JP5154315B2 - Liquid crystal display panel and electronic device - Google Patents

Description

The present invention relates to an electronic device using the liquid crystal display panel of the liquid crystal display panel及Biko capable of achieving stable display quality without display unevenness.

  The liquid crystal display panel includes an array substrate, a color filter substrate provided so as to face the array substrate, and a liquid crystal layer sealed between the array substrate and the color filter substrate. The array substrate includes a plurality of scanning lines and signal lines arranged in a matrix, and pixel electrodes formed at respective positions partitioned by the scanning lines and signal lines. In the color filter substrate, a color filter layer of a predetermined color is disposed at a position corresponding to each pixel electrode of the array substrate, and a light shielding film is formed except for a position corresponding to each pixel electrode. This light-shielding film shields positions that are not directly involved in image display, has the role of clarifying the outline of each pixel and improving contrast. The configuration of this conventional color filter substrate will be described with reference to FIG. 7 which is a schematic sectional view.

  A color filter substrate CFb of a conventional liquid crystal display panel has a light shielding film formed on the surface of a transparent substrate 31 such as a glass substrate. The pattern of the light shielding film differs between the display area 33 and the non-display area 34. Yes. That is, the light shielding film BMd in the display area 33 is formed in a matrix at positions corresponding to scanning lines and signal lines of an array substrate (not shown), and the light shielding film BMn in the non-display area 34 is the same as the light shielding film BMd in the display area 33. It is formed in a solid shape so as to surround the periphery (see Patent Document 1 below). As these light-shielding films BMd and BMn, a metal light-shielding film made of chromium metal or the like or a resin light-shielding film is used. In the following, a case where a resin light-shielding film is used will be described. The generally used resin light shielding film has a thickness of about 1 to 2 μm, and the metal light shielding film has a thickness of about 0.1 to 0.2 μm.

  A color filter layer 32 of a predetermined color, for example, red (R), green (G), and blue (B) is formed for each pixel between and on the light shielding film BMd in the display region 33. FIG. 7 shows a cross section along a specific color direction in each color filter layer formed in a stripe shape.

  The color filter layer 32 is generally formed up to the vicinity of the boundary between the display area 33 and the non-display area 34. This is because, if the configuration is different in this region, a large step is generated near the boundary, and the alignment of liquid crystal molecules may be disturbed by this step.

  A transparent overcoat layer 35 made of, for example, an acrylic resin is formed on the surface of the color filter layer 32 and the surface of the light shielding film BMn in the non-display area 34. The overcoat layer 35 is provided to alleviate unevenness on the surface of the color filter substrate CFb, protect the color filter layer 32 and the resin light shielding films BMd and BMn, and prevent direct contact with the liquid crystal layer. Yes.

  A columnar spacer 38 having a predetermined height is formed at a position corresponding to the light shielding film BMd in the display area 33 and inside the sealing material 50 in the non-display area 34. The columnar spacers 38 are formed by forming a photosensitive resin layer on the surface, and then exposing and developing. The columnar spacer 38 is also referred to as a “photo spacer” because of its manufacturing method.

JP 2004-212741 A JP 11-64837 A

  Incidentally, the color filter substrate CFb as described above has a problem that the height from the transparent substrate 31 to the columnar spacer 38 is different between the display area 33 and the non-display area 34, as shown in FIG. To do. The reason for this is described in paragraph No. “0007” of Patent Document 1 relating to the monochrome liquid crystal display device, but is formed in a light shielding film BMd having a narrow width in the display region 33 and a solid shape in the non-display region 34. This is because there is a difference in the thickness of the layer formed on the light shielding film BMn.

  That is, the color filter layer 32 formed on the light shielding film BMn in the non-display region 34 is formed thicker than the color filter layer 32 formed on the light shielding film BMd in the display region 33. Since the columnar spacers 38 finally formed on the color filter layers 32 having different thicknesses are also affected by this, the height from the surface of the transparent substrate 31 to the upper part of the columnar spacers 38 is displayed. The area 33 and the non-display area 34 will be different.

  As described above, when the so-called columnar spacers 38 have different heights in the display area 33 and the non-display area 34, the color filter substrate CFb and the array substrate are bonded together by the sealing material 50 to form a liquid crystal display panel. In this case, display unevenness due to the difference in cell gap occurs near the boundary between the display area 33 and the non-display area 34. Such display unevenness is particularly noticeable in a liquid crystal display panel in a mode sensitive to a difference in cell gap.

  In Patent Document 2, the thickness of the color filter layer 32 in the non-display area 34 is reduced, the thickness of the color filter layer 32 in the display area 33, the solid light-shielding film BMn in the non-display area 34, and the color filter. A liquid crystal display panel is disclosed in which the total thickness of the layers 32 is the same. However, since the color filter layer 32 in the display area 33 and the color filter layer 32 in the non-display area 34 are usually formed for each color at the same time, the thickness of the color filter layer 32 in the non-display area 34 is set to the display area 33. In order to make it thinner than the color filter layer 32, a special manufacturing process is required. Therefore, there is a problem that it is difficult to adopt the configuration of the invention disclosed in Patent Document 2 in order to increase the manufacturing efficiency of the liquid crystal display panel.

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

Application Example 1 A liquid crystal display panel according to this application example is sealed in a gap in which a first substrate and a second substrate, and the first substrate and the second substrate are bonded to each other through a sealant. a liquid crystal, a display area having a plurality of pixels, located around the table display region, a liquid crystal display panel having a non-display region sheet Lumpur material is arranged, a second substrate, comprises a first light shielding film for partitioning the pixels of multiple, and a color filter layer provided in correspondence to the pixels of multiple, a second light-shielding film provided on the non-display area, a table display region the, at a position corresponding to the first light shielding film and the first columnar spacer is arranged, the non-display area, an inner area color filter layer is formed on the surface of the second light-shielding film, the inner an outer than the side regions, have a, and an outer region where the second column spacer is arranged on the inner side of the sheet Lumpur material That.

  According to this configuration, the non-display area of the second substrate includes the inner area where the color filter layer is formed on the surface of the solid second light shielding film and the surface of the solid second light shielding film. And an outer region in which two columnar spacers are arranged. That is, the color filter layer is formed in the inner region in the non-display region, but the columnar spacer is not formed. On the contrary, the second columnar spacer is formed in the outer region, but the color filter layer is not formed.

  In general, the color filter layer in the second substrate of the liquid crystal display panel is formed simultaneously for each color in both the display area and the non-display area, but the first light shielding film in the display area is finely partitioned. On the other hand, since the second light-shielding film in the non-display area is solid, the thickness of the color filter layer in the non-display area is larger than the thickness of the color filter layer in the display area. Therefore, when a columnar spacer is formed at a position corresponding to the color filter layer in the non-display area, the relative height of the columnar spacer (the height from the surface of the color filter substrate to the top of the columnar spacer) is the first in the display area. It becomes higher than the relative height of the first columnar spacer formed at the position corresponding to the light shielding film.

According to the liquid crystal display panel of the present application example, since the second columnar spacers outside the region where the color filter layer is not present is arranged to suppress the difference in height of the columnar spacers due to the color filter layer This makes it possible to secure a gap between the substrates and prevent display unevenness that occurs near the boundary between the display area and the non-display area. Therefore, the cell gap in the display area can be made uniform without special manufacturing processes such as adjusting the layer thickness of the color filter layer, and stable and uniform display quality without display unevenness can be achieved. a liquid crystal display panel that can be achieved.

Application Example 2 A liquid crystal display panel according to the application example described above, the first shielding Maku及beauty second light shielding film is preferably made of resin.

  According to this configuration, the thickness of a commonly used resin light shielding film is, for example, about 1 to 2 μm, and the thickness of a metal light shielding film such as chromium is, for example, 0.1 to 0.2 μm. Degree. Therefore, the phenomenon that the thickness of the color filter layer in the non-display area becomes thicker than the thickness of the color filter layer in the display area is that the resin-made light shielding film (first light shielding film, second light shielding film) is more metallic. It appears larger than in the case of a light-shielding film. Therefore, according to the liquid crystal display panel of this aspect, the effect is particularly remarkable.

Application Example 3 A liquid crystal display panel according to the application example described above, the surface of the color filter layer, and the surface of the second light-shielding film color filter layer is not such is superimposed, an overcoat layer is formed It is preferable.

  According to this configuration, the color filter layer and the resin light-shielding film may cause impurities to elute into the liquid crystal, but the surface of the color filter layer (including between the color filter layer and the first columnar spacer). ) Since the overcoat layer is formed on the surface of the second light-shielding film (including the space between the second light-shielding film and the second columnar spacer) on which the color filter layer is not superimposed, the impurities are eluted into the liquid crystal. This can prevent the deterioration of the liquid crystal. In addition, the overcoat layer is formed of, for example, a transparent resin layer. Since the surface unevenness is flattened when the overcoat layer is formed, the cell gap can be made more uniform and more uniform display quality can be achieved. A liquid crystal display panel is obtained.

Application Example 4 In the liquid crystal display panel according to the application example described above, the first substrate has a first electrode and a second electrode, Ri by the lateral electric field generated between the first electrode and the second electrode it is preferred that the liquid crystal is driven.

  According to this configuration, the present invention can be applied to various types of liquid crystal display panels, but the display image quality of a liquid crystal display panel of a horizontal electric field type such as an FFS mode or an IPS mode is sensitive to a cell gap. Therefore, the effect is particularly remarkable when applied to a liquid crystal display panel of a horizontal electric field type.

Application Example 5 An electronic apparatus according to this application example is characterized in that it comprises a liquid crystal display panel described above.

  According to this configuration, an electronic apparatus having stable display quality with little display unevenness can be obtained.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples and drawings. However, in the following embodiment, an FFS mode (transverse electric field type) liquid crystal display panel will be described as an example in order to embody the technical idea of the present invention, and the present invention will be described in this embodiment. The present invention is not intended to be specific to an FFS mode liquid crystal display panel, and the present invention is equally applicable to other embodiments within the scope of the claims. In the following description, the same components as those of the color filter substrate CFb of the above-described conventional liquid crystal display panel are given the same reference numerals.

  FIG. 1 is a schematic plan view of a color filter substrate of the FFS mode liquid crystal display panel of the embodiment. FIG. 2 is a schematic plan view of two pixels represented by seeing through the color filter substrate of portion A in FIG. 3 is a cross-sectional view taken along the line CC of FIG. 4 is a cross-sectional view taken along line EE in FIG. FIG. 5 is an enlarged sectional view taken along line FF in FIG. FIG. 6A is a diagram showing a personal computer equipped with a liquid crystal display panel, and FIG. 6B is a diagram showing a mobile phone equipped with a liquid crystal display panel.

  The configuration of the FFS mode liquid crystal display panel 10 of the embodiment will be described mainly with reference to FIG. 3 (FIGS. 1 to 4). The array substrate AR as the first substrate of the FFS mode liquid crystal display panel 10 of this embodiment has a plurality of scanning lines 12 and a plurality of scanning lines 12 made of, for example, Mo / Al two-layer wiring on the surface of a transparent substrate 11 such as a glass substrate. Common wirings 13 are formed to be parallel to each other (see FIG. 2). Further, a lower electrode 14 as a first electrode made of, for example, ITO is formed in each region surrounded by the scanning line 12 and the common wiring 13. The lower electrode 14 is electrically connected to the common wiring 13, but is not connected to the scanning line 12 or the gate electrode G, and acts as a common electrode.

  A gate insulating film 15 made of a silicon nitride layer or a silicon oxide layer is covered over the entire surface of the transparent substrate 11 on which the scanning lines 12, the common wirings 13, and the lower electrodes 14 are formed. Further, a semiconductor layer 16 made of an amorphous silicon (hereinafter referred to as “a-Si”) layer is formed in the TFT formation region on the surface of the gate insulating film 15. The region of the scanning line 12 at the position where the semiconductor layer 16 is formed forms the gate electrode G of the TFT (see FIGS. 2 and 3).

  Further, a signal line 17 and a drain electrode D including a source electrode S made of a conductive layer having a three-layer structure of, for example, Mo / Al / Mo are formed. Both the source electrode S portion and the drain electrode D portion of the signal line 17 partially overlap the surface of the semiconductor layer 16 (see FIGS. 2 and 3). Further, the entire surface of the transparent substrate 11 is covered with a protective insulating film 18 made of a silicon nitride layer, and a contact hole 19 is formed in the protective insulating film 18 at a position corresponding to the drain electrode D.

  Then, an upper electrode 21 as a second electrode made of, for example, ITO having slits 20 is formed on the protective insulating film 18 in the region surrounded by the scanning lines 12 and the signal lines 17 so as to have the pattern shown in FIG. Has been. The upper electrode 21 is electrically connected to the drain electrode D through the contact hole 19 and functions as a pixel electrode. Furthermore, a predetermined alignment film (not shown) is formed over the entire surface.

  On the other hand, the color filter substrate CFa as the second substrate has a resin light shielding film BMd (first light shielding film) and BMn (second light shielding film) formed on the surface of the transparent substrate 31 such as a glass substrate. . The light shielding films BMd and BMn are formed in different patterns in the display area 33 and the non-display area 34 as in the case of the above-described conventional color filter substrate CFb (see FIGS. 1 and 5). That is, the light shielding film BMd in the display area 33 is formed in a matrix at positions corresponding to the scanning lines 12 and the signal lines 17 of the array substrate AR, and the light shielding film BMn in the non-display area 34 is formed in the light shielding film BMd in the display area 33. It is formed in a solid shape so as to surround the periphery of (see FIG. 5). The light shielding film BMd in the display area 33 and the light shielding film BMn in the non-display area 34 are formed by, for example, forming a photoresist layer mixed with a light shielding material on the surface of the transparent substrate 31 and then developing after exposure. Since they are formed at the same time, they are formed at the same height (see FIG. 5).

  The light shielding films BMd and BMn made of resin are a type in which a pixel electrode and a common electrode are formed on the array substrate side like the FFS mode liquid crystal display panel and the IPS mode liquid crystal display panel as in this embodiment. This is particularly preferable in the liquid crystal display panel. This is because if a metal light-shielding film is formed on the color filter substrate side, an unexpected electric field is generated between the metal light-shielding film and the array-side substrate, which may affect liquid crystal molecules. However, such a fear does not occur if the light shielding films BMd and BMn are made of resin.

  Further, as shown in FIG. 5, a color filter layer of a predetermined color, for example, red (R), green (G), or blue (B), is provided for each pixel between and on the surface of the light shielding film BMd of the display region 33. 32 is formed with a predetermined thickness. The non-display area 34 includes an inner area 34i on the display area 33 side and an outer area 34o located on the outer peripheral side of the inner area 34i. In the inner area 34i of the non-display area 34, the color filter layer 32 is formed on the surface of the solid light-shielding film BMn along the display area 33 side.

  The thickness of the color filter layer 32 formed in the inner region 34i of the non-display region 34 is the same as that already described for the conventional example, and the color filter layer formed on the light shielding film BMd in the display region 33. It becomes thicker than 32. Note that the color filter layer is not formed on the surface of the solid light-shielding film BMn in the outer region 34 o of the non-display region 34. Further, the inner region 34i in which the color filter layer 32 is formed in the non-display region 34 is preferably a region of about 2 pixels or a region of about 3 pixels as shown in FIG. If this region becomes too wide (for example, a region of about 10 pixels), columnar spacers are not formed in the inner region 34i (see FIG. 1) as will be described later (see FIG. 1). This is because the substrate cannot be supported and the substrate may be warped.

  Further, the surface of the color filter layer 32 in the display area 33, the surface of the color filter layer 32 in the inner area 34i of the non-display area 34, and the surface of the light-shielding film BMn in the outer area 34o are transparent overcoats made of, for example, acrylic resin. A layer 35 is formed. The overcoat layer 35 is formed to flatten the surface. However, if the overcoat layer 35 is formed to be too thick only for the flattening, there is a problem that the liquid crystal display panel has a yellowish color. If formed in a general range, the surface does not become completely flat as shown in the figure, and generally has a shape along the unevenness of the lower layer.

  The overcoat layer 35 is a type of liquid crystal display panel in which pixel electrodes and common electrodes are formed on the array substrate side, such as an FFS mode liquid crystal display panel and an IPS mode liquid crystal display panel as in this embodiment. And when using resin-made light shielding films, it is especially preferable. This is because if there is no overcoat layer, impurities may elute into the liquid crystal 51 from the light shielding film made of resin. However, in the case of a liquid crystal display panel (TN mode, VA mode, etc.) in which a common electrode is formed on the color filter substrate side, the elution of impurities can be prevented by forming the common electrode. In the case of a liquid crystal display panel of a type in which no common electrode is formed on the side of the color filter substrate, it is possible to prevent impurities from being eluted by the overcoat layer.

  A columnar spacer 38 as a first columnar spacer having a predetermined height is formed (arranged) for each appropriate subpixel at a position corresponding to the light shielding film BMd in the display region 33 of the color filter substrate CFa. ing. In addition, on the overcoat layer 35 at a position corresponding to the light-shielding film BMn in the outer region 34o of the non-display region 34, a predetermined height is provided at an appropriate interval inside (on the inner region 34i side) from the position of the sealing material 50. A columnar spacer 38 as the second columnar spacer is formed (arranged) (see FIGS. 1 and 5).

  The color filter substrate CFa and the array substrate AR thus obtained are opposed to each other, the periphery of both the substrates CFa and AR is sealed with a sealing material 50, and the liquid crystal 51 is sealed in both the substrates CFa and AR. An example FFS mode liquid crystal display panel 10 is obtained. The sealing material 50 may be applied to either the color filter substrate CFa or the array substrate AR.

  Thus, the columnar spacer 38 is not formed in the inner region 34i of the non-display region 34, and the columnar spacer 38 is formed in the outer region 34o. Since the columnar spacer is not formed in the inner region 34i of the non-display region 34 that greatly affects the cell gap of the display region 33, the cell gap of the display region 33 is not affected and the non-display region 34 is not affected. The columnar spacers 38 in the outer region 34o can support the two substrates without substantially affecting the cell gap of the display region 33.

  Further, since the columnar spacers 38 in the outer region 34 o are not formed with the color filter layer 32 in the lower layer, the height from the surface of the transparent substrate 31 is lower than the columnar spacers 38 in the display region 33. That is, the height of the columnar spacer 38 in the display area 33 is the highest from the surface of the transparent substrate 31. Therefore, the cell gap between the color filter substrate CFa and the array substrate AR is substantially defined by the columnar spacers 38 in the display area 33, and the cell gap in the display area 33 becomes very stable. Even if an external force acts from the outside of the liquid crystal display panel 10 and the cell gap in the display region 33 becomes narrow, the columnar spacers 38 in the outer region 34o also play an auxiliary role to ensure the gap. .

  Therefore, according to the FFS mode liquid crystal display panel 10 of this embodiment, the cell gap of the display region 33 can be made uniform, and an FFS mode liquid crystal display capable of achieving stable and uniform display quality without display unevenness. Panel 10 is obtained.

  In addition, embodiment is not limited above, It can also implement with the following forms.

(Modification 1)
The liquid crystal display panel 10 of the embodiment has shown an example in which resin light shielding films BMd and BMn are used. However, the present invention is not limited to this, and a metal light shielding film made of chromium or the like can also be used. The thickness of the light shielding film made of resin generally used is about 1 to 2 μm, and the thickness of the light shielding film made of metal such as chromium is about 0.1 to 0.2 μm. Therefore, when a light shielding film made of metal such as chrome is used, the phenomenon that the thickness of the color filter layer 32 formed in the inner region 34i of the non-display region 34 becomes thicker than the thickness of the color filter layer 32 in the display region 33 is caused. This is lower than when a resin light-shielding film is used. However, since the columnar spacer is not formed in the inner area 34i of the non-display area 34, the influence on the display area 33 is reduced.

(Modification 2)
As described above, the columnar spacers 38 are not limited to being arranged in the display area 33 and the non-display area 34 of the color filter substrate CFa. For example, the same position when the array substrate AR and the color filter substrate CFa are bonded together. The columnar spacers 38 may be disposed on the display area 33 and the non-display area 34 of the array substrate AR.

  As described above, the FFS mode liquid crystal display panel 10 has been described as the embodiment and the modification. However, the present invention is equally applicable to other types of liquid crystal display panels. The liquid crystal display panel 10 can be used for display in various known electronic devices such as a personal computer, a mobile phone, and a portable information terminal. Among these, an example in which the liquid crystal display panel is used in a personal computer and a cellular phone is shown in FIG.

  6A is a diagram showing a personal computer 40 having a display unit 41 on which the liquid crystal display panel 10 is mounted, and FIG. 6B is a mobile phone 45 having a display unit 46 on which the liquid crystal display panel 10 is mounted. FIG. Since the basic configurations of the personal computer 40 and the mobile phone 45 are well known to those skilled in the art, a detailed description thereof will be omitted.

The schematic plan view of the color filter board | substrate of the liquid crystal display panel of the FFS mode of an Example. FIG. 2 is a schematic plan view of two pixels that is seen through a color filter substrate of part A in FIG. 1. Sectional drawing along CC line of FIG. Sectional drawing along the EE line | wire of FIG. The expanded sectional view along the FF line of FIG. (A) is a figure which shows the personal computer carrying a liquid crystal display panel, (b) is a figure which shows the mobile telephone carrying a liquid crystal display panel. FIG. 6 is a schematic cross-sectional view illustrating a configuration of a color filter substrate of a conventional example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display panel, 11 ... Transparent substrate, 12 ... Scan line, 13 ... Common wiring, 14 ... Lower electrode as 1st electrode, 15 ... Gate insulating film, 16 ... Semiconductor layer, 17 ... Signal line, 18 ... Protection Insulating film, 19 ... contact hole, 20 ... slit, 21 ... upper electrode as second electrode, 31 ... transparent substrate, 32 ... color filter layer, 33 ... display region, 34 ... non-display region, 34i ... inner region, 34o ... outer region, 35 ... overcoat layer, 38 ... columnar spacer as first columnar spacer or second columnar spacer, 50 ... sealing material, 51 ... liquid crystal, CFa, CFb ... color filter substrate, BMd ... (display region) First light shielding film), light shielding film, BMn... (Second light shielding film in non-display area) light shielding film.

Claims (5)

A first substrate and a second substrate;
A liquid crystal sealed in a gap in which the first substrate and the second substrate are bonded together with a sealant;
A display area having a plurality of pixels;
A liquid crystal display panel having a non-display area in which the sealing material is disposed, which is positioned around the display area,
The second substrate includes a first light shielding film that partitions the plurality of pixels, a color filter layer provided corresponding to the plurality of pixels, and a second light shielding film provided in the non-display area. And comprising
In the display area, a first columnar spacer is disposed at a position corresponding to the first light shielding film,
The non-display area includes an inner area in which the color filter layer is formed on the surface of the second light shielding film, an outer area than the inner area, and a second columnar spacer inside the seal material. A liquid crystal display panel having an outer region disposed thereon.   The liquid crystal display panel according to claim 1, wherein the first light shielding film and the second light shielding film are made of resin.   3. The liquid crystal display panel according to claim 1, wherein an overcoat layer is formed on a surface of the color filter layer and a surface of the second light shielding film on which the color filter layer is not superimposed.   The first substrate according to claim 1, wherein the first substrate includes a first electrode and a second electrode, and the liquid crystal is driven by a lateral electric field generated between the first electrode and the second electrode. The liquid crystal display panel according to any one of the above. The electronic device provided with the liquid crystal display panel as described in any one of Claims 1 thru | or 4.

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