JP2009222797A - Liquid crystal display panel and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To heighten the utilization of light of a liquid crystal display panel with a micro-lens and to provide a display with high directivity. <P>SOLUTION: This liquid crystal display panel includes a TFT substrate 60, a counter substrate 62, a liquid crystal layer 64 and a plurality of micro-lenses 53 disposed on a first surface on the opposite side to the liquid crystal layer 64 of the TFT substrate 60, wherein each of a plurality of pixels includes an aperture part for transmitting light entering from the first surface toward the outer surface of the counter substrate 62 and a light shielding part for shielding light entering from the first surface, and each of the plurality of micro-lenses 53 has asymetical shape about an axis vertical to the substrate surface and passing the center of the micro-lens 53, and includes a first lens part 53a for condensing incident light toward the aperture part and a second lens part 53b for condensing incident light toward the light shielding part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid crystal display panel and a liquid crystal display device, and more particularly to a liquid crystal display device including a microlens array.

  In recent years, liquid crystal display devices have been widely used as display devices for monitors, projectors, portable information terminals, mobile phones and the like. In general, a liquid crystal display device changes the transmittance (or reflectivity) of a liquid crystal display panel according to a drive signal and modulates the intensity of light from a light source irradiated on the liquid crystal display panel to display an image, text, or the like. The liquid crystal display device includes a direct-view display device that directly observes an image displayed on the liquid crystal display panel, and a projection display device (projector) that projects an image displayed on the liquid crystal display panel on a screen by a projection lens. and so on.

  The liquid crystal display device changes the optical characteristics of the liquid crystal layer in each pixel by applying a driving voltage corresponding to the image signal to each of the pixels regularly arranged in a matrix, and the light that has passed through the liquid crystal layer is changed. Display is performed by dimming using a polarizing plate.

  The liquid crystal display device includes a reflective liquid crystal display device that performs display by reflecting light incident from a display surface, and a transmissive liquid crystal display device that performs display by transmitting light from a backlight light source. In recent years, as display devices for mobile devices and the like, each pixel includes a region that displays using light from a backlight light source, and a region that displays by reflecting light incident from a display surface. Development of a transflective (transmission / reflection) liquid crystal display device provided is underway.

  In order to improve the light utilization efficiency of a liquid crystal display device having a transmissive region, a method for improving the effective aperture ratio of the liquid crystal display panel by providing a microlens for condensing light on each pixel in the liquid crystal display panel is patented It is disclosed in Document 1.

  Further, Patent Document 2 describes a method for forming microlenses with high accuracy. The microlens of Patent Document 2 is formed by irradiating light from a CF substrate side to a photocurable resin applied on a substrate through a pixel opening, and then performing a photolithography process such as development and heating. In the light irradiation process, so-called self-alignment exposure is performed in which exposure is performed by changing the incident angle of light that passes through the pixel opening. According to this exposure method, since the microlens is formed in a self-aligned manner corresponding to each pixel (formation of the microlens by the self-alignment method), alignment of the mask for forming the microlens becomes unnecessary, and the pixel Positioning of the opening and the microlens array can be performed with extremely high accuracy.

  Patent Document 3 describes a liquid crystal display used for a monitor display unit of a car navigation system. FIG. 8 is a diagram used for explaining the problem of the in-vehicle liquid crystal display in Patent Document 3. In FIG.

  As described with reference to FIG. 8, the conventional liquid crystal display 4 used in a car navigation system or the like is not limited to the direction in which the display light is directed toward the driver 1 and the passenger seat, but in other wide azimuth directions and poles. Propagate in the angular direction with almost the same intensity. Therefore, as shown by the hatched lines in FIG. 8, display reflections 4 </ b> A and 4 </ b> B are generated on the front glass 5 or the door glass 6, which hinders the driver 1 from driving.

  In order to solve such a problem, Japanese Patent Application Laid-Open No. H10-228867 discloses a technique for directing light emitted from a display unit of a liquid crystal display by correcting the emission direction of light emitted from a backlight by a light emission direction correcting element. A technique is described that provides a bright display only in a specific direction.

  Patent Document 4 discloses a liquid crystal display device in which micro optical elements having an asymmetric shape with respect to the substrate normal are arranged on the light incident side.

  FIG. 9 shows a cross section of the liquid crystal display device disclosed in Patent Document 4. As shown in FIG. 9, in this liquid crystal display device, in order to improve contrast, incident light is tilted by an asymmetric microlens in a direction that matches the pretilt angle of the liquid crystal.

Patent Document 5 shows an example of a backlight used in a liquid crystal display device.
Japanese Patent Laid-Open No. 11-194332 JP 2005-196139 A (Patent No. 3708112) Japanese Patent Laid-Open No. 7-306411 JP 2006-184673 A JP-A-8-271894

  In order to reduce power consumption, liquid crystal display panels with higher light utilization efficiency are required for liquid crystal display panels for in-vehicle use and mobile use. Further, in use in a bright place such as in a car during the daytime or outdoors, it is required to display with higher luminance in order to improve display quality. Further, as described above, in order to suppress reflection in a window or the like, it is also required to give directivity to the display.

  Patent Document 3 describes that the direction of the emitted light is regulated by using a light emission direction correcting element to give directivity to the display, but a technique for improving the light utilization efficiency is described. It is not done.

  Further, in the liquid crystal display panel of Patent Document 4, the incident angle and the outgoing angle of light are defined in accordance with the pretilt angle of the liquid crystal during vertical alignment. Therefore, in such a liquid crystal display panel, since the direction of the emitted light is completely defined by the pretilt angle of the liquid crystal, the directivity direction cannot be arbitrarily set. Further, since the pretilt angle of the liquid crystal during vertical alignment is usually set to 5 degrees or less with respect to the vertical direction of the substrate, the directivity cannot be increased in the polar angle direction beyond that. Therefore, in this liquid crystal display panel, it is not possible to perform display with strong directivity in the driver direction shown in FIG. Further, it is impossible to prevent the emission of light in unnecessary directions, and it is difficult to reduce the reflection using the liquid crystal display panel of Patent Document 4.

  A transflective liquid crystal display panel that can perform display using external light as well as a backlight is suitable for improving light utilization efficiency and reducing power consumption. However, since the transflective liquid crystal display panel has a wide reflection area in each pixel, the use efficiency of the backlight is reduced due to light shielding by the reflection area. In particular, when used in a dark place, display is performed almost exclusively by the backlight. Therefore, it is necessary to improve the utilization efficiency of the backlight in order to achieve both improvement in luminance and reduction in power consumption.

  The present invention has been made in view of the above problems, and an object thereof is to provide a highly directional display by a transflective liquid crystal display panel having a relatively wide light-shielding region provided with a microlens. At the same time, the utilization efficiency of the backlight is further improved.

  A liquid crystal display device according to the present invention is a liquid crystal display panel including a plurality of pixels, and includes a TFT substrate including an electric element layer including TFTs and pixel electrodes, and a counter substrate including a counter electrode facing the pixel electrodes. And a liquid crystal layer disposed between the electric element layer and the counter electrode, and a first surface of the TFT substrate opposite to the liquid crystal layer so as to correspond to the plurality of pixels. A plurality of microlenses, wherein each of the plurality of pixels transmits an incident light from the first surface of the TFT substrate toward an outer surface of the counter substrate; and A light shielding portion that shields light incident from the first surface, and each of the plurality of microlenses has an asymmetric shape with respect to an axis that is perpendicular to the substrate surface and passes through the center of the microlens. And incident The toward the opening portion comprising a first lens portion for focusing, a second lens portion for condensing light toward the light incident on the light-shielding portion.

  In one embodiment, the optical axis of the first lens portion passes through the opening, and the optical axis of the second lens portion passes through the light shielding portion.

  In one embodiment, the focal position of the first lens portion is in the opening, and the focal position of the second lens portion is in the light shielding portion.

  In one embodiment, the plurality of microlenses are a plurality of lenticular lenses, and each of the plurality of lenticular lenses is a surface perpendicular to a substrate surface and parallel to a first direction in which the plurality of lenticular lenses extend. It has an asymmetric shape with respect to the surface.

  In one embodiment, when viewed perpendicularly to the substrate surface, each central position of the plurality of pixels in a second direction perpendicular to the first direction is different from each central position of the plurality of lenticular lenses.

  In one embodiment, when viewed perpendicular to the substrate surface, the end positions of the plurality of pixels in the second direction are different from the end positions of the plurality of lenticular lenses.

  In one embodiment, when viewed along the second direction perpendicular to the substrate surface, more than half of the light shielding portion overlaps the first lens portion.

  In one embodiment, when viewed along the second direction perpendicular to the substrate surface, all of the second lens portion overlaps the light shielding portion.

  In one embodiment, each of the plurality of microlenses includes a third lens portion that is disposed between the first lens portion and the second lens portion and has a light incident surface substantially parallel to the substrate surface. .

  In one embodiment, when viewed along the second direction perpendicular to the substrate surface, all of the third lens portion overlaps the opening.

  In one embodiment, the liquid crystal display panel includes a transmissive region that performs display by light transmitted through the liquid crystal display panel, and a reflective region that performs display by reflecting light by a reflective layer included in the electrical element layer. The counter substrate includes a color filter layer, and the light shielding portion is a portion from a bottom surface of the electric element layer to an upper surface of the color filter layer in the reflection region, and the opening. The portion is a portion from the bottom surface of the electric element layer to the top surface of the color filter layer in the transmission region.

  In one embodiment, the plurality of microlenses are made of a photocurable resin, and are formed in a self-aligned manner using light irradiated through the opening.

  In one embodiment, a protective layer made of the same material as the microlens or an acrylic material is disposed on the side of the microlens opposite to the TFT substrate.

  A liquid crystal display device according to the present invention includes the above-described liquid crystal display panel, and a backlight disposed on the side of the microlens opposite to the TFT substrate.

  In one embodiment, the backlight emits light having narrow directivity toward the liquid crystal display panel.

  In one embodiment, the backlight emits irradiation light propagating in a direction inclined from a vertical direction of the substrate surface of the liquid crystal display panel toward the liquid crystal display panel, and the plurality of light sources along the inclined direction. The microlens has an asymmetric shape.

  According to the present invention, a large amount of incident light is condensed by the first lens portion of the microlens, a desired directivity is obtained by the condensed light, and an unnecessary direction is obtained by the second lens portion. The optical path to go is obstructed. Therefore, the backlight utilization efficiency of the liquid crystal display panel having a relatively wide light-shielding region can be improved, and a highly directional display can be provided without adding a special element.

  Hereinafter, embodiments of a liquid crystal display device according to the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a cross-sectional view schematically showing the configuration of the liquid crystal display device 100 of the present embodiment. The liquid crystal display device 100 is a transflective liquid crystal display device (LCD) using an active matrix method. As shown in the figure, a liquid crystal display device 100 includes a liquid crystal display panel (liquid crystal display panel with a microlens) 50, and a backlight 30 disposed below the liquid crystal display panel 50 (on the side opposite to the display surface). It has.

  The liquid crystal display panel 50 includes a bonded substrate 51 having a plurality of pixels arranged in a matrix, and a plurality of micros provided on the light receiving surface of the bonded substrate 51 (the bottom surface of the bonded substrate 51 extending perpendicular to the paper surface). A microlens array 52 including lenses 53, a support 59 provided in a peripheral region of the microlens array 52, a front-side optical film 54 provided on the observer side (upper side in the figure) of the bonded substrate 51, A back side optical film 55 provided on the light incident side of the micro lens array 52 and a protective layer 56 disposed between the back side optical film 55 and the micro lens array 52 are provided.

  The microlens array 52 is formed of a photocurable resin. Each microlens 53 of the microlens array 52 is self-aligned so as to correspond to each pixel by irradiating the photocurable resin with light through the opening of the pixel according to a method described in Patent Document 2, for example. Is formed. The microlens 53 may be formed by another conventional method, for example, by forming a resin with a stamper.

  The protective layer 56 is provided so as to be in contact with the microlens array 52 and the support body 59 by the same photocurable resin as that of the microlens array 52. The protective layer 56 and the microlens array 52 are bonded so that the protective layer 56 is in contact with only the vicinity of the apex of each microlens 53, and a gap including air is provided between the microlens array 52 and the protective layer 56. Is formed.

  The front side optical film 54 is attached to the bonded substrate 51 via an adhesive layer 57, and the back side optical film 55 is attached to the protective layer 56 via an adhesive layer 58. Each of the front side optical film 54 and the back side optical film 55 includes a polarizing film that transmits linearly polarized light.

  The protective layer 56 is formed of an acrylic or epoxy UV curable resin having a high visible light transmittance. However, the protective layer 56 may be formed of a thermosetting resin. The protective layer 56 and the support body 59 are preferably formed of the same material as the microlens 53 or a material having a refractive index substantially the same as the refractive index of the material constituting the microlens 53.

  Since the protective layer 56 is fixed by the support body 59 and the tops of the plurality of microlenses 53, the pressing strength of the liquid crystal display panel 50 is increased. Further, by using a curable resin for the protective layer 56, the protective layer 56 and the microlens array 52 can be firmly fixed without using an adhesive layer. Therefore, according to the present embodiment, even if the liquid crystal display panel 50 is pressed, the distance between the back-side optical film 55 and the microlens array 52 is kept constant, so that the distance between the two changes. It is possible to prevent the occurrence of luminance unevenness due to.

  The space between the microlens array 52 and the protective layer 56 may be filled with a material having a refractive index different from that of the microlens array 52. By adopting such a configuration, the strength of the liquid crystal display panel 50 can be increased. Further, although the strength is lowered, the protective layer 56 may be supported only by the support 59 by making the height of the support 59 higher than the height of the microlens array 52.

  It is also possible to adopt a configuration in which the protective layer 56 is not disposed. However, in this case, the adhesive layer 58 comes into contact with the microlens array 52, and when the liquid crystal display panel 50 is pressed, the adhesive may enter the microlens array 52 and cause problems such as display unevenness. There is. By disposing the protective layer 56 as in the present embodiment, such a problem can be prevented from occurring.

  The bonded substrate 51 includes a TFT substrate 60 on which a TFT is formed for each pixel, a counter substrate 62 that is a color filter substrate (CF substrate), and a liquid crystal layer 64. The liquid crystal layer 64 includes a liquid crystal material sealed between the TFT substrate 60 and the counter substrate 62, and is sealed by a sealing material 66 provided on the outer peripheral portion.

  The microlens 53 is a lenticular lens that extends in the column direction (vertical direction in the drawing in the drawing) of pixels arranged in a matrix on the bonded substrate 51. When viewed along the pixel row direction (left and right direction in the drawing), each microlens 53 has an asymmetric shape. FIG. 1 shows a simplified cross-sectional shape of the microlens 53. Details of the cross-sectional shape of the microlens will be described later with reference to FIGS.

  The pixel pitch (the width in the row direction of one pixel) is about 170 μm, and the width of the microlens 53 also corresponds to the pixel pitch. However, as will be described later, when viewed along the row direction, the position of the pixel does not coincide with the position of the lenticular lens. That is, the center of the pixel and the center of the lenticular lens in the row direction do not coincide, and the end position of the pixel and the end position of the lenticular lens are also different.

  When the microlens 53 is a lenticular lens, each microlens 53 is formed so as to cover a plurality of pixels along a row of pixels. You may form the width along the row | line | column of the pixel of each micro lens 53 in the same width as one pixel.

  As the backlight 30, an edge light type backlight using a reverse prism (TL: Turning Lens or RP: Reversed Prism) is used. This type of backlight 30 provides highly directional parallel light (also referred to as light having narrow directivity).

  As shown in FIG. 1, the backlight 30 includes a light guide plate 32, a light source 34 such as an LED or a cold cathode tube disposed on one side surface of the light guide plate 32, and a reflector disposed below the light guide plate 32. 36 and a prism sheet 38 disposed on the light guide plate 32 (on the liquid crystal display panel side).

  A groove is formed in a sawtooth shape below the light guide plate 32 facing the reflection plate 36, and as a result, a plurality of inclined surfaces having different inclination angles θ are formed on the bottom surface of the light guide plate 32. Here, the plurality of inclined surfaces are formed such that the inclination angle θ increases as the distance from the light source 34 increases. The prism sheet 38 has a plurality of prisms pointed downward.

  The light emitted from the light source 34 is reflected by the inclined surface of the reflecting plate 36 or the light guide plate 32, passes through the upper surface (light emitting surface) of the light guide plate 32, is refracted by the prism of the prism sheet 38, and then is liquid crystal. The light is emitted toward the display panel 50.

  Of the light emitted from the light source 34, light incident on the bottom and top surfaces of the light guide plate 32 at an angle equal to or greater than the critical angle is totally reflected by these surfaces. On the other hand, a part of the light incident at an angle smaller than the critical angle is reflected, and the rest is refracted and emitted from the bottom surface or the top surface. The light emitted from the bottom surface is reflected by the reflecting plate 36 and enters the light guide plate 32 again, and the light emitted from the top surface goes to the prism sheet 38.

  With such a mechanism, light propagating through the light guide plate 32 is gradually emitted toward the prism sheet 38 while repeating reflection and refraction. At this time, the light emitted from the light guide plate 32 is reflected on the upper surface. The light has directivity in a direction inclined from the surface vertical direction. This directivity direction is, for example, a polar angle of 45 when the surface vertical direction of the upper surface is a polar angle of 0 °, and the direction away from the light source along the upper surface (the direction from the left to the right in the figure) is 90 °. The direction is at least 90 ° and less than 90 °.

  Here, “having directivity” means that the emitted light has a strong intensity with respect to a certain direction, and the intensity of directivity, that is, with respect to a certain direction, Whether or not the directionality is strong is indicated by the half-value width angle in the intensity distribution of the emitted light. The direction indicated by the center value of the half-value width angle is defined as “direction of directivity”.

  In addition, the backlight described in patent document 5 may be used for the backlight 30, and light with strong directivity can be obtained also by it.

  Next, a more detailed configuration of the bonded substrate 51 will be described.

  FIG. 2 is a sectional view schematically showing a part of the bonded substrate 51. As shown in the figure, the TFT substrate 60 includes a transparent substrate 70 and an electric element layer 78 formed on the transparent substrate 70.

  The electric element layer 78 includes a reflection portion 72 and a pixel electrode 76 formed for each pixel, and an insulating layer 74 formed between the transparent electrode 70 and the pixel electrode 76. The electrical element layer 78 includes, in addition to those shown in the figure, TFTs arranged for each pixel, gate lines (scanning lines) and source lines (signal lines) arranged so as to separate the pixels, and Cs lines (auxiliary capacitance lines). ) Etc. are also formed. The reflection portion 72 has a reflection layer made of a metal such as aluminum, and light incident from the display surface side is reflected by this reflection layer and is emitted from the display surface as reflected light 46. The TFT, the gate line, the source line, and the Cs line can also be a part of the reflective portion.

  The counter substrate 62 includes a counter electrode 84, a CF (color filter) layer 82, and a transparent substrate 80. The upper surface of the transparent substrate 80 becomes the display surface of the liquid crystal display device 100. Note that an alignment film (not shown) that gives vertical alignment to the liquid crystal when no voltage is applied is formed on the surface of the TFT substrate 60 and the counter substrate 62 on the liquid crystal layer side.

  When viewed from the direction perpendicular to the substrate surface, in the liquid crystal display panel 50, the region where the reflection portion 72 is formed is called a reflection region 42, and the light from the backlight 30 is transmitted without the reflection portion 72 being formed. A region that can be transmitted (a region where the transmitted light 44 can be emitted) is referred to as a transmission region 43. In addition, an area defined by gate lines and source lines arranged in a grid so as to surround each of the pixel electrodes 72 is referred to as a pixel area 40.

  Note that an adjustment layer (not shown) made of a transmissive resin or the like may be provided on the counter substrate 62 side above the reflecting portion 72. The adjustment layer can make the optical path length in the liquid crystal layer 64 in the reflective region 42 and the transmissive region 43 the same.

  FIG. 3 is a diagram schematically showing the configuration of the liquid crystal display panel 50 as viewed from the display surface side. As shown in the figure, the microlens array 52 is composed of a plurality of microlenses 53 arranged at the same pitch as the pixel pitch along the row direction B of the pixels. Each micro lens 53 is a lenticular lens extending along the column direction C of the pixels.

  4 and 5 are diagrams schematically showing a cross section of the liquid crystal display panel 50 taken along the line A-A ′ in FIG. 3. FIG. 4 shows an optical path when the incident light 90 is irradiated perpendicularly to the substrate surface from the backlight 30 toward the liquid crystal display panel 50, and FIG. 5 shows a vertical direction of the substrate surface from the backlight 30. The optical path when incident light 90 'inclined with respect to is irradiated is represented. In these drawings, illustration of the front side optical film 54, the back side optical film 55, the protective layer 56, and the like is omitted.

As shown in FIGS. 4 and 5, each microlens 53 has an asymmetric shape with respect to an axis perpendicular to the substrate surface and passing through the center of the microlens 53 in the row direction B.
When the microlenses 53 are considered as lenticular lenses, it can be said that each microlens 53 has an asymmetric shape with respect to a plane perpendicular to the substrate surface and parallel to the column direction C.

  Each microlens 53 has a first portion 53a having a first incidence surface having a first curvature, and a second incidence having a curvature larger than the first curvature (the curvature radius is smaller than that of the first incidence surface). A second lens portion 53b having a surface.

  Of the portion located in the reflection region 42 as viewed from the substrate vertical direction, the portion in the range from the bottom surface of the electric element layer 78 to the top surface of the CF layer 82 in the substrate thickness direction (the reflecting portion 72, the insulating layer 74, The pixel electrode 76, the liquid crystal layer 64, the counter electrode 84, and the CF layer 82) are referred to as a light shielding portion. In addition, among the portions located in the transmission region 43 when viewed from the substrate vertical direction, a portion in the range from the bottom surface of the electric element layer 78 to the top surface of the CF layer 82 in the substrate thickness direction is referred to as an opening.

  The focal point 93a of the first lens portion 53a is located in the opening, and the focal point 93b of the second lens portion 53b is located in the light shielding portion. The optical axis 92a of the first lens portion 53a extends through the opening without passing through the light shielding portion, and the optical axis 92b of the second lens portion 53b extends through the light shielding portion. That is, incident light 90 and 90 'is condensed toward the opening by the first lens portion 53a, and incident light 90 and 90' is condensed toward the light shielding portion by the second lens portion 53b. Therefore, the light 91a that has passed through the first lens portion 53a is hardly shielded by the light-shielding portion, and becomes output light that is strongly inclined in the positive row direction B. The light 91b that has passed through the second lens portion 53b is Almost all is shielded from light by the reflector 72.

  If the microlens 53 is formed so that the optical axis 92b of the second lens portion 53b extends through the reflecting portion 72, more of the light traveling in an unnecessary direction can be shielded. Further, if the microlens 53 is formed so that the focal point 93b of the second lens portion 53b is located in the reflecting portion 72, more unnecessary light can be shielded.

  When viewed perpendicularly to the substrate surface, the end of the micro lens 53 in the row direction B is located in the reflecting portion 72 and is located in a portion different from the end of the pixel. In other words, when viewed perpendicularly to the substrate surface, the center position of each pixel in the row direction B is different from the center position of each microlens 53. Further, when viewed along the row direction B perpendicular to the substrate surface, more than half of the reflecting portion 72 (or the light shielding portion) overlaps with the first lens portion 53a, and the second lens portion 53b is entirely the reflecting portion 72. (Or light shielding part).

  According to the liquid crystal display device 100 of the present embodiment, a display having strong directivity in the positive row direction B can be obtained by the light transmitted through the first lens portion 53a. At the same time, since many of the backlights that are originally shielded by the reflecting portion 72 can be used for display, the light utilization efficiency is improved. In addition, since the second lens portion 53b prevents an optical path in an unnecessary direction, a more directional display can be performed. Therefore, when the liquid crystal display device 100 is used as an in-vehicle liquid crystal display, a brighter display can be obtained and reflection on the window can be prevented.

  FIG. 6 shows the polar angle dependency of the intensity of the display light emitted from the liquid crystal display device 100 according to the present embodiment. FIG. 6A shows the polar angle dependency along the column direction C of the pixel. ) Is a graph showing the polar angle dependency along the row direction B of the pixels. The horizontal axis of the graph in FIG. 6A represents the polar angle when viewed along the column direction C, and the vertical axis represents the intensity of the emitted light. The horizontal axis of the graph in FIG. 6B represents the polar angle when viewed along the row direction B, and the vertical axis represents the intensity of the emitted light. The solid lines in both graphs indicate the characteristics obtained from the liquid crystal display device 100 of the present embodiment, and the dotted lines indicate the characteristics obtained from a liquid crystal display device that does not include the microlens 53 (referred to as a comparative example). .

  As can be seen from FIGS. 6A and 6B, when viewed along the column direction C, the intensity peaks of the emitted light of the liquid crystal display device 100 and the emitted light of the comparative example are at positions where the polar angle is 0 degree. There is almost the same polar angle dependency. However, when viewed along the row direction B, in the comparative example, the peak position of the intensity is in the direction of 0 degree polar angle, whereas in the liquid crystal display device 100, the peak position is in the positive polar angle direction (about 10 degrees). ) Direction. Therefore, it can be seen that a highly directional display can be obtained by using the microlens 53 according to the present invention.

  These graphs show the characteristics when the liquid crystal display panel 50 receives the incident light 90 ′ shown in FIG. 5 from the backlight 30. When the liquid crystal display panel 50 receives the incident light 90 shown in FIG. 4, the intensity peak position (direction of directivity) along the row direction B is slightly more polar angle 0 than the peak shown in FIG. It shifts to the side close to the degree.

(Embodiment 2)
FIG. 7 is a cross-sectional view of the liquid crystal display panel 50 of the liquid crystal display device according to the second embodiment, and is a diagram schematically showing a cross-section at a position corresponding to AA ′ in FIG. 3. However, in these drawings, illustration of the front side optical film 54, the back side optical film 55, the protective layer 56, and the like is omitted. Since the configuration of the liquid crystal display device of the second embodiment is the same as that of the first embodiment except for the shape of the microlens, only the shape of the microlens will be described below, and the description of the other components will be omitted.

  As shown in FIG. 7, the microlens 53 ′ of the liquid crystal display panel 50 according to the second embodiment has a first portion 53 ′ a having a first incident surface having a first curvature, and is larger than the first curvature. A second lens portion 53′b having a second entrance surface having a curvature (a radius of curvature smaller than that of the first entrance surface), and between the first lens portion 53′a and the second lens portion 53′b. And a third lens portion 53'c. The light receiving surface of the third lens portion 53'c is a surface parallel to the substrate surface. When viewed along the row direction B perpendicular to the substrate surface, the entire third lens portion 53'c overlaps the opening.

  The focal points of the first lens portion 53'a and the second lens portion 53'b are located in the opening and the light shielding portion, respectively, as in the first embodiment. Accordingly, the optical axes of the first lens portion 53'a and the third lens portion 53'c pass through the opening, and the optical axis of the second lens portion 53'b passes through the light shielding portion. That is, incident light is condensed toward the opening by the first lens portion 53'a, and incident light is condensed toward the light shielding portion by the second lens portion 53'b. Almost all of the light incident on the third lens portion 53'c passes through the opening without being condensed.

  When viewed perpendicularly to the substrate surface, both end portions in the row direction B of the microlens 53 ′ are located in the reflecting portion 72, and are located in portions different from the end portions of the pixels. When viewed in the row direction B perpendicular to the substrate surface, the width of the reflection portion 72 (or the light shielding portion) and the first lens portion 53′a overlaps with the reflection portion 72 and the second lens portion 53′b. It is wider than the overlapping width.

  By using the microlens 53 ′ having such a shape, it is possible to provide a highly directional display and improve the light use efficiency as in the first embodiment. The light receiving surface of the third lens portion 53′c may be a flat surface inclined with respect to the substrate surface, and the position of the end portion of the third lens portion 53′c on the first lens portion 53′a side is the opening portion. It may be set inside.

  The present invention is suitably used as a liquid crystal display panel for a display that requires low power consumption, a bright and highly directional display, such as a vehicle-mounted display.

1 is a cross-sectional view schematically showing a configuration of a liquid crystal display device according to Embodiment 1. FIG. 3 is a cross-sectional view schematically showing a part of the bonded substrate board according to Embodiment 1. FIG. It is the figure which represented typically the structure of the liquid crystal display panel of Embodiment 1 at the time of seeing from the display surface side. It is the figure which represented typically the cross section of the A-A 'position in FIG. 3 of a liquid crystal display panel. It is the figure which represented typically the cross section of the A-A 'position in FIG. 3 of a liquid crystal display panel. 5 is a graph showing the polar angle dependency of the intensity of display light emitted from the liquid crystal display device according to Embodiment 1, wherein (a) shows the polar angle dependency along the pixel column direction, and (b) shows the pixel angle. Each represents the polar angle dependency along the row direction. It is sectional drawing which represented typically the structure of the liquid crystal display panel of Embodiment 2 by this invention. It is the figure used in order to demonstrate the problem of the vehicle-mounted liquid crystal display in patent document 3. FIG. 10 is a cross-sectional view illustrating a liquid crystal display device disclosed in Patent Document 4. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 30 Backlight 32 Light-guide plate 34 Light source 36 Reflector 38 Prism sheet 40 Pixel area 42 Reflection area 43 Transmission area 44 Transmitted light 46 Reflected light 50 Liquid crystal display panel 51 Bonding board | substrate 52 Microlens array 53, 53 ''a 1st lens part 53b, 53'b 2nd lens part 53'c 3rd lens part 54 Front side optical film 55 Back side optical film 56 Protective layer 57, 58 Adhesive layer 59 Support body 60 TFT substrate 62 Opposite substrate 64 Liquid crystal layer 66 Sealing material 70 Transparent substrate 72 Reflecting portion 74 Insulating layer 76 Pixel electrode 78 Electrical element layer 80 Transparent substrate 82 CF layer 84 Counter electrode 90, 90 'Incident light 91a, 91b Emission light 92a, 92b Optical axes 93a, 93b Focus 100 Liquid crystal display device

Claims (16)

A liquid crystal display panel having a plurality of pixels,
A TFT substrate having an electrical element layer including a TFT and a pixel electrode;
A counter substrate including a counter electrode facing the pixel electrode;
A liquid crystal layer disposed between the electric element layer and the counter electrode;
A plurality of microlenses arranged on the first surface of the TFT substrate opposite to the liquid crystal layer so as to correspond to the plurality of pixels,
Each of the plurality of pixels shields light incident from the first surface of the TFT substrate and an opening that transmits light incident from the first surface of the TFT substrate toward the outer surface of the counter substrate. Including a shading part,
Each of the plurality of microlenses has an asymmetric shape with respect to an axis perpendicular to the substrate surface and passing through the center of the microlens, and collects incident light toward the opening. A liquid crystal display panel, comprising: one lens portion; and a second lens portion that collects incident light toward the light shielding portion.   The liquid crystal display panel according to claim 1, wherein an optical axis of the first lens portion passes through the opening, and an optical axis of the second lens portion passes through the light shielding portion.   3. The liquid crystal display panel according to claim 1, wherein a focal position of the first lens portion is in the opening and a focal position of the second lens portion is in the light shielding portion. The plurality of microlenses are a plurality of lenticular lenses;
4. The device according to claim 1, wherein each of the plurality of lenticular lenses has a shape asymmetric with respect to a surface perpendicular to a substrate surface and parallel to a first direction in which the plurality of lenticular lenses extend. A liquid crystal display panel as described in 1.   The center position of each of the plurality of pixels in a second direction perpendicular to the first direction when viewed perpendicular to the substrate surface is different from the center position of each of the plurality of lenticular lenses. LCD display panel.   6. The liquid crystal display panel according to claim 5, wherein when viewed perpendicularly to the substrate surface, each end position of the plurality of pixels in the second direction is different from each end position of the plurality of lenticular lenses.   7. The liquid crystal display panel according to claim 5, wherein when viewed in the second direction perpendicular to the substrate surface, more than half of the light shielding portion overlaps the first lens portion. 8.   8. The liquid crystal display panel according to claim 5, wherein when viewed in the second direction perpendicular to the substrate surface, all of the second lens portion overlaps the light shielding portion. 9.   Each of the plurality of microlenses includes a third lens portion having a light incident surface substantially parallel to the substrate surface, disposed between the first lens portion and the second lens portion. 9. A liquid crystal display panel according to 8.   10. The liquid crystal display panel according to claim 9, wherein when viewed in the second direction perpendicular to the substrate surface, all of the third lens portions overlap the opening. 10. The liquid crystal display panel includes a transflective liquid crystal including a transmissive region that performs display by light transmitted through the liquid crystal display panel, and a reflective region that performs display by reflecting light by a reflective layer included in the electrical element layer. Display panel,
The counter substrate includes a color filter layer;
The light shielding portion is a portion from the bottom surface of the electric element layer to the top surface of the color filter layer in the reflection region,
The liquid crystal display panel according to claim 1, wherein the opening is a portion from a bottom surface of the electric element layer to an upper surface of the color filter layer in the transmission region.   The liquid crystal display according to claim 1, wherein the plurality of microlenses are made of a photocurable resin and are formed in a self-aligning manner using light irradiated through the opening. panel.   The liquid crystal display panel according to claim 1, wherein a protective layer made of the same material or an acrylic material as the microlens is disposed on the opposite side of the microlens from the TFT substrate. A liquid crystal display panel according to any one of claims 1 to 13,
And a backlight disposed on the opposite side of the microlens from the TFT substrate.   The liquid crystal display device according to claim 14, wherein the backlight emits light having narrow directivity toward the liquid crystal display panel. The backlight emits irradiation light propagating in a direction inclined from the vertical direction of the substrate surface of the liquid crystal display panel toward the liquid crystal display panel,
The liquid crystal display device according to claim 14, wherein the plurality of microlenses have an asymmetric shape along the inclined direction.

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