JP2013054321A - Liquid crystal display device and optical control element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable display unevenness such as moire to be suppressed and enable a bright and high resolution image to be displayed.SOLUTION: In an inventive liquid crystal display device 1, light emitted from light-emitting devices 9, 10 passes through a liquid crystal panel 2 via an optical control element 11. The optical control element 11 is an integral resin sheet including a first face in which a plurality of triangle columnar prisms 14 are arrayed so that longitudinal directions of the triangle columnar prisms 14 are in parallel with one another and a second face in which a plurality of semi-cylindrical lenses 13 are arrayed so that they are arranged back-to-back of the plurality of triangle columnar prisms 14 and longitudinal directions of the semi-cylindrical lenses 13 are in parallel with one another. The longitudinal directions of the plurality of triangle columnar prisms 14 and the longitudinal directions of the plurality of semi-cylindrical lenses 13 have a moire suppression angle θ in plan view.

Description

  The present invention relates to a liquid crystal display device and a light control element for displaying a three-dimensional image.

  A liquid crystal cell of a general liquid crystal display device has a configuration in which a liquid crystal layer is sandwiched between transparent substrates such as glass substrates. The liquid crystal display device includes a liquid crystal panel having a polarizing plate and a retardation plate attached to the front and back of the liquid crystal cell. The liquid crystal display device in the first example includes a backlight as a light source on the back surface of the liquid crystal panel opposite to the observer. The liquid crystal display device in the second example uses an external light source such as room light in addition to the backlight. In a liquid crystal display device capable of displaying a three-dimensional image and a liquid crystal display device capable of controlling a viewing angle, a liquid crystal panel using a backlight or an external light source controls an emission angle of light from the surface of the liquid crystal panel according to the display purpose.

  Various types of liquid crystal display devices or displays capable of displaying a three-dimensional image are known. These methods include a method using glasses and a method not using glasses. The method using glasses includes an anaglyph method using a difference in color or a polarized glasses method using polarized light. In the method using glasses, it is troublesome because the observer needs to wear dedicated glasses during three-dimensional viewing. In recent years, there is a strong demand for a method that does not require glasses.

  The surface of the liquid crystal panel is used to adjust the angle of light emitted from the liquid crystal panel to one or more observers (hereinafter sometimes referred to as “two-lens” and “multi-lens”, respectively). Or the technique which arrange | positions the light control element in the back surface is examined.

  The light control elements used in the liquid crystal display device for three-dimensional image display that does not require glasses are roughly divided into three types.

  The first is a lenticular lens system in which optical lenses are two-dimensionally arranged and regular refraction is used. The lenticular lens is processed into a sheet shape with a transparent resin or the like, and is attached to the front or back surface of the liquid crystal display device. Patent Document 1 (Japanese Patent No. 4010564) and Patent Document 2 (Japanese Patent No. 4213226) disclose a three-dimensional image display technique using a lenticular lens (lenticular screen). Techniques including a prism sheet having a convex lens are disclosed in Patent Documents 3 to 9 (JP 2010-506214 A, JP 2010-524047 A, JP 2010-541019 A, and JP 2010-541020 A). No. 4,655,465, No. 3930021, and No. 3,585,781).

  The second is a parallax barrier system in which light-shielding slits called parallax barriers are two-dimensionally arranged in one direction, and emitted light for right and left eyes is emitted using this two-dimensional arrangement. Patent Document 10 (Japanese Patent Laid-Open No. 2007-11254), Patent Document 11 (Japanese Patent Laid-Open No. 2009-139947), and Patent Document 12 (Japanese Patent Laid-Open No. 2010-210882) disclose a three-dimensional image display technique using a parallax barrier. Is disclosed.

  The third is a flexible lens eye system that uses an optical element (for example, a liquid crystal or a ferroelectric piezoelectric element) whose refractive index or phase axis is variable by voltage application or the like to control emitted light related to a three-dimensional image. is there. A technique using a liquid crystal lens eye is disclosed in Patent Document 13 (Japanese Patent Laid-Open No. 2000-102038) and Patent Document 14 (Japanese Patent No. 3940725).

  Further, Patent Document 9 discloses a technique of applying one prism sheet to 3D image display. A technique for superimposing one of the two condensing sheets having the prism portion at an angle of 5 to 85 ° in the clockwise direction and the other at an angle of 5 to 85 ° in the counterclockwise direction is disclosed in Patent Document 15 (Japanese Patent No. 2723414). ).

Japanese Patent No. 4010564 Japanese Patent No. 4213226 JP 2010-506214 A JP 2010-524047 A JP 2010-541019 A JP 2010-541020 A Japanese Patent No. 4655465 Japanese Patent No. 3930021 Japanese Patent No. 3585781 JP 2007-11254 A JP 2009-139947 A JP 2010-210982 A JP 2000-102038 A Japanese Patent No. 3940725 Japanese Patent No. 3585781

  In the lenticular lens systems as described in Patent Documents 1 to 9, the technique disclosed in Patent Document 1 is to form display elements (pixels) in a parallelogram or triangular shape, or arrange display elements with an offset. This is a technique for providing an angle with the pixel array substantially with respect to the lenticular screen. This Patent Document 1 is a technique for giving a viewer a continuous (smooth) horizontal parallax as in Patent Document 2. In this Patent Document 1, there is a case where the display is jagged by the pixel array arranged substantially obliquely and the edge of the lenticular screen intersecting the pixel array. Patent Document 1 does not disclose a technique for optimizing the orientation of liquid crystal molecules in relation to a three-dimensional light control element and reducing moire in three-dimensional image display by providing an angle θ to a triangular prism. .

  The technique disclosed in Patent Document 2 is a technique for providing an offset angle between the principal axis of a lenticular screen and the arrangement of pixels (picture elements). In Patent Document 2, the lenticule with an offset angle reduces the loss of resolution of the three-dimensional image display, and provides a smooth display when the observer's head moves (the screen switches slowly). However, in Patent Document 2, since the edge of the lenticular screen arranged obliquely intersects the pixel array, the display may be jagged. Patent Document 2 discloses a technique for optimizing the orientation of liquid crystal molecules in relation to a light control element for three-dimensional image display and reducing the moire in three-dimensional image display by providing an angle θ to a triangular prism. Absent.

  In Patent Documents 3 to 6, an optically compensated bend mode (Optically Compensated Bend: OCB) mode liquid crystal is applied to three-dimensional image display. In Patent Documents 3 to 6, OCB is described only from the viewpoint of the response time of liquid crystal necessary for displaying a three-dimensional image. However, Patent Documents 3 to 6 do not disclose a liquid crystal display device that optimizes the light distribution related to the liquid crystal molecules themselves used in the liquid crystal panel and enables bright three-dimensional image display and two-dimensional image display. For example, Patent Documents 3 to 6 describe a three-dimensional image for right and left eyes in which direction the OCB liquid crystal molecules are aligned with respect to the light distribution angle of the light source of the right eye image and the light distribution angle of the light source of the left eye image. It is best disclosed or not disclosed. In addition, the OCB liquid crystal has a worse viewing angle characteristic than IPS (a liquid crystal panel with a horizontal electric field using liquid crystal molecules with horizontal light distribution) or VA (a liquid crystal panel with a vertical electric field using liquid crystal molecules with vertical alignment). In the OCB liquid crystal, a transition operation from the splay alignment, which is the initial alignment, to the bend alignment during driving is necessary every time the panel is activated. For this reason, the OCB liquid crystal may not be preferable as a liquid crystal display device for small portable devices.

  Patent Documents 3 to 7 all disclose a double-sided prism sheet having a cross-sectional shape disclosed in Patent Document 8. In Patent Documents 3 to 7, three-dimensional image display is performed using light sources on both sides of a backlight. However, as in Patent Document 8, Patent Documents 3 to 7 do not disclose a countermeasure for eliminating moire caused by interference between a prism sheet and a liquid crystal panel, which is likely to occur in three-dimensional image display. Furthermore, Patent Documents 3 to 7 do not disclose liquid crystal display devices that optimize light distribution related to liquid crystal molecules used in the liquid crystal panel and enable bright three-dimensional image display and two-dimensional image display.

  Patent Document 8 discloses a double-sided prism sheet that includes a cylindrical lens array parallel to a triangular prism array, and the focal position of the cylindrical lens coincides with the apex of the prism. FIG. 1 or FIG. 2 of Patent Document 8 represents a technique for displaying a three-dimensional image using this double-sided prism sheet and light sources on both sides of the backlight. However, with the technique of Patent Document 8, it is difficult to eliminate moire due to interference between the cylindrical lens array and the liquid crystal panel, which is likely to occur in three-dimensional image display. Furthermore, Patent Document 8 does not disclose a liquid crystal display device that optimizes light distribution related to liquid crystal molecules used in a liquid crystal panel and enables bright three-dimensional image display and two-dimensional image display. Patent Document 8 does not consider matching with a color filter generally used in a color liquid crystal display device, and a double-sided prism sheet may not be sufficient as a light control element for displaying a color three-dimensional image. Furthermore, in Patent Document 8, it is difficult to provide an optimal solution in a three-dimensional image display using a plurality of subpixels for a liquid crystal panel that does not use a color filter. Patent Document 8 does not disclose optimization from the viewpoint of alignment of liquid crystal molecules or liquid crystal operation used in a liquid crystal panel.

  Since the parallax barrier methods such as Patent Documents 10 to 12 described above use light-shielding slits, the light transmittance is low. In the parallax barrier method, when the position of the observer is not preferable, the non-display area due to the light-shielding slit may interfere with the observer's observation, and as a result, the range in which the stereoscopic image cannot be observed may be widened.

  The flexible lens array system as described in Patent Documents 13 and 14 can reduce the lower transmittance than the parallax barrier system. However, when a parallax barrier method and a flexible lens array method are applied to a mobile phone or a game device in which a single observer (two-lens type) uses a small liquid crystal panel, the liquid crystal panel becomes thicker and heavier. Tend.

  Patent Document 15 does not have the concept of 3D image display technology, and does not disclose a method for switching between 3D image display and 2D image display, and optimization of liquid crystal alignment and 3D image display.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal display device and a light control element that effectively realize three-dimensional image display or two-dimensional image display.

  In the first aspect, in the liquid crystal display device, the light emitted from the light emitting element passes through the liquid crystal panel via the light control element. The light control element includes a plurality of triangular prisms arranged back to back with a first surface in which the longitudinal directions of the triangular prisms are parallel to each other, and a plurality of semi-cylindrical lenses. It is an integral resin sheet provided with the 2nd surface arranged so that the longitudinal direction of the said semi-columnar lens may become mutually parallel. The longitudinal direction of the plurality of triangular prisms and the longitudinal direction of the plurality of semi-cylindrical lenses have a moire suppression angle θ in plan view.

  In the second aspect, the light control element includes a first surface in which a plurality of triangular prisms are arranged so that longitudinal directions of the triangular prisms are parallel to each other, and a plurality of semi-cylindrical lenses. An integral resin sheet comprising a triangular prism and a second surface arranged back to back and arranged so that the longitudinal directions of the semi-cylindrical lenses are parallel to each other. The longitudinal direction of the plurality of triangular prisms and the longitudinal direction of the plurality of semi-cylindrical lenses have a moire suppression angle θ in plan view.

  In the embodiment of the present invention, display unevenness such as moire can be reduced, and a bright and high-resolution image can be displayed.

FIG. 3 is a partial cross-sectional view illustrating an example of a liquid crystal display device including the light control element according to the first embodiment. FIG. 3 is a partial plan view showing an example of a light control element according to the first embodiment. FIG. 3 is a plan view showing an example of a relationship between a pixel array and a triangular prism according to the first embodiment. FIG. 3 is a partial cross-sectional view illustrating a first example of a relationship between the liquid crystal panel and the light control element according to the first embodiment. The fragmentary sectional view which shows the 2nd example of the relationship between the liquid crystal panel and light control element which concern on 1st Embodiment. FIG. 3 is a partial cross-sectional view showing an example of the configuration of the liquid crystal display device according to the first embodiment in a state where no voltage is applied. FIG. 3 is a partial cross-sectional view illustrating an example of the configuration of the liquid crystal display device according to the first embodiment in a state in which a liquid crystal driving voltage is applied to the right pixel electrode. FIG. 3 is a partial cross-sectional view showing an example of the configuration of the liquid crystal display device according to the first embodiment in a state in which a liquid crystal driving voltage is applied to the left pixel electrode. The fragmentary sectional view which shows an example of the state of the initial stage vertical alignment of the liquid crystal molecule with a negative dielectric constant anisotropy. The fragmentary sectional view which shows an example of the liquid crystal voltage drive state of the liquid crystal molecule whose dielectric constant anisotropy is negative. FIG. 6 is a partial cross-sectional view showing an example of a state of initial vertical alignment of liquid crystal molecules having a positive dielectric anisotropy. The fragmentary sectional view which shows an example of the liquid crystal voltage drive state of a liquid crystal molecule with positive dielectric anisotropy. The fragmentary sectional view which shows an example of the state before the liquid-crystal drive voltage application of the liquid crystal display device which concerns on 2nd Embodiment. The fragmentary sectional view which shows an example of the state after the liquid-crystal drive voltage application of the liquid crystal display device which concerns on 2nd Embodiment. The figure which shows the relationship between the partial cross section which shows an example of the light control element which concerns on 3rd Embodiment, and a partial plane. The partial top view which shows an example of arrangement | positioning of a sub pixel of "<" shape. The partial top view which shows the 1st example of arrangement | positioning of a parallelogram subpixel. The partial top view which shows the 2nd example of arrangement | positioning of a subpixel of a parallelogram. The fragmentary sectional view which shows an example of the pixel comprised by a rectangular subpixel.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same or substantially the same functions and components are denoted by the same reference numerals, and will be described as necessary.

  In the following embodiments, only characteristic portions will be described, and descriptions of portions that are not different from the components of a normal liquid crystal display device will be omitted.

  In the following embodiments, a single color display unit of the liquid crystal display device is assumed to be one subpixel or one pixel.

[First Embodiment]
FIG. 1 is a partial cross-sectional view illustrating an example of a liquid crystal display device including a light control element according to the present embodiment.

  The liquid crystal display device 1 includes a liquid crystal panel 2, a polarizing plate 3, a backlight unit 4, and the like as basic components.

  The liquid crystal panel 2 has a configuration in which the counter substrate 5 and the array substrate 6 are opposed to each other, and a liquid crystal layer 7 is provided between the counter substrate 5 and the array substrate 6. The liquid crystal panel 2 has a plurality of pixels arranged, each including a red subpixel, a green subpixel, and a blue subpixel.

  The polarizing plate 3 and a retardation plate (not shown) are provided on the front surface (one flat surface) side and the back surface (the other flat surface) side of the liquid crystal panel 2.

  The counter substrate 5 includes a color filter 8. The color filter 8 includes a red filter corresponding to the red subpixel, a green filter corresponding to the green subpixel, and a blue filter corresponding to the blue subpixel.

  The backlight unit 4 is provided on the back surface of the liquid crystal panel 2 via the polarizing plate 3. The backlight unit 4 includes solid light emitting elements 9 and 10 such as LEDs, a light control element 11, a reflector 12 and the like as basic components. The backlight unit 4 may include, for example, a diffusion plate, a light guide plate, a polarization separation film, a retroreflective polarizing element, and the like, but is omitted in FIG.

  For example, when the solid light emitting elements 9 and 10 are LEDs (light emitting diodes), a plurality of white LEDs that emit white light including three wavelengths of red, green, and blue in the emission wavelength region may be applied. A pseudo white LED in which a GaN blue LED and a YAG fluorescent material are combined may be applied. In order to improve the color rendering properties of the pseudo white LED, an LED having one or more main peaks such as a red LED may be used together with the pseudo white LED. For example, a light source combining red and green phosphors may be used for the blue LED. The solid-state light emitting elements 9 and 10 each include LEDs that individually emit red, green, and blue light. By synchronizing field sequential (time-division) light emission with liquid crystal driving, a color filter 8 is not used. Display can be made.

  The solid light emitting elements 9 and 10 may be provided at positions corresponding to two opposite sides of the liquid crystal panel 2.

  The light control element 11 is formed using a transparent resin. The light control element 11 is a resin sheet in which a semi-cylindrical lens 13 and a triangular prism 14 are integrated on the front and back. The arc side of the semicircular cross section of the semi-cylindrical lens 13 faces outward, and the first vertex of the triangular cross section of the triangular prism 14 faces outward. That is, the semi-cylindrical lens 13 and the triangular prism 14 are provided in the light control element 11 so as to be back to back.

  Light emitted from the solid light emitting elements 9 and 10 passes through the liquid crystal panel 2 via the light control element 11 and is observed by an observer.

  FIG. 2 is a partial plan view showing an example of the light control element 11 according to the present embodiment.

  The semi-cylindrical lens 13 has a plurality of semi-cylindrical lens units 131 to 133 arranged so that their optical axes (longitudinal directions) A are parallel to each other.

  The triangular prism 14 has a plurality of triangular prisms 141 to 143 arranged so that their optical axes (longitudinal directions) B are parallel to each other.

  In the present embodiment, the optical axes A and B are the ridge line directions of the semi-cylindrical lens 13 and the triangular prism prism 14, respectively.

  The optical axis A of the semi-cylindrical lens 13 and the optical axis B of the triangular prism 14 have a moire suppression angle θ in plan view. Having this angle θ means that the optical axis A and the optical axis B are not parallel (not 0 °).

The light control element 11 is formed in a rectangular shape in plan view. The optical axis A of the semi-cylindrical lens 13 is parallel to the two opposite sides of the liquid crystal panel 2.
The solid light emitting elements 9 and 10 emit light in a direction perpendicular to the optical axis B of the triangular prism prism 14.

  FIG. 3 is a plan view showing an example of the relationship between the pixel array and the triangular prism 14 according to the present embodiment.

  For example, the liquid crystal panel 2 is configured based on a matrix arrangement of a plurality of pixels or a plurality of subpixels. The longitudinal direction C of the plurality of pixels or the plurality of sub-pixels and the longitudinal direction B of the triangular prism 14 have a moire suppression angle θ in plan view. Thereby, moire at the time of displaying a three-dimensional image can be made inconspicuous.

  Moire can increase the relaxation effect by setting θ to a large angle close to 45 degrees. However, for example, if θ is 45 degrees, there is a possibility of interference with the optical axis of the polarizing plate 3 and a retardation plate (not shown). Therefore, the upper limit of θ is slightly smaller than 45 degrees. Therefore, θ belongs to a range larger than 0 ° and smaller than 45 degrees.

  Considering the alignment error (± 2 °) between the polarizing plate 3 and the liquid crystal panel 2, the maximum value of the angle θ can be set to 43 degrees or less. On the contrary, the moire at the time of displaying a three-dimensional image, when θ is close to zero, a large low-frequency moire is conspicuous, and is easily recognized as light / dark or color unevenness. Considering alignment errors such as bonding, the lower limit is 3 °. As described above, the larger the angle θ between the optical axis A of the semi-cylindrical lens 13 and the optical axis B of the triangular prism 14 is, the less moire is noticeable when displaying a three-dimensional image. In other words, as the angle θ is larger, the low frequency moire has a finer pitch at a high frequency, so that the moire can be made less visible.

  In the present embodiment, even when the angle θ is small, the moiré is effectively reduced by making the formation pitch of the triangular prisms 14 finer than the formation pitch of the semicylindrical lenses 13. can do.

  Specifically, when the arrangement pitch of the semicylindrical lenses 13 is 1, the arrangement pitch of the triangular prisms 14 can be 1 / n (n is an integer in the range of 2 to 150).

  Note that the angle between the optical axis A of the semi-cylindrical lens 13 and the optical axis B of the triangular prism 14 may be an angle obtained by adding 90 °, 180 °, 270 °, etc. to the value of θ in FIG. Moire can be eliminated as in the case of θ in FIG. Further, the angle between the optical axis A of the semi-cylindrical lens 13 and the optical axis B of the triangular prism 14 is symmetric with θ in FIG. As in the case of θ of 2, moire can be eliminated.

  FIG. 4 is a partial cross-sectional view showing a first example of the relationship between the liquid crystal panel 2 and the light control element 11 according to the present embodiment.

  FIG. 5 is a partial cross-sectional view showing a second example of the relationship between the liquid crystal panel 2 and the light control element 11 according to the present embodiment.

  4 and 5, six subpixels each including a red filter R1, a green filter G1, a blue filter B1, a red filter R2, a green filter G2, and a blue filter B2, and one semi-cylindrical lens unit 131. , Six triangular prism-shaped prism units 141 to 146 are associated with each other. In this case, 1 / n is written as “1/6”. For example, when a three-dimensional image display corresponding to the right eye and the left eye is performed in a configuration without the color filter 8, n is 2 or 3 as a minimum unit. As n indicating the number of triangular prism units with respect to one semi-cylindrical lens unit is increased, the moire improvement effect related to the three-dimensional image display is increased. In the configuration in which the color filter 8 including three color filters is provided, n is a multiple of 3, such as 6, 9, 12, 15, 18, for example, by associating the triangular prism unit with each filter. Can be. In the case where the liquid crystal panel 2 does not include the color filter 8, color display is possible by a field sequential method using solid light-emitting elements that emit light of three colors. Based on the wavelength of visible light and its light refraction efficiency, the minimum value of the height H of the triangular prism 14 can be defined. As the triangular prisms 14 are formed with a smaller pitch, the moire reduction effect at the time of displaying a three-dimensional image can be increased, but there is a contrast between liquid crystal display and the relationship between the reduction of moire and the trade-off. In other words, as the triangular prisms 14 are formed with a smaller pitch, the light scattering effect becomes higher, and the contrast of the liquid crystal display decreases due to the inverse correlation with the front luminance. For example, when the height H of the triangular prism 14 is less than 2 μm, there may be a significant decrease in front luminance and a decrease in contrast as a liquid crystal display device. For example, it is assumed that the pitch of the largest semi-cylindrical lens 13 of a large liquid crystal display device is about 300 μm. When the height H of the triangular prism 14 is 2 μm, which is the lower limit, and the pitch 300 μm of the semi-cylindrical lens 13 is divided, the minimum pitch of the triangular prism 14 is calculated as 1/150 for one of the semi-cylindrical lenses 13. Is done. The upper limit of n is set to 150.

  Specific examples of the resin material forming the light control element 11 according to this embodiment include methacrylic resin, polycarbonate resin, styrene resin, cyclic olefin resin, and amorphous polyester resin. The manufacturing method of the light control element 11 using these transparent resins is not particularly limited. For example, the semi-cylindrical lens 13 and the triangular prism prism 14 may be formed on the front and back by injection molding using a mold, and the resin sheet-like light control element 11 may be formed. Alternatively, a resin sheet in which the triangular prism prism 14 is formed on one side is manufactured by extrusion molding, and a resin sheet in which the semi-cylindrical lens 13 is formed on one side is manufactured by extrusion molding, and these two resin sheets are bonded with adhesive. The light control element 11 may be formed by attaching the front and back to the semi-cylindrical lens 13 and the triangular prism prism 14, respectively. The refractive index of the adhesive used here is preferably the same as that of the resin of the light control element 11.

  The example of FIG. 4 shows a state in which a drive voltage is applied to the pixel electrode of the green subpixel corresponding to the green filter G1 and the pixel electrode of the green subpixel corresponding to the green filter G2. In FIG. 4, the longitudinal directions of the liquid crystal molecules 7 a to 7 d are inclined and are in the “ON” state. On the right side of FIG. 4, a solid-state light emitting element 10 that emits white light (including at least red, green, and blue wavelengths) is provided. A light beam L synchronized with the liquid crystal drive of the green subpixel corresponding to the green filter G1 and the liquid crystal drive of the green subpixel corresponding to the green filter G2 is incident on the light control element 11 from the solid light emitting element 10. The light beam L enters the triangular prism prism 14 located below the light control element 11, passes through the semi-cylindrical lens 13, passes through the green filters G 1 and G 2 of the liquid crystal panel 2, and has a light distribution angle α. Emitted.

  The green subpixel corresponding to the green filter G1 in FIG. 4 and the green subpixel corresponding to the green filter G2 are, for example, one side (right side) corresponding to these two subpixels as shown in FIG. By applying a driving voltage to the pixel electrode, liquid crystal alignment is realized to realize the light distribution angle α.

  5 and 4 have the same basic configuration, but the inclination of the liquid crystal molecules 7a to 7d is reversed. FIG. 5 shows a state in which a driving voltage is applied to the pixel electrode of the green subpixel corresponding to the green filter G1 and the pixel electrode of the green subpixel corresponding to the green filter G2. The liquid crystal molecules 7a to 7d in FIG. 5 are inclined in the opposite direction to the liquid crystal molecules 7a to 7d in FIG. 4 and are in the “ON” state. On the left side of FIG. 5, a solid-state emitting element 9 that emits white light (including at least red, green, and blue wavelengths) is provided. A light beam L synchronized with the liquid crystal drive of the green subpixel corresponding to the green filter G1 and the liquid crystal drive of the green subpixel corresponding to the green filter G2 is incident on the light control element 11 from the solid light emitting element 9. The light beam L is incident on the triangular prism prism 14 located below the light control element 11, passes through the semi-cylindrical lens 11, passes through the green filters G 1 and G 2 of the liquid crystal panel 2, and has a light distribution angle α. Emitted.

  The green subpixel corresponding to the green filter G1 in FIG. 5 and the green subpixel corresponding to the green filter G2 are, for example, formed on one side (left side) pixel electrode corresponding to the subpixel as shown in FIG. By applying a driving voltage, the liquid crystal alignment achieves the light distribution angle α.

  In the color filter 8 shown in FIGS. 4 and 5, the arrangement order of red filter → green filter → blue filter is repeated. In other words, in FIG. 4 and FIG. 5, each subpixel is repeatedly arranged in the order of red subpixel → green subpixel → blue subpixel.

  One pixel (display unit) of the liquid crystal panel 2 has two sets of a red filter, a green filter, and a blue filter arranged in the same order in the horizontal direction. For example, one pixel may include a first set including a first red subpixel, a first green subpixel, a first blue subpixel, a second red subpixel, a second green subpixel, And a second set including two blue sub-pixels. By making the arrangement order of the subpixels the same in the adjacent first group and the second group, the emitted light of the adjacent first group and the second group can be made uniform, and the viewing angle can be made uniform. A wide two-dimensional image display can be realized. In the two-dimensional image display, the left and right solid state light emitting devices 9 and 10 emit light at the same timing, and the adjacent first group and second group shown in FIGS. 4 and 5 are “ON” at the same timing. It is realized by putting it in a state. In the case where two active elements are provided in one pixel or one subpixel, a brighter two-dimensional image display can be realized by simultaneously sending drive signals to the two active elements.

  Hereinafter, the liquid crystal alignment of the liquid crystal display device 1 according to the present embodiment will be described with reference to FIGS. In FIG. 6 to FIG. 8, the alignment film, the solid light emitting elements 9 and 10 as the light source, the polarizing plate 3, the light control element 11, the retardation plate 12, and the reflection plate 12 are omitted.

  FIG. 6 is a partial cross-sectional view showing an example of the configuration of the liquid crystal display device 1 according to the present embodiment in a state where no voltage is applied. FIG. 6 shows a vertically aligned state (normally black) in which no voltage is applied to the liquid crystal molecules 71 to 78 of the liquid crystal layer 7.

  FIG. 6 shows a cross section of the green sub-pixel. FIG. 6 is a cross section perpendicular to the longitudinal direction of the two sides of the black matrix frame pattern.

  The counter substrate 5 includes a transparent substrate 15, a black matrix BM, a color filter 8, a transparent resin layer 16, and a plurality of counter electrodes 17a and 17b.

  The black matrix BM is formed on one plane of the transparent substrate 15. The black matrix BM divides the plane of the transparent substrate 15 into pixel units or sub-pixel units. The black matrix BM forms a light shielding part and a plurality of openings through which light passes on the plane of the transparent substrate 15.

  The color filter 8 is formed on the plane of the transparent substrate 15 and the black matrix BM. For example, each color filter R1, G1, B1 is formed in the opening of the black matrix BM.

  The transparent resin layer 16 is formed on the color filter 8.

  The plurality of counter electrodes 17a and 17b are on the upper side of the transparent substrate 15, and are formed on the transparent resin layer 16 in the example of FIG. The plurality of counter electrodes 17a and 17b have a linear shape, a comb-like shape, a strip shape, or a stripe shape, and are formed in pixel units or sub-pixel units. Here, the line shape, the comb shape, the band shape or the stripe shape is a pattern having a certain width and extending in the longitudinal direction. For example, it is assumed that the band shape is wider than the line shape. The line widths of the line shape, the comb shape, the band shape, and the stripe shape can be appropriately adjusted based on conditions such as the screen size of the liquid crystal display, the required aperture ratio, and the light distribution angle.

  In the present embodiment, the black matrix BM includes a frame pattern b1 including two sides facing each other in parallel in a pixel unit or a sub-pixel unit. Further, the black matrix BM includes a linear center pattern b2 that is parallel to the two sides of the frame pattern b1 and is formed at the center of the pixel unit or subpixel unit.

  Each of the counter electrodes 17a and 17b is parallel to the two sides of the frame pattern b1 and the central pattern b2. The counter electrodes 17a and 17b are arranged symmetrically with respect to the central axis E in the vertical direction passing through the central pattern b2 in the cross section of FIG. 6 perpendicular to the longitudinal direction of the two sides of the frame pattern b1.

  When the counter substrate 5 is provided in the liquid crystal display device 1, the other plane side of the transparent substrate 15 faces the viewer side (the surface side of the liquid crystal display device 1), and the counter electrodes 17 a and 17 b side are on the liquid crystal layer 7 side. Placed in.

  In the cross section of FIG. 6, the distance D1 between the cross-sectional center of the counter electrodes 17a and 17b and the cross-sectional center of the frame pattern b1 is the distance D2 between the cross-sectional center of the counter electrodes 17a and 17b and the cross-sectional center of the central pattern b2. Bigger than. In the counter substrate 5, the plurality of counter electrodes 17a17b sandwich the central pattern b2 in a plan view, and in the vertical direction F1, a part of the plurality of counter electrodes 17a, 17b and a part of the central pattern b2 are color filters. 8 and the transparent resin layer 16 are opposed to each other. That is, the counter electrodes 17a and 17b are close to the central axis E side in the horizontal direction F2 of the cross section of FIG.

  The counter electrodes 17 a and 17 b may be formed between the transparent substrate 15, the black matrix BM and the color filter 8, or may be formed between the color filter 8 and the transparent resin layer 16.

  The array substrate 6 includes a transparent substrate 18, insulating layers 19a to 19c, light shielding patterns 20a and 20b, common electrodes 21a and 21b, and pixel electrodes 22a and 22b. The formation side of the pixel electrodes 22a and 22b of the array substrate 6 faces the liquid crystal layer 7 side, and the transparent substrate 18 of the array substrate 6 faces the backlight unit 4 side.

  An insulating layer 19 a is formed on the transparent substrate 18.

  On the insulating layer 19a, light shielding patterns 20a and 20b are selectively formed. The light shielding pattern 20a faces the frame pattern b1 of the black matrix BM in the vertical direction F1. The light shielding pattern 20b faces the central pattern b2 of the black matrix BM in the vertical direction F1. For example, the light shielding patterns 20a and 20b are formed of a light reflective metal thin film.

  An insulating layer 19b is formed on the insulating layer 19a and the light shielding patterns 20a and 20b.

  Common electrodes 21a and 21b are formed on the insulating layer 19b. The common electrodes 21a and 21b can be, for example, linear, comb-shaped, strip-shaped, or striped for each pixel or subpixel.

  An insulating layer 19c is formed on the insulating layer 19b and the common electrodes 21a and 21b.

  Pixel electrodes 22a and 22b are formed on the insulating layer 19c.

  The pixel electrodes 22a and 22b can be, for example, linear, comb-shaped, strip-shaped, or striped for each pixel or subpixel. The pixel electrodes 22a and 22b are electrically connected to the active elements 23a and 23b, respectively.

  The active elements 23a and 23b are connected to the pixel electrodes 22a and 22b, respectively, and can drive the pixel electrodes 22a and 22b. The active elements 23a and 23b are, for example, oxide thin film transistors (TFTs) using a metal oxide as a channel material.

  The counter electrodes 17a and 17b and the common electrodes 21a and 21b have, for example, the same common potential.

  Each of the counter electrodes 17a and 17b is parallel to the longitudinal direction of the two sides (side sides) and the center pattern b2, the pixel electrodes 22a and 22b, and the common electrodes 21a and 21b of the frame pattern b1 of the black matrix BM.

  The plurality of counter electrodes 17a and 17b, the plurality of common electrodes 21a and 21b, and the plurality of pixel electrodes 22a and 22b are arranged symmetrically with respect to the central axis E passing through the central pattern b2 in the cross section of FIG. The plurality of counter electrodes 17a and 17b, the plurality of common electrodes 21a and 21b, and the plurality of pixel electrodes 22a and 22b are shifted from each other in the horizontal direction F2 of the cross section in FIG.

The longitudinal direction of the counter electrodes 17a and 17b and the longitudinal direction of the pixel electrodes 22a and 22b are parallel to each other. The counter electrodes 17a and 17b and the pixel electrodes 22a and 22b are partially opposed to each other through the liquid crystal layer 7 in the direction F1 perpendicular to the plane of the transparent substrates 15 and 18. Part of the pixel electrodes 22a and 22b protrudes beyond the counter electrodes 17a and 17b in a direction opposite to the central axis E (on the end side of the subpixel) in the horizontal direction F2 of the cross section of FIG. , 22b and the longitudinal direction of the common electrodes 21a, 21b are parallel to each other. The pixel electrodes 22a and 22b and the common electrodes 21a and 21b partially face each other through the insulating layer 19c in the vertical direction F1. Part of the common electrodes 21a and 21b protrudes beyond the pixel electrodes 22a and 22b in the direction opposite to the central axis E in the horizontal direction F2 of the cross section of FIG.

  In the liquid crystal panel 2, the array substrate 6 including the pixel electrodes 22 a and 22 b and the common electrodes 20 a and 20 b and the counter substrate 5 including the counter electrodes 17 a and 17 b are opposed to each other. A liquid crystal layer 7 is provided. In the vertical direction F1, the common electrodes 21a and 21b and the counter electrodes 17a and 17b sandwich the pixel electrodes 22a and 22b. As described above, the pixel electrodes 22a and 22b, the common electrodes 21a and 21b, and the counter electrodes 17a and 17b are line-symmetric with respect to the central axis E of one pixel or one subpixel in the cross section. The pixel electrodes 22a and 22b and the counter electrodes 17a and 17b are shifted in a first direction horizontal to the panel plane of the liquid crystal panel 2 in a ½ cross section in which the cross section of one pixel or one subpixel is divided by the central axis E. It has the first arrangement relationship. The pixel electrodes 22a and 22b and the common electrodes 21a and 21b have a second arrangement relationship shifted in a second direction opposite to the first direction in the ½ cross section.

  The active elements 23a and 23b correspond to one half cross section and the other half cross section in which the cross section of one pixel or one subpixel is divided by the central axis E, and are connected to the pixel electrodes 22a and 22b, respectively. The The active elements 23a and 23b perform three-dimensional display in synchronization with the solid state light emitting elements 9 and 10, respectively.

  For example, the liquid crystal molecules 71 to 78 included in the liquid crystal layer 7 have negative dielectric anisotropy, and the initial alignment in the longitudinal direction of the liquid crystal molecules 71 to 78 is vertical.

  FIG. 7 is a partial cross-sectional view showing an example of the configuration of the liquid crystal display device 1 according to the present embodiment in a state in which a liquid crystal driving voltage is applied to the right pixel electrode 22b. In FIG. 7, no voltage is applied to the left pixel electrode 22a.

  When a liquid crystal driving voltage is applied to the pixel electrode 22b, electric lines of force indicated by broken lines from the pixel electrode 22b to the common electrode 21b and the counter electrodes 17a and 17b are formed. The liquid crystal molecules 72 to 78 are tilted in the direction perpendicular to the electric lines of force. At this time, the liquid crystal molecules 78 in the vicinity of the right common electrode 21b and the pixel electrode 22b are placed in an effective strong electric field and start to fall first, and become triggers for the other liquid crystal molecules 72 to 77 to fall. The liquid crystal molecules 72 to 78 are tilted in the same direction, and the light emitted from the green subpixel has a light distribution angle α with respect to the vertical direction.

  FIG. 8 is a partial cross-sectional view showing an example of the configuration of the liquid crystal display device 1 according to the present embodiment in a state in which a liquid crystal driving voltage is applied to the left pixel electrode 22a. In FIG. 8, no voltage is applied to the right pixel electrode 22b.

  When a liquid crystal driving voltage is applied to the pixel electrode 22a, electric lines of force indicated by broken lines from the pixel electrode 22a to the common electrode 21a and the counter electrodes 17a and 17b are formed. The liquid crystal molecules 71 to 77 are tilted in the direction perpendicular to the electric lines of force. At this time, the liquid crystal 71 in the vicinity of the left common electrode 21a and the pixel electrode 22a is placed in an effective strong electric field and starts to fall first, and serves as a trigger for the other liquid crystal molecules 72 to 77 to fall. The liquid crystal molecules 71 to 77 tilt in the same direction, and the light emitted from the green subpixel has a light distribution angle α with respect to the vertical direction.

  The liquid crystal drive by the active element 23 is performed separately for the signals for the right eye and the left eye, or for the signals of the pop-up image and the background image with depth, thereby realizing three-dimensional display.

  Below, the kind of liquid crystal layer 7 which concerns on this embodiment is demonstrated.

  In the above description, the liquid crystal molecules 71 to 78 are driven using an oblique electric field method. However, as the liquid crystal alignment method, IPS (liquid crystal panel with a horizontal electric field using liquid crystal with horizontal light distribution) or VA (liquid crystal panel with a vertical electric field using liquid crystal with vertical alignment) may be applied.

  During black display of the liquid crystal display device 1, the liquid crystal molecules 71 to 78 are aligned vertically with respect to the plane of the liquid crystal panel 2. At the time of gradation display or white display (when a driving voltage is applied to the liquid crystal molecules 71 to 78), the longitudinal direction of the liquid crystal molecules 71 to 78 is inclined from the vertical direction to the horizontal direction.

  Thus, in the present embodiment, the liquid crystal molecules 71 to 78 are assumed to have initial vertical alignment and negative dielectric anisotropy. Further, in the driving of the liquid crystal molecules 71 to 78, the electric field direction of the driving voltage in the liquid crystal display device 1 includes an electric field oblique to the thickness direction (vertical direction) of the liquid crystal panel 2.

  Note that the liquid crystal molecules may have initial vertical alignment and positive dielectric anisotropy. In this case, in the liquid crystal driving, the electric field of the driving voltage may include an electric field in the horizontal direction of the liquid crystal panel or an electric field oblique to the thickness direction of the liquid crystal panel.

  FIG. 9 is a partial cross-sectional view illustrating an example of a state of initial vertical alignment of liquid crystal molecules having a negative dielectric anisotropy. FIG. 9 shows the right side of the central axis E in the half cross section of the subpixel. In FIG. 9, for simplicity of explanation, the color filter 8, the alignment film, the active element 23 b that drives the pixel electrode, the solid-state light emitting element (for example, backlight) 10, the light control element 11, the polarizing plate 3, The phase difference plate, the reflection plate 12 and the like are omitted.

  The liquid crystal molecules 7a to 7f are in the initial vertical alignment. The liquid crystal layer 7 including the liquid crystal molecules 7 a to 7 f is provided between the array substrate 6 and the counter substrate 5 facing each other. The array substrate 6 includes a transparent substrate 18, light shielding patterns 20a and 20b, an insulating layer 19, and a pixel electrode 22b. The counter substrate 5 includes a transparent substrate 15, a frame pattern b1 and a center pattern b2 of a black matrix BM, and a counter electrode 17b at a common potential.

  In FIG. 9, no voltage is applied to the pixel electrode 22b, and the liquid crystal molecules 7a to 7f are in a black display state with the vertical alignment.

  Instead of the vertically aligned liquid crystal, a normally black ECB (Electrically Controlled Birefringence) type liquid crystal of initial horizontal alignment can be suitably used. Since this ECB type liquid crystal requires an expensive elliptically polarizing plate and a horizontal alignment treatment, it is somewhat disadvantageous in terms of cost compared to the case where the above-mentioned vertical alignment liquid crystal is employed. Also, normally white ECBs tend to be inferior to normally black ECBs in terms of contrast and power consumption.

  FIG. 10 is a partial cross-sectional view showing an example of a liquid crystal voltage driving state of liquid crystal molecules having a negative dielectric anisotropy, and is illustrated under the same conditions as in FIG.

  When a voltage is applied between the pixel electrode 22b and the counter electrode 17b, electric lines of force 24 are generated in an oblique direction. The longitudinal (major axis) direction of the liquid crystal molecules 7b to 7e falls from the vertical direction so as to be perpendicular to the generated lines of electric force 24. Light from the solid-state light emitting element 10 is emitted in the direction of the arrow 25 due to refraction by the light control element 11 and transmission by the liquid crystal molecules 7b to 7e. The light distribution angle α, which is the angle between the light emission direction and the vertical direction, can be set in various ways by changing the conditions of the light control element 11. The orientation of the liquid crystal molecules 7b to 7e, the frame pattern b1 and the central pattern b2 of the black matrix BM, and the light shielding patterns 20a and 20b support that the emitted light has a light distribution angle α, greatly improving the quality of the three-dimensional image display. Can be made. Uniform alignment of the liquid crystal molecules 7b to 7e in the direction of emitting light is important in order to avoid a decrease in emission light, coloring, and a decrease in contrast.

  FIG. 11 is a partial cross-sectional view illustrating an example of a state of initial vertical alignment of liquid crystal molecules having positive dielectric anisotropy. FIG. 11 shows the right side of the central axis E in the half cross section of the subpixel. In FIG. 11, for simplicity of explanation, the color filter 8, the alignment film, the active element 23 b that drives the pixel electrode, the solid-state light emitting element (for example, backlight) 10, the light control element 11, the polarizing plate 3, The phase difference plate, the reflection plate 12 and the like are omitted.

  In FIG. 11, the pixel electrode 22b faces the light shielding pattern 20b on the center axis E side of the subpixel through the insulating layer 19 in the vertical direction F1. The common electrode 21b faces the light shielding pattern 20a on the end side of the subpixel through the insulating layer 19. The counter electrode 17b faces the frame pattern b1 of the black matrix BM in the vertical direction F1.

  The liquid crystal molecules 26a to 26f having positive dielectric anisotropy are in the initial vertical alignment. The liquid crystal layer 26 including the liquid crystal molecules 26 a to 26 f is provided between the array substrate 6 and the counter substrate 5 facing each other. The array substrate 6 includes a transparent substrate 18, light shielding patterns 20a and 20b, an insulating layer 19, a pixel electrode 22b, and a common electrode 21b. The counter substrate 5 includes a transparent substrate 15, a black matrix BM, and a counter electrode 17b at a common potential.

  In FIG. 11, no voltage is applied to the pixel electrode 22b, and the liquid crystal molecules 26a to 26f are in a black display state with the vertical alignment.

  FIG. 12 is a partial cross-sectional view showing an example of a liquid crystal voltage drive state of liquid crystal molecules having positive dielectric anisotropy, and is illustrated under the same conditions as in FIG.

  When a voltage is applied between the pixel electrode 22b and the counter electrode 17b, electric lines of force 27 are generated in an oblique direction. Further, when a voltage is applied between the pixel electrode 22b and the common electrode 21b, electric lines of force 27 are generated in the horizontal direction. The longitudinal direction of the liquid crystal molecules 26b to 26e falls from the vertical direction so as to be in the same direction as the generated lines of electric force 27 and 28. Light from the solid-state light emitting element 10 is emitted in the direction of the arrow 29 due to refraction by the light control element 11 and transmission by the liquid crystal molecules 26b to 26e. The light distribution angle α can be variously set by changing the conditions of the light control element 11. The alignment of the liquid crystals 26b to 26e, the frame pattern b1 and the central pattern b2 of the black matrix BM, and the light shielding patterns 20a and 20b support that the emitted light has a light distribution angle α, and greatly improve the quality of three-dimensional image display. be able to.

  In FIG. 11 and FIG. 12, either the counter electrode 17b or the common electrode 21b may be omitted.

  As described above, the liquid crystal may be either a liquid crystal having a negative dielectric anisotropy or a positive liquid crystal. For example, as a liquid crystal having a negative dielectric anisotropy, a nematic liquid crystal having a refractive index anisotropy in the range of 0.08 to 0.16 near room temperature can be used. In order to speed up the liquid crystal response, when the liquid crystal thickness is 3 μm or less, a liquid crystal having a high refractive index anisotropy such as a liquid crystal having Δn in the range of 0.1 to 0.16 can be used. When a liquid crystal having a positive dielectric anisotropy is used, a liquid crystal material having a wider range of characteristics can be used. For example, as will be described later, a liquid crystal material containing a fluorine atom in its molecular structure (hereinafter referred to as a fluorine-based liquid crystal) can be used as the liquid crystal material.

  In general, a liquid crystal material having a small dielectric anisotropy has a low clay. By using a low-viscosity liquid crystal material, the fall time (τdecay) when the liquid crystal driving voltage is turned off can be shortened. Further, in the fluorine-based liquid crystal having a low dielectric constant, the uptake of ionic incombustible materials is small, performance deterioration such as a decrease in voltage holding ratio due to impurities and display burn-in are small, and display unevenness hardly occurs. By using a liquid crystal material having a large absolute value of dielectric anisotropy, the threshold voltage and the rise time (τrise) can be shortened. In the case where a liquid crystal material having a large absolute value of dielectric anisotropy is used, a thinning agent such as an Alkenike compound may be added to the liquid crystal in a small amount in order to reduce the viscosity of the liquid crystal. The thickness of the liquid crystal layers 7 and 26 is not particularly limited. For example, as the thickness of the liquid crystal layers 7 and 26, a thin thickness of 3.5 μm or less, preferably in the range of 1.5 μm to 3.4 μm is applied in order to realize a liquid crystal display with an ultrafast response. In the present embodiment, the power consumption of the liquid crystal display device 1 can be reduced by optimizing the liquid crystal viscosity, the relative dielectric constant of the liquid crystal, the birefringence of the liquid crystal, and the elastic constant of the liquid crystal. Δnd of the liquid crystal layers 7 and 26 that can be effectively applied in the present embodiment is, for example, in the range of approximately 200 nm to 500 nm. As the alignment film, for example, a polyimide organic polymer film or an organic polymer film containing a polysiloxane structure can be used after being heated and hardened. Further, on the front and back of the liquid crystal panel 2, for example, 1 to 3 retardation plates may be attached to the polarizing plate 3.

  In the present embodiment, the counter substrate 5 of the liquid crystal panel 2 may include a light shielding layer as, for example, a black matrix BM. The light shielding layer is a light shielding film in which a light shielding pigment is dispersed in a transparent resin. Photosensitivity is generally imparted to the light shielding layer. The light shielding layer is patterned by a photolithography technique including exposure and development. Further, the counter substrate 5 may include a colored layer as the color filter 8 such as the red filters R1 and R2, the green filters G1 and G2, and the blue filters B1 and B2. The colored layer is a coating film in which an organic pigment is dispersed in a transparent resin. The colored layer is formed by forming a coating film on the opening of the black matrix BM and forming a pattern by photolithography. In the present embodiment, the relative dielectric constant of the colored layer is a relatively important characteristic. The relative dielectric constant of the colored layer is almost uniquely determined based on the ratio of the organic pigment added as a colorant to the transparent resin. For this reason, it is difficult to change the relative dielectric constant greatly. In other words, the type or content of the organic pigment in the colored layer is set based on the color purity required for the liquid crystal display device 1, and the relative dielectric constant of the colored layer is thereby almost determined. The relative dielectric constant can be increased to 4 or more by increasing the ratio of the organic pigment and making the colored layer thin. In addition, the relative dielectric constant can be slightly increased by using a high refractive index material as the transparent resin. The relative dielectric constant of the colored layer using the organic pigment is approximately in the range of 2.9 to 4.5.

  The light distribution angle α may be appropriately adjusted according to the distance and position between the liquid crystal panel 2 and the observer and the number of observers. The light distribution angle α may be adjusted according to the screen size of the liquid crystal panel 2. The light distribution angle α can be selected from a range of 4 ° to 30 °, for example. When the liquid crystal panel 2 is a panel for a small mobile device with one observer, a range of approximately 5 ° to 9 ° is preferable. A sensor for detecting the observer position may be attached to the liquid crystal display device 1 to adjust the light distribution angle α.

  In the liquid crystal display device 1 according to the present embodiment described above, three-dimensional display and two-dimensional display can be effectively realized, and optimal liquid crystal alignment is realized in order to realize three-dimensional display and two-dimensional display. Can be made.

  Furthermore, the liquid crystal display device 1 according to the present embodiment can switch between three-dimensional display and two-dimensional display, can reduce display unevenness such as moire, and performs bright and high-resolution image display. Can do.

  In a general liquid crystal display, in order to display a wide viewing angle, it is difficult to give the right eye and left eye light distribution angles α to the light emitted from one pixel. That the light for the left eye enters the right eye and that the light for the right eye enters the left eye is called crosstalk. This crosstalk reduces the effect of displaying a three-dimensional image. In the present embodiment, three-dimensional image display is performed using vertically aligned liquid crystal. As a result, it is possible to more appropriately impart the light distribution angle α to the outgoing light by using the inclination of the liquid crystal molecules in the longitudinal direction, and greatly reduce the occurrence of crosstalk in the three-dimensional image display. It is possible to improve the accuracy of the three-dimensional image display.

[Second Embodiment]
In the present embodiment, a modified example of the first embodiment will be described.

  FIG. 13 is a partial cross-sectional view showing an example of a state before the liquid crystal driving voltage is applied to the liquid crystal display device according to the present embodiment. In FIG. 13, the liquid crystal panel 31 is mainly shown, and other portions are omitted. FIG. 13 shows a cross section in units of subpixels.

  The counter substrate 32 of the liquid crystal panel 31 provided in the liquid crystal display device 30 according to the present embodiment includes counter electrodes 17 a and 17 b on one plane of the transparent substrate 15. The counter substrate 32 includes the black matrix BM and the transparent resin layer 16 on the transparent substrate 15 on which the counter electrodes 17a and 17b are formed.

  In the counter substrate 32, a plurality of counter electrodes 17a and 17b sandwich the central pattern b2 and are in contact with the central pattern b2. At a position in the horizontal direction F2, the counter electrodes 17a and 17b and the central pattern b2 are adjacent to each other. The counter substrate 32 does not include the color filter 8. The counter substrate 32 and the array substrate 6 are opposed to each other with the liquid crystal layer 7 interposed therebetween. On the back surface of the liquid crystal panel 31, a backlight unit 4 (not shown) is provided. The backlight unit 4 includes solid light emitting elements 9 and 10 such as LEDs, a light control element 11, a reflector 12 and the like as a basic configuration. The pixel electrodes 22a and 22b and the common electrodes 21a and 21b are formed via an insulating layer 19c such as silicon nitride or silicon oxide. The light shielding patterns 20a and 20b are formed of a metal thin film such as an aluminum alloy, for example. A polarizing plate 3 and a retardation plate (not shown) are attached to the front and back of the liquid crystal panel 31.

  FIG. 14 is a partial cross-sectional view showing an example of a state after the liquid crystal driving voltage is applied to the liquid crystal display device 30 according to the present embodiment. FIG. 14 shows the liquid crystal operation during two-dimensional image display and the state of the emitted light at that time. The light is emitted at a light distribution angle α as shown in FIG.

  Thus, by providing the light distribution angle α to the emitted light, a wider viewing angle than that of the conventional liquid crystal display device can be obtained.

  In the horizontal direction F2, the common electrodes 21a and 21b protrude beyond the pixel electrodes 22a and 22b toward the subpixel frame, and the width of the protruding portion is Wa.

  The width of the portion where the pixel electrodes 22a, 22b and the common electrodes 21a, 21b overlap at the position in the horizontal direction F2 (the portion where the pixel electrodes 22a, 22b and the common electrodes 21a, 21b face each other in the vertical direction) is Wb. It is.

  In the horizontal direction F2, the frame pattern b1 protrudes to the center axis E side of the subpixel from the light shielding pattern 20a, and the width of the protruding portion is Wc.

  An operation of a portion corresponding to the width Wa of the common electrodes 21a and 21b (hereinafter referred to as a protruding electrode portion) will be described. Note that portions of the common electrodes 21a and 21b and the pixel electrodes 22a and 22b corresponding to the width Wb can be used as auxiliary capacitors. The width Wb is adjusted based on the electric capacity of the liquid crystal cell (pixel or subpixel).

  FIG. 13 shows a state in which no liquid crystal driving voltage is applied to the pixel electrodes 22a and 22b, and the liquid crystal molecules 71 to 78 are in a black display state with their vertical alignment. As shown in FIG. 14, when a liquid crystal driving voltage is applied to the pixel electrodes 22a and 22b, electric lines of force 33a to 33d are generated in the oblique electric field direction, and the liquid crystal molecules 72 to 77 are tilted in the arrow direction. Since the liquid crystal molecules 71 and 78 in the vicinity of the protruding electrode portion are placed in an electric field stronger than the liquid crystal molecules in other portions, they first fall at a high speed. The tilt of the liquid crystal molecules 71 and 78 propagates to the liquid crystal molecules at other sites, and triggers a high-speed response. The inclination directions of the liquid crystal molecules 71 to 78 are symmetric with respect to the center axis E of the subpixel as shown in FIG. 14, and the field of view of the display image can be expanded.

  The direction in which the liquid crystal molecules 71 to 78 are tilted can be set by the direction in which the counter electrodes 17a and 17b and the common electrodes 21a and 21b are shifted with respect to the pixel electrodes 22a and 22b.

  For example, the width Wa of the protruding portion in the horizontal direction between the pixel electrodes 22a and 22b and the common electrodes 21a and 21b is appropriately adjusted in relation to the dimension of the liquid crystal cell or the liquid crystal driving voltage. For example, when the pixel width or sub-pixel width is 10 μm to 300 μm, the width Wa of the protruding portion may be about 0.5 μm to 6 μm. The width Wa of the protruding portion can be made smaller than the thickness of the liquid crystal layer 7 in order to improve the response of the liquid crystal.

  In the present embodiment, for example, the number of comb teeth of the counter electrodes 17a and 17b that are comb-like patterns for each pixel or sub-pixel may be larger than the number of comb teeth of the pixel electrodes 22a and 22b. The total area of the comb teeth of the counter electrodes 17a and 17b for each pixel or subpixel may be larger than the total area of the comb teeth of the pixel electrodes 22a and 22b. The pixel electrodes 22a and 22b, the common electrodes 21a and 21b, and the counter electrodes 17a and 17b are transparent conductive films in the visible range. The density or pitch of the comb teeth of each electrode can be adjusted as appropriate within the pixel or subpixel. In the cross-sectional view of the pixel or subpixel, it is important from the viewpoint of securing a wide viewing angle of the liquid crystal display to form each electrode at a position that is symmetric from the central axis E of the pixel or subpixel. In order to form each electrode at a position that is symmetric with respect to the central axis E of the pixel or subpixel, the number of comb teeth of each electrode is two or more and an even number in sectional view for one pixel or subpixel. is necessary.

  Generally, a tilt angle (pretilt angle) such as 89 degrees is given to the vertically aligned liquid crystal. The vertically aligned liquid crystal provided with the pretilt angle is tilted in the direction in which the tilt angle in the longitudinal direction of the liquid crystal molecules becomes smaller when the liquid crystal driving voltage is applied. In a general vertical alignment liquid crystal, an initial tilt angle sets a direction in which liquid crystal molecules fall when a liquid crystal driving voltage is applied. When such a general vertical alignment liquid crystal is used, rubbing of an alignment film (not shown) in a plurality of directions and optical alignment in a plurality of directions are required for one pixel or one subpixel.

  On the other hand, in this embodiment, the direction in which the liquid crystal molecules fall is determined based on the electric lines of force 33a to 33d generated by the oblique electric field without giving an inclination angle to the initial alignment of the vertically aligned liquid crystal. In the present embodiment, for example, the initial alignment of the liquid crystal molecules 71 to 78 having negative dielectric anisotropy is set to a vertical alignment of approximately 90 °. As described above, in the present embodiment, it is not necessary to give a pretilt angle to the liquid crystal molecules 71 to 78. However, a pretilt angle of, for example, about 89.7 ° to about 88 ° may be given to the liquid crystal molecules 71 to 78 using the PSA method in order to realize an ultrafast response of several ms in the liquid crystal drive. As described above, by providing the liquid crystal molecules 71 to 78 with a slight pretilt angle, the liquid crystal display device 30 according to the present embodiment can realize liquid crystal driving with an ultrahigh-speed response or a driving voltage lower than that in the past. In the PSA method, a liquid crystal cell is formed using a photosensitive alignment film or a polymerization composition, and then light such as ultraviolet rays is irradiated to the liquid crystal while applying a liquid crystal driving voltage to the pixel electrodes 22a, 22b, etc. A pretilt angle is given to the inner wall of the film or the liquid crystal cell. Then, a pretilt angle is given to the liquid crystal molecules 71 to 78 in accordance with the pretilt angle of the alignment film or the inner wall of the liquid crystal cell.

  Note that in a liquid crystal display device using a horizontally aligned liquid crystal such as IPS or ECB, an alignment process such as rubbing or optical alignment is indispensable. Further, in a liquid crystal display device using a horizontally aligned liquid crystal, strict optical axis alignment between the alignment direction of liquid crystal molecules and the polarizing plate is necessary. The vertically aligned liquid crystal display device 30 that does not require strict optical axis alignment with the polarizing plate has higher black display quality than the liquid crystal display device that is IPS or ECB.

  The active elements 23a and 23b may be formed of a silicon semiconductor or an oxide semiconductor. In the case where the active elements 23a and 23b are formed using an oxide semiconductor, the aperture ratio of a pixel or a subpixel can be improved. As a typical channel material of the active elements 23a and 23b formed of an oxide semiconductor, for example, a composite metal oxide of indium, gallium, and zinc called IGZO is used.

  The liquid crystal display device 30 according to the present embodiment is applicable to two-dimensional image display with a wide viewing angle, but performs liquid crystal operation with each of the left and right solid state light emitting devices 9 and 10 of the backlight unit 4 (not shown). By synchronizing, high-quality three-dimensional image display can be realized. By using solid-state light emitting elements 9 and 10 as individual light emitting LED elements of red, green and blue, it is possible to perform a bright color three-dimensional image display by field sequential driving.

[Third Embodiment]
In the present embodiment, the light control element 11 applied to the liquid crystal display devices 1 and 30 according to the first and second embodiments will be specifically described.

  FIG. 15 is a diagram illustrating a relationship between a partial cross section and a partial plane illustrating an example of the light control element 11 according to the present embodiment. The upper part of FIG. 15 is a partial sectional view of the light control element 11, and the lower part of FIG. 15 is a top plan view of the light control element 11.

  On the front surface (first surface) and back surface (second surface) of the light control element 11, n triangular prism-shaped prism units correspond to one semi-cylindrical lens unit.

  The semi-cylindrical lens 13 is formed with a pitch P1 of approximately 240 μm, for example.

  The triangular prisms 14 are formed with a pitch P2 of approximately 11.6 μm, for example. One unit (141 to 14n) of the triangular prism 14 is provided with respect to one unit (131) of the semi-cylindrical lens 13. The height H of the triangular prism 14 is about 9 μm, for example. The optical axis of the triangular prism 14 (the ridge line direction of one unit of the triangular prism 14 or the longitudinal direction of one unit of the triangular prism 14) is the optical axis of the semi-cylindrical lens 13 (one of the semi-cylindrical lenses 13). It has an angle θ with respect to the unit ridgeline direction or the longitudinal direction of one unit of the semi-cylindrical lens 13. For example, the optical axis of the triangular prism 14 is offset from the optical axis of the semi-cylindrical lens 13 by about 5 °.

  The solid state light emitting device 9 of FIG. 15 shows an approximate arrangement as an LED when the light control device 11 is applied to the backlight unit 4. The light emitted from the solid state light emitting element 9 is incident at a substantially right angle with respect to the optical axis of the triangular prism 14 in a plan view shown in the lower part of FIG. Thereby, the unevenness of the brightness in the downward direction of the liquid crystal panels 2 and 31 of the liquid crystal display devices 1 and 30 can be reduced.

  When the optical axis of the triangular prism 14 has an angle θ with respect to the optical axis of the semi-cylindrical lens 13, the direction of the emitted light from the solid light emitting element 9 is perpendicular to the optical axis of the semi-cylindrical lens 13. With respect to the line G, it has an offset of an angle θ.

  The light control element 11 includes, for example, a total of six subpixels in which one pixel has a pitch of 40 μm, and one pixel has two red subpixels, green subpixels, and blue subpixels arranged in the same order in the horizontal direction. The present invention is applied to the liquid crystal display devices 1 and 39 for three-dimensional image display. Performing three-dimensional image display with a plurality of subpixels as one pixel is important for realizing high-quality three-dimensional image display.

  Note that the arrangement direction and the pitch P1 of the semi-cylindrical lenses 13 are determined almost uniquely according to the pixel arrangement of the liquid crystal panels 2 and 31 to which the light control element 11 is applied. However, the pitch P2 and the height H of the triangular prism 14 and the curvature of the semi-cylindrical lens 13 are the number of observers, the positions of the observers, the liquid crystal panels 2 and 31 of the liquid crystal display devices 1 and 30. Adjustment is made based on the size, the required viewing angle, the required brightness, and the like. The angle between the optical axis of the semi-cylindrical lens 13 and the optical axis of the triangular prism 14 and the pitch P2 and height H of the triangular prism 14 are correlated with the front luminance of the liquid crystal display devices 1 and 30 and the contrast thereof. Yes, it is optimized based on the use conditions of the liquid crystal display devices 1 and 30 to which the light control element 11 is applied.

[Fourth Embodiment]
In the present embodiment, the planar shape of a pixel or subpixel in the liquid crystal display devices 1 and 30 according to the first to third embodiments will be described.

  The pixel or sub-pixel is a polygon whose opposite sides are parallel in plan view. Specifically, the planar shape of the pixel or subpixel may be a square, a rectangle, a parallelogram, or a shape bent in a “<” shape (eg, a V shape, a V shape, or a boomerang shape). .

  FIG. 16 is a partial plan view showing an example of an arrangement of “<”-shaped sub-pixels. In FIG. 16, a plurality of subpixels are arranged in the horizontal direction to form one pixel.

  FIG. 17 is a partial plan view showing a first example of the arrangement of the parallelogram sub-pixels. In FIG. 17, sub-pixels 34r, 34g, 34b of different colors are arranged in the horizontal direction, and sub-pixels 34r, 34g, 34b of the same color are arranged in the vertical direction. In FIG. 17, the central pattern b2 of the black matrix BM arranged at the center of the subpixel is omitted.

  FIG. 18 is a partial plan view showing a second example of the arrangement of the parallelogram sub-pixels. In FIG. 18, subpixels 34r, 34g, 34b of the same color are arranged in the horizontal direction, and subpixels 34r, 34g, 34b of different colors are arranged in the vertical direction. A set of 34r, 34g, 34b arranged in the vertical direction and a plurality of subpixels 34r, 34g, 34b arranged in the horizontal direction constitute a pixel 34.

  FIG. 19 is a partial cross-sectional view illustrating an example of a pixel configured by rectangular sub-pixels 34r, 34g, and 34b. In FIG. 19, sub-pixels 34r, 34g, 34b of different colors are arranged in the horizontal direction, and sub-pixels 34r, 34g, 34b of the same color are arranged in the vertical direction. A set of 34r, 34g, and 34b arranged in the horizontal direction constitutes a pixel 34.

  Each of the embodiments described above can be applied with various modifications within a range where the gist of the invention does not change.

  DESCRIPTION OF SYMBOLS 1,30 ... Liquid crystal display device, 2,31 ... Liquid crystal panel, 3 ... Polarizing plate, 4 ... Backlight unit, 5,32 ... Opposite substrate, 6 ... Array substrate, 7,26 ... Liquid crystal layer, 8 ... Color filter, DESCRIPTION OF SYMBOLS 9,10 ... Solid light emitting element, 11 ... Light control element, 12 ... Reflector plate, 13 ... Semi-cylindrical lens, 14 ... Triangular prism, 15, 18 ... Transparent substrate, 16 ... Transparent resin layer, 17a, 17b ... Opposite Electrodes, 19a to 19c ... insulating layers, 20a, 20b ... light shielding patterns, 21a, 21b ... common electrodes, 22a, 22b ... pixel electrodes, 23 ... active elements.

Claims (18)

In the liquid crystal display device in which the light emitted from the light emitting element passes through the liquid crystal panel via the light control element,
The light control element is:
A plurality of triangular prisms are arranged so that the longitudinal directions of the triangular prisms are parallel to each other, and a plurality of semi-cylindrical lenses are back-to-back with the plurality of triangular prisms. An integral resin sheet comprising a second surface arranged so that the longitudinal directions of the lenses are parallel to each other,
The longitudinal direction of the plurality of triangular prisms and the longitudinal direction of the semi-cylindrical lenses have a moire suppression angle θ in plan view.
A liquid crystal display device characterized by the above. The liquid crystal display device according to claim 1.
In the first surface and the second surface of the liquid crystal panel, the n triangular prisms correspond to one semi-cylindrical lens, and n is in the range of 2 to 150. A liquid crystal display device characterized by being an integer. The liquid crystal display device according to claim 1 or 2,
The liquid crystal panel has a configuration in which an array substrate including pixel electrodes is opposed to a counter substrate including a counter electrode, and a liquid crystal layer is provided between the array substrate and the counter substrate.
The pixel electrode and the counter electrode are line symmetric with respect to a central axis in a vertical direction of one pixel or one subpixel in the cross section,
The pixel electrode and the counter electrode have an arrangement relationship shifted in a horizontal direction with respect to a panel plane of the liquid crystal panel in a ½ cross section in which the cross section of the one pixel or the one subpixel is divided by the central axis. Have,
A liquid crystal display device characterized by the above. The liquid crystal display device according to claim 1 or 2,
The liquid crystal panel has a configuration in which an array substrate including a pixel electrode and a common electrode is opposed to a counter substrate including a counter electrode, and a liquid crystal layer is provided between the array substrate and the counter substrate.
In the vertical cross section of the liquid crystal panel, the common electrode and the counter electrode are at a position sandwiching the pixel electrode,
The pixel electrode, the common electrode, and the counter electrode are line symmetric with respect to a central axis in a vertical direction of one pixel or one subpixel in the cross section,
The pixel electrode and the counter electrode are shifted in a first direction horizontal to a panel plane of the liquid crystal panel in a ½ cross section in which the cross section of the one pixel or the one subpixel is divided by the central axis. Having a first placement relationship,
The pixel electrode and the common electrode have a second arrangement relationship shifted in a second direction opposite to the first direction in the half cross section.
A liquid crystal display device characterized by the above. In the liquid crystal display device according to claim 3 or 4,
Two active elements connected to the pixel electrode further corresponding to one half cross section and the other half cross section of the one pixel or the one subpixel separated by the central axis, Equipped,
The two active elements perform a three-dimensional display in synchronization with the solid state light emitting element.
A liquid crystal display device characterized by the above. The liquid crystal display device according to any one of claims 1 to 5,
The light emitting element includes two light emitting units each including a red light emitting diode, a green light emitting diode, and a blue light emitting diode,
The two light emitting units are respectively provided at positions corresponding to two opposite sides of the liquid crystal panel, and emit the light perpendicular to the longitudinal direction of the plurality of triangular prisms.
A liquid crystal display device characterized by the above. The liquid crystal display device according to any one of claims 1 to 6,
The liquid crystal panel includes a color filter including a red filter, a green filter, and a blue filter,
The light emitting element includes two light emitting units that emit white light including three wavelengths of red, green, and blue.
The two light emitting units are respectively provided at positions corresponding to two opposing sides of the liquid crystal panel, and emit the white light perpendicular to the longitudinal direction of the plurality of triangular prisms.
A liquid crystal display device characterized by the above. The liquid crystal display device according to claim 7.
One display unit of the liquid crystal panel is a liquid crystal display device in which two sets of the red filter, the green filter, and the blue filter are arranged in the same order in the horizontal direction. The liquid crystal display device according to any one of claims 1 to 8,
The longitudinal direction of the liquid crystal molecules contained in the liquid crystal layer of the liquid crystal panel is a direction perpendicular to the panel surface of the liquid crystal panel during black display, and is perpendicular to the panel surface during white display or gradation display. Tilt horizontally from direction,
A liquid crystal display device characterized by the above. The liquid crystal display device according to any one of claims 1 to 9,
The liquid crystal layer of the liquid crystal panel has initial vertical alignment and negative dielectric anisotropy, and an electric field oblique to the thickness direction of the liquid crystal panel is generated in liquid crystal driving.
A liquid crystal display device characterized by the above. The liquid crystal display device according to any one of claims 1 to 8,
The liquid crystal layer of the liquid crystal panel has initial vertical alignment and positive dielectric anisotropy, and in liquid crystal driving, an electric field oblique to the thickness direction of the liquid crystal panel and a panel plane of the liquid crystal panel At least one of an electric field directed in a horizontal direction is generated,
A liquid crystal display device characterized by the above. The liquid crystal display device according to any one of claims 1 to 11,
The liquid crystal panel is configured based on a matrix arrangement of a plurality of pixels or a plurality of subpixels,
The longitudinal direction of the plurality of pixels or the plurality of sub-pixels and the longitudinal direction of the plurality of triangular prisms have the moire suppression angle θ in plan view.
A liquid crystal display device characterized by the above. The liquid crystal display device according to any one of claims 1 to 12,
The moiré suppression angle θ is any angle within a range of 3 ° to 43 °. The liquid crystal display device according to any one of claims 1 to 13,
A liquid crystal display device, wherein the liquid crystal driving in the liquid crystal panel and the driving of the solid light emitting element are synchronized, and the solid light emitting element is driven in a time division manner during three-dimensional display. A plurality of triangular prisms are arranged so that the longitudinal directions of the triangular prisms are parallel to each other, and a plurality of semi-cylindrical lenses are back-to-back with the plurality of triangular prisms. An integral resin sheet comprising a second surface arranged so that the longitudinal directions of the lenses are parallel to each other,
The light control element, wherein a longitudinal direction of the plurality of triangular prisms and a longitudinal direction of the plurality of semi-cylindrical lenses have a moire suppression angle θ in plan view.   In the first surface and the second surface, n triangular prisms correspond to one semi-cylindrical lens, and n is an integer in the range of 2 to 150. The light control element according to claim 15. The integral resin sheet is formed in a rectangular shape,
The longitudinal direction of the plurality of semi-cylindrical lenses is parallel to two opposite sides of the liquid crystal panel.
The light control element according to claim 15 or claim 16, wherein   18. The light control element according to claim 15, wherein the moire suppression angle θ is any angle within a range of 3 ° to 43 °.

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