JP2008116528A - Liquid crystal display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display panel for suppressing light leakage from a projection in a transmissive portion and capable of giving bright display with a high contrast and a high aperture. <P>SOLUTION: The liquid crystal display panel 10A of the present invention comprises: a first substrate on which a switching element TFT and a pixel electrode 19 disposed in each pixel are electrically connected through a contact hole 20; a second substrate on which at least one projection 31 to regulate the tilt of liquid crystal molecules is formed on a common electrode and at a position corresponding to each pixel; a vertical alignment layer deposited on each of the first and second substrates; and a liquid crystal layer having negative dielectric anisotropy and disposed between the first and the second substrates. A light shielding film 36 is formed on the projection 31 disposed on the second substrate, the light shielding film in a plan view covering a peripheral portion of the bottom of the projection 31 and having an aperture 37 smaller than the projection 31. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a liquid crystal display panel, and in particular, M is bright and has good contrast and display quality.
The present invention relates to a VA (Multi-domain Vertically Aligned) type transmissive or transflective liquid crystal display panel.

In recent years, the application of liquid crystal display devices has rapidly spread not only in information communication equipment but also in general electric equipment. Since the liquid crystal display panel does not emit light by itself, a transmissive liquid crystal display device having a backlight is often used. However, since the power consumption of the backlight is large, the power consumption is particularly large for a portable type. A reflection type liquid crystal display panel that does not require a backlight is used for the reduction. However, since this reflective liquid crystal display panel uses external light as a light source, it is difficult to see in a dark room. Thus, in recent years, transflective liquid crystal display panels having both transmissive and reflective properties have been developed.

This transflective liquid crystal display panel has a transmissive portion having a pixel electrode in one pixel region and a reflective portion having both a pixel electrode and a reflector, and the backlight is used in a dark place. Lights up and displays the image using the transmissive part of the pixel area. In bright places, the backlight is not lit and the external part is used to display the image, so the backlight is always lit. Therefore, there is an advantage that power consumption can be greatly reduced.

By the way, the demand for a wide viewing angle with respect to a liquid crystal display panel has not been so high since a user of a small display portion in a mobile device represented by a mobile phone or the like is limited. However, even in recent mobile devices with higher functionality, the demand for a wide viewing angle of the liquid crystal display panel in the display unit has been rapidly increased. Based on such demands for wide viewing angles for mobile devices, TN, which has been widely used for mobile devices in the past
In recent years, transflective liquid crystal display panels as well as MVA transmissive liquid crystal display panels have been developed in place of liquid crystal display panels of the type (see Patent Documents 1 and 2 below).

Here, an MVA transflective liquid crystal display panel disclosed in Patent Document 2 below will be described with reference to FIGS. 7A is a perspective view showing a schematic structure of an MVA-type transflective liquid crystal display panel, and FIG. 7B shows a tilted state of liquid crystal molecules when an electric field is applied to the liquid crystal. FIG. 8 is a schematic view, and FIG. 8 is a cross-sectional view taken along line BB in FIG.

In the transflective liquid crystal display panel 50, an inclined surface or a step 53 is provided between the reflective portion 51 and the transmissive portion 52, and the reflective portion 51 and the transmissive portion 52 are continuous via the step 53. ing. A first opening region 56 is formed in the pixel electrode 55 of the first substrate 54 in the transflective liquid crystal display panel 50 as a region where the pixel electrode 55 is not formed. This first
The opening area 56 constitutes a first alignment dividing means, and the reflection part 51 and the transmission part 5 with the step 53 interposed therebetween.
2 is formed. As a result, the pixel electrode 55 a in the reflective portion 51 and the pixel electrode 55 b in the transmissive portion 52 are connected to each other via a single line 57 extending in the length direction of the transflective liquid crystal display panel 50.

The common electrode 59 of the second substrate 58 has a pixel electrode 55 a and a transmission part 52 in the reflection part 51.
The second opening regions 60a and 60b are formed to face the pixel electrode 55b in FIG. The second opening regions 60a and 60b constitute a second alignment dividing unit. The second opening regions 60a and 60b are configured as cross-shaped slits, and the second opening region 60 is further arranged so that the center of the second opening region 60a coincides with the center of the pixel electrode 55a in the vertical direction.
The center of b is arranged so as to coincide with the center of the pixel electrode 55b.

In the transflective liquid crystal display panel 50, as shown in FIGS. 7B and 8, the liquid crystal molecules 61 have negative dielectric anisotropy when an electric field is applied to the liquid crystal layer. On the first opening region 56, the liquid crystal molecules 61 are inclined in the direction of the line 57 on the common electrode 59 side, and on the reflective portion 51 and the transmissive portion 52, the center of the region corresponding to the reflective portion 51 in the common electrode 59. Alternatively, it is inclined to the center of the region corresponding to the transmission part 52. As described above, in the transflective liquid crystal display panel 50, the alignment direction of the liquid crystal molecules 61 is uniquely determined, so that deterioration of visual characteristics and response speed can be reduced.

The MVA transflective liquid crystal display panel 50 described above is provided with a step 53 between the reflective portion 51 and the transmissive portion 52 on the first substrate 54 side, and a cell gap d1 in the reflective portion 51 as is well known.
And the cell gap d2 in the transmissive part is d1 = (d2) / 2, and the display image quality in the reflective part 51 and the display image quality in the transmissive part are adjusted to be the same. An MVA transflective liquid crystal display panel having a configuration for adjusting the cell gap on the second substrate side is also known.

An example of an MVA transflective liquid crystal display panel according to a conventional example in which a top coat layer as a configuration for adjusting the cell gap is provided on the second substrate side will be described with reference to FIGS.
FIG. 9 is a plan view of one sub-pixel showing the second substrate of a conventional transflective liquid crystal display panel provided with a top coat layer for adjusting the cell gap on the second substrate side, FIG. 10 is a cross-sectional view taken along the line CC of FIG.

In the transflective liquid crystal display panel 70 of the MVA system, a plurality of scanning lines 72 and signal lines 73 are directly or through an inorganic insulating film 74 on a transparent insulating glass substrate 71 of the array substrate AR. It is formed in a matrix. Here, a region surrounded by the scanning line 72 and the signal line 73 corresponds to one sub-pixel, and a TFT (Thin Fil) serving as a switching element.
m Transistor) (not shown) is formed for each pixel, and the surface of the TFT and the like of each pixel is covered with a protective insulating film 83.

Then, a fine uneven portion is formed on the surface of the reflecting portion 75 so as to cover the scanning line 72, the signal line 73, the inorganic insulating film 74, the protective insulating film 83, and the like, and the surface of the transmitting portion 76 is flat. An interlayer film 77 made of the formed organic insulating film is laminated. 9 and 1
In 0, the uneven portion of the reflecting portion 75 is omitted. The interlayer film 77 is provided with a contact hole 80 at a position corresponding to the drain electrode D of the TFT.
On the contact hole 80 and on the surface of the interlayer film 77, a reflecting plate 78 made of, for example, aluminum metal is provided in the reflecting portion 75. On the surface of the reflecting plate 78 and the surface of the interlayer film 77 of the transmitting portion 76, for example, ITO ( A transparent pixel electrode 79 made of Indium Tin Oxide) or IZO (Indium Zinc Oxide) is formed.

On the reflective portion 75 side, the auxiliary capacitance line 81 is disposed below the position where the reflective plate 78 of the interlayer film 77 exists, and the reflective plate 78 and the pixel electrode 79 are adjacent to each other in the plan view. The scanning line 72 and the signal line 73 are formed so as to be slightly overlapped with each other so as not to contact the reflection plate and the pixel electrode, and to prevent light leakage, and the pixel electrode 79 on the transmissive part 76 side is adjacent. The scanning line 72 and the signal line 73 are not in contact with the pixel electrode and the reflection plate of the pixel.
It is formed so as to overlap slightly.

In addition, in the MVA-type transflective liquid crystal display panel 70, a slit 93 is provided in the boundary region between the reflective portion 75 and the transmissive portion 76 of the pixel electrode 79 in order to regulate the orientation of liquid crystal molecules. Is substantially the pixel electrode 79a of the reflection portion 75 and the pixel electrode 79 of the transmission portion 76.
The pixel electrode 79a of the reflective portion 75 and the pixel electrode 79b of the transmissive portion 76 are electrically connected via a narrow portion 94. A vertical alignment film (not shown) is laminated on the surface of the pixel electrode 79 so as to cover all the pixels.

Further, on the display area of the transparent glass substrate 85 of the color filter substrate CF, for example, among red (R), green (G), and blue (B) formed corresponding to each pixel. A striped color filter layer 86 composed of any one color is provided, and a common electrode 87 is provided on the surface of the color filter layer 86. Further, the reflection portion 7
5 and the transmissive part 76 use the same color filter layer 86, a top coat layer 88 having a predetermined thickness is provided on a part of the color filter layer 86 of the reflective part 75. The top coat layer 88 is provided over the entire reflection portion 75, and the thickness thereof is the reflection portion 75.
The so-called cell gap d1 of the liquid crystal layer has a half of the cell gap d2 of the transmissive portion 76, that is, d1 = (d2) / 2.

In addition, protrusions 91 and 92 for regulating the alignment of liquid crystal molecules are respectively formed on a part of the surface of the color filter layer 86 located in the transmission part 76 and a part of the surface of the topcoat layer 88 located in the reflection part 75. In addition, a vertical alignment film (not shown) is laminated on the surfaces of the common electrode 87, the topcoat layer 88, and the protrusions 91 and 92.

Then, the array substrate AR and the color filter substrate CF are opposed to each other, and a sealing material is provided around both the substrates so that the substrates are bonded together, and a liquid crystal having negative dielectric anisotropy is filled between the substrates. Thus, the MVA transflective liquid crystal display panel 70 is obtained. In addition,
A backlight device having a well-known light source, a light guide plate, a diffusion sheet, and the like (not shown) is disposed below the array substrate AR.

In the MVA transflective liquid crystal display panel 70, the pixel electrode 79 and the common electrode 8 are arranged.
7, the major axis of the liquid crystal molecules of the liquid crystal layer 89 is the pixel electrode 79.
In addition, the light is not transmitted because it is oriented so as to be perpendicular to the surface of the common electrode 87, and the light is transmitted when an electric field is applied between the pixel electrode 79 and the common electrode 87. The light leakage at the transmission part does not affect the display image quality so much, and further, the presence of the slits 93 and the protrusions 91 and 92 of the pixel electrode 79 causes the liquid crystal molecules to tilt toward the protrusions 91 to 92, so that the viewing angle is extremely high. It has the characteristic of becoming wide.

However, the protrusions 91 and 92 formed on the color filter substrate CF with no voltage applied.
Near the top surface of the protrusions 91 and 92, the liquid crystal molecules are aligned perpendicular to the second substrate, but the inclination angle is affected at the portions other than the top surfaces of the protrusions 91 and 92. As a result, the film is oriented obliquely with respect to the color filter substrate CF. Therefore, there is a problem that light leakage occurs from the vicinity of the protrusion when no electric field is applied, and the contrast is lowered. Problems caused by protrusions in such an MVA liquid crystal display panel are also shown in Patent Document 3 below. In the invention disclosed in Patent Document 3 below, light leaks due to alignment disturbance due to the presence of protrusions. It is shown that a light-shielding film is provided at a position corresponding to the protrusion for the purpose of preventing the above-described problem and improving the contrast.

In addition, the inventors have formed a protrusion at a position facing the contact hole for the purpose of preventing light leakage due to disorder of alignment of liquid crystal molecules in the contact hole in the MVA type transflective liquid crystal display panel, What formed the light shielding film in the position corresponding to the projection,
A patent application has already been filed as Japanese Patent Application No. 2006-021921.
JP 2003-167253 A (claims, paragraphs [0050] to [0057], FIG. 1) JP 2004-069767 (Claims, paragraphs [0044] to [0053], FIG. 1) Japanese Patent Laying-Open No. 2005-173105 (Claims, paragraphs [0003] to [0004], FIGS. 3 and 4) Japanese Patent Application No. 2006-021921

As in the inventions disclosed in Patent Documents 3 and 4, when a light-shielding film is provided at a position corresponding to the protrusion, the portion of the protrusion can be completely shielded from light. Light leakage due to disorder of molecular orientation can be prevented, and as a result, an excellent effect is obtained that an MVA liquid crystal display panel with good contrast can be obtained.

However, when the light shielding film is provided at a position corresponding to the protrusion in this way, the aperture is reduced by that amount, leading to a reduction in the display area, and a new problem arises that the brightness of the display area is reduced. . Such a problem that the brightness of the display area is reduced particularly appears in a portable liquid crystal display panel in which it is difficult to use a high-power backlight source in order to reduce power consumption.

The inventors have repeated various experiments to increase the aperture of the MVA liquid crystal display panel having protrusions as alignment regulating means. As a result, the long axis of the liquid crystal molecules causes light leakage when no electric field is applied due to the protrusions. It occurs only at the end of the protrusion that is inclined with respect to the common electrode. At the center of the protrusion, liquid crystal molecules are aligned perpendicularly to the common electrode so that no light leakage occurs. Therefore, it is not necessary to shield all of the bottom of the projection in a plan view, and the peripheral portion of the bottom of the projection is covered and an opening smaller than the projection is formed, thereby preventing light leakage caused by the projection and opening degree. The present inventors have found that improvement can be achieved and have completed the present invention.

The light leakage phenomenon when no electric field is applied due to the protrusions will be described in detail with reference to FIGS. FIG. 11 shows the light leakage state of the protrusion 91 when no electric field is applied in the conventional liquid crystal display panel 70 shown in FIGS. 9 and 10 for three adjacent subpixels R, B, and G. FIG. 12 is an enlarged plan view, and FIG. 12 is an enlarged cross-sectional view on the color filter substrate CF side along the line DD in FIG. 9 showing the alignment state of liquid crystal molecules.

When no electric field is applied between the pixel electrode 79 and the common electrode 87, the display is normally black, but as is apparent from the description of FIG. 9, light leakage slightly occurs. It can be seen that the portion where the light leakage occurs is only the end portion of the protrusion 91, and no light leakage occurs from the central portion of the protrusion 91. The alignment state of the liquid crystal molecules at this time is as shown in FIG. That is, since no liquid crystal molecules are aligned perpendicular to the alignment film when no electric field is applied, the protrusion 91
In the flat part around the liquid crystal molecules, the liquid crystal molecules are aligned in a direction perpendicular to the common electrode 87, so that no light leakage occurs. Further, in the central portion of the protrusion 91, the liquid crystal molecules are not substantially leaked because the alignment state of the liquid crystal molecules has a slight inclination with respect to the common electrode 87 from the vertical direction or the vertical direction. On the other hand, at the end portion of the protrusion 91, the liquid crystal molecules are largely inclined from the vertical direction with respect to the common electrode 87, and thus light leakage occurs.

Therefore, the present invention prevents light leakage when no electric field is applied in an MVA type transmissive or transflective liquid crystal display panel provided with protrusions as liquid crystal molecule alignment regulating means to prevent alignment defects caused by protrusions. An object of the present invention is to provide a liquid crystal display panel that can reduce, improve contrast, and display brightly.

In order to solve the above problems, a liquid crystal display panel according to the present invention includes a first substrate in which switching elements and pixel electrodes are formed in each pixel arranged in a matrix, and a position on the common electrode corresponding to each pixel. Are disposed between the first and second substrates, a second substrate on which at least one protrusion for controlling the inclination of liquid crystal molecules is formed, a vertical alignment film laminated on each of the first and second substrates, and the second substrate. In a liquid crystal display panel having a negative dielectric anisotropy liquid crystal layer, a light-shielding film that covers a peripheral portion of the protrusion in a plan view and has an opening smaller than the protrusion is the first substrate and the first It is formed on at least one of the two substrates.

In the liquid crystal display panel according to the present invention, the light-shielding film has the same size as the bottom surface of the protrusion or a shape larger than the bottom surface of the protrusion in a plan view.

According to the present invention, in the liquid crystal display panel, a reflective portion having a reflective film is formed on a lower portion or a surface of the pixel electrode, and the projection is a pixel electrode of a transmissive portion where the reflective film is not provided. It is provided in the position which opposes.

According to the present invention, in the liquid crystal display panel, the light shielding film is formed on the first substrate, and the same material as a part of the switching element is formed when the switching element is formed on the first substrate. It is characterized by being formed of a simple material.

According to the present invention, in the liquid crystal display panel, the light shielding film is formed on the first substrate, is made of the same material as the reflective film, and is formed simultaneously with the formation of the reflective film. It is characterized by that.

According to the present invention, in the liquid crystal display panel, the light shielding film is formed on the second substrate, and is made of the same material as the black matrix that separates pixels on the second substrate. It is characterized by being formed simultaneously.

According to the present invention, in the liquid crystal display panel, the switching element and the pixel electrode on the first substrate are provided in a state of being electrically insulated from each other via an interlayer insulating film, and the interlayer insulating film is formed in the reflective portion. The pixel electrode and the electrode of the switching element are electrically connected through the formed contact hole, and the projection and the entire bottom of the projection are covered in a plan view at a position on the second substrate side facing the contact hole. A light-shielding film is provided.

The present invention provides the following advantageous effects by having the above-described configuration. That is, according to the liquid crystal display panel of the present invention, the protrusion provided on at least one of the first and second substrates covers the periphery of the bottom of the protrusion in plan view and is smaller than this protrusion. Since the light shielding film having the opening is formed, the light leakage portion of the protrusion is shielded by the light shielding film in plan view, but the light shielding film is not formed at the center of the protrusion where light leakage does not occur.

Therefore, according to the liquid crystal display panel of the present invention, the portion that does not contribute to the light leakage of the protrusion is used as an effective display area while effectively suppressing the light leakage due to the disorder of the alignment of the liquid crystal molecules due to the presence of the protrusion. Therefore, an MVA liquid crystal display panel having a good contrast and brightness and a wide viewing angle can be obtained.

Further, according to the liquid crystal display panel of the present invention, since the light shielding film has the same size as the protrusion or a shape larger than the protrusion, it is possible to further reduce light leakage. In addition,
The size of the light-shielding film should be the same as or slightly larger than the bottom of the protrusion in plan view, and the larger the distance from the bottom of the protrusion, the more effectively light leakage can be blocked. This is not preferable because the display becomes dark.

In addition, according to the liquid crystal display panel of the present invention, a transflective liquid crystal display panel having the above effects can be obtained.

Further, according to the liquid crystal display panel of the present invention, when forming the switching element, the light shielding film is formed with a part of the material of the switching element, specifically, the gate electrode G, the source electrode S, and the drain electrode D. Since the same metal material as that used at the time can be formed at the same time, it is not necessary to increase the number of steps for forming the light shielding film, and the light shielding film can be easily formed. .

Further, according to the liquid crystal display panel of the present invention, since the light shielding film can be formed of the same material as that of the reflective film and at the same time, it is not necessary to increase the number of steps for forming the light shielding film. Can be formed.

Further, according to the liquid crystal display panel of the present invention, since the light shielding film can be formed of the same material and at the same time as the black matrix, it is not necessary to increase the number of steps for forming the light shielding film. Can be formed.

Further, according to the liquid crystal display panel of the present invention, in the transflective liquid crystal display panel, the switching element is provided in the reflecting portion so that the switching element can be effectively used for display. The contact hole, which plays the role of conduction between the pixel electrode and the pixel electrode, is formed in a location closer to the switching element when it is formed in the reflective portion, so that reliable conduction is easier and further the reduction of the opening area is prevented. Will be able to.

In addition, the contact hole is usually provided with a circular or square opening, and in this contact hole portion, the orientation of liquid crystal molecules is disturbed, so that light leakage may occur when no electric field is applied. However, in the present invention, since the projection on which the light shielding film covering the entire bottom portion is formed in a plan view is provided on the second substrate side corresponding to the color filter substrate facing the contact hole, the projection in the contact hole portion is provided by the projection. It becomes easy to regulate the alignment of the liquid crystal molecules, and it is possible to simultaneously block both the light leakage from the contact hole and the light leakage due to the alignment failure of the liquid crystal molecules in the vicinity of the protrusions. For this reason, a liquid crystal display panel capable of obtaining a good contrast even in a transflective type and capable of bright display can be obtained.

Hereinafter, the best mode for carrying out the present invention will be described more specifically with reference to examples and drawings. In addition, although the Example shown below shows the transflective or transmissive liquid crystal display panel for actualizing the technical idea of this invention, it intends to limit this invention to what was described here. However, the present invention can be equally applied to various modifications without departing from the technical idea shown in the claims.

An MVA transflective liquid crystal display panel according to Example 1 is shown in FIGS. 1
FIG. 2 is a schematic plan view showing a sub-pixel portion of the transflective liquid crystal display panel 10A through a color filter, and FIG. 2 is a cross-sectional view taken along the line AA in FIG.

This MVA transflective liquid crystal display panel 10A has a plurality of scanning lines 12 and signal lines 1 formed in a matrix on the surface of a transparent substrate 11 made of a glass substrate or the like of an array substrate AR.
3, a plurality of auxiliary capacitance lines 21 parallel to the scanning lines 12 provided between the plurality of scanning lines 12, a source electrode S, a gate electrode G, a drain electrode D, and a semiconductor film 22. A TFT and a pixel electrode 19 covering a region surrounded by the scanning line 12 and the signal line 13 are provided. Here, a region surrounded by each scanning line 12 and signal line 13 corresponds to one sub-pixel.

The scanning lines 12, the gate electrodes G, the auxiliary capacitance lines 21, and the exposed surfaces of the transparent substrate 11 are covered with a first insulating film (also referred to as a gate insulating film) 14. On the surface, for example, a semiconductor film 22 composed of an amorphous silicon (a-Si) layer and an n ⁺ a-Si layer serving as an ohmic contact layer formed on the surface, a source electrode S
In addition, a TFT composed of the drain electrode D and the signal line 13 are formed, and the entire surface of the TFT is covered with a second insulating film 23 (also called a protective insulating film or a passivation film). . The drain electrode D extends from the surface of the first insulating film 14 to the upper portion of the auxiliary capacitance line 21. The drain electrode D and the auxiliary capacitance line 2
An auxiliary capacitor is formed between the first and second capacitors.

Further, on the surface of the second insulating film 23, the reflective portion 15 is formed of an organic insulating film such as a photoresist in which fine irregularities are formed on the surface and the transmissive portion 16 is formed with a flat surface. An interlayer film (also referred to as a planarizing film) 17 is formed, and a contact hole 20 is formed on the surface of the second insulating film 23 and the interlayer film 17 located on the storage capacitor line 21. ITO (Indium Tin Oxide) or IZ formed on the interlayer film 17
A pixel electrode 19 made of a transparent electrode such as O (Indium Zinc Oxide) is electrically connected to the drain electrode D. In FIG. 1 and FIG. 2, the uneven portion of the reflecting portion 15 is omitted.

Further, in the transflective liquid crystal display panel 10A, a slit 33 is provided to regulate the orientation of liquid crystal molecules in the boundary region between the reflective portion 15 and the transmissive portion 16 of the pixel electrode 19, and the pixel electrode 19 is substantially The pixel electrode 19a of the reflection unit 15 and the pixel electrode 19b of the transmission unit 16 are divided, and the pixel electrode 19a of the reflection unit 15 and the pixel electrode 19b of the transmission unit 16 are narrow portions 3.
4 is electrically connected.

On the reflection portion 15 side, the auxiliary capacitance line 21 is disposed below the position where the reflection plate 18 of the interlayer film 17 exists, and the reflection plate 18 and the pixel electrode 19a of the reflection portion in plan view are as follows.
The scanning line 12 and the signal line 13 are provided so as to partially overlap so as not to contact the reflection plate and pixel electrode of the adjacent pixel, and the reflection plate 18 and the pixel electrode 19a of the reflection unit 15 They are provided in substantially the same shape so as to overlap each other. Further, the pixel electrode 19b on the transmissive part 16 side is provided along the signal line 13 so as not to contact the pixel electrode and the reflection plate of the adjacent pixel and not substantially overlap with the signal line. In addition, the scanning line 12 is formed so as to slightly overlap.

Furthermore, in the transflective liquid crystal display panel 10A of this embodiment, the area of the pixel electrode 19b of the transmissive part 16 is larger than that of the pixel electrode 19a of the reflective part 15. As described above, the reason why the area of the pixel electrode 19b in the transmissive part is increased is that the transflective liquid crystal display panel for mobile phones has high definition and many image displays. This is because there are many opportunities for use as a transmissive liquid crystal display panel. A vertical alignment film (not shown) is stacked on the surface of the array substrate AR so as to cover the entire display area, including the surface of the pixel electrode 19.

Further, on the display region of the transparent glass substrate 25 of the color filter substrate CF, for example, any one of red (R), green (G), and blue (B) formed corresponding to each pixel is used. A striped color filter layer 26 and a common electrode 27 are provided. Further, since the color filter layer 26 having the same thickness is used in the reflection portion 15 and the transmission portion 16, a top coat layer 28 having a predetermined thickness is provided on a part of the common electrode 27 of the reflection portion 15. The top coat layer 28 is provided over the entire reflecting portion 15 and has a thickness of the reflecting portion 1.
The thickness of the liquid crystal layer 29 in FIG.
It is set to be half of 2, that is, d1 = (d2) / 2.

Further, a long cross-shaped projection for regulating the alignment of the liquid crystal molecules so as to be located at the center of the pixel electrode 19b of the transmissive portion 16 on a part of the surface of the common electrode 27 located at the transmissive portion 16, respectively. 31 together with (in the region are shown in broken lines in FIG. 1) is provided, the bottom surface in a position facing the contact hole 20 on the surface of the topcoat layer 28 of the reflective portion 15 is provided with a circular protrusion 31 ₃ It has been. Then, these common electrodes 27, a vertical alignment film on the surface of the top coat layer 28 and the projections 31 and 31 ₃ (both not shown) are laminated.

Further, the portion of the color filter layer 26 corresponding to the bottom of the projection 31 of the transmission portion 16 is slightly larger than the bottom of the projection 31 in plan view and covers the peripheral edge of the projection, but the opening 37 (
In FIG. 1, a light shielding film 36 provided with a region indicated by a solid line within a broken line region indicating a protrusion).
There are formed, further, on the portion of the color filter layer 26 corresponding to the bottom portion of the projections 31 ₃ provided in the reflection section 15, slightly larger projections 31 ₃ of the entire surface than the bottom of the projection 31 ₃ in a plan view the light shielding film ₃₆₃ is formed to shield. Reason for providing the light shielding film ₃₆₃ that shields the projections 31 ₃ of the entire surface of the reflective portion 15 is as follows.

That is, in the transflective liquid crystal display panel 10A, the contact hole 20 formed in the reflective portion needs to ensure electrical continuity between the pixel electrode 19a and the drain electrode D of the TFT as a switching element. The contact hole 20 has a certain size and depth, and an inclined surface is formed in the contact hole 20 as shown in FIG. Such an inclination of the contact hole 20 gives a physical force to the liquid crystal molecules of the liquid crystal layer 29 by the alignment film (not shown) used, as shown in FIG. 3, and tilts the liquid crystal molecules. . 3 is an enlarged view conceptually showing a state in which the liquid crystal molecules of the liquid crystal layer 29 are inclined at the contact hole 20 portion of FIG.

In particular, even when an electric field is generated between the pixel electrode 19a and the common electrode 27 to align the liquid crystal molecules, the liquid crystal molecules are strongly influenced by the physical force of the contact hole 20 and tilt in a desired direction. Otherwise, the display quality deteriorates because the display is adversely affected. In addition, since the contact hole 20 is literally formed, the alignment of the liquid crystal molecules becomes unstable due to the influence based on the presence of the contact hole 20 such as unevenness in the alignment film (not shown). Furthermore, since liquid crystal molecules incline obliquely at the entrance portion of the contact hole 20 even when no electric field is applied, light blocking at this portion may be incomplete and light leakage may occur. The light shielding film 36 ₃ even if light leakage from the contact hole 20, it is to act so as not to leak out, the liquid crystal molecules of the light shielding film ₃₆₃ in the light leakage and the projections 31 ₃ near the contact hole 20 It is possible to block both light leakage due to the alignment failure.

The light shielding film 36 and 36 ₃ can be formed simultaneously by the same material as the black matrix 38 provided in each color boundary in the production of striped color filter layer 26. Thus, the light shielding films 36 and ₃ are not increased without increasing the number of steps for forming the light shielding films 36 and 363.
6 ₃ can be easily formed. Specifically, the black matrix 38 uses chromium made of a metal material. Further, a light-shielding material made of resin may be used, but in the case of resin, since it is difficult to manufacture the opening 37, it is better to form it with a metal material. Also,
Although FIG. 2 has been shown that the size of the light shielding film 36 and 36 ₃ is slightly larger than the size of the bottom of the projections 31 and 31 _3, the projections 31 and 31 of the _third bottom size and substantially It may be the same size.

However, the size of the bottom portion of the protrusion 31 _third reflecting unit it is preferably greater than the size of the contact hole 20, for example, with respect to the size of the contact hole 20 of about 7 × 7 [mu] m, the width of the bottom portion of the projections 31 ₃ Is preferably about 8 μm. In the light-shielding film ₃₆₃ of the projections 31 ₃ side in the first embodiment, from where the projection 31 ₃ is provided so as to overlap the contact hole 20 in plan view of the transparent substrate 11, the light shielding film ₃₆₃ is a contact hole 20 Both are arranged so as to overlap in plan view.

Then, the array substrate AR and the color filter substrate CF are opposed to each other, a sealing material is provided around both substrates, the two substrates are bonded together, and a liquid crystal having negative dielectric anisotropy is filled between the substrates. Thus, the MVA transflective liquid crystal display panel 10A is obtained. In addition,
A backlight device having a well-known light source, a light guide plate, a diffusion sheet, and the like (not shown) is disposed below the array substrate AR, thereby completing a liquid crystal display panel.

According to the transflective liquid crystal display panel 10A of the first embodiment, even if light is leaked due to disturbance in the orientation of liquid crystal molecules when no electric field is applied in the vicinity of the protrusion 31 in the transmissive portion, the leaked light Since the light is shielded by the light shielding film 36, it is less likely to come out to the outside. Therefore, it is possible to greatly reduce the decrease in contrast due to light leakage when no electric field is applied even in the transmission part. In addition, since the opening 37 is formed in the light shielding film 36, the peripheral portion of the protrusion 31 that causes light leakage is effectively shielded by the light shielding film 36, and the central portion of the protrusion 31 that does not cause light leakage is formed in the light shielding film 36. Since the opening 37 can be used effectively as a display area, the degree of opening is increased by an amount corresponding to the opening 37 of the light shielding film 36, and a bright display transflective liquid crystal display panel 10A is obtained.

In the MVA transflective liquid crystal display panel, light does not pass through the liquid crystal layer 29 as long as the liquid crystal molecules are aligned vertically without an electric field applied to the liquid crystal molecules. Accordingly, since the vertical alignment film is also provided in the slit 33 portion provided in the pixel electrode 19, no light is transmitted through the slit portion. Therefore, the MVA type transflective type of the first embodiment is used. In the liquid crystal display panel 10A, the auxiliary capacitance line 21 is further extended from the lower portion of the reflector 18 to the slit 33 side on the transmission portion 16 side so that the auxiliary capacitance is increased.

Further, in the MVA type transflective liquid crystal display panel 10A of the first embodiment, the pixel electrode 19b on the transmissive part 16 side is provided along the signal line 13 so as not to overlap the signal line 13 substantially. Although an example is shown, the pixel electrode 19b on the transmissive part 16 side is accurately connected to the signal line 1.
3 is technically difficult to provide, the pixel electrode 19b on the transmissive part side and the signal line 1
3 may be formed between the pixel electrode 19 and the pixel electrode 19 on the transmissive part side.
b and the signal line 13 may overlap each other. Even if a slight gap is formed between the pixel electrode 19b on the transmissive part side and the signal line 13, since the vertical alignment film is provided in the gap part, light does not leak from the gap part. .

In the first embodiment, the light shielding film 36 having the opening 37 is formed on the color filter substrate CF. However, the present invention is not limited to this, and the light shielding film having the opening is formed on the array substrate AR. May be. Specifically, in the process of manufacturing the TFT formed on the array substrate AR side, the light shielding film may be formed of the same material, for example, aluminum or molybdenum, when forming the gate electrode G constituting the TFT, When forming the source electrode S and the drain electrode D constituting the TFT, they may be formed of the same material. That is, when the light shielding film is formed on the array substrate AR side, when the light shielding material is used, the light shielding film is simultaneously formed using the same material. It can be formed easily without increasing the number of steps for forming the film. Therefore, in the case of the transflective liquid crystal display panel as in the first embodiment, it may be formed at the same time using the same material as the reflecting plate 18 formed in the reflecting portion 15. Further, a light shielding film having an opening may be formed on both the array substrate AR and the color filter substrate CF.

In the above-described MVA transflective liquid crystal display panel 10A according to the first embodiment, the example in which the long cross-shaped protrusion 31 is provided as the alignment regulating member provided in the transmissive portion 16 of the color filter substrate CF is shown. The orientation regulating member to be provided is not limited to the long cross shape, and various known shapes can be used. Therefore, in the MVA type transflective liquid crystal display panel 10B of the second embodiment, the pixel electrode of the transmissive portion is divided into two regions, and the shape of the protrusion is formed on the bottom surface so as to face each pixel electrode region. A circular shape was adopted. The transflective liquid crystal display panel 10B of the second embodiment will be described with reference to FIG. 4, which is a schematic plan view showing one sub-pixel portion seen through a color filter. Transmission type liquid crystal display panel 1
The same reference numerals are given to the same components as 0A, and detailed description thereof is omitted.

The transflective liquid crystal display panel 10B of the second embodiment is the transflective liquid crystal display panel 10A of the first embodiment.
The difference between the configuration and
(1) the slit 33 ₁ is provided for controlling the alignment of liquid crystal molecules in the boundary area of the transmissive portion 16 and the reflective portion 15 in the pixel electrode 19, the pixel electrode 19 is pixel electrodes 1 of substantially reflective portion 15
9a and is divided into the pixel electrode 19b of the transmissive portion 16, but are electrically connected via the narrow portion 34 ₁ of the width and the pixel electrode 19a of the reflective portion 15 and the pixel electrode 19b of the transmissive portion 16,
Pixel electrode 19b of the transmissive portion 16 is further divided into two regions 19b ₁ and 19b ₂ by another slit 33 ₂ provided in the middle portion, the narrow portion of the two regions 19b ₁ and 19b ₂ moieties width that they are electrically connected via the 34 _2, and,
(2) A part of the surface of the color filter layer 26 located in the transmission part 16 of the color filter substrate CF is opposed to the central part of the _two regions 19b ₁ and 19b ₂ of the pixel electrode 19b of the transmission part 16, respectively. as has been slightly or size and the same large-shield film 36 ₁ and 36 ₂ of the bottom of the projections 31 ₁ and 31 ₂ respectively plan view form, these light-shielding film 36 ₁ and 3
6 ₂ is the point that opening 37 ₁ and 37 ₂ respectively provided at a position corresponding to the center portion of the projection.

If such a configuration is adopted, the alignment of the liquid crystal molecules can be regulated over the entire pixel electrode 19b of the transmissive part having a large area by the protrusions 31 ₁ and 31 ₂ and the slits 33 ₁ and 33 _2. , the bottom of the projections 31 ₁ and 31 ₂ transmitting portion light-shielding film 36 ₁
And 36 because ₂ is slightly larger or projections 31 ₁ and 31 ₂ in the bottom of the magnitude and the same in a plan view, the disturbance of alignment of liquid crystal molecules when no electric field is applied occurs in the vicinity of the projections 31 ₁ and 31 ₂ even if the light leaks Te, the leaked light is reduced to come out to the outside to be blocked by the light blocking film 36 ₁ and 36 _2. In addition, it uses a region where light leakage projections 31 ₁ and 31 ₂ is not caused by the light shielding film 36 ₁ and 36 openings 37 _{1 2} formed on and 37 ₂ as an effective display area. Therefore, the transflective liquid crystal display panel 1 of Example 2
According to 0B, the viewing angle is wide, the reduction in contrast due to light leakage when no electric field is applied can be greatly reduced, and a bright display MVA transflective liquid crystal display panel 1 is provided.
0B is obtained.

In the MVA-type transflective liquid crystal display panel 10B of Example 2, the color filter substrate CF
Bottom as the orientation regulating member provided in the transmissive portion 16 is an example is shown in which a circular protrusion 31 ₁ and 31 _2, the liquid crystal display panel 10C of an MVA of Example 3, the projection as the projection of the transmission portion of the The shape is a cross-shaped bottom in plan view. The liquid crystal display panel 10 of Example 3
FIG. 5 is a schematic plan view showing one sub-pixel portion of C through a color filter. The transflective liquid crystal display panel 10C of Example 3 and the transflective liquid crystal display panel 10B of Example 2 are shown in FIG. The only difference in the configuration is that the shape of the projections 31 ₁ and 31 ₂ of the transmission part and the shape of the light shielding films 36 ₁ and 36 ₂ are different, so that the transflective liquid crystal display of Example 2 shown in FIG. The same components as those of the panel 10B are denoted by the same reference numerals, and detailed description thereof is omitted.

Although all of the MVA liquid crystal display panels shown in Embodiments 1 to 3 are transflective, the present invention can also be applied to a transmissive MVA liquid crystal display panel. Therefore, as Example 4, similarly to the case of Example 1, an MVA-type transmissive liquid crystal display panel 10D in which the shape of the projection of the transmissive part was a long cross was used. FIG. 6 is a schematic plan view showing one sub-pixel portion of the transmissive liquid crystal display panel 10D of the fourth embodiment seen through a color filter. The transflective liquid crystal display panel of the first embodiment shown in FIG. The same components as 10A are given the same reference numerals, and detailed descriptions thereof are omitted.

In the MVA-type transmissive liquid crystal display panel 10D according to the fourth embodiment, the pixel electrode 19 includes a pixel electrode 19b that transmits light from a backlight functioning as a display region through a slit 33 in order to regulate the alignment of liquid crystal molecules. The pixel electrode 19b and the auxiliary electrode 19c are electrically connected through a narrow portion 34. The pixel electrode 19b and the auxiliary electrode 19c are divided into two regions.

The configuration of the pixel electrode 19b portion of the transmissive liquid crystal display panel 10D of the fourth embodiment, the configuration of the protrusion 31, the light shielding film 36, the opening 37, and the like as the alignment regulating means provided on the color filter substrate CF are the same as those of the first embodiment. There is substantially no difference from the configuration of the transmissive portion 16 of the transflective liquid crystal display panel 10A. However, a transmissive liquid crystal display panel 10D of the fourth embodiment, in the reflection portion is not present, the reflection plate 18 and the projections 31 ₃ are used not provided in the liquid crystal display panel 10A of Example 1, also The ratio occupied by the auxiliary electrode 19c is smaller than the ratio occupied by the pixel electrode 19b. The auxiliary electrode 19c mainly forms an auxiliary capacitance with the auxiliary capacitance line 21 and a contact hole with the drain electrode D of the TFT. It functions as an electrical connection through 20. In the long cross shape of the protrusion 31 in the fourth embodiment or the first embodiment, the opening 37 is formed in a cross shape in accordance with the shape of the protrusion. However, since the short side of the long cross is much shorter than the long side, the long side of the projection 31 of the long cross has a shape in which the opening 37 is not provided on the short side, that is, a bar shape along the long side. There may be a shape in which the opening 37 is provided only on the side.

Under the auxiliary electrode 19c, the light-impermeable auxiliary capacitance line 21, the drain electrode D, the gate electrode G, the source electrode S, and the semiconductor film 22 exist, so that light from the backlight is transmitted. In other words, the area occupied by the auxiliary electrode 19c is relatively smaller than the area occupied by the pixel electrode 19b because it cannot be used as a display region. In the transmissive liquid crystal display panel 10D of Example 4, the auxiliary electrode 19c is provided only at a position excluding the surface of the TFT, but the color filter substrate CF facing the TFT is shielded by providing a black matrix. Therefore, a reduction in contrast due to the presence of a portion through which light around the TFT is transmitted can be ignored.

The MVA-type transmissive liquid crystal display panel 10D according to the fourth embodiment can achieve the same effects as the MVA-type transflective liquid crystal display panel 10A according to the first embodiment has the same effects as the transmissive portion. A light-transmitting transmissive liquid crystal display panel 10D that effectively eliminates light leakage when no electric field is applied between the electrode 19b and the common electrode 27, and has a good contrast.
It becomes. In the transmissive liquid crystal display panel 10D of Example 4, an example in which the slit 33 is provided between the pixel electrode 19b portion and the auxiliary electrode 19c portion is shown, but this is because the alignment regulation ability by the slit 33 is used. Thus, the slit 33 is not always necessary.

Further, in Examples 1 to 4, the shape of the protrusions and the light shielding means as the orientation regulating means provided in the portion that transmits the light from the backlight light source has a cross-shaped, long cross-shaped and circular shape in plan view. In addition to the above, other shapes such as a bar shape, a Y shape, or a Y shape and an inverted Y shape can be used.

FIG. 3 is a schematic plan view illustrating one sub-pixel portion of the transflective liquid crystal display panel of Example 1 through a color filter. It is sectional drawing along the AA line of FIG. FIG. 3 is an enlarged view conceptually showing a state in which liquid crystal molecules are inclined at the contact hole portion of FIG. 2. FIG. 6 is a schematic plan view showing a sub-pixel portion of a transflective liquid crystal display panel of Example 2 through a color filter. FIG. 6 is a schematic plan view showing a sub-pixel portion of a transflective liquid crystal display panel of Example 3 as seen through a color filter. FIG. 10 is a schematic plan view illustrating one sub-pixel portion of a transmissive liquid crystal display panel of Example 4 as seen through a color filter. FIG. 7A is a perspective view showing a schematic structure of a conventional MVA type transflective liquid crystal display panel, and FIG. 7B shows a tilt state of liquid crystal molecules when an electric field is applied to the liquid crystal. FIG. It is the BB sectional view taken on the line of Fig.7 (a). FIG. 6 is a plan view of one sub-pixel showing through a second substrate of a conventional transflective liquid crystal display panel in which a top coat layer for adjusting a cell gap is provided on the second substrate side. It is CC sectional drawing of FIG. FIG. 11 is an enlarged plan view showing a light leakage state of a protrusion 91 portion when no electric field is applied in the conventional liquid crystal display panel 70 shown in FIGS. 9 and 10 for three adjacent R, B, and G sub-pixels. It is an expanded sectional view by the side of the color filter substrate CF along the DD line | wire of FIG. 9 which shows the orientation state of a liquid crystal molecule.

Explanation of symbols

10A to 10C, 50, 70 Transflective liquid crystal display panel 10D Transparent liquid crystal display panel 11, 25 Transparent substrate 12 Scan line 13 Signal line 14 First insulating film 15 Reflecting portion 16 Transmitting portion 17 Interlayer film 18 Reflecting plate 19, 19 a, 19 b, 19 b ₁ , 19 b ₂ pixel electrode 19 c auxiliary electrode 20 contact hole 21 auxiliary capacitance line 23 second insulating film 26 color filter layer 27 common electrode 28 top coat layer 29 liquid crystal layers 31, 31 _{1 to} 31 ₃ protrusion 33 , ₃₃ 1, 33 ₂ slits 34 _1, 34 ₂ narrow portion 36, 36 ₁ to 36 ₃ light shielding film 37 _1, 37 ₂ opening 38 black matrix

Claims (7)

A first substrate on which switching elements and pixel electrodes are formed in each pixel arranged in a matrix;
A second substrate on which at least one protrusion for regulating the inclination of liquid crystal molecules is formed at a position corresponding to each pixel on the common electrode;
Vertical alignment layers respectively stacked on the first and second substrates;
A liquid crystal layer having a negative dielectric anisotropy disposed between the first and second substrates;
In a liquid crystal display panel having
A liquid crystal display panel, wherein a light-shielding film that covers a peripheral portion of the protrusion in plan view and has an opening smaller than the protrusion is formed on at least one of the first substrate and the second substrate. . The liquid crystal display panel according to claim 1, wherein the light-shielding film has the same size as the bottom surface of the protrusion or a shape larger than the bottom surface of the protrusion in a plan view. A reflective portion having a reflective film is formed on a lower portion or a surface of the pixel electrode, and the protrusion is provided at a position facing the pixel electrode of a transmissive portion where the reflective film is not provided. The liquid crystal display panel according to claim 1. The light shielding film is formed on the first substrate, and is formed of the same material as a part of the switching element when forming the switching element on the first substrate. The liquid crystal display panel according to claim 1. 4. The liquid crystal according to claim 3, wherein the light shielding film is formed on the first substrate, is made of the same material as the reflective film, and is formed simultaneously with the formation of the reflective film. Display panel. The light-shielding film is formed on the second substrate, is made of the same material as a black matrix that separates pixels on the second substrate, and is formed simultaneously with the formation of the black matrix. The liquid crystal display panel according to claim 1. The switching element and the pixel electrode on the first substrate are provided in a state of being electrically insulated from each other through an interlayer insulating film,
The pixel electrode and the electrode of the switching element are electrically connected through a contact hole formed in the interlayer insulating film in the reflective portion,
4. The liquid crystal display panel according to claim 3, wherein a light shielding film is provided at a position on the second substrate facing the contact hole so as to cover the entire bottom of the protrusion in plan view.