JP4282926B2 - Liquid crystal display - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device in which a spacer is formed on at least one substrate.
[0002]
[Prior art]
Currently, in a liquid crystal display element that is generally used, the distance between the substrates (cell gap) is kept constant by dispersing plastic beads or the like as spacers between the substrates. However, in such a method, the plastic beads may be unevenly arranged on the substrate. In this case, gap unevenness may occur and display defects may occur.
[0003]
As a method that can avoid the occurrence of such a problem, it is known to form columnar spacers on a substrate using a photolithography technique. According to this method, since the spacer can be arranged at a desired position, it is considered that the above-mentioned problems relating to the plastic beads cannot occur.
[0004]
However, in practice, gap unevenness may occur even when the columnar spacers are formed using photolithography technology.
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and an object thereof is to provide a liquid crystal display device capable of sufficiently suppressing gap unevenness.
[0006]
[Means for Solving the Problems]
  In order to solve the above problems, the present invention provides a first substrate having a first region and a second region raised with respect to the first region on one main surface, and the main surface of the first substrate; A plurality of second substrates that are opposed to each other and that are provided on at least one opposed surface of the first and second substrates and that maintain a constant distance between the first and second substrates.ColumnarA plurality of spacers; and a liquid crystal layer interposed between the first and second substrates.ColumnarThe distance between the spacer located on the second region and the one located nearest to the second region is the plurality of spacers.ColumnarThe spacer is longer than the distance between the spacer positioned on the first region and the spacer positioned closest to the first region.In addition, among the plurality of columnar spacers, those located on the second region have lower number density than those located on the first region, and among the plurality of columnar spacers, the number density on the first region is lower. The distance D between the one located and the one closest to it ₁ A distance D between the plurality of columnar spacers located on the second region and the one located closest to the second region ₂ Ratio D ₂ / D ₁ The first substrate includes a switching element, a wiring, and a pixel electrode on a surface facing the second substrate, and the first region is at least partially connected to the pixel electrode. Overlap, at least part of the second region overlaps the wiringA liquid crystal display device is provided.
[0007]
  The present invention also provides a first substrate having a first region and a second region raised with respect to the first region on one main surface, and a second substrate facing the main surface of the first substrate; A plurality of the first and second substrates provided on at least one opposing surface and maintaining a constant distance between the first and second substrates.ColumnarA plurality of spacers; and a liquid crystal layer interposed between the first and second substrates.ColumnarThe diameter of the spacer located on the second region is the plurality of spacers.ColumnarSmaller than the diameter of the spacer located on the first region.The diameter d of the plurality of columnar spacers located on the first region ₁ And a diameter d of the plurality of columnar spacers located on the second region ₂ Ratio d ₁ / D ₂ The first substrate includes a switching element, a wiring, and a pixel electrode on a surface facing the second substrate, and the first region is at least partially connected to the pixel electrode. Overlap, at least part of the second region overlaps the wiringA liquid crystal display device is provided.
[0008]
In the present invention, among the plurality of spacers, the one located closest to the one located on the second region is either the spacer located on the first region or the spacer located on the second region. Also good. Similarly, the spacer located closest to the one located on the first region among the plurality of spacers may be either the spacer located on the first region or the spacer located on the second region. In addition, the “spacer diameter” in the present invention refers to a cross section obtained by cutting a spacer in parallel between both substrates at an intermediate position between the first substrate and the second substrate when the cross section is viewed from the normal direction of both substrates. Furthermore, it means the shortest of the line segments passing through two points of the outer diameter of the cross section and the center of gravity of the cross section.
[0009]
In the present invention, the plurality of spacers may be provided on a surface of the first substrate facing the second substrate, or may be provided on a surface of the second substrate facing the first substrate. It may be provided on both opposing surfaces of the second substrate.
[0011]
In the present invention, at least one of the first and second substrates may include a color filter layer on the surface facing the other substrate. In this case, the colored layers of the color filter layer may be partially overlapped, and the laminated portion may be used as at least a part of the spacer.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same constituent members are denoted by the same reference numerals, and redundant description is omitted.
[0013]
FIG. 1 is a cross-sectional view showing a liquid crystal display device according to a first embodiment of the present invention. A liquid crystal display device 1 shown in FIG. 1 is a TN drive type color liquid crystal display device, in which an active matrix substrate 2 and a counter substrate 3 are opposed to each other, and a liquid crystal layer 4 is interposed between the substrates 2 and 3. It has a structure. An adhesive layer 15 is provided at the peripheral edge between the substrates 2 and 3 except for an injection port (not shown) for injecting a liquid crystal material, and the injection port is sealed with a sealant. It has been stopped. Further, polarizing plates 5 are attached to both surfaces of the liquid crystal display device 1, and a light source (not shown) is disposed on the back side thereof.
[0014]
In the liquid crystal display device 1 shown in FIG. 1, the active matrix substrate 2 has a transparent substrate 6 such as a glass substrate. On the transparent substrate 6, wirings 7 and switching elements (not shown) are formed. Further, a color filter layer 9 and a peripheral light shielding layer 10 are formed on the surface of the transparent substrate 6 on which the wiring 7 and the switching element are provided, and the pixel electrode 11 and the columnar spacer 12 are laminated on the color filter layer 9. Has been. On the other hand, the counter substrate 3 has a transparent substrate 13 such as a glass substrate. A common electrode 14 is formed on the transparent substrate 13. Although not shown, alignment films are provided on the opposing surfaces of the active matrix substrate 2 and the counter substrate 3.
[0015]
The wiring 7 formed on the active matrix substrate 2 is composed of scanning lines and signal lines arranged in a lattice pattern on the transparent substrate 6. The switching element (not shown) is, for example, a thin film transistor (hereinafter referred to as TFT) using amorphous silicon or polysilicon as a semiconductor layer. This switching element is connected to the wiring 7 such as the scanning line and the signal line and the pixel electrode 11, thereby enabling the voltage to be selectively applied to the desired pixel electrode 11.
[0016]
The color filter layer 9 includes, for example, a red colored layer, a green colored layer, and a blue colored layer provided in a stripe shape corresponding to the pixel electrode 11. These colored layers can be formed using a mixture containing a photosensitive resin and a coloring pigment or coloring dye corresponding to each color.
[0017]
The peripheral light shielding layer 10 is generally called a frame layer or the like, and is formed on the peripheral part of the screen. The peripheral light shielding layer 10 can be formed using, for example, a black pigment such as carbon fine particles or a mixture of a black dye and a photosensitive resin.
[0018]
The pixel electrode 11 and the common electrode 14 are made of a transparent conductive material such as ITO. The electrodes 11 and 14 can be formed by sputtering, for example.
[0019]
The columnar spacer 12 can be formed using a photosensitive resin. That is, the columnar spacer 12 is obtained, for example, by forming a photosensitive resin layer on the color filter layer 9 and then pattern-exposing and developing the photosensitive resin layer. The columnar spacer 12 can be formed at least partly from the same material as the peripheral light shielding layer 10 and in the same process. Further, the colored layers constituting the color filter layer 9 can be partially overlapped, and the laminated portion can be used as the columnar spacer 12.
[0020]
An alignment film (not shown) can be formed by performing an alignment treatment such as a rubbing treatment on a thin film made of a transparent resin such as polyimide.
[0021]
In the active matrix substrate 2 of the liquid crystal display device 1, the concave portions 21 and the convex portions 22 are generated on the surface of the color filter layer 9 and the pixel electrode 11 corresponding to the shape of the lower structure such as the wiring 7. . Therefore, the height of the spacer 12 from the substrate 6 is different between the concave portion 21 and the convex portion 22. The reason why the gap unevenness cannot be sufficiently suppressed by the conventional technique is due to such a concavo-convex structure. This will be described with reference to FIG.
[0022]
2A is a cross-sectional view schematically showing an active matrix substrate of a conventional liquid crystal display device, and FIG. 2B is a schematic view of a liquid crystal display device using the active matrix substrate of FIG. It is sectional drawing shown. 3A is a cross-sectional view schematically showing the active matrix substrate of the liquid crystal display device of FIG. 1, and FIG. 3B is a cross-sectional view schematically showing the liquid crystal display device of FIG. 2 (a), 2 (b) and FIGS. 3 (a), 3 (b), only the substrates 6 and 13, the wiring 7, and the columnar spacer 12 are drawn, and other components are omitted. .
[0023]
The spacers 12 are deformed (collapsed) when the active matrix substrate 2 and the counter substrate 3 are bonded to each other. However, as shown in FIG. 2A, the number density and diameter of the columnar spacers 12 are concave portions 21 and convex portions 22. Between the concave portion 21 and the convex portion 22, there is no significant difference in the deformation amount (collapse amount) of the spacer 12. Therefore, in the prior art, gap unevenness as shown in FIG.
[0024]
On the other hand, in this embodiment, as shown in FIG. 3A, the number density of the columnar spacers 12 is lower in the convex portion 22 than in the concave portion 21. Therefore, the load applied to one spacer is larger at the convex portion 22 than at the concave portion 21. Therefore, in this embodiment, the deformation amount of the spacer located on the convex portion 22 is larger than that in the conventional technique, and gap unevenness can be suppressed as shown in FIG.
[0025]
In general, the number density of the columnar spacers 12 and the distance between adjacent ones of the columnar spacers 12 are correlated. Therefore, the relationship between the number density of the columnar spacers 12 and the gap unevenness can be replaced with the relationship between the distance between adjacent ones of the columnar spacers 12 and the gap unevenness. For example, among the columnar spacers 12, the distance between the one positioned on the convex portion 22 and the one positioned closest to the convex spacer 22 is set between the one positioned on the concave portion 21 and the one positioned closest thereto. By making it longer than the distance, gap unevenness can be suppressed.
[0026]
In the present embodiment, the distance D between the spacer 12 positioned on the recess 21 and the spacer 12 positioned closest thereto.₁The distance D between the spacer 12 located on the convex portion 22 and the spacer 12 located nearest to it₂Ratio D₂/ D₁Is preferably in the range of 1.1 to 2, more preferably in the range of 1.2 to 2. Usually the ratio D₂/ D₁Is within the above range, gap unevenness can be sufficiently suppressed.
[0027]
Next, a second embodiment of the present invention will be described.
FIG. 4 is a cross-sectional view showing a liquid crystal display device according to the second embodiment of the present invention. The liquid crystal display device 1 shown in FIG. 4 has substantially the same structure as the liquid crystal display device 1 shown in FIG. 1 except that the diameter of the spacer 12 is different between the concave portion 21 and the convex portion 22. . That is, in this embodiment, the diameter of the spacer 12 located on the convex portion 22 is made smaller than the diameter of the spacer 12 located on the concave portion 22. According to such a configuration, as in the first embodiment, the amount of deformation of the spacer positioned on the convex portion 22 is larger than in the conventional technique. Therefore, gap unevenness can also be suppressed in this embodiment.
[0028]
In the present embodiment, the diameter d of the spacer 12 positioned on the recess 21₁And the diameter d of the spacer 12 positioned on the convex portion 22₂Ratio d₁/ D₂Is preferably in the range of 1.2 to 4, more preferably in the range of 1.5 to 4. Usually the ratio d₁/ D₂Is within the above range, gap unevenness can be sufficiently suppressed.
[0029]
As described above, the spacer 12 is deformed by bonding the active matrix substrate 2 and the counter substrate 3 together. That is, the diameter of the spacer 12 can change before and after the substrates 2 and 3 are bonded together. However, the spacer 12 usually has a forward tapered cross-sectional shape, so that the deformation of the spacer 12 is mainly performed at the top thereof. In other words, the diameter of the spacer 12 hardly changes before and after bonding the substrates 2 and 3 when measured at the bottom of the spacer 12 or in the vicinity thereof. Therefore, by observing the bottom portion of the spacer 12 or the vicinity thereof, it is easily determined whether or not the diameter of the spacer 12 is different between the concave portion 21 and the convex portion 22 even in the completed liquid crystal display device 1. As well as the ratio d₁/ D₂Can also be measured easily.
[0030]
The technologies according to the first and second embodiments described above can be combined with each other. That is, the above-described liquid crystal display device 1 has, for example, the inequality D₁<D₂And the inequality d shown in₁> D₂Both of these relationships may be satisfied at the same time.
[0031]
In the first and second embodiments, the spacer 12 is formed on the active matrix substrate 2. However, the spacer 12 may be provided on the counter substrate 3 or on both the substrates 2 and 3. In the first and second embodiments, the color filter layer 9 is provided on the active matrix substrate 2, but the color filter layer 9 may be provided on the counter substrate 3. However, when the spacer 12 and the color filter layer 9 are provided on the active matrix substrate 2, the alignment when the substrates 2 and 3 are bonded together is easy.
[0032]
Furthermore, in the first and second embodiments, the liquid crystal display device 1 using switching elements has been described. However, a color-type dot matrix display can be performed by adopting a simple matrix driving method. Furthermore, in the above embodiment, the TN liquid crystal display device 1 has been described. However, the display method may be a GH type, an ECB type, a type using a ferroelectric liquid crystal, or the like.
[0033]
【Example】
Examples of the present invention will be described below.
[0034]
Example 1
The liquid crystal display device 1 shown in FIG. 1 was produced by the following method.
First, TFTs and wirings 7 were formed on a glass substrate 6 by a normal method to obtain an XGA type TFT array substrate.
[0035]
Next, an ultraviolet curable acrylic resin resist CR-2000 (manufactured by Fuji Film Ohlin Co., Ltd.) in which a red pigment was dispersed was applied to the surface of the substrate 6 on which the wiring 7 and the like were formed, using a spinner. A photomask is arranged above the coating film thus formed, and the exposure amount is 100 mJ / cm through the photomask.²Then, ultraviolet rays having a wavelength of 365 nm were irradiated. After the exposure was completed under the conditions described above, a red colored layer having a thickness of 3.2 μm was formed by developing the coating film using a 1% KOH aqueous solution for 20 seconds.
[0036]
Further, an ultraviolet curable acrylic resin resist CG-2000 (manufactured by Fuji Film Ohlin) in which a green pigment is dispersed and an ultraviolet curable acrylic resin resist CB-2000 (manufactured by Fuji Film Ohlin) in which a blue pigment is dispersed are used. The green colored layer and the blue colored layer were sequentially formed in the same manner as described for the red colored layer. The RGB color filter layer 9 was formed as described above.
[0037]
Next, an ITO film was formed on the color filter layer 9 using a sputtering method, and this was patterned using a photolithographic technique and an etching technique to obtain a pixel electrode 11. The pixel electrodes 11 were formed so as to be connected to the TFT source electrode through contact holes provided in the color filter layer 9.
[0038]
Thereafter, a black ultraviolet curable resin was applied to the surface of the substrate 6 on which the pixel electrode 11 was formed. The peripheral coating layer 10 and the spacers 12 were simultaneously formed by patterning the coating film thus obtained using a photolithography technique. In this embodiment, when exposing the coating film, a photomask having a spacer portion opening size of 15 μm × 20 μm is used, and 9 pixels are formed on the wiring (auxiliary capacitance line) 7 corresponding to the convex portion 22. The spacers 12 were formed at a ratio of one to two, and the spacers 12 were formed on the recesses 21 at a ratio of two for nine pixels. The height of the spacer 12 obtained by such a method was 4.8 μm.
[0039]
Further, the alignment film material AL-3046 (manufactured by JSR) is applied to the surface of the substrate 6 on which the pixel electrode 11 is formed in a thickness of 600 mm, and the resulting coating film is rubbed to form an alignment film. Formed. The active matrix substrate 2 was completed as described above.
[0040]
While the active matrix substrate 2 was manufactured by the method described above, the counter substrate was manufactured by the following method. That is, first, an ITO film was formed on the glass substrate 13 using a sputtering method, and the common electrode 14 was obtained. Thereafter, AL-3046 (manufactured by JSR), which is an alignment film material, is applied to the surface of the substrate 13 on which the common electrode 14 is formed in a thickness of 600 mm, and the obtained coating film is rubbed to form an alignment film. Formed. The counter substrate 3 was completed as described above.
[0041]
Next, the adhesive 15 was printed on the peripheral portion of the surface of the counter substrate 3 on which the alignment film was formed so as to leave the injection port. Further, an electrode transition material (not shown) for applying a voltage from the active matrix substrate 2 to the common electrode 14 was formed on an electrode transition material (not shown) in the periphery of the adhesive 15.
[0042]
Thereafter, the active matrix substrate 2 and the counter substrate 3 are bonded so that their alignment films face each other and their rubbing directions are orthogonal to each other, and further heated to cure the adhesive 15 so that the cell is cured. Formed. A liquid crystal layer 4 was formed by injecting ZLI-1565 (manufactured by MERCK) as a liquid crystal material into the cell by an ordinary method. Further, the inlet was sealed with an ultraviolet curable resin, and the polarizing plate 5 was attached to each of the glass substrates 6 and 13.
[0043]
The cell gap of the liquid crystal display device 1 obtained as described above was a very good value of 4.80 ± 0.20 μm. Further, in the liquid crystal display device 1, no gap unevenness was observed, and the display quality was extremely good.
[0044]
In this embodiment, when the spacer 12 is formed, a photomask having an opening size of 15 μm × 20 μm is used, but the opening size is 5 μm.²~ 40μm²It is preferable to be within the range. In this embodiment, the spacers 12 are formed at a ratio of one or two to nine pixels. However, it is preferable to form the spacers at a ratio of one to three pixels and one to eighteen pixels.
[0045]
(Example 2)
The liquid crystal display device 1 shown in FIG. 4 was produced by the following method.
First, TFT and wiring 7, RGB color filter layer 9, and pixel electrode 11 were formed on the glass substrate 6 by the same method as described in Example 1.
[0046]
Thereafter, a black ultraviolet curable resin was applied to the surface of the substrate 6 on which the pixel electrode 11 was formed. The coating film obtained in this manner was patterned by using a photolithography technique, thereby simultaneously forming the peripheral light shielding layer 10 and the spacer 12 having a height of 4.8 μm. In this embodiment, the spacers 12 are formed on the wiring (auxiliary capacitance line) 7 corresponding to the convex portion 22 at a ratio of one for nine pixels, and the spacers are also formed on the concave portion 21 at a ratio of one for every nine pixels. 12 was formed. Moreover, when exposing the said coating film, the photomask whose opening size of a spacer part is 30 micrometers x 20 micrometers on the recessed part 21, and is 15 micrometers x 20 micrometers on the convex part 22 was used.
[0047]
Thereafter, an alignment film was formed on the surface of the substrate 6 on which the pixel electrode 11 was formed by the same method as described in Example 1. The active matrix substrate 2 was completed as described above. Further, by using the active matrix substrate 2 and carrying out the same processes as described in Example 1, the liquid crystal display device 1 shown in FIG. 4 was obtained.
[0048]
The cell gap of the liquid crystal display device 1 obtained as described above was a very good value of 4.80 ± 0.15 μm. Further, in the liquid crystal display device 1, no gap unevenness was observed, and the display quality was extremely good.
[0049]
In this embodiment, when the spacer 12 is formed, a photomask having an opening size of 15 μm × 20 μm and 30 μm × 20 μm is used, but the opening size is 5 μm.²~ 40μm²It is preferable to be within the range. In this embodiment, the spacers 12 are formed at a rate of one for every nine pixels, but it is preferable to form the spacers at a rate of one for every three pixels to one for every 18 pixels.
[0050]
(Example 3)
FIG. 5 is a cross-sectional view schematically showing a liquid crystal display device according to Embodiment 3 of the present invention. In this example, the liquid crystal display device 1 shown in FIG. 5 was produced by the following method.
[0051]
First, the TFT 16 and the wiring were formed on the glass substrate 6 by a normal method. Next, a positive ultraviolet curable resin was applied to the surface of the substrate 6 on which the TFT 16 and the like were formed to a thickness of about 1 μm to 4 μm by spin coating or the like. After pre-baking the coating film obtained in this way, the exposure amount is 200 mJ / cm at the part where the contact hole of the coating film is to be formed.²~ 2000mJ / cm²Then, ultraviolet rays having a wavelength of 365 nm were irradiated. Furthermore, the insulating film 17 provided with the contact hole was formed by developing the coated film after exposure.
[0052]
Next, an ITO film was formed on the insulating film 17 by a sputtering method. The pixel electrode 11 was obtained by patterning this using a photolithographic technique and an etching technique. These pixel electrodes 11 were formed so as to be connected to the source electrode of the TFT 10 through contact holes, respectively.
[0053]
Next, a negative ultraviolet curable resin was applied to the surface of the substrate 6 on which the pixel electrode 11 was formed to a thickness of about 1 μm to 4 μm by spin coating or the like. After pre-baking the coating film obtained in this way, the exposure amount is 200 mJ / cm at the portion of the coating film where the spacer 12 is to be formed.²~ 2000mJ / cm²Then, ultraviolet rays having a wavelength of 365 nm were irradiated. Furthermore, columnar spacers 12 having a height of 4.8 μm were formed by developing the coated film after exposure. In the present embodiment, of the spacers 12, when the active matrix substrate 2 and the counter substrate 3 are bonded together, the diameter of the spacer 12 located on the peripheral light-shielding layer 10 corresponding to the concave portion is 25 μm × 25 μm, and the convex portion The diameter of the corresponding one on the color filter layer 9 was 15 μm × 15 μm. The spacers 12 were formed at a rate of one for every nine pixels.
[0054]
Thereafter, AL-3046 (manufactured by JSR), which is an alignment film material, is applied to the surface of the substrate 6 on which the pixel electrode 11 is formed in a thickness of 600 mm, and the obtained coating film is rubbed to form an alignment film. Formed. The active matrix substrate 2 was completed as described above.
[0055]
Using the active matrix substrate 2 and the counter substrate 3 thus obtained, the same processes as described in Example 1 were performed, thereby obtaining the liquid crystal display device 1 shown in FIG. The counter substrate 3 used here forms a color filter layer 9 having a red colored layer 9a, a green colored layer 9b, and a blue colored layer 9c, and a peripheral light shielding layer 10 on a glass substrate 13, The common electrode 14 is formed on the color filter layer 9.
[0056]
The cell gap of the liquid crystal display device 1 obtained as described above was a very good value of 4.80 ± 0.15 μm. Further, in the liquid crystal display device 1, no gap unevenness was observed between the display area and the vicinity of the frame, and the display quality was extremely good.
[0057]
(Example 4)
A plurality of liquid crystal display devices 1 were produced by the same method as described in Example 1 except that the height of the convex portion 22 with respect to the concave portion 21 and the interval between the spacers 12 were different. In the present embodiment, the height of the convex portion 22 with respect to the concave portion 21 is made different between the liquid crystal display devices 1 within a range of 0.5 μm to 2 μm, and between the columnar spacers 12 on the concave portion 21. Ratio of the average interval between the columnar spacers 12 on the convex portion 22 with respect to the average interval (here, since the columnar spacers 12 are periodically arranged, the above ratio D₂/ D₁In the range of 1-5. Next, for each of these liquid crystal display devices 1, the presence or absence of occurrence of cell gaps and gap unevenness was examined. The result is shown in FIG.
[0058]
FIG. 6 is a graph illustrating the relationship between the spacer interval and the gap unevenness in the liquid crystal display device 1 according to the fourth embodiment. In the figure, the horizontal axis is the ratio D₂/ D₁The vertical axis represents the difference in cell gap between the concave portion 21 and the convex portion 22. In the figure, a curve 31 indicates data when the height of the convex portion 22 with respect to the concave portion 21 is 0.5 μm, and a curve 32 indicates data when the height of the convex portion 22 with respect to the concave portion 21 is 1.0 μm. A curve 33 indicates data when the height of the convex portion 22 relative to the concave portion 21 is 2.0 μm.
[0059]
As is apparent from the curve 31 in FIG. 6, when the height of the convex portion 22 with respect to the concave portion 21 is 0.5 μm, the ratio D₂/ D₁By setting the value within the range of 1.1 to 2, gap unevenness could be prevented. Further, as apparent from the curves 32 and 33 in FIG. 6, when the height of the convex portion 22 with respect to the concave portion 21 is 1.0 μm or 2.0 μm, the ratio D₂/ D₁By setting the value in the range of 1.2 to 2, it was possible to prevent the occurrence of gap unevenness.
[0060]
(Example 5)
A plurality of liquid crystal display devices 1 were produced by the same method as described in Example 1 except that the height of the convex portion 22 with respect to the concave portion 21 and the diameter of the spacer 12 were different. In this embodiment, the height of the convex portion 22 with respect to the concave portion 21 is made different between the liquid crystal display devices 1 within a range of 0.5 μm to 2 μm, and the ratio d described above is used.₁/ D₂Were different from each other within the range of 1 to 5 [range of (15 μm × 20 μm) / (15 μm × 20 μm) to (30 μm × 50 μm) / (15 μm × 20 μm)]. Next, for each of these liquid crystal display devices 1, the presence or absence of occurrence of cell gaps and gap unevenness was examined. The result is shown in FIG.
[0061]
FIG. 7 is a graph illustrating the relationship between the spacer diameter and the gap unevenness in the liquid crystal display device 1 according to the fifth embodiment. In the figure, the horizontal axis is the ratio d.₁/ D₂The vertical axis represents the difference in cell gap between the concave portion 21 and the convex portion 22. Further, in the figure, a curve 41 indicates data when the height of the convex portion 22 with respect to the concave portion 21 is 0.5 μm, and a curve 42 indicates data when the height of the convex portion 22 with respect to the concave portion 21 is 1.0 μm. A curve 43 represents data when the height of the convex portion 22 with respect to the concave portion 21 is 2.0 μm.
[0062]
As is apparent from the curve 41 in FIG. 7, when the height of the convex portion 22 with respect to the concave portion 21 is 0.5 μm, the ratio d₁/ D₂By setting the value within the range of 1.2 to 4, it was possible to prevent the occurrence of gap unevenness. Further, as is apparent from the curves 42 and 43 in FIG. 7, when the height of the convex portion 22 relative to the concave portion 21 is 1.0 μm or 2.0 μm, the ratio d₁/ D₂The occurrence of gap unevenness could be prevented by setting the value in the range of 1.5 to 4.
[0063]
【The invention's effect】
As described above, in the present invention, the amount of deformation of the spacer can be reduced by increasing the distance between the spacers in the convex portion compared to the concave portion, or by reducing the diameter of the spacer in the convex portion compared to the concave portion. Since it can be made larger in the convex portion than in the concave portion, occurrence of gap unevenness can be suppressed.
That is, according to the present invention, a liquid crystal display device capable of sufficiently suppressing gap unevenness is provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a liquid crystal display device according to a first embodiment of the present invention.
2A is a cross-sectional view schematically showing an active matrix substrate of a conventional liquid crystal display device, and FIG. 2B is a cross-sectional view schematically showing a liquid crystal display device using the active matrix substrate of FIG.
3A is a cross-sectional view schematically showing an active matrix substrate of the liquid crystal display device of FIG. 1, and FIG. 3B is a cross-sectional view schematically showing the liquid crystal display device of FIG.
FIG. 4 is a cross-sectional view showing a liquid crystal display device according to a second embodiment of the present invention.
FIG. 5 is a sectional view schematically showing a liquid crystal display device according to Embodiment 3 of the invention.
FIG. 6 is a graph showing the relationship between spacer spacing and gap unevenness in the liquid crystal display device according to Example 4;
7 is a graph showing a relationship between a spacer diameter and gap unevenness in a liquid crystal display device according to Example 5. FIG.
[Explanation of symbols]
1. Liquid crystal display device
2 ... Active matrix substrate
3 ... Counter substrate
4 ... Liquid crystal layer
15 ... Adhesive layer
5 ... Polarizing plate
6 ... Transparent substrate
7 ... Wiring
9 Color filter layer
10: Perimeter light shielding layer
11: Pixel electrode
12 ... Columnar spacer
13 ... Transparent substrate
14 ... Common electrode
21 ... Recess
22 ... convex part
9a to 9c ... colored layer
16: Switching element
17 ... Insulating layer
31-33 ... curve
41-43 ... curve

Claims (3)

A first substrate having a first region on one main surface and a second region raised with respect to the first region;
A second substrate facing the main surface of the first substrate;
A plurality of columnar spacers provided on at least one opposing surface of the first and second substrates and maintaining a constant distance between the first and second substrates;
A liquid crystal layer interposed between the first and second substrates,
Among the plurality of columnar spacers, the distance between the one positioned on the second region and the one closest to the second spacer is the same as the distance between the plurality of columnar spacers positioned on the first region. rather longer than the distance between the those located near, those located on the second region of the plurality of columnar spacers more is the number density than those located in the first region Low, among the plurality of columnar spacers, located on the second region among the plurality of columnar spacers with respect to the distance D ₁ between the one located on the first region and the one located nearest to the first region. The ratio D ₂ / D ₁ of the distance D ₂ between the first substrate and the closest _one is in the range of 1.1 to ₂ , and the first substrate is a switching element on the surface facing the second substrate. And wiring and pixel electrodes A liquid crystal display device wherein the first region is at least partially overlap with the pixel electrode, at least a portion of the second region is characterized by overlapping the wiring. A first substrate having a first region on one main surface and a second region raised with respect to the first region;
A second substrate facing the main surface of the first substrate;
A plurality of columnar spacers provided on at least one opposing surface of the first and second substrates and maintaining a constant distance between the first and second substrates;
A liquid crystal layer interposed between the first and second substrates,
Diameter although located on the second region of the plurality of columnar spacers, the plurality of rather smaller more than the diameter of those located in the first region of the columnar spacers, the plurality of columnar spacers wherein the diameter d ₁ of those located on the first region, the ratio d ₁ / d ₂ in the range of 1.2 to 4 with the diameter d ₂ but positioned on the second region of the plurality of columnar spacers The first substrate includes a switching element, a wiring, and a pixel electrode on a surface facing the second substrate, the first region at least partially overlaps the pixel electrode, and at least one of the second regions. The liquid crystal display device is characterized in that the portion overlaps the wiring . The liquid crystal display device according to claim 1, wherein the first substrate has a color filter layer on a surface facing the second substrate.

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