JP5359240B2 - Liquid crystal device and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein when the directions of alignment axes formed in two substrates, respectively, are shifted from predetermined directions (e.g. parallel direction), light leakage occurs in black display, so that desired transmittance is not obtained to deteriorate contrast. <P>SOLUTION: A shift angle [&phiv;t] between the alignment axes is multiplied by a factor [k], and two directions opened to both sides for the angle [k&times;&phiv;t/2] obtained by bisecting the multiplication value [k&times;&phiv;t] with reference to a bisecting line CL of the angle [&phiv;t], are taken as the directions of a transmission axis &phiv;p3 of an upper sheet polarizer 60 and an absorption axis &phiv;a1 of a lower sheet polarizer 50. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a liquid crystal device and an electronic apparatus including the liquid crystal device.

  A liquid crystal device having a liquid crystal sandwiched between two substrates and controlling the alignment direction of the liquid crystal by an electric field, thereby modulating light from a light source passing through the liquid crystal and controlling the light transmittance Are used in various electronic devices. Normally, polarized light is used as the light used for controlling the transmittance. Therefore, the optical axis of the polarizing plate on the side where light from the light source enters, the respective orientation axes formed on the liquid crystal side in the two substrates, and the optical axis (transmission axis or absorption axis) of the polarizing plate on the side from which light exits Must be combined so that they are each correctly oriented in a predetermined direction.

  In particular, a horizontal electric field method (for example, FFS (Fringe-Field Switching) method or IPS) that controls the transmittance by applying a horizontal electric field along the substrate to the liquid crystal, which has been widely used in recent years because of its wide viewing angle characteristics. In the (In-Plane Switching) type liquid crystal device, it is important to precisely match the optical axes of the two polarizing plates and the alignment axes formed on the liquid crystal sides of the two substrates.

  Many techniques have already been disclosed regarding the technique for aligning the axes. For example, Patent Document 1 or Patent Document 2 proposes a technique for matching the transmission axis of a polarizing plate with the alignment axis of a substrate.

JP 2002-14347 A JP 2003-107452 A

  However, using the techniques disclosed in Patent Document 1 and Patent Document 2, for example, a polarizing plate may be attached to a substrate on which an alignment axis is formed so that the transmission axis and the alignment axis of the polarizing plate coincide with each other. If the direction of the alignment axis formed on each of the two substrates deviates from a predetermined direction (for example, parallel direction), light leakage occurs in black display, and the desired transmittance cannot be obtained and the contrast is lowered. There is a problem of doing it.

  For example, in a lateral electric field type liquid crystal device, when polarizing plates are arranged in a crossed Nicol arrangement so as to perform black display with the minimum transmittance when no electric field is applied to the liquid crystal, the alignment axes are formed in parallel to each other. There is a need. However, when two substrates are bonded to each other with the liquid crystal sandwiched therebetween, the orientation axis varies not only slightly depending on the formation method (for example, rubbing treatment). Due to this, the alignment axes are not parallel to each other, but are formed in a twisted state twisted clockwise or counterclockwise in plan view. As a result, the liquid crystal is also twisted according to the twist of the alignment axis. When light that is linearly polarized by one polarizing plate enters the twisted liquid crystal, the polarization state changes according to the twist, so that the incident linearly polarized light becomes elliptically polarized light and enters the other polarizing plate. To do. For this reason, light that is not cut is generated in the other polarizing plate, so that light leakage occurs in black display, and a desired transmittance cannot be obtained.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

Application Example 1 A first substrate, a second substrate facing the first substrate, a liquid crystal layer sandwiched between the first substrate and the second substrate, and the first substrate the liquid crystal layer side, a first orientation film having an orientation axis, the liquid crystal layer side of the second substrate, which is formed so as to be parallel to the alignment axis of the first alignment layer orientation a second alignment film having an axis, said first side opposite to the liquid crystal layer of the substrate, a first polarizing plate having a transmission axis, on the opposite side of the liquid crystal layer of said second substrate, said A second polarizing plate having an absorption axis intersecting the transmission axis of the first polarizing plate, wherein the alignment axis of the first alignment film formed offset from each other and the second polarizing plate the first acute angle range and the orientation axis forms crosses of the second alignment film, the transmission axis of the first polarizing plate and the absorption axis of the second polarizer Are set in the second acute angle ranges forming intersecting the transmission axis of the first polarizing plate, the alignment axis of the second alignment layer said first forming the first acute angle Arranged in the direction beyond the alignment axis of the alignment film, the absorption axis of the second polarizing plate is the direction in which the alignment axis of the first alignment film is disposed with respect to the alignment axis of the second alignment film It is arrange | positioned in the direction opposite to.

  According to this configuration, the black display light leakage caused by the twist of the liquid crystal due to the displacement of the alignment axis with respect to the setting direction between the alignment films has a shift angle larger than the shift angle of the alignment axis with respect to the setting direction. It can suppress by the polarizing plate which has. As a result, a decrease in contrast can be suppressed.

  Application Example 2 In the liquid crystal device, the first acute angle center line and the second acute angle center line are substantially in the same direction.

  According to this configuration, it is possible to suppress the leakage of black display light caused by the twist of the liquid crystal accompanying the shift of the alignment axis between the alignment films with respect to the setting direction.

  Application Example 3 In the liquid crystal device, the second acute angle is 7.5 degrees or less.

  According to this configuration, it is possible to substantially suppress the light leakage of black display with respect to the shift amount with respect to the setting direction of the alignment axis assumed in the actual manufacturing process of the liquid crystal device.

  Application Example 4 In the above liquid crystal device, the angle ratio k of the second acute angle to the first acute angle indicates that the refractive index anisotropy of liquid crystal molecules in the liquid crystal layer is Δn, and the thickness of the liquid crystal layer. Where d is a value satisfying k = a × exp (b × Δnd) + c (a, b, c are constants determined according to the wavelength of light passing through the liquid crystal layer). And

  According to this configuration, since the deviation angle of the polarizing plate with respect to the setting direction is set to a value according to the layer thickness of the liquid crystal material and the liquid crystal actually used in the liquid crystal device, the alignment axis is displaced with respect to the setting direction between the alignment films. The light leakage of black display caused by the twist of the liquid crystal can be suppressed to be minimized.

  Application Example 5 In the above-described liquid crystal device, an electric field in a direction along the first substrate or the second substrate is applied to either the first substrate or the second substrate, and the liquid crystal device is applied. A pair of electrodes for controlling the alignment direction of the liquid crystal molecules in the layer is provided.

  According to this configuration, in the horizontal electric field drive type liquid crystal device that changes the direction in which the liquid crystal is aligned in the direction along the first substrate or the second substrate, that is, in the horizontal direction, with respect to the setting direction of the alignment axis between the alignment films. Light leakage of black display caused by the twist of the liquid crystal accompanying the shift can be suppressed.

  Application Example 6 In the liquid crystal device, at least one of the pair of electrodes has a shape provided with a slit-like opening or a comb-like shape.

  According to this configuration, an FFS mode or IPS mode liquid crystal device with a wide viewing angle can be employed as the lateral electric field drive type liquid crystal device.

  Application Example 7 In the above-described liquid crystal device, a light that irradiates the liquid crystal device passes through the liquid crystal layer once to perform display, and the liquid crystal layer passes through the liquid crystal layer twice to perform display. A reflective display area is provided.

  According to this configuration, it is possible to realize a liquid crystal device capable of visually recognizing display contents even under external light and suppressing light leakage of black display.

  Application Example 8 The liquid crystal device includes a light source that emits illumination light, and the illumination light travels from the first polarizing plate toward the second polarizing plate, or the second polarizing plate. It irradiates in any direction of the direction which goes to the said 1st polarizing plate from.

  The polarizing plate on the side from which the illumination light is emitted, regardless of whether the transmission axis of the polarizing plate on which the illumination light from the light source is incident is substantially parallel or substantially orthogonal to the alignment axis direction of the alignment film If the transmission axis is substantially perpendicular to the transmission axis of the polarizing plate on the side where the illumination light is incident, black display can be obtained in the same manner. Therefore, as in this configuration, it is possible to realize a liquid crystal device that can suppress light leakage of black display regardless of which side of the two polarizing plates is irradiated with illumination light from the light source.

  Application Example 9 In the liquid crystal device, the light source is an LED light source.

  According to this configuration, in a liquid crystal device using an LED having a long light emission life as a light source, light leakage of black display can be suppressed.

  Application Example 10 An electronic device including the liquid crystal device.

  According to this device, it is possible to provide an electronic device capable of performing display in which a decrease in contrast is suppressed by suppressing light leakage of black display.

  Hereinafter, the present invention will be described based on examples. It should be noted that the drawings used in the following description may be exaggerated for the sake of description, and needless to say, they do not necessarily indicate the actual size or length.

(Configuration of liquid crystal device)
FIG. 1 is an explanatory view schematically showing a liquid crystal device 100 according to an embodiment of the present invention. The liquid crystal device 100 has a structure in which a substrate 10 as a first substrate and a substrate 30 as a second substrate are bonded with a sealing material (not shown) with a liquid crystal layer (not shown) sandwiched between them. doing.

  The substrate 10 has a data driving circuit 110, a scanning driving circuit 120, and an electrode terminal 130 formed on the outer peripheral portion thereof on a light-transmitting flat plate such as glass, quartz, or resin (on the drawing surface side). It is. Further, a data line 111 is wired from the data driving circuit 110, a scanning line 121 is wired from the scanning driving circuit 120, and a common wiring 131 is wired from the electrode terminal 130 as shown in FIG. A thin film transistor (not shown) is formed near the intersection of the data line 111 and the scanning line 121 corresponding to each pixel. The thin film transistor is controlled to be turned on and off by the voltage supplied by the scanning line 121. When the thin film transistor is turned on, the voltage supplied by the data line 111 is supplied to one electrode (this is referred to as “ (Referred to as a “pixel electrode”).

  The electrode terminal 130 is supplied with the same voltage (for example, ground potential voltage) for each pixel by the common wiring 131 connected thereto, to another electrode (this is referred to as “common electrode”) provided for each pixel. Supply. Therefore, in each pixel, when the thin film transistor is turned on, the voltage between the voltage supplied by the data line 111 and the voltage supplied by the common wiring 131 is substantially parallel to the substrate 10 with respect to the liquid crystal layer corresponding to the pixel. A predetermined electric field having a certain direction is generated. In other words, the liquid crystal device 100 includes an FFS (Fringe-Field Switching) system that generates an electric field in a direction substantially parallel to the substrate 10 with respect to the liquid crystal layer to control alignment of liquid crystal molecules and modulates light passing through the liquid crystal layer. This is a so-called horizontal electric field type liquid crystal device.

  Next, the substrate 30 is made of glass, quartz, or resin so that the target region on which an image is displayed by performing light modulation is a pixel S, and other region portions (for example, a region between adjacent pixels S) are shielded from light. A light shielding layer is formed on a light-transmitting flat plate (the back side of the drawing).

  In this embodiment, the region of the pixel S has a rectangular shape, and is formed as a transmissive display region that transmits light from illumination means (not shown) provided on the opposite side of the substrate 30 from the substrate 30. In the region of the pixel S, a filter layer that transmits a predetermined wavelength is formed. Therefore, an image is displayed by emitting light having a wavelength specified by the filter layer from the region of the pixels S, where the pixels S are shielded from light by the light shielding layer.

  Next, the configuration of the liquid crystal device 100 will be described in detail with reference to FIGS. FIG. 2 is a plan view showing a configuration relating to one pixel S, and shows the substrate 10 viewed from the substrate 30 side in a transparent state. FIG. 3 is a cross-sectional view showing the peripheral configuration of the pixel S. In the following description, the substrate 10 is referred to as the element substrate 10 and the substrate 30 is referred to as the counter substrate 30 in order to avoid confusion between the substrate 10 and the substrate 30.

  As shown in FIG. 2, the data line 111 and the scanning line 121 are formed on the element substrate 10. Near the intersection of the two wirings, the source electrode 20s formed by extending the wiring of the data line 111, the semiconductor layer 20a formed with the channel region, the gate electrode 20g serving as the scanning line 121, the drain A thin film transistor 20 including the electrode 20d is formed. The drain electrode 20d is connected to the pixel electrode 11 through the contact hole CH1. Therefore, when the thin film transistor 20 is turned on by the voltage supplied to the scanning line 121, that is, the gate electrode 20g, the voltage supplied to the data line 111 is applied to the pixel electrode 11 via the drain electrode 20d. The pixel electrode 11 is formed of an electrode having a size including the region of the pixel S, and a plurality of slits SL for performing FFS driving are formed as illustrated.

  A common wiring 131 is formed on the element substrate 10. The common electrode 13 electrically connected to the common wiring 131 through the contact hole CH2 is formed as a solid electrode having a size including the pixel S region.

  By the voltage applied between the pixel electrode 11 and the common electrode 13 formed in this way, the alignment control of the liquid crystal molecules by the FFS method is performed as described above. Note that the pixel electrode 11 and the common electrode 13 are formed of a light-transmitting material having conductivity (for example, ITO).

  Next, the configuration of the liquid crystal device 100 will be described in more detail with reference to the cross-sectional view shown in FIG. FIG. 3 is a schematic diagram showing a BB cross section in FIG. 2. As shown in the figure, the liquid crystal device 100 has a configuration in which a liquid crystal layer 40 having a predetermined thickness is sandwiched between an element substrate 10 and a counter substrate 30, and further on the opposite side of the element substrate 10 from the liquid crystal layer 40. A polarizing plate 60 is attached to the polarizing plate 50 on the opposite side of the counter substrate 30 from the liquid crystal layer 40.

  First, the counter substrate 30 will be described. The counter substrate 30 is obtained by sequentially forming a light shielding layer 32, a filter layer 33, an overcoat layer 34, and an alignment film 39 on a surface on the liquid crystal layer 40 side with respect to a flat plate 31 made of a glass material in this embodiment. is there.

  The light shielding layer 32 is made of a metal film (for example, chromium) or a resin. The filter layer 33 is made of, for example, acrylic resin and contains a color material corresponding to the color displayed by the pixels. The overcoat layer 34 is formed so as to cover the light shielding layer 32 and the filter layer 33. The overcoat layer 34 is made of a translucent resin.

  The alignment film 39 is formed so as to cover the overcoat layer 34. The alignment film 39 is made of, for example, a polyimide resin. The surface of the alignment film 39 is subjected to an alignment process in a predetermined direction by rubbing or the like. The alignment direction formed by the alignment treatment is hereinafter referred to as “alignment axis”.

  Next, the element substrate 10 will be described. The element substrate 10 has a scanning line 121 (gate electrode 20g) and a common wiring 131, a gate insulating layer 15, a semiconductor layer 20a, data on the surface on the liquid crystal layer 40 side with respect to the flat plate 14 made of a glass material in this embodiment. A line 111 (source electrode 20s) and a drain electrode 20d, an interlayer insulating layer 16, a planarizing layer 17, a common electrode 13, an insulating layer 18, a pixel electrode 11, and an alignment film 19 are sequentially formed.

  The scanning line 121 (gate electrode 20g), common wiring 131, data line 111 (source electrode 20s), and drain electrode 20d are formed of a metal material (for example, aluminum). The gate insulating layer 15 is made of, for example, silicon oxide, the semiconductor layer 20a is made of a semiconductor such as amorphous silicon or polysilicon, and the interlayer insulating layer 16 is made of, for example, silicon nitride. The

  The planarizing layer 17 is formed using a light-transmitting resin (for example, a positive or negative photosensitive acrylic resin or a UV curable resin). Further, the flat surface located on the liquid crystal layer 40 side of the flattening layer 17 has a common light-transmitting conductive material (for example, ITO (Indium Tin Oxide)) over a region corresponding to the region of the pixel S. An electrode 13 is formed. The common electrode 13 is electrically connected to the common wiring 131 through the contact hole CH2.

  The insulating layer 18 formed so as to cover the common electrode 13 is formed of a light-transmitting transparent layer using, for example, silicon oxide or silicon nitride. A pixel electrode 11 made of a light-transmitting conductive material (for example, ITO) is formed over a region corresponding to the region of the pixel S across the insulating layer 18. The pixel electrode 11 is electrically connected to the drain electrode 20d through a contact hole CH1.

  The alignment film 19 is formed on the side of the pixel electrode 11 in contact with the liquid crystal layer 40 so as to cover at least the pixel electrode 11. The alignment film 19 is made of, for example, a polyimide resin. Similar to the alignment film 39, alignment processing is performed by rubbing or the like, and an alignment axis is formed in a predetermined direction.

  In the liquid crystal device 100 of the present embodiment, an illuminating means (backlight) including a light source 90 and a light guide member 91 is further provided on the polarizing plate 50 side (lower side in the drawing), and light from the light source 90 is supplied to the polarizing plate 50. It is configured as a transmissive display device that displays an image by controlling the amount of light irradiated and emitted from the polarizing plate 60. When no voltage is applied to the pixel electrode 11 and the common electrode 13, black display, that is, normally black display that cuts off the light from the light source 90 is configured.

  In the liquid crystal device 100 of the present embodiment, as described above, the transmission axis of the polarizing plate 50 and the polarization of the polarizing film 50 with respect to the misalignment between the alignment axis of the alignment film 19 and the alignment axis of the alignment film 39 that may occur in manufacturing. By sticking so that the transmission axis of the plate 60 is positioned in a predetermined direction, the occurrence of light leakage in black display is suppressed. This will be described with reference to FIG.

(Polarizing method)
FIG. 4 is an explanatory diagram illustrating the set directions of the alignment axes of the alignment film 19 and the alignment film 39 and the transmission axes of the polarizing plate 50 and the polarizing plate 60 in the liquid crystal device 100. FIG. 4A shows the polarizing plate 50, the alignment film 19, the alignment film 39, and the polarizing plate 60 among the constituent members of the liquid crystal device 100, and the direction of the transmission axis and the alignment axis formed in each is indicated by arrows. FIG. FIG. 4B is an explanatory diagram showing the transmission axis and the alignment axis in a state where they are stacked in a plane, that is, in a state where the liquid crystal device 100 is viewed in plan from the polarizing plate 60 side. For convenience of explanation, the polarizing plate 50 is also called a lower polarizing plate, and the polarizing plate 60 is also called an upper polarizing plate.

  In this embodiment, the liquid crystal device 100 performs normally black display, which is black display when no electric field is applied to the liquid crystal layer. Therefore, as shown in FIG. 4A, the transmission axis φp1 of the lower polarizing plate 50 is set to be orthogonal to the transmission axis φp3 of the upper polarizing plate 60 so as to achieve a normally black display. The directions of the alignment axis HD1 and HD3 are set in a direction parallel to the absorption axis φa1 of the lower polarizing plate 50. Of course, in the lower polarizing plate 50, the absorption axis φa1 is perpendicular to the transmission axis φp1.

  Now, as shown in FIG. 4A, the alignment axis HD1 of the alignment film 19 and the alignment axis HD3 of the alignment film 39 are anti-parallel alignment axes that are originally opposite in direction and parallel to each other. Set to However, due to the formation variation of the orientation axis, etc., it deviates from the parallel direction as shown in FIG. Here, when the acute angle formed by the deviation between the direction of the alignment axis HD1 and the direction of the alignment axis HD3 is “φt”, in this embodiment, the angle “φt” is multiplied by a coefficient “k” described later, The upper polarizing plate 60 has two directions opened on both sides with respect to the bisector CL of the angle “k × φt / 2” and the angle “φt”, which is obtained by dividing the multiplication value “k × φt” into two equal parts. And the absorption axis φa1 of the lower polarizing plate 50. By doing so, it is intended to suppress light leakage in black display.

  Here, in FIG. 4B, when the clockwise direction in the drawing is a plus direction, the orientation axis HD3 of the orientation film 39 provided on the counter substrate 30 is rotated (twisted) by an angle φt in the plus direction. Is parallel (anti-parallel) to the direction of the alignment axis HD1 of the alignment film 19 provided on the element substrate 10. Therefore, in this embodiment, similarly, the direction in which the transmission axis φp3 of the upper polarizing plate 60 attached to the counter substrate 30 is rotated by the angle “k × φt” in the plus direction is attached to the element substrate 10 below. The upper polarizing plate 60 and the lower polarizing plate 50 are attached so that the absorption axis φa1 of the polarizing plate 50 is obtained.

  In this embodiment, a reference direction (for example, an end face direction of the element substrate 10) when attaching the polarizing plate is set as a reference axis KZ (0 degree). Therefore, the angle of the reference axis KZ is expressed as “0 degree”, the clockwise angle is expressed as plus, and the counterclockwise angle is expressed as minus. Further, an angle (acute angle) formed by the bisector CL and the reference axis KZ is “φc”.

  An example of the effect of the polarizing plate attaching method in this embodiment is shown in FIG. FIG. 5 is a contrast contour (contour line) diagram with respect to the bonding angle between the upper polarizing plate 60 and the lower polarizing plate 50 with respect to the reference axis KZ, and FIG. 5 (a) is between the alignment axis HD1 and the alignment axis HD3. In a state where there is no angular deviation (φt = 0 degree), FIG. 5B shows a state where the orientation axis HD3 is displaced by 1 degree clockwise relative to the orientation axis HD1 parallel to the reference axis KZ (φt = + 1 degree). FIG. 2 shows the relationship between the polarizing direction of the polarizing plate and the contrast. Note that the closer to the center of the region indicated by the substantially elliptical shape, the higher the contrast.

  As shown in FIG. 5A, when there is no angular deviation between the alignment axes, the highest contrast portion, that is, the portion where light leakage is most suppressed in the black display (the center of the shaded portion in the figure) is the upper polarization. The transmission axis φp3 direction of the plate 60 is 0 degree, and the transmission axis φp1 direction of the lower polarizing plate 50 is 90 degrees.

  On the other hand, when there is an angle shift of 1 degree between the alignment axes, the highest contrast portion, that is, the portion where light leakage is most suppressed in the black display (the center of the shaded portion in the figure) is shown in FIG. ), The transmission axis φp3 direction of the upper polarizer 60 is −0.5 degrees, and the transmission axis φp1 direction of the lower polarizer 50 is 91.5 degrees. Therefore, from the description of FIG. 4B, the angle φt is 1 degree, and the angle φc is an angle obtained by dividing the angle φt into two equal parts, which is 0.5 degrees. Therefore, 0.5−k × φt / 2 The coefficient k = 2 is calculated from the relational expression of = −0.5.

  Thus, in the example shown in FIG. 5, the coefficient k is set to 2 and the angle φt is multiplied by the angle φt, so that the twist direction is the same as the twist direction (clockwise or counterclockwise) of the orientation axis. It can be seen that by pasting the transmission axis between the upper and lower polarizing plates so as to widen φt by 90 degrees or more, light leakage in black display can be suppressed and display with high contrast can be obtained.

(How to determine the value of coefficient k)
In FIG. 5, it has been described that the light leakage of black display can be suppressed by taking the case of k = 2 as an example. Here, how the value of the coefficient k is determined in this embodiment will be described. In the liquid crystal device 100 of the present embodiment, the transmittance is controlled by changing the polarization state of light passing through the liquid crystal layer 40 by changing the direction of the liquid crystal molecules in a horizontal plane by a lateral electric field. For this reason, the optical characteristics (transmittance, etc.) differ depending on the retardation Δnd, which is the product of the refractive index anisotropy Δn and the thickness d of the liquid crystal layer 40, which affects the value of the coefficient k. Therefore, in this embodiment, the range of retardation Δnd assumed in the liquid crystal device 100 in advance in order to determine the value of the coefficient k will be described with reference to FIG.

  FIG. 6A is a graph showing the relationship between the retardation Δnd (horizontal axis) and the transmittance (vertical axis) of the liquid crystal layer 40 in a state where the aperture ratio of the pixel S and the transmittance of the filter layer are not considered. is there. In the present embodiment, since the practically required transmittance in the actual liquid crystal device 100 is 20% or more, it is desirable that the retardation Δnd be 300 nm or more.

  On the other hand, the response speed of the liquid crystal when the moving image is displayed on the liquid crystal device 100 correlates with the thickness d of the liquid crystal layer 40 in the case of the FFS method, and the response speed increases as the thickness d increases (Δnd increases). Become slow. In view of this, the actual liquid crystal device 100 displayed moving images and evaluated the display performance (for example, MPRT (motion picture response time) evaluation, subjective evaluation of tail display by the examiner, etc.).

  FIG. 6B is a table showing the relationship between the display performance evaluation results and the values of the retardations Δnd of the liquid crystal layer 40. Here, “◯” indicates that the display characteristic is a desirable level, “Δ” indicates that the display characteristic is an allowable level, and “X” indicates that the display characteristic is less than the allowable level. Therefore, from the result of FIG. 6B, the retardation Δnd is preferably 390 nm or less.

  As a result, the retardation Δnd range of the liquid crystal layer 40 in the liquid crystal device 100 is preferably set to 300 nm ≦ Δnd ≦ 390 nm in terms of both response characteristics and transmittance. Therefore, in the liquid crystal device 100 according to the present embodiment, when determining the value of the coefficient k, the retardation Δnd of the liquid crystal layer 40 is specified in the range of 300 nm to 390 nm.

  As is well known, the optical characteristics of the liquid crystal device 100 are calculated by the Jones matrix method. Therefore, when the liquid crystal layer 40 is twisted due to an angular shift between the alignment axis HD1 and the alignment axis HD3 sandwiching the liquid crystal layer 40 within the specified retardation Δnd, the optimum polarizing plate calculated by the Jones matrix method is used. The shift angle is substantially proportional to the twist angle of the liquid crystal layer 40, that is, the angle φt between the alignment axis HD1 and the alignment axis HD3. The proportional coefficient, that is, the angle ratio is the coefficient k.

  In addition to the retardation Δnd of the liquid crystal layer 40, the coefficient k also depends on the light from the light source that irradiates the liquid crystal device 100, that is, the wavelength λ of the illumination light. FIG. 7 shows the value of the coefficient k obtained for the specific wavelength between 405 nm and 650 nm in the wavelength λ of the illumination light in the specific range of the retardation Δnd of the liquid crystal layer 40 described above. As shown in the figure, in the substantially visible light region used in the liquid crystal device 100, the coefficient k is k> 1. Accordingly, it is preferable that the shift angle between the upper polarizing plate 60 and the lower polarizing plate 50 is equal to or larger than the shift angle between the alignment axis HD1 and the alignment axis HD3. In FIG. 7, the value of the coefficient k when the retardation Δnd of the liquid crystal layer 40 is 300 nm and the wavelength λ is 650 nm is a large value different from the other digits, and therefore is denoted as “EE” here.

  By the way, the light source 90 used for the liquid crystal device 100 of the present embodiment is an LED (light emitting diode) light source having a long light emission lifetime. In such light from the LED light source, it has been found that the wavelength λ having a dominant influence on the luminance is 470 nm ≦ λ ≦ 650 nm. As shown in FIG. 8, the maximum visibility wavelength is 555 nm. When the visibility at this time is 100, the visibility is 10 or more, that is, the wavelength in the range where the relative visibility is 1/10. This is because it is considered that has a dominant influence on luminance. Therefore, in this embodiment, the value of the coefficient k may be determined from the wavelength 470 nm to the wavelength 650 nm.

Therefore, fitting is performed for the value of the wavelength λ of 470 nm to 650 nm among the values of the coefficient k shown in FIG. In this embodiment, the coefficient k can be fitted by the following equation (1).
k = a × exp (b × Δnd) + c (1)

  Here, a, b, and c are constants determined by the wavelength λ, and examples of the values are shown in FIG. As shown in FIG. 9, when the retardation Δnd assumed as the liquid crystal layer 40 is 300 nm to 390 nm, for example, when the wavelength λ of the illumination light is 470 nm, the constant a is “319.23” and the constant b Is “−0.0916617” and the constant c is “1.05153”. When the wavelength λ of the irradiation light is 650 nm, the constant a is “1.68321E + 20”, the constant b is “−0.132”, and the constant c is “3.19”. When the wavelength λ of the illumination light is between 470 nm and 650 nm, the constants a, b, and c have intermediate values according to the wavelength. For example, when the wavelength λ is 532 nm The constant a is “25050”, the constant b is “−0.031”, and the constant c is “1.35”.

  Therefore, when the wavelength λ of the illumination light is specified with respect to the range (300 nm to 390 nm) of the expected desirable retardation Δnd of the liquid crystal layer 40, constants a, b, c corresponding to the value of the wavelength λ. To determine the value of the coefficient k corresponding to each retardation Δnd. Thereafter, as described above, high contrast can be obtained by attaching the upper and lower polarizing plates so that the deviation angle calculated by k × φt is obtained.

  When the wavelength λ is not specified, such as when the illumination light includes a plurality of different wavelengths, the constant a is about “319” or more, the constant b is about “−0.132” or more, and about “−0.019”. Hereinafter, the value of the coefficient k corresponding to each retardation Δnd is determined using any value in the range of the constant c of about “1.05” or more and about “3.19” or less. Thereafter, high contrast can be obtained by pasting the upper and lower polarizing plates so that the deviation angle calculated by k × φt is similarly obtained.

  As described above, according to the method of attaching the upper and lower polarizing plates in the liquid crystal device 100 of the present embodiment, the twist of the liquid crystal generated in the liquid crystal layer 40 due to the shift in the alignment axis direction between the alignment film 19 and the alignment film 39. The light leakage of black display caused by the above can be suppressed by the upper and lower polarizing plates having a deviation angle larger than the deviation angle of the alignment axis. As a result, a decrease in contrast can be suppressed. In this embodiment, the upper polarizing plate 60 corresponds to the first polarizing plate described in the claims, and the lower polarizing plate 50 corresponds to the second polarizing plate described in the claims. The alignment film 39 corresponds to the first alignment film recited in the claims, and the alignment film 19 corresponds to the second alignment film recited in the claims.

  The embodiments of the present invention have been described with reference to the examples. However, the present invention is not limited to these examples, and can be implemented in various forms without departing from the spirit of the present invention. Of course. Hereinafter, a modification will be described.

(First modification)
In the above embodiment, when the value of the coefficient k is calculated and determined using the equation (1), when there are a plurality of wavelengths in the illumination light, the constant a, the constant b, and the constant c are respectively set according to the wavelength. Because of the difference, the coefficient k is calculated as a plurality of values. However, since the shift angle between the upper and lower polarizing plates to be finally bonded is one, the value of the coefficient k needs to be one. Therefore, in this modification, the value of the coefficient k is determined as one of the most preferable values considering practicality. By doing so, it is possible to reduce the calculation load associated with the calculation of the coefficient k.

  As described in the above embodiment, the visibility for each wavelength is different between the wavelength of 470 nm and the wavelength of 650 nm (see FIG. 8). Therefore, in the present modification, as shown in FIG. 10, the spectral intensity and the ratio of the wavelength of the light source 90 to the value of the coefficient k calculated by the equation (1) for each retardation Δnd and each wavelength λ. Weighting is performed by multiplying visibility. Then, for each retardation Δnd of the liquid crystal layer 40, an average value of the weighted coefficient k is calculated, and the calculated average value is set as a value of one coefficient k corresponding to each retardation Δnd.

  As an example, when the refractive index anisotropy Δn = 0.1 and the thickness d = 3.6 μm of the liquid crystal layer 40, that is, the retardation Δnd = 360 nm, the average value of the coefficient k corresponding to the LED light source is Although it varies depending on the spectrum intensity, it is calculated as approximately “2.13 to 2.15”. Incidentally, in a monochromatic light source with a wavelength λ = 555 nm, k = 1.97 (see FIG. 7).

  Furthermore, in this modification, the maximum value of one coefficient k used in common for all retardation Δnd ranges assumed in practice is determined. Specifically, an average of the values of one coefficient k calculated according to the value of each retardation Δnd is obtained, and the maximum value among the obtained average values is obtained. In this modification, the maximum value of the coefficient k is calculated as “7.5” when the LED light source is used and the retardation Δnd of the liquid crystal layer 40 is in the range of 300 nm to 390 nm.

  As described above, when the liquid crystal layer 40 is twisted due to an angle shift between the alignment axis HD1 and the alignment axis HD3 sandwiching the liquid crystal layer 40, the optimum shift angle of the polarizing plate calculated by the Jones matrix method is the liquid crystal layer 40. The twist angle, i.e., the angle φt between the orientation axis HD1 and the orientation axis HD3, is approximately proportional to the coefficient k. Therefore, in practice, the optimum shift angle between the polarizing plates was calculated by the Jones matrix method for a plurality of twist angles. The result is shown in FIG.

  FIG. 11 is a graph showing the relationship between the optimum shift angle between the polarizing plates and the twist angle in the entire range of the LED light source retardation Δnd of 300 nm to 390 nm. For reference, the relationship between the optimal shift angle and twist angle between polarizing plates when the retardation Δnd is 360 nm for an LED light source, and between the polarizing plates when the retardation Δnd is 360 nm is a monochromatic light source with a wavelength of 550 nm The relationship between the optimal shift angle and twist angle is also shown.

  As shown in the figure, it can be seen that the twist angle of the liquid crystal layer and the shift angle between the polarizing plates are substantially proportional. Therefore, by making k times the twist angle φt the shift angle between the upper and lower polarizing plates, light leakage of black display is suppressed and high contrast display can be obtained.

  By the way, the alignment axis is formed by rubbing the alignment film using a rubbing apparatus. Therefore, the angular deviation that occurs between the alignment axis HD1 and the alignment axis HD3 will be considered. The cause of the angle deviation is caused by the mechanical accuracy of the rubbing device (rubbing roll, substrate suction stage angle, etc.), the direction in which the rubbing cloth piles down, and the misalignment when the element substrate 10 and the counter substrate 30 are bonded together. It has been found that the deviation angle between the orientation axes that actually occurs can be considered to be a maximum of 1 degree.

  Therefore, in this modification, it is assumed that the twist angle φt generated in the liquid crystal layer 40 is 1 degree. Accordingly, the coefficient k calculated as the maximum value is “7.5” as described above, and the twist angle φt of the liquid crystal layer is 1 degree, so that the shift angle between the polarizing plates is k × φt = 7.5. Degree. As a result, if an LED light source is used and the retardation Δnd of the liquid crystal layer 40 is in the range of 300 nm to 390 nm and the shift angle between the upper and lower polarizing plates is not more than “7.5 degrees”, the actual liquid crystal device 100 has black The light leakage of the display is suppressed and the probability that a high contrast display is obtained increases.

  Incidentally, in the example described with reference to FIG. 5 in the above embodiment, when the twist angle φt of the liquid crystal layer is “1 degree” and the value of the coefficient k is “2” (for example, the retardation Δnd = This is an example of a case of approximately close to 360 nm).

(Second modification)
In the above embodiment, the liquid crystal device 100 has been described as a display device that performs transmissive display in the pixel S region. However, the liquid crystal device 100 is not limited to this, and in addition to the transmissive display region in the pixel S region. Thus, the display device may be a so-called transflective display device provided with a reflective display region that reflects external light such as sunlight incident from the counter substrate 30 side. In this way, the display of the pixel S can be visually recognized even in an environment where the outside light is bright.

  The configuration of the liquid crystal device 100 according to this modification will be described with reference to FIGS. 12 and 13. FIG. 12 is a plan view showing a configuration relating to one pixel S, and shows the element substrate 10 viewed from the counter substrate 30 side in a state where the counter substrate 30 is seen through. FIG. 13 is a cross-sectional view showing the peripheral configuration of the pixel S. FIG. 12 corresponds to FIG. 2 in the above embodiment, and FIG. 13 corresponds to FIG. 3 in the above embodiment. Therefore, components having the same function are denoted by the same reference numerals, and description thereof is omitted as appropriate.

  Now, as shown in FIG. 12, in the liquid crystal device 100 of the present modification, in the pixel S, the area portion on the lower side of the drawing indicated by hatching in the drawing is the reflective display area R, and the other area portion is the transmissive display area. T. Therefore, in the liquid crystal device 100 of this modification example, by forming the reflective display region R in the region of the pixels S in this way, the display content can be easily visually recognized in an environment where the outside light is bright, and the black in the transmissive display region T. Since the light leakage of the display is suppressed, the liquid crystal device can provide a high-contrast display regardless of indoors or outdoors.

  Next, the configuration of the pixel S formed in the liquid crystal device 100 of the present modification will be described in detail with reference to the cross-sectional view shown in FIG. FIG. 13 is a schematic view showing a BB cross section in FIG. As shown in the figure, the liquid crystal device 100 has a configuration in which a liquid crystal layer 40 is sandwiched between an element substrate 10 and a counter substrate 30.

  First, the counter substrate 30 will be described. In this modification, unlike the above-described embodiment, the counter substrate 30 has a retardation plate 35 disposed between the overcoat layer 34 and the alignment film 39 in a portion corresponding to the reflective display region R. It is.

  For example, the retardation plate 35 is cured in a state where a photocurable material having birefringence is oriented in a predetermined direction to form a slow axis, and has a predetermined phase difference (1) with respect to incident external light. / 2 wavelength). The retardation plate 35 also serves as a liquid crystal layer thickness adjusting member that varies the thickness of the liquid crystal layer 40 between the reflective display region R and the transmissive display region T depending on its own thickness. Although the description of the retardation plate 35 is omitted here, in order to make the display in the reflective display region R and the transmissive display region T (normally black display in the present modification example) equivalent, Mostly formed.

  Next, the element substrate 10 will be described. In the present modification, unlike the above embodiment, a reflective layer 17R is formed on the element substrate 10 between the common electrode 13 and the planarization layer 17 in a portion corresponding to the reflective display region R. The reflective layer 17R is made of a material such as aluminum, aluminum and copper, an alloy of aluminum and neodymium, or APC (silver-palladium-copper alloy). Further, the surface of the reflective layer 17R is uneven as necessary.

  The reflection layer 17R is provided so as to perform display using the external light in the pixel S by reflecting (diffuse reflection) external light incident from the counter substrate 30 side and returning it to the counter substrate 30 side. Accordingly, in the transmissive display region T, light passes through the liquid crystal layer 40 once for display, whereas in the reflective display region R, light passes through the liquid crystal layer 40 twice, in other words, the upper polarizing plate 60. The display is performed by passing twice.

  Now, in the reflective display region R provided in the pixel S in this way, the upper and lower polarizing plates are attached at different angles in order to suppress light leakage of black display in the transmissive display region T as in the above embodiment. When attached, the angle of the upper polarizing plate 60 is shifted in the reflective display region R. Therefore, in the reflective display region R, it was examined how the light that passes through the upper polarizing plate 60 with the attachment angle shifted twice affects the black display.

  FIG. 14 shows the reflectivity during black display with respect to the deviation angle of the upper polarizing plate 60 when the wavelength λ of the illumination light is “550 nm” and the twist angles are “0 degree” and “1 degree”. It is the graph which showed the result computed by Jones matrix method etc. Note that the phase difference plate 35 gives a ½ wavelength phase difference to the illumination light at a slow layer axis angle of 22.5 degrees, and the liquid crystal layer 40 gives a ¼ wavelength phase difference.

  As shown in the figure, when the liquid crystal layer 40 has a twist of “1 degree”, the position where the reflectivity is smallest, that is, the optimum shift angle of the upper polarizing plate 60 is shifted in the negative direction (counterclockwise). You can see that This is the same direction as the shifting direction of the upper polarizing plate 60 in the transmissive display region T, as described with reference to FIG. Therefore, also in the liquid crystal device 100 of the present modification which is a transflective display device, the reflectance is improved also in the reflective display by pasting the upper polarizing plate so as to suppress the light leakage of the black display in the transmissive display. The effect which suppresses the rise of can be expected. As a result, it is possible to obtain a display with high contrast even in the transflective liquid crystal device 100 as in this modification.

(Third Modification)
The liquid crystal device 100 of the above embodiment or the liquid crystal device 100 of the above modification may be an electronic device in which the display device is incorporated. By so doing, it is possible to provide an electronic device capable of performing display in which a reduction in contrast is suppressed by suppressing light leakage of black display.

  FIG. 15 is an explanatory diagram showing a mobile phone 1 as an electronic apparatus on which the liquid crystal device 100 of the above-described embodiment and the above-described modification is mounted. The liquid crystal device 100 is a lateral electric field driving type liquid crystal device that is driven by applying a lateral electric field in a direction substantially parallel to the liquid crystal layer sandwiched between two substrates, and has a wide viewing angle and a back surface. Since it is possible to reduce the thickness even if a light is included, the device is suitable for a thin electronic device that displays images and characters. Therefore, it is effective as a display device mounted on the mobile phone 1. In particular, since the liquid crystal device 100 according to the above-described modification can perform display with good contrast by using external light, it can be used outdoors as well as indoors. Therefore, portable electronic devices such as the mobile phone 1 can be used. It is effective for. Of course, it can be installed not only in mobile phones but also in other electronic devices such as digital cameras and mobile computers.

(Other variations)
In the above embodiment, the liquid crystal device 100 uses the alignment axis HD1 of the alignment film 19 and the alignment axis HD3 of the alignment film 39 as the direction along the absorption axis φa1 of the lower polarizing plate 50. For example, the orientation axis HD1 of the orientation film 19 and the orientation axis HD3 of the orientation film 39 may be the direction along the transmission axis φp1 of the lower polarizing plate 50. In the above-described embodiment, the display mode uses the light (ordinary light) in the direction orthogonal to the long axis direction of the liquid crystal molecules, but the display mode uses the light (abnormal light) in the long axis direction of the liquid crystal molecules. Even so, if the transmission axis of the polarizing plate on the side from which the illumination light exits is arranged so as to be substantially orthogonal to the transmission axis of the polarizing plate on the side on which the illumination light is incident, black display can be obtained similarly. Accordingly, the same effect can be obtained by sticking the upper and lower polarizing plates in a shifted manner as in the above embodiments and modifications. In this modification, the lower polarizing plate 50 corresponds to the first polarizing plate described in the claims, and the upper polarizing plate 60 corresponds to the second polarizing plate described in the claims. The alignment film 19 corresponds to the first alignment film recited in the claims, and the alignment film 39 corresponds to the second alignment film recited in the claims.

  In the above embodiment, an LED light source is used as the light source 90, but the present invention is not limited to this. For example, a cold cathode fluorescent lamp (CCFL) that is commonly used as a light source of a liquid crystal device can be used. For example, the average value of the coefficient k calculated for the cold cathode tube is approximately k = 2.13 when the retardation Δnd is 360 nm, and a commercially available LED light source (for example, a pseudo white LED manufactured by Nichia Corporation) This is because it exhibits approximately the same value as the average value (k = 2.133 to 2.145) of the coefficient k calculated for Sharp RG phosphor LED).

  Alternatively, in the above embodiment, the liquid crystal device 100 includes the backlight including the light source 90. However, the present invention is not limited to this. There may be no back light (light source). For example, the case where external light is used as a light source can be considered. In this case, there is no need for a backlight, and the liquid crystal device 100 can also be reduced in thickness. Alternatively, the liquid crystal device 100 may be used as a light valve of a projector. In this case, the liquid crystal device 100 does not need a light source.

  Further, in the above-described embodiment, with reference to the bisector CL of the angle “φt” that is an acute angle formed by the orientation axis HD1 and the orientation axis HD3, two angles opened on both sides by the angle “k × φt / 2” are provided. The direction is the direction of the transmission axis φp3 of the upper polarizing plate 60 and the absorption axis φa1 of the lower polarizing plate 50, but it is needless to say that the direction is not necessarily limited thereto. At least the angle φt may exist within an acute angle formed by the transmission axis φp3 of the upper polarizing plate and the absorption axis φa1 of the lower polarizing plate. Specifically, the direction of the transmission axis φp3 of the upper polarizing plate 60 is positioned in the counterclockwise direction with respect to the direction in which the angle φt is expanded, that is, the orientation axis HD3, and the direction of the transmission axis φp1 of the lower polarizing plate 50 is the angle φt The upper polarizing plate 60 and the lower polarizing plate 50 may be attached to each other in a direction in which the angle is widened, that is, in a range positioned clockwise with respect to the orientation axis HD1. Although it is assumed that the effect is less than in the case of the above embodiment, it is possible to suppress light leakage in black display.

  In the above embodiment, a voltage is applied between the pixel electrode 11 and the common electrode 13 formed on the element substrate 10 to generate an electric field in a direction parallel to the element substrate 10 with respect to the liquid crystal layer 40, thereby generating liquid crystal molecules. Although it has been described as an FFS (Fringe-Field Switching) type liquid crystal device that controls the orientation of the liquid crystal, it is of course not limited thereto. As described above, an IPS (In-Plane Switching) method may be used. As is well known, in the case of an IPS mode liquid crystal device, unlike the FFS mode, the pixel electrode and the common electrode each have a comb-tooth shape, so that the respective comb-tooth portions do not overlap each other in plan view. It is formed with a predetermined gap.

  Alternatively, although not shown, the common electrode 13 is formed on the counter substrate 30 side, and a vertical electric field system (applied with an electric field between the pixel electrode 11 formed on the element substrate 10 and the common electrode 13 formed on the counter substrate 30 ( For example, the VA (Vertical Alignment) method or the like may be applied if light leakage occurs in the black display described above.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which showed typically about the liquid crystal device used as one Example of this invention. FIG. 3 is a plan view illustrating a configuration related to a pixel in the liquid crystal device according to the embodiment. FIG. 6 is a partial cross-sectional view of a pixel structure in the liquid crystal device of this embodiment. It is a figure which shows the relationship between the direction of an orientation axis | shaft, the transmission axis of a polarizing plate, and an absorption axis, (a) is a perspective view, (b) is the top view which accumulated each axis. In the contrast contour diagram, (a) shows the optimum direction of the polarizing plate when there is no deviation between the orientation axes, and (b) shows the optimum direction of the polarizing plate when there is a deviation between the orientation axes. . (A) is a graph which shows the relationship between retardation and the transmittance | permeability, (b) is a table which shows the evaluation result of retardation and animation display. The list figure which shows the value of the coefficient k calculated | required about the wavelength and retardation of illumination light. The figure which shows a visibility characteristic. Explanatory drawing which shows the value of the constant in the fitting type | formula which calculates | requires the coefficient k. Explanatory drawing regarding the weighting when calculating | requiring the average value of the coefficient k. Explanatory drawing which shows the twist angle | corner and the optimal deviation | shift angle of the polarizing plate calculated in the 1st modification. The top view which showed the structure regarding the pixel in a liquid crystal device in the 2nd modification. The fragmentary sectional view about the structure of the pixel in a liquid crystal device in a 2nd modification. Explanatory drawing which shows the relationship between the shift | offset | difference angle of an upper polarizing plate, and a reflectance in a 2nd modification. The figure which shows the mobile telephone which is an example of the electronic device provided with the liquid crystal device in the 3rd modification.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Mobile phone, 10 ... Element board | substrate, 11 ... Pixel electrode, 13 ... Common electrode, 14 ... Flat plate, 15 ... Gate insulating layer, 16 ... Interlayer insulating layer, 17 ... Planarization layer, 17R ... Reflective layer, 18 ... Insulation Layer 19, alignment film 20, thin film transistor 20 a semiconductor layer 20 d drain electrode 20 g gate electrode 20 s source electrode 30 counter substrate 31 flat plate 32 light shielding layer 33 filter layer 34 ... Overcoat layer, 35 ... Retardation plate, 39 ... Alignment film, 40 ... Liquid crystal layer, 50 ... Lower polarizing plate, 60 ... Upper polarizing plate, 90 ... Light source, 91 ... Light guide member, 100 ... Liquid crystal device, DESCRIPTION OF SYMBOLS 110 ... Data drive circuit, 111 ... Data line, 120 ... Scan drive circuit, 121 ... Scan line, 130 ... Electrode terminal, 131 ... Common wiring.

Claims (10)

A first substrate;
A second substrate facing the first substrate;
A liquid crystal layer sandwiched between the first substrate and the second substrate;
A first alignment film having an alignment axis on the liquid crystal layer side of the first substrate;
The liquid crystal layer side of the second substrate, a second alignment layer having alignment shaft formed so as to be parallel to the alignment axis of the first alignment layer,
A first polarizing plate having a transmission axis on the opposite side of the liquid crystal layer of the first substrate;
A second polarizing plate having an absorption axis intersecting the transmission axis of the first polarizing plate on the opposite side of the liquid crystal layer of the second substrate;
A liquid crystal device comprising:
The first acute angle range formed by crossing the alignment axis of the first alignment film and the alignment axis of the second alignment film formed so as to be shifted from each other is the transmission axis of the first polarizing plate. Is set within a second acute angle range formed by intersecting the absorption axis of the second polarizing plate;
The transmission axis of the first polarizing plate is disposed in a direction beyond the alignment axis of the first alignment film forming the first acute angle from the alignment axis of the second alignment film, and the second polarization An absorption axis of the plate is arranged in a direction opposite to a direction in which the alignment axis of the first alignment film is arranged with respect to the alignment axis of the second alignment film. The liquid crystal device according to claim 1,
The liquid crystal device according to claim 1, wherein the first acute angle center line and the second acute angle center line are substantially in the same direction. The liquid crystal device according to claim 1 or 2,
2. The liquid crystal device according to claim 2, wherein the second acute angle is 7.5 degrees or less. The liquid crystal device according to any one of claims 1 to 3,
The angle ratio k of the second acute angle to the first acute angle is expressed as follows: Δn is the refractive index anisotropy of the liquid crystal molecules in the liquid crystal layer, and d is the thickness of the liquid crystal layer.
k = a × exp (b × Δnd) + c
(A, b, c are constants determined according to the wavelength of light passing through the liquid crystal layer)
A liquid crystal device having a value satisfying The liquid crystal device according to claim 1, wherein the liquid crystal device is a liquid crystal device according to claim 1.
A pair of either the first substrate or the second substrate applies an electric field in a direction along the first substrate or the second substrate to control the alignment direction of the liquid crystal molecules in the liquid crystal layer. A liquid crystal device comprising an electrode. The liquid crystal device according to claim 5,
At least one electrode of the pair of electrodes has a shape provided with a slit-like opening or a comb-like shape. The liquid crystal device according to any one of claims 1 to 6,
A transmissive display region in which light that irradiates the liquid crystal device passes through the liquid crystal layer once to perform display;
A liquid crystal device, comprising: a reflective display region that performs display by passing through the liquid crystal layer twice. A liquid crystal device according to any one of claims 1 to 7,
It has a light source that emits illumination light,
The illumination light is irradiated in one of a direction from the first polarizing plate toward the second polarizing plate, or a direction from the second polarizing plate toward the first polarizing plate. A liquid crystal device characterized by the above. The liquid crystal device according to claim 8,
The liquid crystal device, wherein the light source is an LED light source.   An electronic apparatus comprising the liquid crystal device according to claim 1.

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