JP5194339B2 - Liquid crystal display element - Google Patents

Description

  The present invention relates to a lateral electric field control type liquid crystal display element.

  As a liquid crystal display element, liquid crystal is sealed between a pair of substrates on the opposite side and an observation side facing each other with a gap, and the inner surfaces of one of the pair of substrates are insulated from each other on the inner surface of one of the substrates. A lateral electric field control type provided with first and second display electrodes that generate a lateral electric field in a direction substantially parallel to the substrate surface between them by supplying a display driving voltage therebetween. (See Patent Documents 1 and 2).

This horizontal electric field control type liquid crystal display element supplies a display drive voltage corresponding to image data between the first and second display electrodes on the inner surface of the one substrate, and generates a horizontal voltage generated between these display electrodes. An image is displayed by controlling the orientation direction of the liquid crystal molecules (direction of the molecular major axis) in a plane substantially parallel to the substrate surface by an electric field, and has a wide viewing angle.
Japanese Patent Laid-Open No. 9-159996 JP-A-11-202356

  However, in the lateral electric field control type liquid crystal display element, since static electricity applied from the observation side greatly affects the control of the orientation direction of the liquid crystal molecules by the lateral electric field, a charged object such as a finger is touched or brought close to the observation side surface. The display becomes unstable.

  The present invention can provide stable display that is not affected by static electricity from the observation side, has a touch input function with almost no complexity and thickness, and has the effect of touch input. An object of the present invention is to provide a liquid crystal display element capable of performing a display with no remaining.

A liquid crystal display element according to a first aspect of the present invention is a first conductive film which is formed in a flat plate shape, has a first main surface and a second main surface, and is transparent on the first main surface. A first substrate having a flat plate shape, a third main surface and a fourth main surface, wherein the third main surface is opposed to the second main surface. A second substrate bonded to the first substrate by a sealing material; and disposed between the first substrate and the second substrate; and disposed on the second main surface and the third main surface. A liquid crystal layer in which liquid crystal molecules are aligned in parallel to each other, a flat main plate having a fifth main surface and a sixth main surface, and a transparent second conductive film formed on the sixth main surface. A contact position between the third substrate formed and disposed so that the sixth main surface faces the first main surface, and the first conductive film and the second conductive film is detected. With coordinate detection means The provided, it is formed on the first electrode and the second electrode is the third major surface the voltage to change the alignment direction of the liquid crystal molecules is applied between each other of the electrodes, the said liquid crystal molecules first A viewing angle control electrode that is obliquely raised and oriented with respect to the main surface 3 and generates a vertical electric field that is parallel to the thickness direction of the liquid crystal layer between the one main electrode and the second main surface. The viewing angle control electrode is a horizontal electric field generated by a display driving voltage supplied between the first electrode and the second electrode when performing a wide viewing angle display. And the liquid crystal layer is provided so as to correspond to the entire region in which the orientation direction of the liquid crystal molecules is controlled by the lateral electric field that controls the orientation direction of the liquid crystal molecules in a plane parallel to the third main surface. The viewing angle control electrode, the first electrode and the front electrode Between one of the electrodes of the second electrode, the independent viewing angle control voltage to the display driving voltage is supplied, in the case of the narrow viewing angle display, the viewing angle control to generate the vertical electric field It is further characterized by further comprising a viewing angle control driving means for not supplying the viewing angle control voltage when supplying a voltage while performing a wide viewing angle display.
According to a second aspect of the present invention, in the liquid crystal display element according to the first aspect, a color filter is formed on the second main surface.
According to a third aspect of the present invention, in the liquid crystal display element according to the first or second aspect, a first polarizing plate is affixed to the fifth main surface, and a second is applied to the fourth main surface. The polarizing plate is affixed.
The invention according to claim 4 is the liquid crystal display element according to any one of claims 1 to 3, wherein each of the first conductive film, the second conductive film, the first electrode, and the second electrode. Is made of ITO.
According to a fifth aspect of the present invention, in the liquid crystal display element according to any one of the first to fourth aspects, the first electrode and the second electrode are formed in different layers through an insulating film. It is characterized by being.

A liquid crystal display element according to an invention of claim 6 is formed in a flat plate shape, has a first main surface and a second main surface, and the first conductive film is transparent on the first main surface. A first substrate having a flat plate shape, a third main surface and a fourth main surface, wherein the third main surface is opposed to the second main surface. A second substrate bonded to the first substrate by a sealing material; and disposed between the first substrate and the second substrate; and disposed on the second main surface and the third main surface. A liquid crystal layer in which liquid crystal molecules are aligned in parallel to each other, a flat main plate having a fifth main surface and a sixth main surface, and a transparent second conductive film formed on the sixth main surface. A contact position between the third substrate formed and disposed so that the sixth main surface faces the first main surface, and the first conductive film and the second conductive film is detected. With coordinate detection means The provided, it is formed on the first electrode and the second electrode a third main surface of the transverse electric field controls the liquid crystal molecules for each pixel, obliquely the liquid crystal molecules with respect to said third main surface And a viewing angle control electrode for generating a vertical electric field between the first electrode and the vertical electric field, which is parallel to the thickness direction of the liquid crystal layer, is formed on the second main surface. The viewing angle control electrode is a lateral electric field generated by a display driving voltage supplied between the first electrode and the second electrode when performing a wide viewing angle display, and the electrode of the liquid crystal layer The viewing angle control electrode provided corresponding to the entire region in which the orientation direction of the liquid crystal molecules is controlled by the lateral electric field for controlling the orientation direction of the liquid crystal molecules in a plane parallel to the third main surface. And one of the first electrode and the second electrode Between poles, the independent viewing angle control voltage to the display driving voltage is supplied, in the case of the narrow viewing angle display, while supplying the viewing angle control voltage for generating the vertical electric field, wide field It is further characterized by further comprising viewing angle control driving means for preventing the viewing angle control voltage from being supplied when performing the angle display.

A liquid crystal display element according to a seventh aspect of the present invention is the liquid crystal display element according to the first or sixth aspect, wherein the first electrode or the second electrode is a comb-like electrode .

According to the present invention, stable display that is not affected by static electricity from the observation side can be performed, and a touch input function can be provided without making the structure almost complicated and thick. It is possible to perform a display that does not leave any influence.

(First embodiment)
1 to 8 show a first embodiment of the present invention. FIG. 1 is a sectional view of a part of a liquid crystal display element, and FIG. 2 is a plan view of a part of one substrate of the liquid crystal display element.

  As shown in FIGS. 1 and 2, the liquid crystal display element of this embodiment includes an observation side (upper side in FIG. 1) facing each other with a gap and a pair of transparent substrates 11 and 12 on the opposite side, One of the liquid crystal layer 13 made of nematic liquid crystal having positive dielectric anisotropy sealed between the pair of substrates 11 and 12 and the inner surfaces of the pair of substrates 11 and 12 facing each other, for example, the observation side Are provided so as to be insulated from each other on the inner surface of the substrate 12 opposite to each other, and by supplying a display driving voltage therebetween, a lateral electric field in a direction substantially parallel to the surface of the substrate 12 is applied to the liquid crystal layer 13 therebetween. First and second transparent display electrodes 14 and 15 to be generated, and a pair of polarizing plates 29 and 30 arranged with the pair of substrates 11 and 12 interposed therebetween.

  In other words, this liquid crystal display element is used for image data between the first and second display electrodes 14 and 15 provided on the inner surface of the one substrate (hereinafter referred to as the opposite substrate) 12 so as to be insulated from each other. By supplying a corresponding display driving voltage, a horizontal electric field in a direction substantially parallel to the surface of the substrate 12 is generated between the first and second display electrodes 14 and 15, and the pair of substrates is generated by the horizontal electric field. 11. An image is displayed by controlling the orientation direction (direction of the molecular long axis) of the liquid crystal molecules of the liquid crystal layer 13 enclosed between 11 and 12 within a plane substantially parallel to the surface of the substrate 12. A pixel A, which is a minimum unit for displaying an image, is formed by a region in which the orientation direction of liquid crystal molecules is controlled by a lateral electric field generated between the first and second display electrodes 14 and 15.

  The pixels A are arranged in a matrix in the row direction (the horizontal direction of the screen of the liquid crystal display element) and the column direction (the vertical direction of the screen), and the first and the first arranged on the inner surface of the opposite substrate 12. Among the two display electrodes 14 and 15, the first display electrode 14 is formed so as to correspond to at least the entire area of the pixel A, and the second display electrode 15 is the first display electrode 14. Is formed in a shape having an area smaller than that of the pixel A, and is opposed to the first display electrode 14 at the edge thereof.

  This liquid crystal display element is an active matrix liquid crystal display element in which a plurality of pixels A arranged in a matrix are selected and driven by an active element composed of a TFT (thin film transistor) 16, and the first display electrode 14 includes: Each pixel row is provided corresponding to a plurality of pixels A in the row, and the second display electrode 15 is provided corresponding to each pixel A and formed on the inner surface of the opposite substrate 12. The plurality of TFTs 16 are connected to each other.

  The TFT 16 includes a gate display electrode 17 formed on the opposite substrate 12, a gate insulating film 18 that covers the gate display electrode 17 and is formed on substantially the entire surface of the opposite substrate 12, and the gate. An i-type semiconductor film 19 formed on the insulating film 18 so as to face the gate display electrode 17, and an n-type semiconductor film (not shown) on both sides of the i-type semiconductor film 19. The source electrode 20 and the drain electrode 21 are provided.

  Further, a plurality of gate wirings 22 for supplying gate signals to the TFTs 16 in each row and a plurality of data wirings 23 for supplying data signals to the TFTs 16 in each column are provided on the inner surface of the opposite substrate 12. The gate line 22 is formed integrally with the gate display electrode 17 of the TFT 16 on the opposite substrate 12, and the data line 23 is formed on the gate insulating film 18. It is connected to the drain electrode 21.

  The first display electrode 14 is formed of an ITO film 14a formed on the gate insulating film 18 in a shape corresponding to each pixel row and corresponding to the entire area of the pixel A. These ITO films 14a are commonly connected at their end portions.

  In this embodiment, the width of the portion between the regions corresponding to each pixel A of the ITO film 14a is reduced, but this ITO film 14a has a width corresponding to the entire area of the pixel A over its entire length. You may form in.

  The second display electrode 15 is provided on the interlayer insulating film 24 covering the first display electrode 14 so as to correspond to each pixel A, and has a comb shape having a plurality of comb teeth portions. The comb-like ITO film 15a is patterned and is connected to the source electrode 20 of the TFT 16 at one end of the base connecting the comb-tooth portions of the comb-like ITO film 15a.

  The interlayer insulating film 24 is provided on the substantially entire surface of the opposite substrate 12 so as to cover the first display electrode 14, the TFT 16 and the data wiring 23, and the comb-shaped ITO film 15 a A contact hole (not shown) provided in the insulating film 24 is connected to the source electrode 20 of the TFT 16.

  The comb-shaped ITO film 15a has, for example, four comb-tooth portions formed at equal intervals, and one pixel (a horizontal electric field generated between the first and second display electrodes 14 and 15). The region A in which the orientation direction of liquid crystal molecules is controlled is formed by the ITO film 14a having a shape corresponding to the entire area of the pixel A, and four comb teeth portions corresponding to the ITO film 14a of the comb-shaped ITO film 15a. Has been.

  Each comb-tooth portion of the comb-shaped ITO film 15a has an angle θ of 5 ° to 15 ° in the vertical direction of the screen of the liquid crystal display element, that is, in the left or right direction with respect to the vertical axis O of the screen. The ratio b / a between the width a of these comb teeth and the interval b between adjacent comb teeth is preferably 1/3 to 3/1. Is set to 1/1.

  Further, the liquid crystal display element includes at least the pixel (a lateral electric field generated between the first and second display electrodes 14 and 15) on the other of the pair of substrates 11 and 12, that is, the inner surface of the observation-side substrate 11. The transparent viewing angle control electrode 25 is provided corresponding to the entire region A) in which the orientation direction of the liquid crystal molecules is controlled.

  The viewing angle control electrode 25 is supplied between the first and second display electrodes 14 and 15 between the first and second display electrodes 14 and 15. A viewing angle control voltage independent of the driving voltage is supplied, and a vertical electric field in a direction substantially parallel to the thickness direction of the liquid crystal layer 13 is generated between the one display electrode 14 or 15. The display electrode is made of a single ITO film facing the entire array region of the plurality of pixels A.

  The liquid crystal display element is a color image display element including three color filters 26R, 26G, and 26B corresponding to each of the plurality of pixels A, and the color filters 26R and 26G. 26B are formed on the observation side substrate 11, and the viewing angle control electrode 25 is formed thereon.

  Further, horizontal alignment films 27 and 28 are provided on the inner surfaces of the observation side substrate 11 and the opposite side substrate 12 so as to cover the first and second display electrodes 14 and 15 and the viewing angle control electrode 25, respectively. These alignment films 27 and 28 are respectively arranged in a direction obliquely intersecting with a direction of a lateral electric field generated between the first and second display electrodes 14 and 15 at a predetermined angle. Alignment treatment is performed by rubbing in the opposite directions along each other.

  That is, the alignment films 27 and 28 are inclined at a predetermined angle with respect to the length direction of the edge of the second display electrode 15, that is, the edge of each comb tooth of the comb-shaped ITO film 15 a. Are aligned in directions opposite to each other along the direction intersecting with each other.

  The observation-side substrate 11 and the opposite-side substrate 12 are bonded via a frame-shaped sealing material (not shown) surrounding the array region and the screen region of the plurality of pixels A, and the liquid crystal layer 13 is A region surrounded by the sealing material between the observation side substrate 11 and the opposite side substrate 12 is enclosed.

  The liquid crystal molecules of the liquid crystal layer 13 are aligned substantially parallel to the surfaces of the substrates 11 and 12 with their molecular long axes aligned in the alignment treatment direction of the alignment films 27 and 28.

  The liquid crystal molecules of this liquid crystal display element are aligned in the alignment treatment direction of the alignment films 27 and 28 with their molecular long axes aligned in parallel with the substrates 11 and 12 (Δnd) The value of the product of the property Δn and the liquid crystal layer thickness d) is set in the vicinity of about 275 nm, which is a half value of the intermediate wavelength in the visible light band.

  FIG. 3 shows the alignment processing directions (rubbing directions) 11a, 12a of the alignment films 27, 28 on the observation side substrate 11 and the opposite substrate 12 of the liquid crystal display element, and the transmission axes 29a, 30a of the pair of polarizing plates 29, 30. Indicates the direction.

  As shown in FIG. 3, the alignment films 27 and 28 on the observation side substrate 11 and the opposite side substrate 12 are in a direction substantially parallel to the vertical direction (the vertical axis O of the screen) of the screen of the liquid crystal display element, that is, the screen. For the second display comprising a comb-shaped ITO film 15a having a comb-tooth portion formed in an elongated shape along a direction inclined at an angle θ of 5 ° to 15 ° in either the left or right direction with respect to the vertical axis O of The electrodes 15 are oriented in opposite directions along the direction inclined at the angle θ in the direction opposite to the tilt direction, and the polarizing plate on the observation side out of the pair of polarizing plates 29 and 30. 29 is arranged with its transmission axis 29a substantially parallel to the alignment processing directions 11a and 12a, and the opposite polarizing plate 30 has its transmission axis 30a substantially identical to the transmission axis 29a of the observation-side polarizing plate 29. Are arranged orthogonally or parallel to each other.

  That is, in this liquid crystal display element, the alignment processing directions 11a and 12a of the alignment films 27 and 28 of the substrate 12 opposite to the observation side substrate 11 are substantially aligned with respect to the vertical direction of the screen (vertical axis O of the screen). The longitudinal direction of the comb-teeth portion of the comb-shaped ITO film 15a is formed in a direction inclined at an angle θ of 5 ° to 15 ° with respect to the alignment processing directions 11a and 12a, and the pair of polarized light Of the plates 29 and 30, the transmission axis 29a of the observation side polarizing plate 29 is arranged substantially parallel to the alignment treatment directions 11a and 12a.

  In this embodiment, the transmission axis 29a of the observation side polarizing plate 29 and the transmission axis 30a of the opposite side polarizing plate 30 are orthogonal to each other to constitute a normally black mode liquid crystal display element.

  Further, the liquid crystal display element is a single-film transparent first static electricity shielding film 31 made of ITO or the like provided on the outer surface of the observation-side substrate 11 so as to correspond to the entire area of the liquid crystal layer 13. (Hereinafter, referred to as a static electricity shielding conductive film) and a transparent touch film 32 disposed opposite to the outer surface of the observation side substrate 11 with a gap.

  Note that the observation-side polarizing plate 29 is attached to the outer surface (observation-side surface) of the touch film 32, and the outer surface of the observation-side polarizing plate 29 is touched with a touch pen 51 (see FIG. 8) or the like. A transparent surface film (not shown) for protecting the observation side polarizing plate 29 against the input is attached.

  The touch film 32 includes a transparent film substrate 33 having substantially the same outer shape as the observation-side substrate 11, and a transparent second conductive film 34 made of ITO or the like provided on one surface of the film substrate 33. The second conductive film (hereinafter referred to as touch-side conductive film) 34 is formed in a single film shape having substantially the same outer shape as the static electricity shielding conductive film 31.

  Then, the touch film 32 is connected to the touch-side conductive film 34 on the outer surface side of the observation-side substrate 11 via a frame-like spacer (not shown) surrounding the screen region. A touch input unit that detects a pressing position on the film substrate 33 from the observation side is formed by the electrostatic shielding conductive film 31 that is disposed to face each other with an appropriate gap therebetween.

  In this embodiment, the touch input unit is a contact in which the film substrate 33 is bent and deformed by a local touch from the observation side, and the touch-side conductive film 34 is brought into contact with the electrostatic shielding conductive film 31 locally. It is a mold input part.

  This liquid crystal display element includes a first display electrode 14 and a second display electrode 15 provided between the observation side and one of the pair of substrates 11 and 12 on the opposite side, for example, the inner surface of the opposite substrate 12 and insulated from each other. By supplying a display drive voltage corresponding to the image data to the first and second display electrodes 14 and 15, a horizontal electric field in a direction substantially parallel to the surface of the substrate 12 is generated, and the horizontal electric field is generated. By controlling the orientation direction (direction of the molecular long axis) of the liquid crystal molecules of the liquid crystal layer 13 enclosed between the pair of substrates 11 and 12 within a plane substantially parallel to the surface of the substrate 12, an image is displayed. In this liquid crystal display element, since the static electricity shielding conductive film 31 corresponding to the entire area of the liquid crystal layer 13 is provided on the outer surface of the observation side substrate 11, static electricity applied from the observation side is caused by the lateral electric field. It affects the control of the orientation direction of liquid crystal molecules. Rather, therefore, it is possible to perform stable display that is not affected by the said electrostatic.

  Further, in this liquid crystal display element, the orientation direction of the liquid crystal molecules is controlled on the inner surface of the other substrate, that is, the observation-side substrate 11 by at least a lateral electric field generated between the first and second display electrodes 14 and 15. Between the first and second display electrodes 14 and 15 between the first and second display electrodes 14 and 15 so as to correspond to the entire area of the pixel A consisting of the region to be formed. A viewing angle control voltage that is independent of the display drive voltage supplied to the liquid crystal layer 13 is supplied, and a vertical direction in a direction substantially parallel to the thickness direction of the liquid crystal layer 13 is provided between the one display electrode 14 or 15. Since the viewing angle control electrode 25 for generating an electric field is provided, the liquid crystal molecules are inclined with respect to the surfaces of the substrates 11 and 12 by the wide viewing angle display, which is a characteristic of the horizontal electric field control type liquid crystal display element, and the vertical electric field. Narrow field of view with narrowed viewing angle Performs a display, the viewing angle can be stably controlled over a wide enough angular range.

  That is, as shown in FIGS. 4 to 7, the liquid crystal display element includes a signal source 36 that generates a display drive voltage corresponding to image data, and a display drive voltage from the signal source 36. Display driving is performed by an image display driving means 35 having a drive control switch 34 for supplying between the first and second display electrodes 14 and 15 of each pixel A.

  The image display driving means 35 supplies a display driving voltage corresponding to the image data between the first and second display electrodes 14 and 15 of each pixel A of the liquid crystal display element by turning on the writing switch 37. Then, a lateral electric field (an electric field in a direction substantially parallel to the surface of the substrate 12) corresponding to the display driving voltage is generated between the first and second display electrodes 14 and 15.

  Further, as shown in FIGS. 4 to 7, the liquid crystal display element includes a signal source 39 that generates a viewing angle control voltage having a predetermined value and the viewing angle control voltage from the signal source 36. A visual field for statically supplying one of the first and second display electrodes 14 and 15 of each pixel A of the display element, for example, between the first display electrode 14 and the viewing angle control electrode 25. Driven by viewing angle control driving means 38 having an angle control switch 40, the viewing angle of display is controlled from a wide viewing angle to a narrow viewing angle.

  The viewing angle control driving means 38 is configured to display the image between the first display electrode 14 and the viewing angle control electrode 25 of each pixel A of the liquid crystal display element by turning on the viewing angle control switch 39. An independent viewing angle control voltage is supplied to the display driving voltage supplied from the driving means 35 between the first and second display electrodes 14 and 15, and the first display electrode 14 and the viewing angle are supplied. A vertical electric field in a direction substantially parallel to the thickness direction of the liquid crystal layer 13 is generated between the control electrode 25 and the viewing angle control voltage. Set to a value that generates a vertical electric field between the angle control electrode 25 and a liquid crystal molecule that rises and aligns obliquely at a predetermined angle within a range of, for example, 45 ° to 70 ° with respect to the surfaces of the substrates 11 and 12. Has been.

  The viewing angle control switch 39 is turned off in conjunction with the selection of a wide viewing angle by a viewing angle selection key provided in an electronic device such as a mobile phone having the liquid crystal display element, and the viewing angle selection key. It is an automatic change-over switch that is turned on in conjunction with selection of a narrow viewing angle, and the viewing angle control driving means 38 is turned off when a wide viewing angle is selected by the viewing angle selection key, that is, the viewing angle control switch 39 is turned off. When the viewing angle control voltage is not supplied between the first display electrode 14 and the viewing angle control electrode 25 and a narrow viewing angle is selected by the viewing angle selection key, the viewing angle control is performed. When the switch 39 is turned on, the viewing angle control voltage is supplied between the first display electrode 14 and the viewing angle control electrode 25.

  Thus, the liquid crystal display element supplies the display drive voltage corresponding to the image data between the first and second display electrodes 14 and 15 on the inner surface of the opposite substrate 12 by the image display drive means 35. Then, a horizontal electric field corresponding to the display driving voltage is generated between the first and second display electrodes 14 and 15 to display an image, and the viewing angle control driving means 38 allows the opposite substrate 12 to be displayed. The first display electrode 14 on the inner surface and the region on the inner surface of the observation-side substrate 11 in which the liquid crystal molecules change the orientation direction by at least the pixel (a horizontal electric field generated between the first and second display electrodes 14 and 15). ) A viewing angle control voltage independent of the display driving voltage is supplied between the viewing angle control electrodes 25 provided corresponding to the entire area A, and the first display electrode 14 and the viewing angle are supplied. The viewing angle control with the control electrode 25 Is intended to narrow the viewing angle of the display to generate a vertical electric field corresponding to the pressure, if not generating the vertical electric field is obtained wide viewing angle, the viewing angle is narrowed when generating the vertical electric field.

  4 and 5 are diagrams schematically showing changes in the orientation of liquid crystal molecules in a state where no vertical electric field is generated in one pixel A of the liquid crystal display element, and FIG. 4 shows the first and second configurations. FIG. 5 shows the orientation direction when a horizontal electric field is generated between the first and second display electrodes 14 and 15, when the horizontal electric field is not generated between the display electrodes 14 and 15. ing.

  In the applied state in which the vertical electric field is not generated, the liquid crystal molecules 13a are aligned substantially parallel to the surfaces of the substrates 11 and 12, and a horizontal electric field is generated between the first and second display electrodes 14 and 15. If not, the first and second display electrodes are aligned by aligning the molecular major axes in the alignment treatment directions 11a and 12a of the alignment films 27 and 28 of the pair of substrates 11 and 12, as shown in FIG. When a horizontal electric field is generated between 14 and 15, the molecular major axis is aligned in the direction of the horizontal electric field as shown in FIG.

  That is, the first display electrode 14 is formed so as to correspond to at least the entire area of the pixel A, and the second display electrode 15 is an interlayer insulating film that covers the first display electrode 14. Is formed in a shape having an area smaller than that of the pixel A, and is opposed to the first display electrode 14 at the edge thereof, so that the first and second display electrodes 14, When a display drive voltage is supplied between the first display electrode 14 and the second display electrode 15, the display drive voltage is supplied between the second display electrode 15 and the second display electrode 15. A transverse electric field in a direction substantially parallel to the surface of the opposite substrate 12 is generated, and the transverse electric field causes the liquid crystal molecules 13a to be aligned with the molecular major axis aligned in the direction of the transverse electric field, and the behavior of the liquid crystal molecules Under the influence, other regions in the pixel A (comb-like ITO film 15 The second liquid crystal molecules 13a in the area) corresponding to the center between the central and adjacent comb teeth of the comb tooth portions of the display electrodes 15 consisting also similarly oriented.

  In a state where the vertical electric field is not generated, the liquid crystal molecules 13a are surfaces substantially parallel to the surfaces of the substrates 11 and 12 due to the horizontal electric field generated between the first and second display electrodes 14 and 15. Since the orientation orientation (the direction of the molecular long axis) is changed, the viewing angle dependency of Δnd of the liquid crystal display element is small, and thus a wide viewing angle, which is a characteristic of the lateral electric field control type liquid crystal display element, can be obtained.

  6 and 7 are diagrams schematically showing the orientation direction of liquid crystal molecules in a state where a vertical electric field is generated in one pixel A of the liquid crystal display element, and FIG. 6 shows the first and second displays. FIG. 7 shows the orientation direction when a horizontal electric field is generated between the first and second display electrodes 14 and 15, when the horizontal electric field is not generated between the display electrodes 14 and 15. Yes.

  When the viewing angle control voltage is supplied between the first display electrode 14 and the viewing angle control electrode 25 of the pixel A, a first display composed of the ITO film 14a having a shape corresponding to the entire area of the pixel A is provided. A portion of the electrode 14 that opposes the viewing angle control electrode 25 (a portion corresponding to a portion between the comb-tooth portions of the second display electrode 15 made of the comb-shaped ITO film 15a) and the entire area of the pixel A A vertical electric field in a direction substantially parallel to the liquid crystal layer 13 is generated between the viewing angle control electrode 25 and the liquid crystal molecules 13a rise obliquely with respect to the surfaces of the substrates 11 and 12 due to the vertical electric field. Orient.

  The vertical electric field is generated in a substantially inverted trapezoidal region whose width increases from the portion of the first display electrode 14 facing the viewing angle control electrode 25 toward the viewing angle control electrode 25. The liquid crystal molecules 13a in the region are obliquely raised and aligned by the vertical electric field, and the liquid crystal molecules 13a in the region having a weak vertical electric field in the pixel A are similarly raised and aligned due to the behavior of the liquid crystal molecules.

  In the state where the vertical electric field is generated, the liquid crystal molecules 13a are generated between the first and second display electrodes 14 and 15 in a state where the liquid crystal molecules 13a are inclined and aligned with respect to the surfaces of the substrates 11 and 12 as described above. The orientation direction is changed by the transverse electric field.

  That is, in the state where the vertical electric field is generated, when no horizontal electric field is generated between the first and second display electrodes 14 and 15, the liquid crystal molecules 13a are in the rising orientation direction as shown in FIG. When alignment directions 27a and 28a of the substrates 11 and 12 are aligned in the alignment processing directions 11a and 12a with the molecular long axes aligned, and a horizontal electric field is generated between the first and second display electrodes 14 and 15. As shown in FIG. 7, the molecular major axis is aligned in the direction of the transverse electric field.

  In the state in which the vertical electric field is generated, the viewing angle dependency of Δnd of the liquid crystal display element increases due to the oblique alignment of the liquid crystal molecules 13a, and therefore the front direction of the liquid crystal display element (the direction near the normal line of the liquid crystal display element). The display viewed from (1) is a display with good contrast that is almost the same as the display in the state where the vertical electric field is not generated. However, when viewed from a direction inclined obliquely with respect to the front direction, the display angle dependence of Δnd A phase difference different from that seen from the front direction is generated, and the display can hardly be visually recognized.

  Therefore, at this time, the viewing angle at which the display can be viewed with sufficient contrast is in a narrow range in the front direction, and it is possible to perform a highly secure narrow viewing angle display without fear of being looked into by others from an oblique direction. it can.

  The liquid crystal display element of this embodiment is a normally black mode display element in which the transmission axes 29a and 30a of the pair of polarizing plates 29 and 30 are substantially orthogonal to each other. In any state where an electric field is generated, the display when the horizontal electric field is not generated is a dark display, and the display when the horizontal electric field is generated is a bright display.

  This liquid crystal display element generates a lateral electric field on the inner surface of one substrate (opposite substrate) 12 by supplying a display driving voltage therebetween, in a direction substantially parallel to the surface of the substrate 12 therebetween. The first and second display electrodes 14 and 15 are provided to be insulated from each other, and are generated on the inner surface of the other substrate (observation side substrate) 11 between at least the first and second display electrodes 14 and 15. One of the first and second display electrodes 14, 15, for example, the first display electrode, corresponding to the entire area of the pixel A composed of the region in which the orientation direction of the liquid crystal molecules 13 a is controlled by the horizontal electric field. A viewing angle control voltage independent of the display drive voltage supplied between the first and second display electrodes 14 and 15 is supplied between the electrode 14 and the first display electrode 14. In between, the direction substantially parallel to the thickness direction of the liquid crystal layer 13 Since the viewing angle control electrode 25 for generating the vertical electric field is provided, as described above, the liquid crystal molecules 13a are converted into the liquid crystal molecules 13a by the wide viewing angle display, which is a characteristic of the horizontal electric field control type liquid crystal display element, and the vertical electric field. A narrow viewing angle display in which the viewing angle is narrowed by obliquely rising with respect to the surfaces of the substrates 11 and 12 and the viewing angle can be stably controlled over a sufficiently wide angle range.

  In this embodiment, a viewing angle control voltage is supplied between the first display electrode 14 and the viewing angle control electrode 25. However, the viewing angle control voltage is applied to the second display electrode. 15 and the viewing angle control electrode 25, and a vertical electric field may be generated between the second display electrode 15 and the viewing angle control electrode 25. Wide viewing angle display and narrow viewing angle display can be performed.

  In addition, the liquid crystal display element includes alignment films 27 and 28 formed on the inner surfaces of the pair of substrates 11 and 12, respectively, along a direction substantially parallel to the vertical direction of the screen (the vertical axis O of the screen). Alignment treatment is performed in the opposite direction, and the observation-side polarization plate 29 of the pair of polarization plates 29 and 30 is disposed with its transmission axis 29a substantially parallel to the alignment treatment direction 11a and 12a. The polarizing plate 30 is arranged so that the transmission axis 30a thereof is substantially orthogonal to the transmission axis 29a of the polarizing plate 29 on the observation side, so that each of the polarizing plates 30 is approximately left and right with respect to the normal line of the liquid crystal display element. It is possible to obtain a wide viewing angle in the angle range inclined by the same angle and a narrow viewing angle in which the angle range is narrowed by approximately the same angle from the left-right direction.

  In this liquid crystal display element, since the electrostatic shielding conductive film 31 corresponding to the entire area of the liquid crystal layer 13 is provided on the outer surface of the observation side substrate 11, the observation side surface (the outer surface of the observation side polarizing plate 29). ) Does not affect the control of the orientation direction of the liquid crystal molecules 13a by the lateral electric field, and thus is not affected by the static electricity. Stable display can be performed.

  In addition, the liquid crystal display element includes a touch film 32 including a film substrate 33 and a touch-side conductive film 34 provided on one surface of the observation-side substrate 11, and the touch-side conductive film 34. The touch-shielding film 31 and the static-shielding conductive film 31 are arranged so as to face each other with a gap, and the touch-side film 31 is touched by a local touch of the touch-film 32 from the observation side. Since the touch input portion for locally contacting the conductive film 34 with the static electricity shielding conductive film 31 is formed, the conductive film is provided on one surface on the observation side of the liquid crystal element in which the liquid crystal layer is sealed between the pair of substrates. Compared with a liquid crystal display element with a touch panel in which a touch input panel in which a pair of substrates provided with a touch panel are stacked is laminated, the structure is hardly complicated and thickened. It can be provided with switch input function.

  FIG. 8 shows a touch position coordinate detecting means connected to the touch input unit of the liquid crystal display element.

  The touch position coordinate detection means has a horizontal position of the screen of the liquid crystal display element as an X axis and a vertical direction of the screen as a Y axis, and a touch position by the touch pen 51 of the touch film 32, that is, the static electricity shielding conductive material. The X-axis coordinate and the Y-axis coordinate of the contact position of the touch-side conductive film 34 with respect to the film 31 are detected alternately, and one of the electrostatic-shielding conductive film 31 and the touch-side conductive film 34, for example, a static-shielding conductive film. An X-axis power supply system 41 that intermittently supplies a constant X-axis direction voltage between both ends of the film 31 in the X-axis direction at a constant period, and the other conductive film, that is, the touch-side conductive film 34 in the Y-axis direction. A Y-axis power supply system 45 that intermittently supplies a constant Y-axis direction voltage between both end edges at a period shifted from the supply period of the X-axis direction voltage, and the X-axis to the electrostatic shielding conductive film 31. When directional voltage is supplied An X-axis coordinate detection unit 49 that detects an X-axis coordinate of the touch position based on a voltage value at one end edge in the Y-axis direction of the touch-side conductive film 34, and the Y-axis direction voltage applied to the touch-side conductive film 34. And a Y-axis coordinate detection unit 50 that detects the Y-axis coordinate of the touch position based on the voltage value at one end edge in the X-axis direction of the static electricity shielding conductive film 31.

  The X-axis power supply system 41 is connected to a constant-voltage X-axis power supply 42, one end edge in the X-axis direction of the electrostatic shielding conductive film 31 and one pole of the X-axis power supply 42, or In synchronization with the power supply / detection unit change-over switch 43 and the power supply / detection unit change-over switch 43, the connection between the one end edge of the conductive film 31 in the X-axis direction and the Y-axis coordinate detection unit 50 is switched at a predetermined cycle. It comprises an open / close switch 44 for turning on / off the connection between the other pole of the X-axis power source 42 and the other end edge of the electrostatic shielding conductive film 31 in the X-axis direction.

  The Y-axis power supply system 45 includes a constant-voltage Y-axis power supply 46, a connection between one end edge of the touch-side conductive film 34 in the Y-axis direction and one pole of the Y-axis power supply 46, or the touch side. Power supply / detection unit switching for alternately switching the connection between one end edge of the conductive film 34 in the Y-axis direction and the X-axis coordinate detection unit 49 at the timing opposite to that of the power supply / detection unit switch 43 of the X-axis power supply system 41 An open / close switch that turns ON / OFF the connection between the other pole of the Y-axis power supply 46 and the other end edge in the Y-axis direction of the touch-side conductive film 34 in synchronization with the switch 47 and the power supply / detection unit switch 47 48.

  It should be noted that the X-axis direction voltage is applied to both ends of the electrostatic shielding conductive film 31 in the X-axis direction and both ends of the touch-side conductive film 34 in the Y-axis direction, respectively. In order to apply the Y-axis direction voltage uniformly to the entire touch-side conductive film 34, linear electrodes 31a made of a low-resistance metal film formed over the entire length of the edge. A connection terminal (not shown) for the X-axis power supply system 41 and the Y-axis power supply system 45 is formed on the linear electrodes 31a and 34a.

  The touch position coordinate detecting means includes the X-axis direction voltage and the Y-axis direction voltage between both end edges in the X-axis direction of the static electricity shielding conductive film 31 and between both end edges in the Y-axis direction of the touch-side conductive film 34. Are alternately supplied, and when the voltage in the X-axis direction is supplied to the electrostatic shielding conductive film 31, the touch-side conductive film 34 passes through the contact portion between the electrostatic shielding conductive film 31 and the touch-side conductive film 34. Based on the voltage value in the X-axis direction corresponding to the position of the contact portion transmitted to the edge in the Y-axis direction, the X-axis coordinate detection unit 49 detects the X-axis coordinate of the touch position, Corresponds to the position of the contact portion transmitted through the contact portion between the electrostatic shielding conductive film 31 and the touch-side conductive film 34 to the edge in the X-axis direction of the electrostatic shielding conductive film 31 when the Y-axis direction voltage is supplied. The Y-axis coordinate based on the Y-axis direction voltage value The output unit 50 detects the Y-axis coordinate of the touch position.

  In the touch position coordinate detecting means shown in FIG. 8, the X-axis power supply system 41 and the Y-axis power supply system 45 are provided with constant voltage power supplies 42 and 46, respectively. It is good also as a structure which shares two constant voltage power supplies.

  Since the liquid crystal display element forms the contact type touch input unit by disposing the touch film 32 on the outer surface side of the observation side substrate 11, when the touch film 32 is strongly touched, the observation side substrate 11 is Deformed by being pushed inward.

  However, since this liquid crystal display element displays an image by controlling the orientation direction of the liquid crystal molecules 13a by the lateral electric field, the observation side substrate 11 is deformed inward by the touch of the touch film 32, and the liquid crystal layer Even if the display of the portion is disturbed due to the change in thickness, since the large electric field is not disturbed in the portion where the thickness of the liquid crystal layer is changed, local charge accumulation or the like does not occur.

  For this reason, after the observation-side substrate 11 is restored by touch release of the touch film 32, the display disorder can be quickly eliminated, and thus a display without the influence of touch input can be performed.

  Although the liquid crystal display element of the above embodiment is of a normally black mode, the polarizing plates 29 and 30 on the opposite side to the observation side are made substantially parallel to each other with their transmission axes 29a and 30a. It is good also as the arranged normally white mode.

(Second Embodiment)
9 and 10 are a sectional view of a part of a liquid crystal display element and a plan view of a part of one substrate of the liquid crystal display element according to a second embodiment of the present invention. In this embodiment, the same reference numerals are given to the components corresponding to those of the first embodiment described above, and the description of the same components is omitted.

  In the liquid crystal display element of this embodiment, a comb-shaped ITO film 14b in which both the first and second display electrodes 14 and 15 on the inner surface of the opposite substrate 12 are patterned into a comb shape having a plurality of comb teeth portions, The display electrodes 14 and 15 are formed at a distance in the direction along the surface of the substrate 12, and other configurations are the same as those of the first embodiment.

  In this embodiment, the first comb-shaped ITO film 14b forming the first display electrode 14 is formed by integrating the comb-shaped ITO films 14b corresponding to a plurality of pixels A in each row for each pixel row. The comb-shaped ITO films 14b of the respective rows are connected in common at the ends thereof, and the second comb-shaped ITO film 15b forming the second display electrode 15 is connected to each pixel. A corresponding to each A and connected to a plurality of TFTs 16 formed on the inner surface of the opposite substrate 12.

  In addition, each comb-tooth portion of the first comb-shaped ITO film 14b and the second comb-shaped ITO film 15b is in the vertical direction of the screen of the liquid crystal display element, that is, either the left or right with respect to the vertical axis O of the screen. Are formed in an elongated shape along a direction inclined at an angle θ of 5 ° to 15 °, and the widths a1 and a2 of the comb teeth and the comb teeth of the first comb-shaped ITO film 14b The ratios c / a1 and c / a of the distance c between the second comb-shaped ITO film 15c and the comb teeth portion are set to 1/3 to 3/1, preferably 1/1.

  Further, the alignment films 27 and 28 formed on the inner surfaces of the pair of substrates 11 and 12 of the liquid crystal display element are opposite to each other along a direction substantially parallel to the vertical direction of the screen (vertical axis O of the screen). Of the pair of polarizing plates 29 and 30, the polarizing plate 28 on the observation side is arranged with its transmission axis substantially parallel to the alignment processing, and the polarizing plate 30 on the opposite side is The transmission axis is arranged so as to be substantially orthogonal or parallel to the transmission axis of the polarizing plate 29 on the observation side.

  Also in the liquid crystal display element of this embodiment, since the static electricity shielding conductive film 31 corresponding to the entire area of the liquid crystal layer 13 is provided on the outer surface of the observation side substrate 11, the static electricity applied from the observation side is liquid crystal molecules due to a lateral electric field. Therefore, stable display without being affected by the static electricity can be performed.

  Moreover, this liquid crystal display element has a touch film 32 comprising a film substrate 33 and a touch-side conductive film (second conductive film) 34 provided on one surface thereof on the outer surface side of the observation-side substrate 11. The touch-side conductive film 34 is disposed so as to face the static electricity shielding conductive film 31 with a gap therebetween, and the touch film 32 and the static electricity shielding conductive film 31 are used to localize the touch film 32 from the observation side. Since the touch input part is formed by bringing the touch-side conductive film 34 into contact with the static electricity shielding conductive film 31 locally by a mechanical touch, the touch input function is provided without making the structure almost complicated and thick. Can be made.

  Since the liquid crystal display element displays an image by controlling the orientation direction of the liquid crystal molecules by the lateral electric field, the observation side substrate 11 is warped and deformed inward by the touch of the touch film 32. Even if the display is disturbed, the disturbance of the display can be eliminated simultaneously with the restoration of the observation side substrate 11 by the release of the touch, and therefore, the display without the influence of the touch input can be performed.

  Further, similarly to the liquid crystal display element of the first embodiment described above, this liquid crystal display element is provided with the viewing angle control electrode 25 on the inner surface of the observation side substrate 11, so that a wide viewing angle display and a narrow viewing angle are provided. In addition to performing display, the viewing angle can be stably controlled over a sufficiently wide angle range.

(Other embodiments)
In the liquid crystal display elements of the first and second embodiments, the first and second display electrodes 14 and 15 for generating a lateral electric field are provided on the inner surface of the substrate 12 opposite to the observation side, and the observation is performed. The viewing angle control electrode 25 is provided on the inner surface of the side substrate 11. On the contrary, the first and second display electrodes 14 and 15 are provided on the inner surface of the observation side substrate 11 to control the viewing angle. The electrode 25 may be provided on the inner surface of the opposite substrate 12.

  The present invention can also be applied to a liquid crystal display element that does not perform viewing angle control, in which case the viewing angle control electrode 25 is unnecessary.

1 is a cross-sectional view of a part of a liquid crystal display device showing a first embodiment of the present invention. The top view of a part of one board | substrate of the said liquid crystal display element. The figure which shows the orientation process direction of the orientation film | membrane provided in the inner surface of a pair of board | substrate of the said liquid crystal display element, respectively, and the direction of the transmission axis of a polarizing plate. FIG. 4 is an orientation diagram when a horizontal electric field is not generated, schematically showing a change in alignment of liquid crystal molecules in a state where a vertical electric field of one pixel of the liquid crystal display element is not generated. The orientation azimuth | direction figure when producing | generating a horizontal electric field which shows typically the change of the orientation of a liquid crystal molecule in the state which does not produce | generate the vertical electric field of the said 1 pixel. FIG. 3 is an orientation diagram when a horizontal electric field is not generated, schematically showing a change in alignment of liquid crystal molecules in a state where a vertical electric field of one pixel is generated. FIG. 6 is an orientation diagram when a horizontal electric field is generated, schematically showing a change in alignment of liquid crystal molecules in a state where a vertical electric field of the one pixel is generated. The block diagram of the touch position coordinate detection means connected to the touch input part of the said liquid crystal display element. Sectional drawing of the part of liquid crystal display element which shows 2nd Example of this invention. The top view of a part of one board | substrate of the liquid crystal display element of a 2nd Example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11,12 ... Board | substrate, 13 ... Liquid crystal layer, 13a ... Liquid crystal molecule, 14 ... 1st display electrode, 15 ... 2nd display electrode, 16 ... TFT, 22 ... Gate wiring, 23 ... Data wiring, 24 ... Interlayer insulating film, 25 ... viewing angle control electrode, 26R, 26G, 26B ... color filter, 27, 28 ... alignment film, 29, 30 ... polarizing plate, 31 ... static electricity shielding conductive film (first conductive film), 32 ... Touch film, 33 ... Film substrate, 34 ... Touch-side conductive film (second conductive film).

Claims (7)

A first substrate having a first main surface and a second main surface formed in a flat plate shape, and a transparent first conductive film formed on the first main surface;
It is formed in a flat plate shape, has a third main surface and a fourth main surface, and is affixed to the first substrate by a sealing material so that the third main surface faces the second main surface. A combined second substrate;
A liquid crystal layer disposed between the first substrate and the second substrate and having liquid crystal molecules aligned parallel to the second main surface and the third main surface;
It is formed in a flat plate shape and has a fifth main surface and a sixth main surface, a transparent second conductive film is formed on the sixth main surface, and the sixth main surface is the first main surface. A third substrate arranged to face the main surface of
Coordinate detection means for detecting a contact position between the first conductive film and the second conductive film,
A first electrode and a second electrode that change the orientation direction of the liquid crystal molecules by applying a voltage between the electrodes, and are formed on the third main surface;
A viewing angle control electrode that vertically aligns the liquid crystal molecules with respect to the third main surface and generates a vertical electric field that is parallel to the thickness direction of the liquid crystal layer with the one electrode. Is formed on the second main surface,
The viewing angle control electrode is:
When performing a wide viewing angle display, the horizontal electric field generated by a display driving voltage supplied between the first electrode and the second electrode, and the orientation direction of the liquid crystal molecules of the liquid crystal layer Provided in correspondence with the entire region in which the orientation direction of the liquid crystal molecules is controlled by the lateral electric field controlled in a plane parallel to the third main surface;
A viewing angle control voltage independent of the display driving voltage is supplied between the viewing angle control electrode and one of the first electrode and the second electrode,
Narrow when performing angle display, while supplying the viewing angle control voltage for generating the vertical electric field, the case of displaying a wide viewing angle, the viewing angle control drive means so as not to supply the viewing angle control voltage A liquid crystal display element, further comprising:   The liquid crystal display element according to claim 1, wherein a color filter is formed on the second main surface.   3. The liquid crystal according to claim 1, wherein a first polarizing plate is attached to the fifth main surface, and a second polarizing plate is attached to the fourth main surface. 4. Display element.   4. The liquid crystal display element according to claim 1, wherein each of the first conductive film, the second conductive film, the first electrode, and the second electrode is made of ITO. 5.   5. The liquid crystal display element according to claim 1, wherein the first electrode and the second electrode are formed in different layers with an insulating film interposed therebetween. A first substrate having a first main surface and a second main surface formed in a flat plate shape, and a transparent first conductive film formed on the first main surface;
It is formed in a flat plate shape, has a third main surface and a fourth main surface, and is affixed to the first substrate by a sealing material so that the third main surface faces the second main surface. A combined second substrate;
A liquid crystal layer disposed between the first substrate and the second substrate and having liquid crystal molecules aligned parallel to the second main surface and the third main surface;
It is formed in a flat plate shape and has a fifth main surface and a sixth main surface, a transparent second conductive film is formed on the sixth main surface, and the sixth main surface is the first main surface. A third substrate arranged to face the main surface of
Coordinate detection means for detecting a contact position between the first conductive film and the second conductive film,
A first electrode and a second electrode for controlling a horizontal electric field of the liquid crystal molecules for each pixel are formed on the third main surface;
A viewing angle control electrode that vertically aligns the liquid crystal molecules with respect to the third main surface and generates a vertical electric field that is parallel to the thickness direction of the liquid crystal layer with the one electrode. Is formed on the second main surface,
The viewing angle control electrode is:
When performing a wide viewing angle display, the horizontal electric field generated by a display driving voltage supplied between the first electrode and the second electrode, and the orientation direction of the liquid crystal molecules of the liquid crystal layer Provided in correspondence with the entire region in which the orientation direction of the liquid crystal molecules is controlled by the lateral electric field controlled in a plane parallel to the third main surface;
A viewing angle control voltage independent of the display driving voltage is supplied between the viewing angle control electrode and one of the first electrode and the second electrode,
Narrow when performing angle display, while supplying the viewing angle control voltage for generating the vertical electric field, the case of displaying a wide viewing angle, the viewing angle control drive means so as not to supply the viewing angle control voltage A liquid crystal display element, further comprising:   The liquid crystal display element according to claim 1, wherein the first electrode or the second electrode is a comb-like electrode.

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