction of the upper substrate 30 and the lower substrate 31, the display portion of the adjacent common electrode 38 and the segment electrode 39 The distance from the display portion is more preferably 1.5 times or more the distance between the upper substrate 30 and the lower substrate 31.

  4 and 5 are schematic plan views in which a part of the comb-tooth shaped portions of the common electrode 38 and the segment electrode 39 shown in FIGS. 3B and 3C are enlarged, respectively. It is a top view when these two electrodes are arrange | positioned on an upper-lower board | substrate, and it sees from the normal line direction of the two board | substrates bonded so that it might oppose. For all three drawings, the comb-shaped electrode portion constituting the portion “E” of the character string “TITLE” is shown.

  Please refer to FIG. For example, to display “E”, the common electrode 38 includes a plurality of comb-shaped electrode portions having the same length in the left-right direction of the drawing. For example, the length of one piece is 2.15 mm, the width is 20 μm, and the distance between them is 60 μm.

  Please refer to FIG. For example, in order to display “E”, the segment electrode 39 includes three types of comb-shaped electrode portions having different lengths in the horizontal direction of the drawing. Their lengths are, for example, 2.15 mm, 1.9 mm, and 0.65 mm, and the width and interval are the same as those of the common electrode 38 shown in FIG.

  Please refer to FIG. As shown in the figure, in the liquid crystal display element, when viewed from the normal direction of the substrate, the letter “E” fits in a range of, for example, 2 mm in length and 2 mm in width by arranging the comb-shaped portions of both electrodes alternately. Can be displayed.

  Next, the inventors of the present application simulated the equipotential distribution and the liquid crystal molecule director distribution when the comb-shaped portions of the upper and lower electrodes (segment electrode 39 and common electrode 38) are alternately arranged. For the simulation, a LCDMASTER 6 two-dimensional LCD simulator manufactured by Shintech Co., Ltd. was used.

  7A to 7C show the simulation results.

  FIG. 7A is a cross-sectional view showing an outline of the structure of the electrodes and the liquid crystal layer of the liquid crystal display element used in the simulation. It was assumed that the thickness of the liquid crystal layer 37 was 5 μm, and the segment electrode 39 and the common electrode 38 were electrodes having comb-shaped portions. The interval (the distance in the horizontal direction) between the alternately arranged comb-shaped electrode portions was 10 μm. Further, the electrode width of both the upper and lower electrodes was 10 μm.

  As the liquid crystal of the liquid crystal layer 37, ZLI-4792 having a positive dielectric anisotropy (Δε> 0) was used. In addition, the liquid crystal alignment directions of the upper substrate 30 and the lower substrate 31 when no voltage is applied are both azimuthally shifted by 5 ° with respect to the direction in which the comb-shaped electrode portion extends. The pretilt angle was 0.5 ° and the antiparallel alignment conditions were used. Further, 10 V was applied to the common electrode 38, and the segment electrode 39 was set to 0V.

  FIG. 7B is a diagram illustrating an equipotential distribution obtained as a result of the simulation. It can be seen that the electric field is generated obliquely with respect to the horizontal direction in the vicinity of the ends of the comb-shaped electrode portion, but the horizontal electric field is generally dominant between the upper and lower electrodes.

  FIG. 7C is a simulation result showing the distribution of liquid crystal molecule directors between the upper and lower substrates in a steady state after a sufficient time has elapsed after applying a voltage between the upper and lower electrodes. In the region of the electrode part, there are also regions where the liquid crystal molecules are oriented and deformed in the out-of-plane direction (non-horizontal direction with respect to the substrate) with respect to the substrates (upper substrate 30 and lower substrate 31). In this region, it can be seen that the liquid crystal alignment deformation is substantially only in the horizontal direction.

  According to the results shown in FIGS. 7A to 7C, the liquid crystal display element shown in FIG. 1 can switch liquid crystal molecules only in a substantially horizontal direction. Even when electrodes are alternately formed on the upper substrate 30 and the lower substrate 31, it can be said that substantially the same effect as in the conventional case where electrodes are formed on one substrate can be obtained.

  Note that the same calculation results were confirmed in these cases even when the liquid crystal layer 37 was simulated using a liquid crystal material having a negative dielectric anisotropy (Δε <0). Further, the same effect could be confirmed when the TN alignment mode was used instead of the uniaxial alignment mode.

  In the case of using a liquid crystal material having a negative dielectric anisotropy (Δε <0) and a transparent electrode made of ITO or the like, other components of the liquid crystal cell according to the embodiment are those of a conventional TN mode liquid crystal cell. Can be exactly the same.

  Further, the liquid crystal display element according to the embodiment has a structure in which each of the upper substrate 30 and the lower substrate 31 includes electrodes (segment electrode 39 and common electrode 38), so that the liquid crystal display which is not in the conventional in-plane switching mode. An in-plane switching mode liquid crystal display element can be manufactured by the same manufacturing process as the element manufacturing process.

  In the in-plane switching mode liquid crystal display element shown in FIG. 1, the electrodes on the upper and lower substrates (segment electrode 39 and common electrode 38) are both electrodes having comb-shaped portions, and the comb-shaped electrode portions are arranged alternately. It was formed to constitute. The pair of electrodes on the upper and lower substrates may be configured of electrodes having a shape having openings provided at least partially at periodic intervals.

  FIGS. 8A and 8B are plan views schematically showing common electrodes and segment electrodes that can be used as electrode pairs formed on the upper and lower substrates of the liquid crystal display element according to the embodiment. A configuration of the common electrode and the segment electrode capable of displaying the letter “T” illustrated in FIG. Both are on the upper substrate 30 and the lower substrate 31, respectively, when viewed from the normal direction of the upper substrate 30 and the lower substrate 31, the range of the dotted lines in FIGS. 8A and 8B (effective display area) Arranged so that they overlap.

  In both the common electrode shown in FIG. 8A and the segment electrode shown in FIG. 8B, a part of the electrode is not formed in a comb-tooth shape, but a rectangular opening is formed in the effective display area. They are regularly provided at regular intervals (pitch) in the vertical direction (vertical direction in the figure) and in the horizontal direction (horizontal direction in the figure). The openings of both electrodes are, for example, congruent.

  When the effective display areas of both electrodes are overlapped on the common electrode and the segment electrode, the respective openings are shifted by a half pitch along a direction parallel to a pair of parallel sides of the rectangular opening, for example. An opening is formed in the effective display area. FIGS. 8A and 8B show two electrodes in which openings are formed so as to be offset from each other by a half pitch in the effective display area. The segment electrode and the common electrode as shown in the figure are arranged so that the effective display areas of both electrodes overlap when viewed from the normal direction of the upper substrate 30 and the lower substrate 31 (so that the openings of both electrodes are shifted), respectively. It is formed on the upper and lower substrates.

  In the effective display area, the electrode portions extending in the vertical direction overlap. These electrode portions do not generate a horizontal electric field. Within the effective display area, the electrode portions extending in the horizontal direction are alternately arranged in the vertical direction. These electrode portions generate a horizontal electric field to control display.

  FIGS. 9A to 9E are diagrams for explaining the arrangement of electrodes having two openings.

  FIG. 9A is a schematic plan view showing a part of the common electrode 38 having an opening. The common electrode 38 has an electrode portion extending in the vertical direction and an electrode portion extending in the horizontal direction, whereby rectangular openings are defined in the vertical direction and the horizontal direction at regular intervals (pitch).

  FIG. 9B is a schematic plan view showing a part of the segment electrode 39 having an opening. The segment electrode 39 also has an electrode portion extending in the vertical direction and an electrode portion extending in the horizontal direction, thereby defining an opening. The openings have the same size and the same pitch as the openings of the common electrode 38 shown in FIG. 9A, but are formed so as to be shifted by a half pitch in the vertical direction.

  FIG. 9C is a plan view when the common electrode 38 and the segment electrode 39 shown in FIGS. 9A and 9B are formed on the substrate and viewed from the normal direction of the substrate. Shown is a part of the display area 45 of the liquid crystal display element.

  When viewed from the normal direction of the substrate, one of the electrodes is disposed so as to extend laterally through the center of the other opening.

  A horizontal electric field for display is formed by the electrode portion extending in the horizontal direction of the common electrode 38 and the electrode portion extending in the horizontal direction of the segment electrode 39. Therefore, these become display portions 38a and 39a of the respective electrodes. Further, the electrode portions extending in the vertical direction of the common electrode 38 and the segment electrode 39 do not generate a horizontal electric field for display. For this reason, these become the voltage supply portions 38b and 39b of the respective electrodes. When viewed from the normal direction of the substrate, in the display region 45, the display portions 38a and 39a of both electrodes are alternately arranged, and the voltage supply portions 38b and 39b are arranged to overlap each other. Further, the extending direction of the display portions 38a and 39a intersects the extending direction of the voltage supply portions 38b and 39b.

  The size of the opening is, for example, 60 μm in the horizontal direction and 30 μm in the vertical direction. The width of the display portions 38a and 39a is, for example, 10 μm, and the vertical pitch of the openings is 40 μm at this time. The width of the voltage supply portions 38b and 39b is, for example, 20 μm, and the horizontal pitch of the openings is 80 μm at this time. Since it is shifted by a half pitch in the vertical direction, the distance between the display portion 38a of the adjacent common electrode 38 and the display portion 39a of the segment electrode 39 is 10 μm when viewed from the normal direction of the substrate.

  FIG. 9D is a cross-sectional view taken along line 9D-9D in FIG. Shown are the display portions 38 a and 39 a of the common electrode 38 and the segment electrode 39. These appear alternately at regular intervals.

  FIG. 9E is a cross-sectional view taken along line 9E-9E in FIG. Shown in the figure are voltage supply portions 38 b and 39 b of the common electrode 38 and the segment electrode 39. Both face each other at a certain distance.

  The display using the electrode having the opening will be described in detail with reference to FIGS. 10 and 11 to 13.

  10A and 10B are schematic plan views showing examples of the common electrode 38 and the segment electrode 39, respectively.

  Reference is made to FIG. The common electrode 38 is formed so that a part thereof has a rectangular opening. In the drawing, the region where the opening is formed is shown by hatching.

  Reference is made to FIG. The segment electrode 39 is also formed so that a part thereof has a rectangular opening. Similar to FIG. 10A, the region where the opening is formed is indicated by hatching. By using these two electrodes, the character string “TITLE” as shown in FIG. 3A can be displayed on the liquid crystal display element.

  FIG. 11 is an enlarged schematic plan view of a part where the opening of the common electrode 38 shown in FIG. 10A is formed. The electrode part in which the opening part which comprises the part of "E" of character string "TITLE" was formed is shown. For example, in order to display “E”, the common electrode 38 has a large number of small rectangular openings in the “E” -shaped region. The size of the opening is, for example, 40 μm in the vertical direction and 60 μm in the horizontal direction of the letter “E”.

  FIG. 12 is a schematic plan view enlarging a part where the opening of the segment electrode 39 shown in FIG. 10B is formed. Similarly to FIG. 11, an electrode part in which an opening part constituting the part “E” of the character string “TITLE” is formed is shown. For example, for displaying “E”, the segment electrode 39 is also provided with a large number of small openings in the “E” character-shaped region.

  In both the common electrode shown in FIG. 11 and the segment electrode shown in FIG. 12, rectangular openings are regularly provided at regular intervals (pitch) in the vertical and horizontal directions. The size and pitch of the openings of both electrodes are the same.

  FIG. 13 is a plan view when the common electrode 38 and the segment electrode 39 shown in FIGS. 11 and 12 are arranged on the substrate and viewed from the normal direction of the substrate. As shown in the figure, in the liquid crystal display element, when viewed from the normal direction of the substrate, the openings of both electrodes are arranged so as to be shifted by a half pitch in the vertical direction of the letter “E”. The letter “E” that falls within the range of 2 mm can be displayed. By disposing the openings of both electrodes in the vertical direction by a half pitch, the display portions 38a and 39a of both electrodes are alternately arranged in the display area 45 displaying the letter “E”, and the voltage supply portion 38b and 39b are arrange | positioned so that it may overlap.

  By providing openings as described above in the common electrode and the segment electrode, electrodes having comb-shaped portions are formed on the upper and lower substrates, and the comb-shaped portions are alternately arranged when viewed from the normal direction of the substrate. The same effect as can be obtained.

  In order to display any effective display area without creating a disconnection area and displaying an effective display area for any character or design pattern display, the size of the rectangular opening is vertical (one pair of It is preferable that the length of parallel sides is 40 μm or less and the width (length of the other pair of parallel sides) is 50 μm or more. The pitch of the openings is preferably 60 μm or less in the vertical direction and 60 μm or more in the horizontal direction. The size of the rectangular openings is more preferably 40 μm or less and 60 μm or more in width, and the pitch of the openings is more preferably 40 μm or less in the vertical direction and 60 μm or more in the horizontal direction. In addition, it is a value when the direction which shifts an opening part is made into the vertical direction.

  14A to 14E are views for explaining a modification of the common electrode 38 and the segment electrode 39 shown in FIGS. 9A and 9B and a liquid crystal display element using them. .

  FIG. 14A is a schematic plan view showing a part of the common electrode 38 having an opening. In the common electrode 38 shown in FIG. 9A, the opening is formed in a rectangular shape, and therefore, the electrode portion extending in the horizontal direction and the electrode portion extending in the vertical direction are both formed linearly. In the common electrode 38 shown in FIG. 14A, the electrode portion extending in the lateral direction has a bent portion periodically.

  FIG. 14B is a schematic plan view showing a part of the segment electrode 39 having an opening. The segment electrode 39 also has a bent portion periodically extending in the lateral direction. The openings are formed to be the same size and pitch as the openings of the common electrode 38 shown in FIG. 14A, but can be shifted by a half pitch in the vertical direction. The angle at which the bent portion bends from the lateral direction is, for example, 5 °.

  FIG. 14C is a plan view when the common electrode 38 and the segment electrode 39 shown in FIGS. 14A and 14B are formed on the substrate and viewed from the normal direction of the substrate. . As in FIG. 9C, a part of the display area 45 of the liquid crystal display element is illustrated.

  When viewed from the normal direction of the substrate, one of the electrodes is disposed so as to extend in the lateral direction as a whole through the center of the other opening. The electrode portions extending in the horizontal direction of the common electrode 38 and the segment electrode 39 are display portions 38a and 39a, the electrode portions extending in the vertical direction are voltage supply portions 38b and 39b, and the former is alternately arranged and the latter is arranged to overlap. This is the same as that described with reference to FIG.

  FIG. 14D is a cross-sectional view taken along line 14D-14D of FIG. Shown are the display portions 38 a and 39 a of the common electrode 38 and the segment electrode 39. These appear alternately at regular intervals.

  FIG. 14E is a cross-sectional view taken along line 14E-14E in FIG. Shown in the figure are voltage supply portions 38 b and 39 b of the common electrode 38 and the segment electrode 39. Both face each other at a certain distance.

  Even when the common electrode 38 and the segment electrode 39 having the bent portions as shown in FIGS. 14A and 14B are used, the openings as described with reference to FIGS. 10 and 11 to 13 are used. The display using the electrode which has can be possible. Furthermore, by using the common electrode 38 and the segment electrode 39 having a bent portion, regions (multidomains) having different alignment directions of the liquid crystal can be formed, so that the viewing angle dependency of display can be further improved. .

  The electrode pairs shown in FIGS. 8A, 8B, 9A, 9B, 14A, and 14B are based on an electrode pattern such as a conventional TN mode. It can be easily manufactured. In addition, the electrode pattern can be easily designed.

  FIG. 15 is a diagram schematically showing the alignment state (response state) of the liquid crystal in the liquid crystal layer 37.

  (1) uses a TN-aligned liquid crystal with a positive dielectric anisotropy (Δε> 0) as the liquid crystal of the liquid crystal layer 37, and the voltage of the liquid crystal when a voltage is applied between the common electrode 38 and the segment electrode 39. The alignment state is shown. When the liquid crystal is aligned as shown in the figure, for example, light does not pass through the liquid crystal layer 37.

  (2) uses a TN-aligned liquid crystal having a positive dielectric anisotropy (Δε> 0) as the liquid crystal of the liquid crystal layer 37, and the liquid crystal when the voltage is not applied between the common electrode 38 and the segment electrode 39. The alignment state is shown. When the liquid crystal is in the alignment state as shown in the figure, for example, the light rotates along the director of the liquid crystal molecules and passes through the liquid crystal layer 37.

  (3) is a liquid crystal obtained by applying a uniaxial parallel alignment liquid crystal having a positive dielectric anisotropy (Δε> 0) as the liquid crystal of the liquid crystal layer 37 and applying a voltage between the common electrode 38 and the segment electrode 39. The orientation state of is shown. When the liquid crystal is aligned as shown in the figure, for example, light does not pass through the liquid crystal layer 37.

  (4) is a liquid crystal when liquid crystal of the liquid crystal layer 37 is uniaxial parallel alignment with positive dielectric anisotropy (Δε> 0) and no voltage is applied between the common electrode 38 and the segment electrode 39. The orientation state of is shown. When the liquid crystal is aligned as shown in the figure, for example, light passes through the liquid crystal layer 37.

  (5) uses a TN-aligned liquid crystal having a negative dielectric anisotropy (Δε <0) as the liquid crystal of the liquid crystal layer 37, and the liquid crystal when the voltage is applied between the common electrode 38 and the segment electrode 39. The alignment state is shown. When the liquid crystal is aligned as shown in the figure, for example, light does not pass through the liquid crystal layer 37.

  (6) uses a TN-aligned liquid crystal having a negative dielectric anisotropy (Δε <0) as the liquid crystal of the liquid crystal layer 37, and the liquid crystal when the voltage is not applied between the common electrode 38 and the segment electrode 39. The alignment state is shown. When the liquid crystal is in the alignment state as shown in the figure, for example, the light rotates along the director of the liquid crystal molecules and passes through the liquid crystal layer 37.

  (7) is a liquid crystal when a liquid crystal of the liquid crystal layer 37 is a uniaxial parallel alignment having a negative dielectric anisotropy (Δε <0) and a voltage is applied between the common electrode 38 and the segment electrode 39. The orientation state of is shown. When the liquid crystal is aligned as shown in the figure, for example, light does not pass through the liquid crystal layer 37.

  (8) is a liquid crystal when a liquid crystal of the liquid crystal layer 37 is a uniaxial parallel alignment having a negative dielectric anisotropy (Δε <0) and no voltage is applied between the common electrode 38 and the segment electrode 39. The orientation state of is shown. When the liquid crystal is aligned as shown in the figure, for example, light passes through the liquid crystal layer 37.

  When the TN mode is adopted, there is an advantage that the cell thickness margin is increased. The parallel orientation adopted in the conventional liquid crystal display element that performs the in-plane switching drive operation is due to the change in birefringence similar to STN when switching between voltage application and non-application, and there is a margin for the cell gap. Get smaller. On the other hand, in the case of the above-described TN mode in-plane switching type liquid crystal display element, the change in voltage application / non-application is due to optical rotation, so that the margin for the cell gap becomes larger.

  The cell setting when the TN mode is adopted is preferably in the range of retardation Δnd of 0.48 to 0.49 μm in the case of normally white, and the twist angle is not limited to 90 °. In the case of normally black, that is, when the polarizing plate is arranged in a parallel Nicol arrangement, the retardation Δnd is preferably larger than 1.5 μm, and the twist angle is most preferably 90 °.

  Finally, supplementary explanation will be given on the arrangement and formation of the common electrode 38 and the segment electrode 39.

  First, the case where the liquid crystal layer 37 is formed of a liquid crystal material with uniaxial parallel alignment will be described. A part of both electrodes is formed in, for example, a comb-tooth shape, and when both of the electrodes form a staggered arrangement between the upper and lower substrates, the direction in which the staggered arrangement extends (direction perpendicular to the teeth), When the dielectric anisotropy of the liquid crystal material is negative (Δε <0), the direction of displacement when the openings are arranged so as to be displaced between the upper and lower substrates is as follows. The liquid crystal molecules preferably have a direction substantially parallel to the major axis orientation direction of the liquid crystal molecules. When the dielectric anisotropy of the liquid crystal material is positive (Δε> 0), the direction is substantially perpendicular to the major axis orientation direction of the liquid crystal molecules. Is preferred.

  Next, the case where the liquid crystal layer 37 is formed of a twisted nematic liquid crystal material will be described. A part of both electrodes is formed in, for example, a comb-tooth shape, and when both of the electrodes form a staggered arrangement between the upper and lower substrates, the direction in which the staggered arrangement extends (direction perpendicular to the teeth), When the dielectric anisotropy of the liquid crystal material is negative (Δε <0), the direction of displacement when the openings are arranged so as to be displaced between the upper and lower substrates is as follows. It is preferable that the direction is substantially parallel to the major axis alignment direction of the liquid crystal molecules on the surface of the substrate (upper substrate 30 or lower substrate 31), and when the dielectric anisotropy of the liquid crystal material is positive (Δε> 0) The liquid crystal molecules on the surface of the substrate surface are preferably substantially perpendicular to the major axis alignment direction.

  As mentioned above, although this invention was demonstrated along the Example, this invention is not limited to these. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

  The present invention can be applied to segment liquid crystal display elements, simple matrix drive dot matrix liquid crystal display elements including character display, simple matrix drive dot matrix liquid crystal display elements, and the like.

It is a schematic sectional drawing which shows the liquid crystal display element by an Example. (A) is a top view showing an example of the shape and arrangement | positioning of the electrode (common electrode 38 and segment electrode 39) formed on both board | substrates, (B) is along the 2B-2B line of (A). FIG. (A) is a schematic plan view showing an example of a display area of a liquid crystal display element, and (B) and (C) are schematic plan views showing examples of a common electrode 38 and a segment electrode 39, respectively. FIG. 6D is a schematic plan view showing an example of the arrangement of the common electrode 38 and the segment electrode 39 in the display area. FIG. 4 is an enlarged schematic plan view of a part of a comb-tooth shaped portion of a common electrode shown in FIG. FIG. 4 is a schematic plan view in which a part of a comb-tooth shaped portion of a segment electrode 39 shown in FIG. 3 (B) is enlarged. FIG. 6 is a plan view when the two electrodes shown in FIGS. 4 and 5 are arranged on the upper and lower substrates and viewed from the normal direction of the two substrates bonded to face each other. (A) is sectional drawing which shows the outline of the structure of the electrode and liquid crystal layer of the liquid crystal display element used for simulation, (B) is a figure which shows equipotential distribution obtained as a result of simulation, (C ) Is a simulation result showing a liquid crystal molecule director distribution between the upper and lower substrates in a steady state after a sufficient time has elapsed after applying a voltage between the upper and lower electrodes. (A) And (B) is a top view which shows the outline of the common electrode and segment electrode which can be used as an electrode pair formed on the upper and lower substrates of the liquid crystal display element by an Example, respectively. (A)-(E) is a figure for demonstrating arrangement | positioning of the electrode which has two opening parts. (A) And (B) is a schematic plan view which shows an example of the common electrode 38 and the segment electrode 39, respectively. FIG. 11 is a schematic plan view showing an enlarged part of the common electrode 38 shown in FIG. FIG. 11 is a schematic plan view in which a part of an opening of the segment electrode 39 shown in FIG. 10B is enlarged. FIG. 13 is a plan view when the common electrode and the segment electrode 39 shown in FIGS. 11 and 12 are arranged on the substrate and viewed from the normal direction of the substrate. (A)-(E) are the figures for demonstrating the modification of the common electrode 38 and the segment electrode 39 which were each shown to FIG. 9 (A) and (B), and a liquid crystal display element using them. FIG. 6 is a diagram schematically showing an alignment state (response state) of liquid crystal in a liquid crystal layer 37. (A) And (B) is a schematic top view showing the display pattern and electrode pattern in a segment type liquid crystal display element, respectively.

Explanation of symbols

30 Upper substrate 31 Lower substrate 32, 33 Glass substrate 34, 35 Alignment film 37 Liquid crystal layer 38 Common electrode 39 Segment electrodes 38a, 39a Display portions 38b, 39b Voltage supply portions 40, 41 Polarizing plate 45 Display region

Claims (7)

A first substrate comprising a first electrode including a voltage supply portion and a display portion;
A second substrate comprising a second electrode including a voltage supply portion and a display portion, and disposed substantially parallel to the first substrate;
A liquid crystal display element having a liquid crystal layer sandwiched between the first substrate and the second substrate and performing display in a display region,
When viewed from the normal direction of the first and second substrates, the display area of the first electrode and the display area of the second electrode are alternately arranged in the display area. A liquid crystal display element in which a distance between the display portion of the first electrode and the display portion of the second electrode adjacent to each other is equal to or greater than the distance between the first substrate and the second substrate. When viewed from the normal direction of the first and second substrates, the distance between the display portion of the first electrode and the display portion of the second electrode that are adjacent to each other is the distance between the first substrate and the second substrate. The liquid crystal display element according to claim 1, wherein the distance is 1.5 times or more of a distance from the second substrate. The voltage supply portion of the first electrode and the voltage supply portion of the second electrode are arranged so as not to be close to each other when viewed from the normal direction of the first and second substrates. Or the liquid crystal display element of 2. The liquid crystal display element according to claim 1, wherein both the first and second electrodes have comb-shaped portions. When viewed from the normal direction of the first and second substrates, in the display region, the voltage supply portion of the first electrode and the voltage supply portion of the second electrode are arranged so as to overlap, 3. The liquid crystal according to claim 1, wherein voltage supply portions of the first and second electrodes extend in a direction crossing an extending direction of the display portion of the first and second electrodes. Display element. The liquid crystal display element according to claim 1, wherein the first and second electrodes both have openings provided at periodic intervals. The liquid crystal display element according to claim 6, wherein the display portions of the first and second electrodes have a bent portion.

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