TWI228631B - Liquid crystal display apparatus - Google Patents

Abstract

A liquid crystal display apparatus includes: a liquid crystal display device including a pair of light-transmitting substrates and a liquid crystal layer interposed between the pair of light-transmitting substrates, the liquid crystal layer including liquid crystal molecules, wherein a transparent electrode layer and an alignment film are formed on a face of each of the pair of light-transmitting substrates adjoining the liquid crystal layer; a pair of polarizers provided on opposite faces of the liquid crystal display device; and at least one inclined phase difference plate provided between the liquid crystal display device and at least one of the pair of polarizers, the inclined phase difference plate including a refractive ellipsoid having three main refractive indices na, nb, and nc. The three main refractive indices na, nb, and nc of the refractive ellipsoid are of the relationship na=nc > nb. The refractive ellipsoid is tilted by a predetermined tilt angle such that a direction of main refractive index nb extending in parallel to a normal direction of the surface of the inclined phase difference plate and a direction of main refractive index nc or na extending within the plane of the surface are tilted around the main refractive index direction na or nc. The liquid crystal molecules have an apparent twist angle of about 90 DEG or less when viewed at a predetermined angle in a forward viewing angle direction.

Description

1228631 V. Description of the invention Background of the invention 1. Scope of the invention: The present invention relates to a liquid crystal α Γ ± ic ^ ^ ^ ^) · item π device, and in particular relates to the availability of LC _ stateless equipment together with ^ ^ m. Board, an LC display device refined to improve the viewing angle correlation of the image. 2 · Related technical descriptions: Traditionally, there is a directed LC + &, ”. The LC display device that is not surprising is now widely used in the numerical segmentation or > Deer j —, ,, and two , Type < display device, such as used in clocks or computers. Recently, Lr Vegetable + Alliance has been used for word processors, notebook personal computers, and automotive TVs. The LC display device generally includes a light-transmitting substrate on which electrode lines for turning on and off pixels and the like are provided. For example, in an active matrix type LC display device, the active elements such as thin film transistors (TFTs) are formed on the aforementioned substrate as switching elements to selectively drive the pixel electrodes. A certain voltage is applied to the LC layer. In the case of an LC display device that performs a color display function, red, green, and blue color filter layers can be provided on a substrate. Various LC display methods can be selected according to the twist angle of the LC molecules to be applied to the LC display device. For example, the well-known twisted nematic l c _ display mode (hereinafter referred to as "T N mode") and the multiplexed super twisted nematic l C display mode (hereinafter referred to as "STN mode"). According to this TN mode, the nematic LC molecule is 90. The twist direction is placed so that light is transmitted along the twist direction of the LC molecule. According to this STN mode, the twist angle of nematic LC molecules will expand more than 90. , This paper size applies to China National Standard (CNS) A4 (210 X 297 public love) 1228631 A7

The sudden changes in the transmission layer occur near the value of the voltage gate swing applied to the LC layer. The p Θ S TN prismatic system is based on the birefringence of L c, so for a given display, the θ% of the image may be dyed in a specific color. In order to perform the early color display function of the STN mode without being affected by this problem, the optical compensation board should be regarded as an effective method. The display mode used for the photon compensation plate at the bottom can be generally divided into double super twisted nematic = compensation mode (hereinafter referred to as 4 "DSTN mode"), and film phase compensation: Wu type (herein, "film addition method"), and This person uses a film having optical anisotropy. The fine TN mode uses a two-layer structure, including-a dagger used to perform display. The grid 'and one of its L c molecules are twisted at opposite angles: to the LC cell where the display function is performed. As for the film addition method, U 疋 utilizes a structure with an optically anisotropic film. The film addition method is considered to be promising because of its advantages such as lightness and low cost. ~ J ^ Bi-phase t complementation method The improved monochromatic display characteristics, so = by using only the V-color STN LC display device, the color display layer can be produced by providing a color filter layer of the STN type display device. Ding-type-generally can be divided into normally black mode And normally white mode. According to the normally black mode and I 疋, polarizing plates are provided so that their polarization directions are parallel to each other. Therefore, in the “0FF” (off) state, that is, when no 0N (on) voltage is applied to the LC layer To display a black image. According to the normally black mode, a pair of polarized light is provided: the polarized light directions are perpendicular to each other, so it is displayed under "OFF": white and image. Just _ image contrast, color reproduction, visual angle related to development, etc. -6-1228631

Wait for g, the normally white mode may be more advantageous. , ...: And the TN _ display device will be accompanied by a wide viewing angle correlation problem (in other words, depending on its orientation and / or the angle at which the viewer views the image, the displayed image will be perceived as a variable contrast) Because the LC molecules have an anisotropy of the refractive index An, and because the LC molecules are oriented obliquely relative to the upper and lower substrates. FIG. 12 is a cross-sectional view illustrating the structure of a TN-type LC display device 31. In a 4 k condition, an intermediate gray scale voltage is applied, so that the LC molecules 32 can be tilted up slightly. In the TN_type Lc display device 31, the linearly polarized light 35 passing along the positive axis direction of the surfaces opposite to the pairs of the substrates 33 and 34 will form an angle with each LC molecule 32, and this angle will not be equal to The angle formed between the LC molecule 32 and the linearly polarized light 36 or 37 relative to the positive axis direction. Since the LC molecules 32 have an anisotropy of the refractive index An, when the linearly polarized light 35, 36, or 37 passes through the LC molecules 32, a Jintong light and an abnormal light are generated. It is converted into elliptically polarized light according to its phase difference. This is the cause of perspective correlation. In addition, in the real LC layer, the LC molecules 32 have different oblique angles depending on whether they are located in the intermediary portion between the substrate 33 and the substrate 34 or near the substrate 33 or the substrate 34. . In addition, the LC molecules 32 are also reduced to 90 around the positive axis. distortion. From the foregoing facts, the linearly polarized lights 35, 36, and 37 are affected by various refraction effects according to their directions and / or angles, resulting in complex viewing angle correlations. In particular, when the viewing angle is in the forward viewing direction or lower than this paper, the Chinese National Standard (CNS) A4 specification (210 X 297 mm) is applicable. 1228631 A7 _________ B7 __________ 5. Description of the invention (4) Display screen positive axis direction When tilting over a certain value, it will either be in the form of "colorization phenomenon", that is, the displayed image will have unwanted colors, or it will be "inversion phenomenon", that is, the black and white of the displayed image Some will change to the opposite form 'and observe this perspective correlation. If the viewing angle is opposite to the viewing angle or higher than the positive axis of the display screen, the contrast will deteriorate even more. When the display screen is enlarged, the aforementioned LC display device is also problematic because its acceptable viewing angle range becomes narrower. In other words, when a large LC display device is viewed from its front direction at a close distance, the upper and lower screens of the display screen will appear to present the same image in different colors. This is because the viewing angle of the display screen is increased (that is, when measured from the positive axis direction); in fact, the viewer will observe the display 7F screen in a more inclined direction. In order to improve these viewing angle correlations, it has been proposed that a retardation plate (a retardation film) may be inserted between the L c display device and one of their polarizing plates. This method allows light that has been transformed into linearly polarized light into elliptically polarized light (because the other has indeed guided through the L c molecules with refractive index anisotropy) and passed through one or both sides of the LC layer. It has a retardation plate with refractive index anisotropy on top of it to transform the light back into linear polarization, but it can compensate the variation of the phase difference between a normal light and an abnormal light at a certain viewing angle, thereby improving the viewing angle correlation. The retardation plate placed in such a way that the principal refractive index direction of the refraction ellipse and the positive axis direction of the retardation plate surface are parallel to each other is disclosed in, for example, "Japanese Publication-8-The yoke scale is applicable to the Chinese National Standard (CNS) A4 specification" (21〇X297 mm) " --- 1228631 A7 B7 V. Description of Invention (5) Patent Bulletin ", No. 5-313159. However, using this retardation plate technology can only slightly improve the inversion phenomenon in the forward viewing direction. Japanese Patent Publication Nos. 6-1 18406 and 6-194645 disclose a technique to eliminate this inversion phenomenon, in which an optical phase difference plate with a so-called pixel discrimination method is used, and each display pattern unit ( Pixels) will be divided into multiple parts, and the already distinguished parts will be slightly weakened with independent viewing angle characteristics through the pointing control. The LC display device disclosed in "Japanese Laid-Open Patent Publication" No. 6-118406 can provide improved contrast effects, etc., because an optically anisotropic film (optical retardation plate) is inserted between the LC panel and the polarizing plate. The compensation plate (optical retardation plate) disclosed in the "Japanese Laid-Open Patent Publication" No. 6-19 4 6 4 5 has a negative refractive index value, because the method of selecting this refractive index is to make them have a value lower than Refractive index in a plane extending parallel to the compensation plate. Therefore, the compensation plate (optical retardation plate) can compensate the positive refractive index, which will rise when the LC display device is applied with a voltage, thereby reducing the viewing angle correlation. However, even with this phase difference plate and the same pixel discrimination method, when the viewing angle is tilted more than 45 ° -direction, colorization will still occur, and the contrast will not be controlled along the vertical direction to reduce the problem. . Therefore, the use of a non-tilted refractive elliptical retardation plate, that is, the direction of the main refractive index of the refracting ellipse, can be parallel to the direction of the surface of the retardation plate, the retardation plate, can only produce these The contrast variation, clever phenomenon, and inversion phenomenon are slightly improved to a certain extent. '^ Therefore, this publication patent publication No. 6-75116 is built in the text -9-1228631 A7 B7 V. Description of the invention (6) The proposed method uses a phase difference plate to make the main refractive index directions of each refractive ellipse' and the phase The positive axis direction of the differential plate surface forms an angle. This method uses two types of retardation plates as described later. One type of retardation plate is the main refraction of three refracting ellipses: the direction 'is parallel to the surface of the retardation plate, and the other two: two = the direction in which will form an angle θ with the surface of the retardation plate, and -A square with a refractive index that forms an angle of 0 with the positive axis direction of the phase difference plate surface, of which 20. $ 0 $ 70. . As for the other retardation plate, there is a retardation plate with an oblique refracting ellipse. Let the three principal refractive indices of the refracting ellipse ", 讪, and" is such a relationship as ㈣ = μ> nb 'and the principal refractive index ^ (this is The f-axis direction extending parallel to the surface) and the direction of the main refractive index (or na) extending along the surface plane will be along the main refractive index direction na (or nc) extending around the surface plane. , Tilt in the clockwise or counterclockwise direction. In these two phase difference plates, the former can be used in a single-axis or dual-axis version. The latter application is not limited to using a single phase difference plate, but 疋Two such retardation plates can be combined and used in such a manner that the tilt direction of the main refractive index nb and each of them are 90 °. An LC display device including at least one of these . The phase difference plate between the headless device and the polarizing plate can improve the contrast variation, colorization phenomenon and inversion phenomenon caused by the angle of view relative to the imaging beyond a certain range. Because the traditional TN LC imaging device uses Approx. 90. L c Promoter, so when obliquely viewing angle at 6 o'clock, L c apparent molecular twist angle could -10-

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j is over 90. . When viewed from the front, the twist angle exceeds 90. At the same time, the phenomenon of inversion occurs in the direction of the direction; the same applies to the situation when the viewing angle is inclined. Because: 'According to the conventional TNLC imaging device, when the viewing angle is oblique to the 6 o'clock direction', the phenomenon of inversion will inevitably occur because the watch exceeds 90. . J & therefore, it is not disclosed in the previous "Japanese Patent Publication" No. 6_75i 16

The mounting-difference plate itself and the method appropriately prevent the above-mentioned inversion phenomenon to obtain high contrast and wide viewing angle characteristics. Another invention summary: A liquid crystal display device according to the present invention includes: a liquid crystal display device comprising a pair of transparent substrates and a liquid crystal layer interposed between the pair of transparent substrates, and the liquid crystal display device The layer contains liquid crystal molecules, wherein a transparent electrode layer is formed on each surface of the pair of transparent substrates connected to the crystal layer; a pair of polarizers are provided on the other side of the liquid crystal display device; and at least one The inclined retardation plate provided between the liquid crystal display device and the pair of polarized light is at least one, and the inclined retardation plate includes a refractive index ellipse having two king refractive indices na, nb, and nc. The relationship between the three principal refractive indices na, 111) and 11 (: of the refractive index ellipse is ⑽ = this> nb. The refractive index ellipse is inclined to a predetermined oblique angle so as to be parallel to The direction of the principal refractive index nb extending perpendicular to the surface of the inclined retardation plate and the direction of the principal refractive index or w extending in the plane of the surface will be inclined around the principal refractive index direction na or nc, where These liquid crystal molecules have an apparent twist angle of 90 ° or less when viewed from a predetermined angle in the direction of the viewing angle. -11-This paper size is subject to the Chinese National Standard (CNS) Α4 specification ( 21〇X 297 mm) 1228631 A7 -------------- B7 V. Description of the invention (8 ~ 7 ~----In the specific embodiment of the present invention, the apparent twist The angle system is greater than or equal to, and less than or equal to about 89. In another embodiment of the present invention, the apparent twist angle system is greater than or equal to about 84, and less than or equal to about 88. In another embodiment of the present invention, In the example, the liquid crystal molecules have an anisotropy of a refractive index Δη, and the liquid crystal molecules have The refractive index (55 °) anisotropy of light at 1 wavelength is greater than 0 side and less than 0.120. In still another specific embodiment of the present invention, the refractive index of the liquid crystal molecules with respect to light having a wavelength of 550 nm Δη (55〇) anisotropy will be in the range of about 0.070 or more and about 0.095 or less. On the other hand, a liquid crystal display device according to the present invention includes: A light-transmitting substrate and a liquid crystal display device with a liquid crystal layer interposed between the pair of light-transmitting substrates, and the liquid crystal layer contains liquid crystal molecules, and a transparent electrode layer and an alignment film are formed on the pair to connect the liquid crystal Layers of light-transmitting substrates; a pair of polarizers for placing on the other side of the liquid crystal display device; and at least one inclined retardation plate for placing between the liquid crystal display device and at least one of the pair of polarizers, The inclined retardation plate includes a refractive index ellipse having three principal refractive indices na, nb, and nc. The relationship between the three principal refractive indices na, nb, and nc of the refractive index ellipse is na = nc > nb The refractive index ellipse is tilted at a predetermined oblique angle 'to allow the direction of the principal refractive index nb extending parallel to the vertical direction of the surface of the inclined retardation plate, and the principal refractive index extending in the plane of the surface The direction of nc or na will tilt around the principal refractive index direction na or nc.

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: ’Wherein, when viewed from a certain angle in the direction of the viewing angle from a predetermined angle, the / one-liquid TO knife has a size of about 80 or more. And a true twist angle of less than or equal to about 0. Therefore, the present invention can provide the following advantages (丨): an Lc display device incorporating an LC display device and a phase difference plate, in which the apparent pre-bevel angle of the pseudo molecules relative to the alignment film of the display device is optimized , Based on the phase difference plate to provide & improved viewing angle correlation and compensation effects; and (2) to provide an Lc display device, which can effectively improve the inversion of the forward viewing direction universal (that is, 6 o'clock) phenomenon. For those who twist this technology, after reading and knowing the detailed descriptions in the following columns, > After Ik Figure 7F, the above and other advantages of the present invention will be shown briefly. Figure 1 is An expanded cross-sectional view of an exemplary display device consistent with the present invention is described. 2A and 2B are diagrams illustrating the relationship between the alignment film imprinting direction and the forward viewing angle direction in the 2LC display device depicted in FIG. Fig. 3 is a perspective view illustrating the principal refractive index of the phase difference plate in the LC display device as shown in Fig. U. A picture. 4 is an expanded view of the polarizing plate and the retardation plate as shown in FIG. 丨, which is not an optical arrangement of the device. FIG. 5 is a perspective view illustrating a measurement system for measuring the viewing angle dependence of the Lc display device as shown in FIG. Figures 6A to 6C are in accordance with the examples of the present invention and comparative examples, illustrating -13- This paper size applies Chinese National Standard (CNS) A4 specifications (210X 297 mm) 1228631 A7 B7 V. Description of the invention (10 LC display An illustration of the characteristics of a device's transmission applied voltage. Fig. 7 is a diagram illustrating the viewing angle characteristics TF in accordance with an example rlc display device according to the present invention. ^ 8 is an illustration of the kLc display angle characteristics in accordance with the comparative example. Fig. 9 In order to explain the twist angle β and the angle of view. It is a graphical representation of the change in the apparent twist angle when it is changed in the direction of 6 o'clock. FIGS. Graphic illustration of applied voltage characteristics. Figures 1 1 A to 11 C are illustrations illustrating transmission applied voltage characteristics of an L c display device in accordance with Comparative Example 2. Figure 12 illustrates a cross-section of a TN type LCD display device. Viewing the outline sketch 0 The description of the preferred embodiment The present invention is described in detail with reference to the attached drawings i to 9. In other words, as shown in FIG. 1, the LC display device 100 conforming to the present invention includes a device. i, a pair of optical retardation plates 2 3, and a pair of polarizers (ie, polarizing plates) 4 and 5. The Lc display device 1 includes an L c layer 8 interposed between electrode substrates 6 and 7 placed oppositely. The electrode substrate 6 includes The j τ 〇 (ie, indium tin oxide) transparent electrode on the surface of the 1 ^ (: layer 8 glass substrate (light, spring substrate) 9) is continued. The aligning thin film 1 1 is formed on the electrode 丨〇. The electrode substrate 7 includes an I T 0 transparent electrode provided on the surface of a glass substrate (light transmission substrate) 12 connected to the LC layer 8 of the buyer. The thin film 4 is composed of On this -14-1231231 A7 B7 V. Invention description (n) electrode 1 3. For simplicity, Figure 1 only illustrates the part of the Lc display device corresponding to a pixel. However, 'in the entire LC In the display device i, the transparent electrodes 10 and 13 have a preset width, and when viewed from the front surface of the substrate, they extend perpendicularly to each other in the staggered interval of their glass substrates 9 and 12. Are provided in the form of stripes, and the portions where these transparent electrodes 10 and 13 are intersected with each other can correspond to these The pixels are responsible for the display function. These pixels are arranged in a matrix column on the entire LC display device 100. The electrode substrates 6 and 7 are attached to each other by a sealant 15 and they are [0 layer 8 package It is sealed in the mid-gastric space defined / defined by both the electrode substrates 6 and 7 and the sealant 15. That is, as explained further below, the LC layer 8 in the display device 100 is made of-LC material. Group < 'The material selection method of Shaw is to satisfy the predetermined condition of the anisotropy of the refractive index Δη, so as to provide the best characteristics with the phase difference compensation function of the phase difference plates 2 and 3. Indicator device 1. Optical phase can define an LC cell. The LC display device 100 is a unit containing lc display retardation plates 2 and 3 and polarizing plates 4 and 5. 16 °-align the line earlier Films 1 1 and 1 3 are referred to. ♦ 丨 ^^ 〆, υ Ding Yiyue treatment, that is, the imprinting treatment, so as to let the LC layer inside, and intervene in Taida 1 "

丨 The LC molecules straight between the clad substrates 6 and 7 are arranged in a twisted direction. It is enough that the LC head is shown as the reference coordinate of device 1 (/ 5 from (X, y, ζ). Figure 2 A is a description from the position of a viewer, that is, above the electrode substrate 6, to observe the lc Display device! The outline plan view. The substrate of the Lc display device i-15-

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The f-plane is a plane extending in the plane of FIG. 2A, and the x-y plane is defined according to this. It can be defined by the 12: 4 li gimbal (the direction of the reverse viewing angle) and the 6 o'clock direction (the direction of the forward viewing angle). The 3 o'clock direction and 9 o'clock direction σ define the y-axis direction. The positive axis direction of the substrate surface can be defined as the z-axis square. The imprinting direction of the thin film 1 1 of Tuwan and the salt is shown as R 1, and the imprinting direction of the alignment film 14 is shown as R 2. The angle between these imprinting directions ri ^ 2 can define the twist angle α of the Lc molecule. According to the present invention, it is necessary to perform the "pointing process" first in order to obtain the twist angle α, and the value is greater than or equal to about 80 and less than or equal to about 88. . This creative body recognizes the fact that when the viewing angle is tilted, the twist angle will change on it, and it is found that the viewing angle of the TN-type LC display device can be improved, especially by optimizing the twist angle. And use a phase plate (described later) to substantially improve the inversion phenomenon at 6 o'clock. Later, the appearance of the twist angle when the angle of view is inclined to 6 o'clock The way and size of the change are explained in detail. When the tilt is tilted, the twist angle appears to change. Assume that when the viewing angle Φ is from the front direction (that is, the positive axis direction) and forward to the viewing direction direction (that is, the direction of 6 o'clock). At the same time, it is assumed that even when the 1 (3 display device 丨 is viewed from the front direction (ie, the positive axis direction), that is, Φ ~ 〇, or when the viewing angle is not tilted, the twist angle still has a definable value. When observing the L c display device 1 in the front direction (that is, the positive axis direction), according to the imprinting direction R1 shown in the three-dimensional coordinate system previously disclosed, it is the origin (〇5〇) and the point on a connected xy plane. (1, tanU / 2_ α / 2) ⑽Φ), and the orientation of the true imprint of the thin M11

Η

-16-

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Together. Therefore, the twist angle α is substantially equal to the twist angle 々. Then 'when the view ^ φ is tilted from the front direction (that is, the positive axis direction) to the forward viewing direction direction (that is, the direction of o'clock), the watch T and the watch imprint gimbal seem to be facing the R3 gimbal, and the child This is different from the real imprinting direction R1. Therefore, 'this: universal direction R3 produces an apparent change, and along the line direction connecting = (0, 〇) and the point (1,-Yixin —) ^ when the angle of view Φ changes so that the twist angle In the case of ruggedization, as shown in FIG. 9 according to different real twist values, & can be seen from FIG. 9, for example, when the straight real twist angle “straight is 84”, φ = 0. Then the apparent twist angle point is 84, which means that the true twist angle α coincides. And when the apparent "incline gradually, the apparent twist angle / 9 also gradually increases, and # φ = 26. # Becomes, such as when Φ is more inclined, the apparent twist angle stone continues to increase more than 90%. Similarly. 'When the true twist angle α = 9 °, at φ = 0. Then the apparent twist angle is not: 0. i is coincident with the true twist angle α. When the viewing angle ① gradually tilts, the child The apparent twist angle / 5 also gradually increases and is always higher than 90. Generally speaking, if the TN type indicator device is viewed at a given angle, the apparent twist angle in that direction exceeds 90. In this direction, the inversion phenomenon is more likely to occur in that direction. &Amp; When the apparent twist angle increases, the inversion phenomenon becomes more significant. If the twist angle system is preset in the traditional TN type LC display device, If it is 90 °, the apparent twisted stone is always larger than 90 ° because the angle of view φ is inclined, so it is easy to occur the inversion phenomenon, even if the angle of view Φ is only slightly deviated from the positive direction. On the other hand, if the true torsion angle α is preset to be about 84 °, for example, the angle of view ① is indeed -17-

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V. Description of the invention Deflection, the apparent twisted stone will also be kept relatively low. Therefore, the chance of inversion can be minimized and the viewing angle characteristics can be significantly improved ... and the phase difference plates 2 and 3 are interposed between the LC display device and the polarizing plates 4 and 5 respectively, and then Each of the two and two retardation plates 2 and 3 provided on the reverse side of the L c display device 1 is constituted by providing discotic liquid crystals on a transparent organic polymer support and skewing or mixing the points and interlinking. Therefore, according to this, the refraction ellipses (details described later) on the retardation plates 2 and 3 can form an angle with the retardation plates 2 and 3, respectively. Mounted on the supports of the retardation plates 2 and 3, triacetylceUuiose cellulose acetate (TAC) 'is often used for polarizing plates and is extremely suitable for its reliability. Otherwise, you can also use colorless and transparent organic films, such as polycarbide (pc) or polyethylene terephthalate (PET), which have excellent resistance to the surrounding environment and chemicals. As shown in FIG. 3, the retardation plates 2 and 3 each have a king refractive index na, ⑶ and a refractive index ellipse in different directions. The universal index of principal refractive index coincides with the y-axis direction in the positive coordinate system (x, y, z). The direction of the main refractive index nb is 'the phase material is perpendicular to the phase difference plate ... The surface extension is inclined toward the direction of arrow A', which corresponds to the display (that is, the positive axis direction of the surface). The principal refractive indices of the respective phase plates 2 and 3 will satisfy the relational expression plus = such as >: b 'The table not only shows an optical axis. Therefore, each of the retardation plates 2 and 3 has a negative refractive index anisotropy. The retardation value (nc_na) xd of each of the phase difference plates 2 and 3 is about 0, please, because μ, (where -18 paper paper scales are applicable to a standard (CNS) A4 specification (2ι〇 × 297 mm) 1228631 A7

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I ~~ --- 1228631 A7 V. Description of the invention (17) Table 1 shows the results of the image review of samples # 1 to # 5 and the long-lasting samples # 100 and # 10 1. Into the white light. Table 1 --- ------ --_ ^ corner (.,) 78 80 82 .--- one_ # 3 86 88 90 # 100 # 1 ----- # 2 # 4 Cooking 1 (11 front X Δ Δ 〇〇TT J 〇 丄 丄 ui 〇 70 ° at 12 o'clock X Δ △ 〇〇〇〇 at 6 o'clock-50 ° directional 〇〇 〇〇 ^ 〇〇X Γ "ΊΡ · Γ Γ ^ (These notes are in the" front "and" at 7 o'clock in the direction of i 2 o'clock ".) The code in the column can be defined as follows: 〇 = 优 △ = Contrast slightly reduced and acceptable X = Contrast reduction is unacceptable) (These notes are in the "50 at 6 o'clock direction." The code in the column can be defined as follows: 〇 = excellent X = observable inversion phenomenon) This sample # 3 to # 5 may Provides excellent image quality, so that when viewed from the front or at 12 o'clock 70. The contrast ratio is negligible when viewed from an angle. This sample # 3 to # 5 can also provide excellent image quality, so when from 6 o'clock 21 This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) 1228631 V. Description of the invention (18 A7 B7 50 °) When viewed from an angle, the inversion phenomenon will not be recognized. And when When viewing at 70 angles from the front or 12 o'clock direction, samples # 丨 and # 2 will observe a decrease in the contrast ratio of the part ', but these samples can still provide acceptable image quality. When viewed from 6 o'clock 50. When viewed from the corner, samples # 1 and # 2 still provided acceptable image quality without confirming the phenomenon of inversion. On the other hand, 'comparative sample # 1〇〇 showed that when viewed from the front or at 12 o'clock Direction 70. When viewed from the angle, the contrast ratio will show an unacceptable decrease in love / brother. Comparative sample # 1 〇 丨 also shows that even when viewed from 6 o'clock in the direction of 50 °, the inverse will appear. Xia Lizhong, Ming Yi, a measurement system 501 including a light-sensing element 21, an amplifier 22, and a recording device 23 is used to measure the viewing angle correlation of the display device. In this measurement system 5 0 〇, the LC display of the L c display device 〇〇〇16, so that it is attached to the front surface of the glass substrate 9 6 & can be located in the X-y-z coordinate system reference plane X _ y The light-sensitive element 21 is a type capable of receiving at a certain stereo angle. The device of light is placed at a predetermined distance from the origin of the coordinate along a direction extending at a Φ angle (ie angle of view) with respect to the z-axis direction, and the person extends vertically to the front At 16a. During the measurement, monochromatic light (wavelength: 55nm) is transmitted through the other side of the front surface 16a, and radiated to the surface of the LC cell 16 of the measurement system 500,000. Part of the monochromatic light transmitted through the LC cell 16 will enter the light-sensitive element 21. The output of the light-sensing element 21 is amplified to a pre-sufficient level by an amplifier 22, and then recorded by, for example, a waveform memory or a recording device 23 of a recorder. -22- This paper size applies to China National Standard (CNS) A4 (210X 297 public inspection)

Decoration 1228631 A7 ________ Β7 ^ ~: ~:--~ ——----- V. Description of the invention (19) ~ ^ Sample # 3 and comparative samples # 100 and # 1〇1 need to be added to the tester. In particular, the samples # 3 and the comparative samples # 100 and # 1〇1 are placed in the measurement system 5 0 0 of FIG. 5, and the measurement is performed in response to the samples 趵 and the comparative sample # 100 and The voltage of # 101 is the output level of the light-sensing element 21, and the light-sensing element 21 is fixed at an angle of φ. Now suppose that the y direction corresponds to the top of the display or the 12 o'clock direction, and the X direction corresponds to the left-hand side of the display or the 9 o'clock direction, which is on the front, 50 o'clock at 6 o'clock. Angle and 60 o'clock at 12 o'clock. The position of the light-sensitive element 21 is changed between corners, and the measurement operation is performed in a manner similar to this example. The results are shown in Figs. FIGS. 6-8 to 60 illustrate the light transmission of the Lc display device according to the example 1 and the comparative example of the present invention in response to the voltage applied to the samples # 3 and the comparative samples # 1〇〇 and # 1〇1. Graphical representation of the situation (ie "transmission applied voltage characteristics"). Figure 6A shows the measurement results on the front (see Figure 2); Figure 6B shows the 6 o'clock universal 50. The result of the measurement at the angle; and Figure 6c is the clock direction 60. Measurement results on the corner. In Figs. 6A-6C, the curves li, L4, and L7 represent about 90%. Comparative sample coffee with twist angle; dashed curves L2, L5 # L8 represent having about 84. Sample # 3 of the twist angle; and the dashed curves L3, L6, and L9 represent the comparative sample # 1 具有 having a twist angle of about 78 °. With reference to FIG. 6A, between the sample # 3 and the comparative samples # 1〇〇 and # 1〇1 ^ In terms of the characteristics of the positive transmission voltage applied, the following comparative analysis results were observed: indicates a comparative sample The rigid curve L3 shows that the corresponding -23-

1228631 A1 B7 20 V. Description of the invention (Not enough transmission occurs when about 5 to 6 V is applied, and 0 1 seeks & lowers the situation. The curve L2 representing sample # 3 shows that it corresponds to about 5.5 of the applied knife edge V or higher, there will be a sufficient reduction in transmission. As for Tai Tai, Qi 7 and 10, it also shows that corresponding to her increase of about 5.5 V or higher, there is a sufficient reduction in transmission. Now see! Figure 6B 'May be at 6 o'clock in the direction of 5 o'clock. The characteristic of the applied voltage at the corner is T'. The following comparative analysis was observed. The result of Wang Dao analysis. Curve L representing sample # 3 and comparative sample # 1 〇〇 respectively. 5 buckle τ _,

Summation L 6 shows that it corresponds to a fixed transmission situation around 3 V to 6 V. Ben-m, the curve L4 of the comparative sample # 101 shows that 'the transmission is increased near 3 V, but the transmission is reduced near 4 V, which indicates the inversion phenomenon. . Referring now to FIG. 6C, 6G can be viewed at 12 o'clock. In terms of the characteristics of the applied voltage at the corners, the following comparative analysis results were observed: The curve L9 representing the comparative sample # 100 showed that there was not enough transmission reduction corresponding to the application of about 6 乂. Curves L7 and L8, which represent the comparative sample # 丨 〇 丨 and sample # 3, respectively, show that when about 6 施加 is applied, sufficient transmission reduction occurs. In this way, it can be confirmed that the sample # 3 can show a balanced improvement in both the 6 o'clock direction and the 12 o'clock direction. Similar results as above can also be observed in the comparative examples identical to samples # 1 to # 5 and comparative samples # 100 and # 1 〇1 of this example, except that the discotic liquid crystal system is provided in a mixed-pointing manner. Beyond the transparent support. Figure 7 shows an area where the inversion phenomenon does not appear in the sample # 3 (that is, the twist angle is 86 °), and the contrast level is 5 or higher, and a voltage is applied to display the intermediate grayscale hue. . The centripetal perimeters are shown in Table -24-. This paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 public love) 1228631 A7 B7. 5. Perspective of invention (21) and 70. If this is the case, show 10 regardless of the viewing direction. , 20. , 30. , 40. , 50. , 60. It can be seen in FIG. 7 that when the viewing angle range is about 0. To 50. Why did not appear the phenomenon of inversion. According to the present invention, by specifying a certain true view ", the distortion obtained" when the viewing angle is oblique to the forward viewing direction (that is, the 6 o'clock direction) can be less than about 9G. , It can improve the inversion of the grayscale tone in the display ^ forward viewing direction (that is, at 6 o'clock). This example is based on a refractive index ellipse whose principal refractive indices na, nb, and nc coincide with the y-axis direction, z-axis direction, and y-axis direction, respectively. Note that this is based on 15 of the elliptic refractive index. The reference oblique angle is equivalent to the 75 reference oblique angle of the refractive index ellipse whose principal refractive indices na, nb, and nc coincide in the y-axis direction, χ-axis direction, and redundant axis direction, respectively. Therefore, the oblique angle can be preset to ^ 5. Any value from 7 to 5 °. (Example 2) By appropriately selecting the anisotropy value of the refractive index Δη of the liquid crystal material of the LC layer 8, the viewing angle characteristics of the LC display device can be further improved. In Example 2, three samples # 21 to # 23 are prepared, and the LC layer 8 in the lc cell 6 of the L c display device shown in FIG. 4 is taken at a wavelength of 55 nm. The refractive index Δ !! (550) is an LC material having an anisotropy of about 0-070, about 0.80 or 0.095, respectively. The cell thickness of each sample (ie, the thickness of the LC layer 8) was approximately 0.5 m. For example, the direction difference plates 2 and 3 in the samples # 21 to # 23. These direction sound plates are similar to the optical directions obtained in the discotic liquid crystal provided in the skew direction in Example 1. Bad board. -25- This paper size is in accordance with Chinese National Standard (CNS) A4 specification (210X 297 mm) 1228631 A7 ______B7 V. Description of the invention (22) Use the measurement system 50 as described in Example 1 and refer to Figure 5 to fix The light sensor element 21 at the angle Φ is used to measure the wheel output level of the light sensor element 2 in response to the voltage applied to samples # 2 1 to # 2 3. Assuming that the y direction corresponds to the left-hand direction of the display screen, and the 乂 direction corresponds to the bottom of the display screen (that is, the forward viewing direction), then it is above or at 2 o'clock (that is, the reverse viewing direction), below, or 6 The measurement operation is performed by changing the position of the M light sensor element 21 between the clock direction (that is, the forward viewing direction), the right-hand side or 3 o'clock direction, and the left-hand side or 9 o'clock direction. The angle φ of the light-sensitive element 21 is fixed at each position. The results are not shown in FIGS. 10A to 10C. Figures 10a to 10c are diagrams illustrating the light transmission in response to the voltages applied to the samples # 2 1 to # 2 3 (ie, "transmission applied voltage characteristics"). Fig. 10 A shows the measurement results in the 12 o'clock direction (that is, the direction of the reverse viewing angle). Fig. 10 B shows the measurement results in the 3 o'clock cheek; while Fig. 100 shows the measurement results at 9 o'clock. Measurement results in the direction. In FIGS. 10A to 10C, dotted dotted lines L21, L24, and L27 represent sample # 21 in which the LC layer 8 is made of an lc material having Δ !! (550) = 0.07. The solid curves L22, L2, 5 and L28 represent sample # 22 of the 1 ^ layer 8 system composed of an LC material having-(550) = 0.080. The discontinuous curves L23, L26, and L29 represent sample # 2 3 in which the LC layer 8 is composed of an LC material having An (55 °) = 〇95. In Figs. 10a to 10c, it can be confirmed that at about 5 to 6 V, a sufficient reduction in transmission occurs, but this does not cause an inversion phenomenon. This shows that the effect on the characteristics of the sample according to Comparative Example 2 (as described later; Figures 11A to 11C) can be significant. -26- This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) Ϊ228631 A7 B7

V. Description of the invention (23 eliminations. (Comparative example 2) If comparative example 2 is compared to example 2, the comparative samples # 2〇1 and # 2〇2 are prepared according to the same method as in example 2 except that In addition to the L c material portion, at a wavelength of 550 nm, for the LC display device shown in FIG. 1! LC layer 8 in the LC cell 16 of 〇〇, the refractive index Δη (55) of the The anisotropy is about 0.060 or about 0.20, respectively. Using the measurement system 5 0 〇 described in Example 1 and referring to FIG. 5, the light perception is measured in response to the voltages applied to the samples # 201 and # 202. The output level produced by element 21 is that the light-sensitive element 21 is fixed at an angle of φ. Similar to Example 2, it is assumed that the y direction corresponds to the left-hand direction of the display screen, and the X direction corresponds to the bottom of the display screen ( That is, forward viewing direction), then in the upper or 12 o'clock direction (that is, the reverse viewing direction), the downward or $ o'clock direction (that is, the forward viewing direction), the right-hand side or 3 o'clock direction, and the left-hand side or 9 o'clock In the direction of the clock, change the position of the light-sensitive element 21 to perform the measurement operation. In each In position, the angle 21 of the light-sensing element is fixed to 5000. The results are shown in Figs. 1 A to 1 1 C. Figs. 1 A to 1 1 c are illustrations in response to being applied to the samples # 20 The voltage from 1 to # 202 is a graphic representation of the transmission of light (that is, "transmission applied voltage characteristics"). Figure 1 1 A shows the measurement and choice of fruit in the 12 o'clock direction (that is, the direction of the reverse viewing angle); 1 1 B shows the measurement results in the 3 o'clock direction; and Figure J ic shows the measurement results in the 9 o'clock direction.

In Figures 1 A to 1 1 C, the solid curves L201, L203, and L205 4LC -27- This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 1228631 A7 B7 V. Description of the invention ( 24) Layer 8 is a sample # 201 made of an LC material having Δη (550) = 0.060. The discontinuous curves L202, L204, and L206 represent the sample # 2〇2 of the LC layer 8 series made of an LC material having An (550) = 0.120. In Fig. 1A, the comparative sample # 20 1 (curve L20 1) shows a characteristic that is affected by an inversion artifact at a voltage of about 4 V or higher. On the other hand, the comparative sample # 202 (curve L202) shows that at a voltage of about 4 V or higher, 'there is not enough reduction in transmission. In Fig. 11B, the comparative sample # 202 (curve L204) shows a characteristic affected by the inversion phenomenon at a voltage of about 4 V or higher. In Fig. IC, the comparative sample # 2〇2 (curve L206) shows the characteristics of being affected by the inversion phenomenon at a voltage of about 4 V or higher like L203. As mentioned above, according to the present invention, an LC display device incorporating an LC display device and a phase difference plate can be provided, wherein the apparent pre-bevel angle of the L c molecules relative to the alignment film of the display device is optimized, thereby Provides improved viewing angle correlation and compensation effects based on retardation plates. In addition, according to the present invention, it is possible to provide an L c display device which can effectively improve the inversion phenomenon in the forward viewing angle direction (that is, the 6 o'clock direction) when a gray scale tone is displayed. For those skilled in the art, it is obviously easy to make other modifications, but it still does not depart from the spirit and scope of the present invention. Therefore, the enclosed application patent is not limited to the previous disclosure, but should be interpreted in a broad manner.

1228631 A7 B7 V. Description of the invention (25) Explanation of the symbols of the graphic elements 1 LC display device 2 Phase difference flat plate 3 Phase difference flat plate 4 Polarized flat plate 5 Polarized flat plate 6 Electrode substrate 7 Electrode substrate 8 LC layer 9 Glass substrate (Light transmission substrate) 10 Transparent electrode 11 Alignment film 12 Glass substrate (Light transmission substrate) 13 Transparent electrode 14 Alignment film 15 Sealant 16 LC cell 16a Front of LC cell 17 Drive circuit 21 Optical element 22 Amplifier 23 Record Device 31 TN-type LC display device 32 LC molecule-29- This paper size applies Chinese National Standard (CNS) A4 specification (210 X 297 mm) 1228631 A7 B7 V. Description of the invention (26) 33 Substrate 34 Substrate 35 Linear polarized light 36 Linear polarized light 37 Linear polarized light 100 LC display device 500 Measurement system R1 Imprinting direction of the alignment film 11 R2 Imprinting direction of the alignment film 14 d Thickness of the retardation plate 2 or 3 na Main refractive index nb Main refractive index nc Main refractive Rate AX1 Absorption axis AX2 Absorption axis LI Real curve L4 Real curve L7 Real curve L2 Dummy curve L5 Dummy curve L8 Dummy Curve L3 Dotted curve L6 Dotted curve L9 Dotted curve L21 Point Dotted curve -30-This paper size applies Chinese National Standard (CNS) A4 specification (210 X 297 mm) 1228631 A7 B7 V. Description of the invention (27) L24 point dotted curve L27 point imaginary curve L22 solid curve L25 solid curve L28 solid curve L23 discontinuous curve L26 discontinuous curve L29 discontinuous curve L201 solid curve L203 solid curve L205 solid curve L202 discontinuous curve L204 discontinuous curve L206 discontinuous curve

Paper -31-This paper size applies to China National Standard (CNS) A4 (210 X 297 mm)

Claims (1)

1228631 as B8 C8 ___D8 VI. Patent application scope " '4. For the liquid crystal display device of the first patent application scope, wherein the liquid crystal molecules have refractive index anisotropy An; and the liquid crystal molecules have a wavelength of 550 nm relative to The refractive index anisotropy Δη (550) of light is in a range of more than 0.060 and less than 012. 5. The liquid crystal display device according to item 1 of the application, wherein the refractive index anisotropy Δη (550) of the liquid crystal molecules with respect to light having a wavelength of 550 nm is greater than or equal to 0007, and less than or equal to Equal to the range of about 0.095. 6. A liquid crystal display device comprising: a liquid crystal display device comprising a pair of transparent substrates and a liquid crystal layer disposed between the pair of transparent substrates, the liquid crystal layer containing liquid crystal molecules, a transparent electrode layer and An alignment film is formed on each side of the pair of transparent substrates connected to the liquid crystal layer of the liquid crystal layer; a pair of polarizers are disposed on opposite sides of the liquid crystal display device; and at least one inclined retardation plate is disposed on the liquid crystal Between the display device and at least one of the pair of polarizers, the inclined retardation plate includes a refractive index ellipse having two principal refractive indices na, nb, and nc, where the three principal refractive indices na, 11 | 3 and ^ have a relationship of ⑽ = nc >nb; the refractive index ellipse is inclined at a predetermined oblique angle so as to be parallel; 泫 is the main refractive index η inclined and extending on the surface of the phase difference plate in a vertical direction Seven directions, and the direction of the main refractive index μ or μ extending in the plane of the surface will be inclined around the main refractive index direction na or nc; and -2- ABCD 1228631 Patent Application The range of the liquid crystal molecules has a true twist angle of greater than or equal to 80 ° and less than 88 ° to completely eliminate the liquid crystal molecules when a moderate grayscale voltage is applied to the liquid crystal layer and viewed from a forward viewing direction at a certain predetermined angle. The resulting reversal phenomenon. -3-This paper size applies to China National Standard (CNS) A4 (210 X 297 mm)