JP5952038B2 - Liquid crystal display element - Google Patents

Description

  The present invention relates to a liquid crystal display element.

A TN liquid crystal cell in which liquid crystal molecules are aligned horizontally with respect to the substrate and the alignment direction of the liquid crystal molecules is twisted by 90 ° between the upper and lower substrates is placed between two parallel Nicols polarizers, and the liquid crystal on one substrate surface When the polarizing plate absorption axis is arranged parallel or perpendicular to the molecular orientation, the transmitted light intensity T is as follows when the refractive index anisotropy of the liquid crystal material is Δn, the distance between the upper and lower substrates is d, and the incident wavelength is λ. It is shown by Formula (1).
(1)

FIG. 14 shows a plot of changes in transmitted light intensity when Δnd is a parameter for each of λ = 450, 550, and 650 nm in the above equation (1). As the Δnd increases, the minimum value at which the transmitted light intensity becomes 0 is obtained, and the parameters obtained at the smallest Δnd are followed by the first minimum, and the second and third minimums. It can also be seen that the value of Δnd that takes the minimum value varies depending on the wavelength of the transmitted light.

  In the case of the conventional normally white type TN liquid crystal display element, Δnd is often set to the first minimum, but in the case of the normally black type TN liquid crystal display element, a good achromatic dark state is obtained as shown in FIG. It is considered difficult to obtain.

  In a 90 ° twisted TN liquid crystal cell, when the retardation Δnd of the liquid crystal layer is significantly larger than the incident wavelength λ, that is, Δnd >> λ, linearly polarized light incident from one substrate surface of the liquid crystal cell is polarized in the liquid crystal layer at all wavelengths. The light is rotated 90 ° without changing the state at all, and is emitted as linearly polarized light from the other substrate surface.

  This condition is called the Morgan condition, but when applied to an actual liquid crystal display element, the response time for switching between bright and dark displays becomes slow and unpractical. Therefore, by reducing the transmittance at least at the three main wavelengths of RGB A technique for realizing a substantially achromatic dark state is known (see, for example, Patent Documents 1 and 2). Patent Document 1 discloses that Δnd is set to approximately 2.64 μm in a TN liquid crystal display element having a twist angle of 90 °, and Patent Document 2 discloses that Δnd can be set to 2.3 to 2.5 μm. It is shown. In these liquid crystal display elements, all the polarizing plates arranged outside the liquid crystal cell have a parallel Nicol arrangement.

JP-A-6-160800 JP 2002-107765 A

  For example, when placing a display on the dashboard between the driver's seat and front passenger seat in a car, it is preferable that the contrast between the driver's seat and front passenger seat, which are diagonally left and right, is observed higher than when viewed from the front There is. However, in the conventional normally black type TN liquid crystal display element, since a product is manufactured by a design method in which the contrast at the time of front observation is emphasized, improvement thereof is demanded.

  An object of the present invention is to provide a normally black type TN liquid crystal display element that can obtain a good dark state when observed from an oblique direction in the horizontal direction.

  According to one aspect of the present invention, a liquid crystal display element is provided on a first substrate and a second substrate that are arranged to face each other at a predetermined interval, and on each facing surface side of the first and second substrates. Formed on the opposing surface side of the first substrate and formed on the opposing surface side of the second substrate, and on the opposing surface side of the second substrate; A second alignment film that has been subjected to alignment treatment in the direction 2 and an alignment state that is sandwiched between the pair of substrates and twisted from one substrate toward the other substrate, with a twist angle of 60 ° or more and 90 ° A liquid crystal layer having retardation [Delta] nd of 2 [mu] m to 3 [mu] m, and a first polarizing plate and the second substrate adjacent to the first substrate, sandwiching the first and second substrates A second polarizing plate adjacent to the first polarizing plate, wherein the first polarizing plate has an absorption axis and the first direction. The angle formed is 5 ° or less with respect to the twisting direction of the liquid crystal layer when light propagates from the first polarizing plate to the second polarizing plate, and is 2. with respect to the direction opposite to the twisting direction. The second polarizing plate is disposed so as to be within a range of 5 ° or less, and the absorption axis of the second polarizing plate is rotated by 90 ° in a direction opposite to the twist direction with reference to the absorption axis of the first polarizing plate. After that, the twisted direction is arranged by rotating the twisted angle by 2.5 ° to 15 ° from the twisted angle, and the dark state at the time of the front observation is relative to the horizontal direction of the liquid crystal display element based on the front observation. It is characterized by being higher than the transmittance when tilted obliquely.

  According to another aspect of the present invention, a liquid crystal display element includes a first substrate and a second substrate that are disposed to face each other at a predetermined interval, and each of the first and second substrates facing each other. An electrode formed on the surface side, a first alignment film formed on the opposite surface side of the first substrate and subjected to alignment treatment in the first direction, and formed on the opposite surface side of the second substrate A second alignment film that has been subjected to an alignment treatment in the second direction, and is held between the pair of substrates and has an alignment state twisted from one substrate to the other, and a twist angle of 90 ° A liquid crystal layer having a retardation of greater than or equal to 120 ° and a retardation Δnd of 2 μm to 3 μm, a first polarizing plate disposed close to the first substrate, and the first polarizing plate disposed between the first and second substrates; A second polarizing plate proximate to the second substrate, the first polarizing plate having its absorption axis and front The angle formed by the first direction is 5 ° or less with respect to the twist direction of the liquid crystal layer when light propagates from the first polarizing plate to the second polarizing plate, and is opposite to the twist direction. The second polarizing plate is arranged so that the absorption axis of the second polarizing plate is 90 in the twist direction with reference to the absorption axis of the first polarizing plate. After rotating, it is arranged by rotating 2.5 degrees to 15 degrees from the twist angle in a direction opposite to the twist direction, and the dark state at the time of front observation is a liquid crystal display based on the front observation It is characterized by being higher than the transmittance when tilted with respect to the lateral direction of the element.

  ADVANTAGE OF THE INVENTION According to this invention, the normally black type | mold TN liquid crystal display element from which a favorable dark state is acquired when it observes from the diagonal of a horizontal direction can be provided.

1 is a schematic cross-sectional view of a normally black TN liquid crystal display element 100 in one pixel according to an embodiment of the present invention. 1 is a conceptual diagram showing a coordinate system of a normally black TN liquid crystal display element 100 according to an embodiment of the present invention. It is the table | surface which put together the calculation result of the transmittance | permeability at the time of front observation and polar angle observation of a left twist 90 degree liquid crystal cell ((DELTA) nd = 2.5micrometer). Backside substrate orientation orientation R1, front side substrate orientation orientation R2, backside polarizing plate absorption axis P1, front side polarizing plate absorption axis P2, center of liquid crystal layer, which can obtain the minimum transmittance at the time of front view and polar angle observation of a left-handed 90 ° liquid crystal cell It is a graph which shows the relationship of a molecular orientation direction. It is the table | surface which put together the calculation result of the transmittance | permeability at the time of polar angle observation of the left twist 90 degree liquid crystal cell ((DELTA) nd = 2micrometer and 3 micrometers). It is the table | surface which put together the calculation result of the transmittance | permeability at the time of polar angle observation of the left twist 90 degree liquid crystal cell (P1, P2 = 125 degrees -145 degrees). In the table of FIG. 6, the back side substrate orientation direction R1, the front side substrate orientation direction R2, the back side polarizing plate absorption axis P1, and the front side polarizing plate absorption axis that can obtain the minimum transmittance at the time of front observation and polar angle observation of the left twist 90 ° liquid crystal cell. It is a graph which shows the relationship between P2 and a liquid crystal layer center molecular orientation direction. It is the table | surface which put together the calculation result of the transmittance | permeability at the time of polar angle observation of a right twist 90 degree liquid crystal cell ((DELTA) nd = 2.5micrometer). In the table of FIG. 8, the back side substrate orientation direction R1, the front side substrate orientation direction R2, the back side polarizing plate absorption axis P1, and the front side polarizing plate absorption axis that can obtain the minimum transmittance at the time of front observation and polar angle observation of the right twist 90 ° liquid crystal cell. It is a graph which shows the relationship between P2 and a liquid crystal layer center molecular orientation direction. It is the table | surface which put together the calculation result of the transmittance | permeability at the time of front observation and polar angle observation of the left twist 70 degree liquid crystal cell. In the table of FIG. 10, the back side substrate orientation direction R1, the front side substrate orientation direction R2, the back side polarizing plate absorption axis P1, and the front side polarizing plate absorption axis that can obtain the minimum transmittance at the time of front observation and polar angle observation of the right twist 90 ° liquid crystal cell. It is a graph which shows the relationship between P2 and a liquid crystal layer center molecular orientation direction. A table summarizing the calculation results of transmittance during polar angle observation of a left-twisted 110 ° liquid crystal cell, and a back side substrate orientation direction R1, a front side substrate orientation direction R2, a back side polarizing plate absorption axis P1, and a front side polarizing plate that can obtain the minimum transmittance It is a graph which shows the relationship between the absorption axis P2 and a liquid crystal layer center molecular orientation direction. A table summarizing the calculation results of transmittance during polar angle observation of a left-twisted 110 ° liquid crystal cell, and a back side substrate orientation direction R1, a front side substrate orientation direction R2, a back side polarizing plate absorption axis P1, and a front side polarizing plate that can obtain the minimum transmittance It is a graph which shows the relationship between the absorption axis P2 and a liquid crystal layer center molecular orientation direction. It is the graph which plotted the change of the transmitted light intensity when (DELTA) nd was made into the parameter about each of incident wavelength (lambda) = 450,550,650nm.

  FIG. 1 is a schematic cross-sectional view in a pixel of a normally black TN liquid crystal display element 100 according to an embodiment of the present invention. A normally black type TN liquid crystal display element 100 according to the embodiment includes a front side substrate 1, a back side substrate 2, and a twisted nematic liquid crystal layer 3 sandwiched between the substrates 1 and 2, which are opposed to each other in parallel. Is done.

  The front substrate 1 includes a front transparent substrate 12, a transparent electrode 13 formed on the front transparent substrate 12, and a front alignment film 14 formed on the transparent electrode 13. The back side substrate 2 includes a back side transparent substrate 22, a transparent electrode 23 formed on the back side transparent substrate 22, and a back side alignment film 24 formed on the transparent electrode 23.

  The front and back transparent substrates 12 and 22 are made of glass, for example. The transparent electrodes 13 and 23 are made of a transparent conductive material such as ITO, for example.

  The liquid crystal layer 3 is disposed between the front side alignment film 14 of the front side substrate 1 and the back side alignment film 24 of the back side substrate 2. The liquid crystal molecules in the liquid crystal layer 3 have an alignment state in which the molecular arrangement is substantially horizontal and twisted from one substrate to the other substrate. The liquid crystal material used for the liquid crystal layer 3 is, for example, nematic liquid crystal having Δn of 0.25. A chiral agent is added to the liquid crystal material forming the liquid crystal layer 3. When the chiral pitch p and the liquid crystal layer thickness (cell thickness) d are set, d / p is adjusted to be 0.1. In the analysis by the simulator described later, the thickness d of the liquid crystal layer 3 was set to 10 μm, 8 μm, and 12 μm, respectively.

  The front side and back side alignment films 14 and 24 are subjected to an alignment process by rubbing. Analysis by the simulator was performed with the angle ψ between the orientation treatment directions (rubbing orientations) of the front side orientation film 14 and the back side orientation film 24 set to 90 °, 75 °, 110 °, etc. as will be described later. The pretilt angle expressed by the orientation treatment was 1.5 °.

  A driving power source 20 is electrically connected to the front and back transparent electrodes 13 and 23. A voltage can be applied to the electrodes 13 and 23 by the drive power supply 20.

  A front-side polarizing plate 11 and a back-side polarizing plate 21 are disposed on the surfaces of the front-side substrate 1 and the back-side substrate 2 opposite to the liquid crystal layer 3. As both the polarizing plates 11 and 21, for example, SHC13U made by Polatechno can be used.

  The light source is disposed under the back side polarizing plate 21, and light from the light source enters from the back side polarizing plate 21 and exits from the front side polarizing plate 11 through the liquid crystal layer 3 and the like.

  FIG. 2 is a conceptual diagram illustrating a coordinate system of a normally black TN liquid crystal display element 100 according to an embodiment of the present invention. The coordinate system shown in FIG. 2 is used in this specification and all drawings.

  As shown in FIG. 2, the coordinate system of the normally black type TN liquid crystal display element 100 according to the embodiment of the present invention is a counterclockwise azimuth coordinate system having a right azimuth of 0 ° as viewed from the observer (from the front substrate 1 side). The various axis orientations are those observed from the surface of the liquid crystal display element.

  The rubbing orientation (dotted arrow) of the back substrate 2 is the back substrate orientation R1, the rubbing orientation (broken arrow) of the front substrate 1 is the front substrate orientation R2, and the absorption axis of the back polarizing plate 21 (dotted line arrow). Is the back side polarizing plate absorption axis P1, and the front side polarizing plate 11 is the front side polarizing plate absorption axis P2, and the two substrates when light propagates from the back side polarizing plate 21 to the front side polarizing plate 11 The angle between the back side substrate orientation direction R1 and the front side substrate orientation direction R2, which is the twist angle of the liquid crystal layer 3 between 1 and 2, is ψ, the angle between the back side substrate orientation direction R1 and the back side polarizing plate absorption axis P1 is φ1, and the front side substrate orientation The angle between the orientation R2 and the front-side polarizing plate absorption axis P2 is defined as φ2. Further, in this example, the liquid crystal layer central molecular orientation direction was fixed at 270 ° (6 o'clock orientation).

  The “twist direction” in the present specification and drawings is a direction when light propagates from the back-side polarizing plate 21 to the front-side polarizing plate 11, that is, when light enters from the back surface of the paper and exits from the front surface. The clockwise rotation is “left twist”, and the counterclockwise rotation is “right twist”. For example, as shown in FIG. 4, in the case of “90 ° counterclockwise”, it is shown to rotate 90 ° in the clockwise direction (rightward) on the drawing (when viewed from the observer). Therefore, when the twist direction of the liquid crystal layer 3 is “counterclockwise”, the counterclockwise direction is “twist direction” and the clockwise direction is “reverse twist direction”. Further, when the twist direction of the liquid crystal layer 3 is “clockwise”, the clockwise direction is the “twist direction”, and the counterclockwise direction is the “reverse twist direction”.

  The embodiment of the present invention adjusts the relationship among the back side substrate orientation (rubbing) orientation R1, the front side substrate orientation (rubbing) orientation R2, the back side polarizing plate absorption axis P1, the front side polarizing plate absorption axis P2, and the liquid crystal layer central molecular orientation direction. Thus, a normally black type TN liquid crystal display element is realized in which the transmittance in the dark state (when no voltage is applied) is lower when observed obliquely in the left-right direction than when viewed from the front. Therefore, in order to obtain the optimum values of the back side substrate orientation direction R1, the front side substrate orientation direction R2, the back side polarizing plate absorption axis P1, the front side polarizing plate absorption axis P2, and the liquid crystal layer central molecular orientation direction, the present inventors The optical characteristics of the element 100 were analyzed by a liquid crystal display simulator LCDMASTER 7.2 manufactured by Shintec.

  FIG. 3 shows a back side polarizing plate absorption axis P1 and a front side polarizing plate using a left side twisted 90 ° liquid crystal cell with a back side substrate orientation direction R1 = −45 °, a front side substrate orientation direction R2 = + 45 °, and a twist angle Ψ = −90 °. Calculation of transmittance at the right and left azimuth (180 ° and 0 °) polar angle 40 ° with reference to the transmittance at the time of frontal observation and the normal direction of the liquid crystal display element when the absorption axis P2 is changed from 35 ° to 55 °. It is the table | surface which put together the result. 3A is a front view, FIG. 3B is a right azimuth polar angle of 40 ° observation, and FIG. 3C is a left azimuth polar angle of 40 ° observation in a dark state (when no voltage is applied). Indicates the rate. The liquid crystal layer thickness d was 10 μm, and Δnd = 2.5 μm.

  FIG. 4 is a graph showing the relationship between the back side substrate orientation azimuth R1, the front side substrate orientation azimuth R2, the back side polarizing plate absorption axis P1, the front side polarizing plate absorption axis P2, and the liquid crystal layer central molecular orientation direction. FIG. 4A shows the relationship for obtaining the optimum value (minimum transmittance) at the time of frontal observation, and FIG. 4B shows the relationship for obtaining the optimum value (minimum transmittance) at the time of observation at the left and right azimuth polar angles of 40 °. Show.

  As shown in the table of FIG. 3 (A), the transmittance is lowest when viewed from the front under the condition of the back side polarizing plate absorption axis P1 = front side polarizing plate absorption axis P2 = 45 °. It was 0.188%. As is apparent from the table, it can be seen that the transmittance increases with distance from this value centering on the back side polarizing plate absorption axis P1 = front side polarizing plate absorption axis P2 = 45 °. If the conditions at this time are shown in the same coordinate system as FIG. 2, it will become like FIG. 4 (A). That is, the front side substrate absorption axis P2 is a so-called parallel Nicol arrangement in which the front side substrate absorption axis P2 is arranged at 45 ° which is the same direction as the orientation direction R2 of the adjacent front side substrate, and the back side substrate absorption axis P1 is also arranged at 45 °.

  In the tables shown in FIG. 3 to FIG. 13, the numerical value enclosed by the double line frame is dark under the conditions (angle of the side polarizing plate absorption axis P <b> 1 and the front side polarizing plate absorption axis P <b> 2) at which the minimum transmittance can be obtained during frontal observation. The transmittance in the state (when no voltage is applied), and the numerical values shown in bold are when the angle (azimuth) of the back-side polarizing plate absorption axis P1 and the front-side polarizing plate absorption axis P2 is the same as the front observation, In the case of the condition (FIGS. 3A to 3C) where the transmittance in the dark state (when no voltage is applied) is low and the minimum transmittance is shown during front observation, the back side polarizing plate absorption axis P1 = Transmissivity at the time of observation of left and right azimuth polar angles of 40 ° at the front side polarizing plate absorption axis P2 = 45 ° (“0.494%” in FIG. 3B, “0.404%” in FIG. 3C)) The transmittance in a dark state (when no voltage is applied). In addition, the numerical value in which bold is underlined is a dark state (no voltage applied) that shows a transmittance that is lower than or substantially equivalent to the minimum transmittance (“0.188%” in FIG. 3A) during frontal observation. ). That is, in the condition (the angle between the back-side polarizing plate absorption axis P1 and the front-side polarizing plate absorption axis P2) obtained in bold and bold underlined values (angles of the back-side polarizing plate absorption axis P2), it was superior in the left and right azimuth 40 ° polar angle than in the front observation. Optical characteristics (low transmittance in dark state (no voltage applied)) can be obtained.

  From the table of FIG. 3 (B), when observed at a right angle of 40 ° polar angle, the back side polarizing plate absorption axis P1 is 35 ° to 40 °, and the front side polarizing plate absorption axis P2 is 42.5 to 50 °. Sometimes, the transmittance is lower than the transmittance under the same conditions (same absorption axis P1 and front-side polarizing plate absorption axis P2 angle) during frontal observation shown in FIG. 3 (A), and the minimum transmittance during frontal observation. The transmittance is lower than the transmittance ("0.494%") observed at the right and left azimuth polar angles of 40 ° under the conditions (back side polarizing plate absorption axis P1 = front side polarizing plate absorption axis P2 = 45 °). I understand that.

  Further, when the back side polarizing plate absorption axis P1 is 37.5 ° to 40 ° and the front side polarizing plate absorption axis P2 is 45 °, the transmittance is almost the same as the minimum transmittance (“0.188%”) during frontal observation. It can be seen that (0.19% and 0.196%, respectively) were obtained.

  From the table of FIG. 3 (C), when observed at a left orientation of 40 ° polar angle, when the back side polarizing plate absorption axis P1 is 35 ° and the front side polarizing plate absorption axis P2 is 45 to 47.5 °, the back side When the polarizing plate absorption axis P1 is 37.5 ° to 40 °, the front side polarizing plate absorption axis P2 is 42.5 to 50 °, and the back side polarizing plate absorption axis P1 is 42.5 °, the front side polarizing plate absorption axis P2 When the angle is 50 °, the transmittance is lower than the transmittance under the same conditions (same absorption axis P1 and front-side polarizing plate absorption axis P2 angle) during frontal observation shown in FIG. The transmittance is lower than the transmittance ("0.494%") at the observation of the left and right azimuth polar angles of 40 ° under the conditions showing the minimum transmittance (back side polarizing plate absorption axis P1 = front side polarizing plate absorption axis P2 = 45 °). It can be seen that the rate was obtained.

  Further, when the back-side polarizing plate absorption axis P1 is 40 ° and the front-side polarizing plate absorption axis P2 is 45 °, the transmittance (“0.182%”) lower than the minimum transmittance (“0.188%”) during frontal observation. ) Is obtained.

  As mentioned above, the conditions which show the optical characteristic which was superior to the time of front observation at the right and left azimuth 40 ° polar angle are 35 ° to 40 ° for the back side polarizing plate absorption axis P1 and 42.5 to 50 ° for the front side polarizing plate absorption axis P2. More preferably, the back side polarizing plate absorption axis P1 is 37.5 to 40 ° and the front side polarizing plate absorption axis P2 is 42.5 to 47.5 °. More preferably, it is considered that the back side polarizing plate absorption axis P1 is 40 ° and the front side polarizing plate absorption axis P2 is 45 °.

  When the optimum conditions in the tables shown in FIGS. 3B and 3C are shown in the same coordinate system as in FIG. 2, the result is as shown in FIG. That is, in the left-side twist 90 ° liquid crystal cell with the back side substrate orientation direction R1 = −45 °, the front side substrate orientation direction R2 = + 45 °, and the twist angle Ψ = −90 °, the front side substrate absorption axis P2 is the orientation of the adjacent front side substrate. When arranged at 45 °, which is the same orientation as the orientation R2, the back substrate absorption axis P1 is arranged at 40 °. As a result, it is possible to obtain superior optical characteristics during left-right orientation observation than during frontal observation. As described above, if the back side polarizing plate absorption axis P1 satisfies the conditions of 35 ° to 40 ° and the front side polarizing plate absorption axis P2 of 42.5 to 50 °, it is superior in the left-right orientation observation than in the front observation. Optical characteristics can be obtained.

  Next, the optical characteristics at the time of front observation and right-angle 40 ° polar angle observation when the thickness of the liquid crystal layer 3 is d = 8 μm and d = 12 μm, that is, Δnd = 2 μm and 3 μm were calculated. FIG. 5A is a table showing calculation results of optical characteristics when observing a right-angle 40 ° polar angle of Δnd = 2 μm. FIG. 5B is a table showing a right-angle 40 ° polar angle observation of Δnd = 3 μm. It is a table | surface which shows an optical characteristic calculation result.

  In the case of Δnd = 2 μm, the minimum transmittance at the time of frontal observation was 0.314%, which is considerably higher than the minimum transmittance in the case of Δnd = 2.5 μm shown in FIG. From this, in the table shown in FIG. 5A, the region (the back side polarizing plate absorption axis P1 is 37.5 to 40 °, the front side polarizing plate absorption axis P2 is lower than the transmittance (“0.314%”). 42.5-45 ° condition) is displayed in bold and underlined. Compared to the example shown in FIG. 3B, the range in which good optical characteristics can be obtained at the right-side 40 ° polar angle is wide. It has become.

  On the other hand, when Δnd = 3 μm, the minimum transmittance at the time of front observation is 0.136%, which is lower than the condition of Δnd = 2.5 μm. (Conditions except that the back side polarizing plate absorption axis P1 is 35 to 40 °, the front side polarizing plate absorption axis P2 is 40 to 50 °, except that the back side polarizing plate absorption axis P1 is 35 ° and the front side polarizing plate absorption axis P2 is 50 °. )

  Therefore, the conditions that show superior optical characteristics at the 40 ° polar angle in the horizontal direction from the front observation cover that both Δnd = 2 μm and 3 μm cover the range of Δnd = 2.5 μm shown in FIG. I understood.

  Therefore, in both cases of Δnd = 2.5 μm, 2 μm, and 3 μm, the back-side substrate orientation azimuth R1 = −45 °, the front-side substrate orientation azimuth R2 = + 45 °, and the left twist 90 ° liquid crystal with the twist angle Ψ = −90 ° In the cell, the conditions showing the optical characteristics superior to those at the time of front observation at the right and left azimuth angle of 40 ° are as follows: the back side polarizing plate absorption axis P1 is 35 ° to 40 ° and the front side polarizing plate absorption axis P2 is 42.5 to 50 °. More preferably, the back side polarizing plate absorption axis P1 is 37.5 to 40 ° and the front side polarizing plate absorption axis P2 is 42.5 to 47.5 °. More preferably, it is considered that the back side polarizing plate absorption axis P1 is 40 ° and the front side polarizing plate absorption axis P2 is 45 °.

  Next, a back side polarizing plate absorption axis P1, front side polarizing plate absorption, using a left side twist 90 ° liquid crystal cell with a back side substrate orientation direction R1 = −45 °, a front side substrate orientation direction R2 = + 45 °, and a twist angle Ψ = −90 °. The transmittance at the frontal observation when the axis P2 was changed from 125 ° to 145 ° and at the left and right azimuth (180 ° and 0 °) polar angle of 40 ° with respect to the normal direction of the liquid crystal display element was calculated. The liquid crystal layer thickness d was 10 μm, and Δnd = 2.5 μm. FIGS. 6A and 6B show the calculation results of the transmittance in the left azimuth (180 °) and right azimuth (0 °) polar angles of 40 °, respectively.

  6A and 6B, the transmittance is lowest when viewed from the front. The back side polarizing plate absorption axis P1 = the front side polarizing plate absorption axis P2 = 135 °. It was the condition of. FIG. 7A shows the conditions at this time in the same coordinate system as that in FIG. That is, the back side substrate absorption axis P1 is arranged at 135 ° (−45 °) which is the same orientation as the orientation direction R1 of the adjacent back side substrate, and the front side substrate absorption axis P2 is also arranged at 135 °, so-called parallel Nicols. Arrangement.

  From the tables shown in FIGS. 6 (A) and (B), the conditions indicating the optical properties superior to those at the time of front observation at the 40 ° polar angle in the horizontal direction are such that the back side polarizing plate absorption axis P1 is 130 ° to 137.5 °, The front side polarizing plate absorption axis P2 is 140 to 145 °, more preferably the back side polarizing plate absorption axis P1 is 132.5 to 137.5 °, the front side polarizing plate absorption axis P2 is 140 to 142.5 °, and the front side is more preferable. It is considered that the back side polarizing plate absorption axis P1 and the front side polarizing plate absorption axis P2 at which the equivalent transmittance during observation is obtained at a 40 ° polar angle are 135 ° and 140 °.

  When the optimum conditions in the tables shown in FIGS. 6A and 6B are shown in the same coordinate system as in FIG. 2, the result is as shown in FIG. That is, in the left twist 90 ° liquid crystal cell with the back substrate orientation R1 = −45 °, the front substrate orientation R2 = + 45 °, and the twist angle Ψ = −90 °, the back substrate absorption axis P1 is the orientation of the adjacent back substrate. When it is arranged at 45 °, which is the same orientation as the orientation R1, the front substrate absorption axis P2 is arranged at 140 °. As a result, it is possible to obtain superior optical characteristics during left-right orientation observation than during frontal observation. As described above, if the back side polarizing plate absorption axis P1 satisfies the conditions of 130 ° to 137.5 ° and the front side polarizing plate absorption axis P2 satisfies 140 to 145 °, it is superior in the left-right orientation observation than in the front observation. Optical characteristics can be obtained.

  Next, a back-side polarizing plate absorption axis P1, a front-side polarizing plate absorption axis, using a right-handed 90 ° liquid crystal cell with a back-side substrate orientation direction R1 = −135 °, a front-side substrate orientation direction R2 = + 135 °, and a twist angle Ψ = + 90 ° The transmittance at the time of front observation when P2 was changed from 35 ° to 55 ° and the horizontal direction (180 ° and 0 °) polar angle of 40 ° with respect to the normal direction of the liquid crystal display element was calculated. The liquid crystal layer thickness d was 10 μm, and Δnd = 2.5 μm. FIGS. 8A and 8B show the calculation results of the transmittance at the left azimuth (180 °) and right azimuth (0 °) polar angle 40 °, respectively.

  8A and 8B, the transmittance is lowest when viewed from the front, as indicated by the double lines in the table. The back side polarizing plate absorption axis P1 = the front side polarizing plate absorption axis P2 = 45 °. It was the condition of. If the conditions at this time are shown in the same coordinate system as FIG. 2, it will become like FIG. 9 (A). That is, the back substrate absorption axis P1 is a so-called parallel Nicol arrangement in which the back substrate absorption axis P1 is arranged at 45 °, which is the same orientation as the orientation direction R1 of the adjacent back substrate, and the front substrate absorption axis P2 is also arranged at 45 °.

  8A and 8B, the conditions indicating the optical characteristics superior to those at the time of frontal observation at the 40 ° polar angle in the horizontal direction are 42.5 ° to 50 ° on the back side polarizing plate absorption axis P1, and the front side. The polarizing plate absorption axis P2 is 35 to 40 °, more preferably the back side polarizing plate absorption axis P1 is 45 to 47.5 °, the front side polarizing plate absorption axis P2 is 37.5 to 40 °, and more preferably at the time of frontal observation. It is considered that the back side polarizing plate absorption axis P1 at which the equivalent transmittance is obtained at a 40 ° polar angle is 45 ° and the front side polarizing plate absorption axis P2 is 40 °.

  When the optimum conditions in the table shown in FIGS. 8A and 8B are shown in the same coordinate system as that in FIG. 2, it is as shown in FIG. 9B. That is, in the right-handed 90 ° liquid crystal cell with the back side substrate orientation R1 = −135 °, the front side substrate orientation R2 = + 135 °, and the twist angle Ψ = + 90 °, the back side substrate absorption axis P1 is the orientation direction of the adjacent back side substrate. When arranged at 45 ° (−135 °) which is the same orientation as R1, the front substrate absorption axis P2 is arranged at 40 °. As a result, it is possible to obtain superior optical characteristics during left-right orientation observation than during frontal observation. As described above, if the back side polarizing plate absorption axis P1 satisfies the conditions of 42.5 ° to 50 ° and the front side polarizing plate absorption axis P2 satisfies 35 to 40 °, it is superior in the left-right orientation observation than in the front observation. Optical characteristics can be obtained.

  Next, a back side polarizing plate absorption axis P1, front side polarizing plate absorption, using a left side twisted 70 ° liquid crystal cell with a back side substrate orientation direction R1 = −55 °, a front side substrate orientation direction R2 = + 55 °, and a twist angle Ψ = −70 °. The transmittance was calculated at the time of front observation when the axis P2 was changed from 25 ° to 65 ° and at the left and right azimuth (180 ° and 0 °) polar angles of 40 ° with reference to the normal direction of the liquid crystal display element. The liquid crystal layer thickness d was 10 μm, and Δnd = 2.5 μm. 10A to 10C show the calculation results of the transmittance at the left azimuth (180 °) and right azimuth (0 °) polar angle 40 ° during frontal observation.

  As surrounded by a double line in the table of FIG. 10 (A), the conditions for obtaining the minimum transmittance during frontal observation were the back side polarizing plate absorption axis P1 = 35 ° and the front side polarizing plate absorption axis P2 = 55 °. It was. The transmittance obtained under these conditions was as low as 0.122%. When the optimum condition at the time of frontal observation is shown in the same coordinate system as in FIG. 2, it becomes as shown in FIG. That is, the front side substrate absorption axis P2 is arranged at 55 ° which is the same direction as the orientation direction R2 of the adjacent front side substrate, and the back side substrate absorption axis P1 is arranged at 35 °.

  10 (B) and 10 (C), the conditions that show the optical characteristics superior to those at the time of front observation at the right / left azimuth angle of 40 ° are as follows: the back side polarizing plate absorption axis P1 is 25 ° to 30 °, and the front side polarizing plate. The absorption axis P2 is 55 to 60 °, and more preferably, the back side polarizing plate absorption axis P1 is 30 °, and the front side polarizing plate absorption axis P2 is 55 ° so that an equivalent transmittance during front observation is obtained at a 40 ° polar angle. It is considered to be a condition. Since the transmittance at the time of frontal observation is low, the range of conditions showing optical characteristics superior to those at the time of frontal observation at the 40 ° polar angle in the horizontal direction is narrower than in the case where the twist angle is 90 °.

  When the optimum conditions in the tables shown in FIGS. 10B and 10C are shown in the same coordinate system as in FIG. 2, the result is as shown in FIG. That is, in a left-handed twisted 70 ° liquid crystal cell with a rear-side substrate orientation direction R1 = −55 °, a front-side substrate orientation direction R2 = + 55 °, and a twist angle Ψ = −70 °, the front-side substrate absorption axis P2 is the orientation of the adjacent front-side substrate. When arranged at 55 °, which is the same orientation as the orientation R2, the back substrate absorption axis P2 is arranged at 30 °. As a result, it is possible to obtain superior optical characteristics during left-right orientation observation than during frontal observation. As described above, if the back side polarizing plate absorption axis P1 satisfies the conditions of 25 ° to 30 °, and the front side polarizing plate absorption axis P2 satisfies 55 to 60 °, the optical performance is superior in the left-right direction observation than in the front view. It is possible to obtain characteristics.

  In addition, the present inventors have confirmed by the analysis other than the simulation analysis that the same tendency as the above-described simulation analysis result is observed in the liquid crystal element having a twist angle of 60 ° to 90 °.

  Summarizing the above calculation results, in the normally black TN liquid crystal display element 100 in which the twist angle is 60 ° or more and 90 ° or less and the retardation Δnd of the liquid crystal layer 3 is 2 μm to 3 μm, the liquid crystal display element is based on the front observation time. It is possible to derive a condition that the transmittance in the dark state when the 100 is tilted in the left-right direction is lower than the transmittance in the dark state during frontal observation.

  That is, the angle φ2 between the orientation orientation R2 on the front side substrate 1 adjacent to the front side polarizing plate absorption axis P2 is between the two substrates 1 and 2 when light propagates from the back side polarizing plate 21 to the front side polarizing plate 11. 2.5 ° or less with respect to the twist direction of the liquid crystal layer 3 and 5 ° or less with respect to the reverse twist direction, more preferably 2.5 ° or less, and more preferably 0 ° in both the twist direction and the reverse twist direction. When the front-side polarizing plate absorption axis P2 is disposed on the back side, the back-side polarizing plate absorption axis P1 is rotated by 90 ° in the twist direction with respect to the front-side polarizing plate absorption axis P2, and then the predetermined angle α is subtracted from the twist angle in the reverse twist direction. Rotate the angle (twist angle-α). At this time, α is 2.5 ° or more and 15 ° or less, more preferably 2.5 ° or more and 10 ° or less, and further preferably 5 °.

  In addition, the angle φ1 between the orientation direction R1 on the front side substrate 2 adjacent to the back side polarizing plate absorption axis P1 is between the two substrates 1 and 2 when light propagates from the back side polarizing plate 21 to the front side polarizing plate 11. 5 ° or less with respect to the twist direction of the liquid crystal layer 3 and 2.5 ° or less with respect to the reverse twist direction, more preferably 2.5 ° or less, and more preferably 0 ° in both the twist direction and the reverse twist direction. When the back side polarizing plate absorption axis P1 is disposed on the front side, the front side polarizing plate absorption axis P2 is rotated by 90 ° in the reverse twist direction with respect to the back side polarizing plate absorption axis P1, and then the predetermined angle α is subtracted from the twist angle in the twist direction. Rotate the angle (twist angle-α). At this time, α is 2.5 ° or more and 15 ° or less, more preferably 2.5 ° or more and 10 ° or less, and further preferably 5 °.

  Note that the above two conditions are that the twist direction of the liquid crystal layer 3 is not the twist direction of light during normal observation when the light is directed from the light source (backlight) to the observer, but from the one polarizing plate as a reference. By defining the direction in which light is twisted when light propagates to the other polarizing plate as the twist direction, it is possible to summarize as follows. That is, the angle formed by the absorption axis of one polarizing plate and the orientation direction of the substrate adjacent to the one polarizing plate is the distance between the two substrates when light propagates from the one polarizing plate to the other polarizing plate. 5 ° or less with respect to the twist direction of the liquid crystal layer and 2.5 ° or less with respect to the reverse twist direction, more preferably within a range of 2.5 ° or less in both the twist direction and the reverse twist direction, more preferably 0. When the absorption axis of one polarizing plate is arranged so as to be (parallel), the absorption axis of the other polarizing plate is rotated 90 ° in the reverse twist direction with respect to the absorption axis of the one polarizing plate. A twist angle is obtained by rotating the twist angle by subtracting a predetermined angle α from the twist angle (a twist angle minus α). At this time, α is in the range of 2.5 ° to 15 °, more preferably in the range of 2.5 ° to 10 °, and still more preferably 5 °.

  Next, a back-side polarizing plate absorption axis P1, front-side polarizing plate absorption, using a left-side twisted 110 ° liquid crystal cell with a back-side substrate orientation azimuth R1 = −35 °, a front-side substrate orientation azimuth R2 = + 35 °, and a twist angle Ψ = −110 °. The transmittance was calculated at the time of front observation when the axis P2 was changed from 25 ° to 65 ° and at the right azimuth (180 ° and 0 °) polar angle of 40 ° with reference to the normal direction of the liquid crystal display element. The liquid crystal layer thickness d was 10 μm, and Δnd = 2.5 μm. FIG. 12A shows the calculation result of the transmittance at the right orientation (0 °) polar angle of 40 °. The minimum transmittance during frontal observation was 0.269% obtained with the back side polarizing plate absorption axis P1 = 55 ° and the front side polarizing plate absorption axis P2 = 35 °.

  As shown in the table of FIG. 12 (A), there is no numerical value underlined in bold because there was no 40 ° polar angle transmittance equal to or lower than the minimum transmittance during frontal observation, In the polarizing plate arrangement condition of 40 ° polar angle observation at the time of 40 ° polar angle observation is lower than the transmittance at the time of 40 ° polar angle observation (double line frame) under the condition of obtaining the minimum transmittance at the front observation. It was found that the transmittance shown in bold is obtained. The conditions that show superior optical characteristics at the time of 40 ° polar angle in the horizontal direction are 45 to 50 ° for the back side polarizing plate absorption axis P1 and 30 to 40 ° for the front side polarizing plate absorption axis P2, more preferably the back side polarized light. The plate absorption axis P1 is 50 °, the front-side polarizing plate absorption axis P2 is 30 to 40 °, and more preferably, the back-side polarizing plate absorption axis P1 that provides a transmittance equivalent to that at the front observation at a 40 ° polar angle is 50 °. The front-side polarizing plate absorption axis P2 is considered to be 35 °.

  When the optimum conditions in the table shown in FIG. 12 (A) are shown in the same coordinate system as in FIG. 2, it becomes as shown in FIG. 12 (B). That is, in the left-handed 110 ° liquid crystal cell with the back-side substrate orientation direction R1 = −35 °, the front-side substrate orientation direction R2 = + 35 °, and the twist angle Ψ = −110 °, the front-side substrate absorption axis P2 is the orientation of the adjacent front-side substrate. When arranged at 35 °, which is the same orientation as the orientation R2, the back side substrate absorption axis P1 is arranged at 50 °. As a result, it is possible to obtain superior optical characteristics during left-right orientation observation than during frontal observation. As described above, when the back side polarizing plate absorption axis P1 satisfies the conditions of 45 ° to 50 ° and the front side polarizing plate absorption axis P2 satisfies 30 to 40 °, the optical system is superior in the left-right direction observation than in the front observation. It is possible to obtain characteristics.

  Next, a back-side polarizing plate absorption axis P1, front-side polarizing plate absorption, using a left-side twisted 110 ° liquid crystal cell with a back-side substrate orientation azimuth R1 = −35 °, a front-side substrate orientation azimuth R2 = + 35 °, and a twist angle Ψ = −110 °. The transmittance at the time of front observation when the axis P2 was changed from 115 ° to 155 ° and the right direction (180 ° and 0 °) polar angle of 40 ° with respect to the normal direction of the liquid crystal display element was calculated. The liquid crystal layer thickness d was 10 μm, and Δnd = 2.5 μm. FIG. 13A shows the calculation result of the transmittance at the right orientation (0 °) polar angle of 40 °. The minimum transmittance during frontal observation was 0.269% obtained with the back side polarizing plate absorption axis P1 = 145 ° and the front side polarizing plate absorption axis P2 = 125 °.

  As shown in the table of FIG. 13 (A), there is no numerical value underlined in bold because a transmittance at 40 ° polar angle observation equal to or lower than the minimum transmittance at the front observation was not obtained. In the polarizing plate arrangement condition of 40 ° polar angle observation at the time of 40 ° polar angle observation is lower than the transmittance at the time of 40 ° polar angle observation (double line frame) under the condition of obtaining the minimum transmittance at the front observation. It was found that the transmittance shown in bold is obtained. The conditions that show superior optical characteristics at the 40 ° polar angle in the horizontal direction are as follows: the back side polarizing plate absorption axis P1 is 145 to 150 °, the front side polarizing plate absorption axis P2 is 130 to 135 °, more preferably the back side polarized light. The plate absorption axis P1 is 145 °, the front-side polarizing plate absorption axis P2 is 130 to 135 °, and more preferably, the back-side polarizing plate absorption axis P1 is 145 °, which provides a transmittance equivalent to that at the front observation at a 40 ° polar angle. The front side polarizing plate absorption axis P2 is considered to be 130 °.

  FIG. 13B shows the optimum conditions in the table shown in FIG. 13A in the same coordinate system as that in FIG. That is, in the left twist 110 ° liquid crystal cell with the back substrate orientation R1 = −35 °, the front substrate orientation R2 = + 35 °, and the twist angle Ψ = −110 °, the back substrate absorption axis P1 is the orientation of the adjacent back substrate. When arranged at −35 ° (145 °) which is the same orientation as the orientation R1, the front substrate absorption axis P1 is arranged at 130 °. As a result, it is possible to obtain superior optical characteristics during left-right orientation observation than during frontal observation. As described above, if the back side polarizing plate absorption axis P1 satisfies the conditions of 145 ° to 150 ° and the front side polarizing plate absorption axis P2 satisfies 130 ° to 135 °, the optical performance is superior in the lateral direction observation than in the front direction observation. It is possible to obtain characteristics.

  Note that the present inventors have confirmed by analysis other than simulation analysis that the same tendency as the above-described simulation analysis result is observed in a liquid crystal element having a twist angle of greater than 90 ° and not greater than 120 °.

  Summarizing the above calculation results, in the normally black type TN liquid crystal display element 100 in which the twist angle is greater than 90 ° and not more than 120 ° and the retardation Δnd of the liquid crystal layer 3 is 2 μm to 3 μm, the liquid crystal display is based on the front observation. A condition can be derived in which the transmittance in the dark state when the element 100 is tilted in the left-right direction is lower than the transmittance in the dark state during frontal observation.

  The direction of twist of the liquid crystal layer 3 is not the twist direction of light during normal observation when light travels from the light source (backlight) to the viewer, but light propagates from one polarizing plate as a reference to the other polarizing plate. If the direction in which the light is twisted is defined as the twist direction, the angle formed by the absorption axis of one polarizing plate and the orientation direction of the substrate adjacent to the one polarizing plate is the one polarizing plate to the other polarizing plate. 5 ° or less with respect to the twist direction of the liquid crystal layer between the two substrates when light propagates to the surface, and within a range of 2.5 ° or less with respect to the reverse twist direction, more preferably both the twist direction and the reverse twist direction. In the case where the absorption axis of one polarizing plate is arranged in a range of 2.5 ° or less, more preferably 0 ° (parallel), the absorption axis of the other polarizing plate is the absorption axis of the one polarizing plate. As a reference, after rotating 90 ° in the twist direction In the reverse twist direction, the rotation angle is set by subtracting a predetermined angle α from the twist angle (twist angle portion minus α). At this time, α is in the range of 2.5 ° to 15 °, more preferably in the range of 2.5 ° to 10 °, and still more preferably 5 °.

  As described above, according to the embodiment of the present invention, when a normally black type TN liquid crystal display element is observed from an oblique direction in the left-right direction, a good dark state can be obtained, and the effect of widening the viewing angle characteristics can be obtained. . Therefore, a liquid crystal display element suitable for a display device that is observed from an oblique direction can be provided.

  In the above-described embodiment, only the case where the cell thickness d of the liquid crystal display element 100 is uniform has been described. However, irregularities are randomly arranged on at least one substrate surface, and the retardation Δnd of the liquid crystal layer 3 is 2 μm to 2 μm. If the structure is within the range of 3 μm, it is possible to obtain the same effect as the embodiment.

  Further, when a dichroic dye of about 2 wt% or less is added in the liquid crystal layer 3, the dark state when no voltage is applied is further improved.

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

DESCRIPTION OF SYMBOLS 1 ... Front side substrate, 2 ... Back side substrate, 3 ... Twist nematic liquid crystal layer, 11 ... Front side polarizing plate, 12 ... Front side transparent substrate, 13 ... Transparent electrode, 14 ... Front side oriented film, 21 ... Back side polarizing plate, 22 ... Back side transparent Substrate, 23 ... transparent electrode, 24 ... back side orientation film, R1 ... back side substrate orientation, R2 ... front side substrate orientation, P1 ... back side polarizing plate absorption axis, P2 ... front side polarizing plate absorption axis, 100 ... normally black type TN Liquid crystal display element

Claims (8)

A first substrate and a second substrate disposed to face each other at a predetermined interval;
Electrodes formed on opposing surfaces of the first and second substrates,
A first alignment film formed on the opposite surface side of the first substrate and subjected to an alignment treatment in a first direction;
A second alignment film formed on the opposite surface side of the second substrate and subjected to an alignment treatment in a second direction;
A liquid crystal layer sandwiched between the pair of substrates, having an orientation state twisted from one substrate toward the other, a twist angle of 60 ° to 90 °, and a retardation Δnd of 2 μm to 3 μm;
A first polarizing plate disposed adjacent to the first substrate and a second polarizing plate disposed adjacent to the second substrate, the first polarizing plate disposed between the first substrate and the second substrate;
The angle between the absorption axis of the first polarizing plate and the first direction is in the twist direction of the liquid crystal layer when light propagates from the first polarizing plate to the second polarizing plate. It is arrange | positioned so that it may become in the range of 2.5 degrees or less with respect to the direction opposite to the said twist direction with respect to 5 degrees or less,
The second polarizing plate is rotated by 90 ° in the direction opposite to the twisting direction with respect to the absorption axis of the first polarizing plate, and then the second polarizing plate is rotated by 2. from the twist angle. Placed at an angle of 5 ° to 15 ° rotated,
A liquid crystal display element characterized in that a dark state during front viewing is higher than a transmittance when tilted obliquely with respect to the left and right orientations of the liquid crystal display element with reference to front viewing. The first polarizing plate is disposed such that an angle formed between the absorption axis and the first direction is within a range of 2.5 ° or less with respect to the twist direction and the direction opposite to the twist direction. And
The second polarizing plate is rotated by 90 ° in the direction opposite to the twisting direction with respect to the absorption axis of the first polarizing plate, and then the second polarizing plate is rotated by 2. from the twist angle. The liquid crystal display element according to claim 1, wherein the liquid crystal display element is arranged by being rotated at an angle of 5 ° to 10 °. The first polarizing plate is disposed such that its absorption axis and the first direction are parallel,
The second polarizing plate is rotated by 90 ° in the direction opposite to the twisting direction with respect to the absorption axis of the first polarizing plate, and then 5 ° from the twisting angle in the twisting direction. The liquid crystal display element according to claim 1, wherein the liquid crystal display element is arranged to be rotated at a pulled angle. A first substrate and a second substrate disposed to face each other at a predetermined interval;
Electrodes formed on opposing surfaces of the first and second substrates,
A first alignment film formed on the opposite surface side of the first substrate and subjected to an alignment treatment in a first direction;
A second alignment film formed on the opposite surface side of the second substrate and subjected to an alignment treatment in a second direction;
A liquid crystal layer sandwiched between the pair of substrates, having an orientation state twisted from one substrate toward the other, a twist angle of greater than 90 ° and not greater than 120 °, and a retardation Δnd of 2 μm to 3 μm; ,
A first polarizing plate disposed adjacent to the first substrate and a second polarizing plate disposed adjacent to the second substrate, the first polarizing plate disposed between the first substrate and the second substrate;
The angle between the absorption axis of the first polarizing plate and the first direction is in the twist direction of the liquid crystal layer when light propagates from the first polarizing plate to the second polarizing plate. It is arrange | positioned so that it may become in the range of 2.5 degrees or less with respect to the direction opposite to the said twist direction with respect to 5 degrees or less,
The second polarizing plate is rotated by 90 ° in the twisting direction with respect to the absorption axis of the first polarizing plate as a reference, and then from the twisting angle in a direction opposite to the twisting direction. Placed at an angle of 5 ° to 15 ° rotated,
A liquid crystal display element characterized in that a dark state during front viewing is higher than a transmittance when tilted obliquely with respect to the left and right orientations of the liquid crystal display element with reference to front viewing. The first polarizing plate is disposed such that an angle formed between the absorption axis and the first direction is within a range of 2.5 ° or less with respect to the twist direction and the direction opposite to the twist direction. And
The second polarizing plate is rotated by 90 ° in the twisting direction with respect to the absorption axis of the first polarizing plate as a reference, and then from the twisting angle in a direction opposite to the twisting direction. The liquid crystal display element according to claim 4, wherein the liquid crystal display element is disposed by being rotated at an angle of 5 ° to 10 °. The first polarizing plate is disposed such that its absorption axis and the first direction are parallel,
The second polarizing plate is rotated by 90 ° in the twist direction with respect to the absorption axis of the first polarizing plate, and then 5 ° from the twist angle in a direction opposite to the twist direction. The liquid crystal display element according to claim 4, wherein the liquid crystal display element is arranged to be rotated at a pulled angle. Random irregularities are arranged on at least one surface of the first and second substrates,
The liquid crystal display element according to claim 1, wherein retardation Δnd of the liquid crystal layer is distributed in a range of 2 μm to 3 μm.   The liquid crystal display element according to claim 1, wherein 2 wt% or less of a dichroic dye is added in the liquid crystal layer.