JPH08262426A - Liquid crystal display element - Google Patents

Abstract

PURPOSE: To improve a view angle and to obtain a wide view angle by making an upper side electrode of a color filter correspond to a prescribed area of each pixel and making the lower side electrode correspond to another area. CONSTITUTION: Respective pixels DR, DG, DB are divided into two areas respectively, and a counter electrode 11 corresponding to one side area is provided on the lower side of the color filters 13R, 13G, 13B, and the counter electrode 12 corresponding to the other side area is provided on the upper side of the color filters 13R, 13G, 13B. Then, the counter electrodes 12 are provided on one side part of the color filters 13R, 13G, 13B of respective colors along the longitudinal direction of the color filters 13R, 13G, 13B, and these upper side counter electrodes 12 are connected electrically to the lower side counter electrode 11 through light shield films 14 in gap parts between mutual adjacent color filters 13R, 13G, 13B. Further, the color filters 13R, 13G, 13B of respective colors are formed to have the thickness of about 1.2μm-2.0μm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device.

[0002]

2. Description of the Related Art Generally, TN is used as a liquid crystal display device.
(Twisted nematic) mode or STN
(Super Twisted Nematic) mode is used.

The above-mentioned TN-mode and STN-mode liquid crystal display elements are ones in which a liquid crystal is sandwiched between a pair of substrates provided with electrodes and an alignment film, and the molecules of the liquid crystal are twist-oriented between the two substrates. In a liquid crystal display element for displaying a multicolor image, color filters of a plurality of colors, for example, three colors of red, green and blue are provided on one of the pair of substrates.

A liquid crystal display element in which liquid crystal molecules such as TN mode and STN mode are twist-aligned has a problem that the viewing angle is narrow. This is because Δn · d (the product of the refractive index anisotropy Δn of the liquid crystal and the liquid crystal layer thickness D) of the liquid crystal display element apparently changes depending on the viewing angle (display viewing angle). Even if the voltage applied between the electrode of the substrate and the electrode of the other substrate is the same, that is, the rise angle of the liquid crystal molecules with respect to the substrate surface is the same, the light transmittance (display brightness) Since the voltage-transmittance characteristic of the liquid crystal display element varies depending on the viewing angle, it depends on the viewing angle.

The viewing angle dependency is that the applied voltage between the electrodes is equal to or lower than the threshold voltage Vth of the liquid crystal, or is equal to or higher than the voltage Va at which the liquid crystal molecules rise and are oriented almost vertically to the substrate surface. It is relatively small at one time, but V
Since the viewing angle dependence becomes large at a voltage value between th and Va, if gradation display with brightness gradation is performed,
The brightness of the display of the halftone changes greatly depending on the viewing angle, resulting in an extreme decrease in contrast and inversion of gradation.

Therefore, the conventional liquid crystal display element has a problem that the range of the viewing angle where the display can be observed as an image of good quality is limited, and therefore the viewing angle is narrow. Therefore, conventionally, an alignment control method and a voltage control method have been proposed as means for improving the viewing angle of the liquid crystal display element.

In the above alignment control system, one or both substrates of the liquid crystal display element are subjected to an alignment treatment for aligning liquid crystal molecules with different pretilt angles in a region of one pixel for each pixel. The initial alignment state of liquid crystal molecules is partially different within each pixel area, and a region where the rising angle of the liquid crystal molecule is different when a voltage is applied between the electrodes is formed in one pixel. Is.

In the above voltage control method, the electrodes on one substrate of the liquid crystal display element are divided into a plurality of electrodes for each pixel, and different voltage values are applied between the divided electrodes and the electrodes on the other substrate. The rising angle of the liquid crystal molecules is made different in each part of the pixel by applying the drive signal of.

That is, in the above-mentioned alignment control system and voltage control system, the change in the apparent Δn · d depending on the viewing angle is made different in each part of the pixel by partially changing the rising alignment state of the liquid crystal molecules in each pixel. By doing so, even if the viewing angle changes, the average value of Δn · d in the entire pixel does not change much, so that the viewing angle dependence of the voltage-transmittance characteristic is reduced, and the viewing angle is reduced. Becomes wider.

[0010]

However, in the above alignment control method, it is difficult to perform alignment treatment for aligning liquid crystal molecules with different pretilt angles in each pixel, and therefore it is difficult to put into practical use. I have

On the other hand, in the above voltage control method, the alignment treatment may be a normal treatment and the divided electrodes can be formed by the current photolithography technique, so that it can be put into practical use.
In this voltage control method, since drive signals having different voltage values must be supplied to the divided electrodes, drive control of the liquid crystal display element becomes complicated.

An object of the present invention is to partially raise the rising alignment state of liquid crystal molecules in each pixel without supplying drive signals having different voltage values to the divided electrodes as in the conventional voltage control method. An object of the present invention is to provide a liquid crystal display device having a wide viewing angle and a simple display drive, which can be made different to improve the viewing angle.

[0013]

According to the present invention, a liquid crystal is sandwiched between one substrate provided with an electrode and an alignment film and the other substrate provided with an electrode, a plurality of color filters of a plurality of colors and an alignment film. In the liquid crystal display element in which the molecules of the liquid crystal are twist-aligned between both substrates, the electrodes on the substrate side provided with the color filter are provided on the lower side and the upper side of the color filter, and on the upper side of the color filter. The electrode of (1) corresponds to a predetermined region of each pixel, and the electrode below the color filter corresponds to another region of each pixel.

In this liquid crystal display element, the lower electrode and the upper electrode of the color filter in each pixel are electrodes to which the same drive signal is applied, and therefore these electrodes may be electrically connected. .

The thickness of the color filter is about 1.
It is preferably 2 μm to about 2.0 μm, and the ratio S1 of the area S1 of the region corresponding to the lower electrode of the color filter to the area S2 of the region corresponding to the upper electrode of each color filter in each pixel.
: S2 is preferably from about 2: 8 to about 5: 5.

For example, the thickness of the color filter is about 1.4.
In the case of μm, it is desirable that the ratio S1: S2 of the area S1 of the region corresponding to the lower electrode of the color filter and the area S2 of the region corresponding to the upper electrode in each pixel is about 3: 7. .

However, when the color filters are three-color filters of red, green, and blue, and the thickness of each of these color filters is about 1.4 μm, the electrode below the color filter in each pixel corresponds. Ratio S1 of the area S1 of the region to the area S2 of the region corresponding to the upper electrode S1: S2
Is preferably about 3: 7 in pixels to which the red and green filters correspond and about 4: 6 in pixels to which the blue filter corresponds.

Also, the thickness of the color filter is set to about 1.8 μm.
In the case of m, the ratio S1: S2 between the area S1 of the region corresponding to the lower electrode of the color filter and the area S2 of the region corresponding to the upper electrode in each pixel may be about 5: 5.

When the color filters are filters of three colors of red, green and blue, the thickness of the red and green filters among these color filters is about 1.8.
.mu.m, and the thickness of the blue filter is preferably about 1.4 .mu.m. Even in that case, the ratio S1: S2 between the area S1 of the region corresponding to the lower electrode of the color filter and the area S2 of the region corresponding to the upper electrode in each pixel may be about 5: 5.

[0020]

In the liquid crystal display element of the present invention, even if the voltage applied between the electrode of one substrate and the electrodes above and below the color filter of the other substrate in each pixel is the same, The effective voltage applied to the liquid crystal of a pixel is
Since the area corresponding to the lower electrode of the color filter and the area corresponding to the upper electrode of the color filter are different, liquid crystal molecules in these areas are oriented in different rising states.

Therefore, according to this liquid crystal display element, the rising alignment state of the liquid crystal molecules is partially different in each pixel to improve the viewing angle, and a wide viewing angle can be obtained. The drive signals applied to the lower electrode and the upper electrode of the color filter in the pixel may be the same signal, and thus drive signals of different voltage values are supplied to the divided electrodes as in the conventional voltage control method. Since it is not necessary, display driving can be performed easily.

[0022]

1 to 3 show a first embodiment of the present invention. FIG. 1 is a sectional view of a part of a liquid crystal display element, and FIG. 2 omits an alignment film on a substrate provided with the color filter. FIG.

The liquid crystal display element of this embodiment is an active matrix type in which a TFT (thin film transistor) is an active element, and of a pair of transparent substrates made of glass or the like, an upper substrate (hereinafter, referred to as an upper substrate in FIG. 1). The substrate 1 is provided with a plurality of pixel electrodes 3 made of a transparent conductive film such as an ITO film arranged in the row direction and the column direction, and a plurality of TFTs 4 respectively corresponding to the pixel electrodes 3, and An alignment film 10 is formed on top.

The TFT 4 has a gate electrode 5 formed on the substrate 1 and a gate insulating film 6 covering the gate electrode 5.
An i-type semiconductor film 7 formed on the gate insulating film 6 so as to face the gate electrode 5, and an n-type semiconductor film (not shown) on both sides of the i-type semiconductor film 7. It is composed of a source electrode 8 and a drain electrode 9 which are formed via the above.

Although not shown in FIG. 1, the upper substrate 1 is provided with gate lines for supplying gate signals to the TFTs 4 in each row and data lines for supplying data signals to the TFTs 4 in each column. The gate line is wired on the substrate 1, and the gate electrode of the TFT 4 is formed integrally with the gate line.

The gate insulating film (transparent film) 6 of the TFT 4 is formed on almost the entire surface of the substrate 1, and the data line is wired on the gate insulating film 6 and connected to the drain electrode of the TFT 4. The pixel electrode 3 is formed on the gate insulating film 6 and connected to the source electrode of the TFT 4.

On the other hand, all the pixel electrodes 3 of the upper substrate 1 are formed on the lower substrate 2 (hereinafter referred to as the lower substrate) 2 in FIG.
A first film-shaped first counter electrode 11 facing each other and a second counter electrode 12 partially facing the pixel electrode 3, and a plurality of colors, for example, three colors of red, green, and blue. A color filter 13R, 13G, 13B and a light shielding film 14 generally called a black matrix are provided, and an alignment film 15 is formed thereon.

The above first and second counter electrodes 11, 12
Is made of a transparent conductive film such as an ITO film,
The first counter electrode 11 in the form of a single film is a color filter 13
The second counter electrode 12 is provided below R, 13G and 13B, and above the color filters 13R, 13G and 13B.

That is, the first counter electrode (hereinafter referred to as the lower counter electrode) 11 is formed on the lower substrate 2, and the light shielding film 14 and the color filter are formed on the lower counter electrode 11. 13R, 13G, 13B are provided, and the second counter electrode 12 is formed on the color filters 13R, 13G, 13B.

The light shielding film 14 is made of Cr (chrome).
And the like, and is formed in a grid pattern in which the portions corresponding to the respective pixel electrodes 3 and 3 of the upper substrate 1 are opened.

Further, the color filters 13R, 13
G and 13B are formed in stripes respectively corresponding to the respective pixel electrode columns, and are arranged alternately in the order of red filter 13R, green filter 13G, and blue filter 13B. These color filters 13R, 13G, 13B
Is each pixel DR, D regulated by the light-shielding film 14.
It is formed to be slightly wider than the widths of G and DB (opening width of the light shielding film 14), and both side edges thereof overlap the light shielding film 14.

The second counter electrode (hereinafter referred to as the upper counter electrode) 12 is a color filter 13 for each color.
The color filters 13R, 13G, 13B are provided on one side of the color filters 13R, 13G, 13B along the length direction of the color filters 13R, 13G, 13B. In the space between them, they are electrically connected to the lower counter electrode 11 through the light shielding film 14. The upper counter electrode 12 is formed from the upper surface to the side surface of one side portion of the color filters 13R, 13G, 13B, and the light shielding film 14 is formed at the lower end of the portion formed on the side surface of the filter.
It is connected to the.

In addition, the color filters 13R,
13G and 13B are formed to have a thickness of about 1.2 .mu.m to about 2.0 .mu.m, and each of the pixels DR, DG, and DB has a region corresponding to the lower counter electrode 11 (parallel to the upper right in FIG. 2). The ratio S1: S2 between the area S1 of the hatched area) and the area S2 of the area corresponding to the upper counter electrode 12 (the area hatched to the upper left in FIG. 2) is about 2: 8.
~ About 5: 5.

In this embodiment, the color filters 13R, 13G, 13B for all colors are formed to have a thickness of about 1.4 μm, and the upper counter electrode 12 is formed in each pixel DR, DG, DB. The width is formed to be about 30% of the pixel width, and the area S1 of the region corresponding to the lower counter electrode 11 and the area S2 of the region corresponding to the upper counter electrode 12 in each of the pixels DR, DG, and DB. Ratio of S1: S2
Is about 3: 7.

The two substrates 1 and 2 are joined together with a frame-shaped sealing material (not shown) in a state in which the surfaces on which the electrodes 3 and 11, 12 are formed face each other. , 2, a nematic liquid crystal 16 having positive dielectric anisotropy is sandwiched.

A levorotatory or dextrorotatory optically active substance (for example, a chiral liquid crystal) is added to the nematic liquid crystal 16, and the molecules of the liquid crystal 16 are aligned in the alignment film 10 on both substrates 1 and 2 side. The substrates 1 and 2 are aligned in the alignment treatment direction with a certain pretilt angle with respect to 15 planes.
Between the specified twist angle (approximately 90 in TN mode)
, 180 to 270 ° in the STN mode). The alignment films 10 and 15 are formed of a horizontal alignment material such as a polyimide-based alignment material, and the film surface is subjected to an alignment treatment by rubbing.

The liquid crystal display element has a pair of polarizing plates (not shown) arranged on both surfaces thereof (outer surfaces of both substrates 1 and 2).
Is used to display an image by controlling the transmission of light, and the light incident on the liquid crystal display element (for example, light from the backlight) is linearly polarized by one polarizing plate and enters the liquid crystal layer. In the process of passing through this liquid crystal layer, a birefringent effect is exerted, and among the light, light of a polarization component which passes through the other polarizing plate passes through this polarizing plate and is emitted.

Further, this liquid crystal display device has the lower substrate 2
The same drive signal (reference potential signal) is applied to the lower counter electrode 11 and the upper counter electrode 12 electrically connected to the lower counter electrode 11, and the gate lines of the upper substrate 1 are sequentially applied. By supplying a gate signal and supplying a data signal to each data line in synchronization with the gate signal, T
It is driven by applying a drive voltage corresponding to the potential of the data signal to each pixel electrode 3 via FT4.

In this case, the molecules of the liquid crystal 16 are vertically aligned according to the voltage applied between each pixel electrode 3 and the counter electrodes 11 and 12, and the liquid crystal layer is aligned according to the change in the alignment state of the liquid crystal molecules. Since the birefringence effect of light changes at, the voltage applied between the electrodes is the threshold voltage Vth of the liquid crystal and the voltage Va at which the liquid crystal molecules rise and align to a state almost vertical to the substrate surface. It is possible to perform gradation display in which brightness has gradation by controlling the intervals.

In this liquid crystal display device, the pixel electrodes 3 of the upper substrate 1 and the lower and upper counter electrodes 11, 12 of the color filters 13R, 13G, 13B of the lower substrate 2 in each of the pixels DR, DG, DB. , The effective voltage applied to the liquid crystal 16 of each pixel DR, DG, and DB is the same between the region corresponding to the lower counter electrode 11 and the upper counter electrode 12. Since the corresponding regions are different, the liquid crystal molecules in these two regions are oriented in different rising states.

That is, the liquid crystal molecules are vertically aligned at a rising angle according to the strength of the applied electric field. However, in the liquid crystal display element described above, the same voltage is applied between the pixel electrode 3 and the lower counter electrode 11 and between the pixel electrode 3 and the upper counter electrode 12, but the lower counter electrode 11 corresponds thereto. The effective voltage applied to the liquid crystal 16 in the area to be applied is a voltage that causes a voltage drop due to the impedance of the color filters 13R, 13G, and 13B, and the effective voltage applied to the liquid crystal 16 in the area to which the upper counter electrode 11 corresponds. Is a high voltage with no voltage drop in the color filter, so the rising angle of liquid crystal molecules in each pixel (angle with respect to the substrate 1 and 2 surfaces)
Is small in the region corresponding to the lower counter electrode 11 and large in the region corresponding to the upper counter electrode 12.

Therefore, according to this liquid crystal display element, the rising alignment states of the liquid crystal molecules when a voltage is applied are different from each other in the two regions in each of the pixels DR, DG and DB, and therefore the apparent Δn depending on the viewing angle. Since the change in the value of d, that is, the viewing angle dependence of the voltage-transmittance characteristic is different in the two regions, the apparent viewing angle dependence of the entire pixel is reduced, and when displaying halftone in gradation display. Also, a wide viewing angle can be obtained.

The size (area) of the pixel of the liquid crystal display element is a very small size such that human eyes cannot recognize each pixel from a normal viewing distance. For example, a personal computer. Since the pixel width is about 100 μm to 200 μm even for OA devices such as the above, the two regions cannot be recognized by the resolution of human eyes, and therefore, the pixels DR and DG of the liquid crystal display device are not recognized.
, DB are recognized as pixels having a brightness obtained by averaging the intensities of the emitted light in the two areas.

In the above liquid crystal display element, the color filters 13R, 13R, and
Since the drive signals applied to the lower counter electrode 11 and the upper counter electrode 12 of 13G and 13B may be the same signal, the drive signals having different voltage values are applied to the divided electrodes as in the voltage control method conventionally considered. Therefore, it is possible to easily drive the display.

In the above embodiment, the color filter 1 is used.
Although 3R, 13G, and 13B are formed to have a relatively thin thickness of about 1.4 μm, a region corresponding to the lower counter electrode 11 and a region corresponding to the upper counter electrode 12 in each pixel DR, DG, and DB are formed. Since the area ratio S1: S2 is about 3: 7, it is possible to obtain a good display without gradation inversion over a wide viewing angle range.

That is, in the above liquid crystal display device,
The area S1 of the region corresponding to the lower counter electrode 11 of the color filters 13R, 13G, 13B and the upper counter electrode 12
Is almost equal to the area S2 of the corresponding region (S1: S2 =
It is convenient for the design to be about 5: 5), but when the color filters 13R, 13G, 13B are formed to have a relatively thin thickness of about 1.4 μm, the area ratio S1: S2 is about 5: When the value is 5, the change in the voltage-transmittance characteristic depending on the viewing angle of the liquid crystal display element does not become a sufficient monotonous change, and the inversion of gradation occurs when the display is observed at a viewing angle more than a certain degree.

However, the color filters 13R, 13G,
Area S1 of the region corresponding to the counter electrode 11 on the lower side of 13B
Is smaller than the area S2 of the region corresponding to the upper counter electrode 12, the change in the voltage-transmittance characteristic depending on the viewing angle becomes more monotonous, so that a good display without gradation inversion can be obtained over a large viewing angle range. Obtainable.

If the area S1 of the region corresponding to the lower counter electrode 11 is made too small, the effect of the viewing angle dependence of the voltage-transmittance characteristic in this region is almost eliminated and a wide viewing angle can be obtained. Becomes smaller, the thickness of the color filters 13R, 13G, 13B should be about 1.4.
The area ratio S1: S2 of the two regions in each of the pixels DR, DG, and DB, where μm is set, is S1: S as described above.
It is desirable that 2 = about 3: 7.

FIG. 3 shows color filters 13R, 13G,
The thickness of 13B is about 1.4 μm, and each pixel DR, DG,
The area ratio S1: S2 of the two regions in DB is approximately 3: 7.
The change in the voltage-transmittance characteristic depending on the viewing angle is shown when the liquid crystal display element of the above-mentioned embodiment is driven by applied voltages of V1 to V8 to display eight gradations.

The voltage-transmittance characteristic shown in FIG.
It is a characteristic of a liquid crystal display element designed so that the viewing direction of the display is on a line along the vertical direction of the screen.
The viewing angle of indicates the angle to the lower edge direction of the screen with respect to the normal line of the liquid crystal display element (direction of viewing angle 0 °), and the + viewing angle indicates the angle to the upper edge direction of the screen with respect to the normal line. The transmittance (Y value) is the average transmittance of the entire screen.

As shown in FIG. 3, in the liquid crystal display element of the above-mentioned embodiment, the change of the voltage-transmittance characteristic depending on the viewing angle is about -50 ° to about + 15 ° with respect to the normal line of the liquid crystal display element. The change is almost monotonic, so that a good display without gradation inversion can be obtained over a large viewing angle range of about −50 ° to about + 15 ° with respect to the normal line.

However, also in this liquid crystal display element, when the display is viewed from the upper edge direction of the screen with respect to the normal line,
Applied voltages V1 to V from the vicinity where the viewing angle exceeds approximately 15 °
Although the change in transmittance with respect to 8 is reversed and gradation inversion occurs, the display screen of OA equipment such as personal computers and television receivers should be displayed near the normal line or in the lower edge direction of the screen with respect to the normal line. It is usually observed from a direction slightly inclined to, and therefore, about -50 ° to about + 15 °.
It is sufficient to obtain a good display without gradation inversion over the viewing angle range of.

In the first embodiment, the area ratios S1: S2 of the regions of all the pixels DR, DG, DB are set to about 3: 7, but the area ratios S1: S2 are You may make it different according to the color of 13R, 13G, 13B.

That is, FIG. 4 is a sectional view of a part of a liquid crystal display device showing a second embodiment of the present invention. In this embodiment, the thickness of the color filters 13R, 13G and 13B of each color is about 1. In the liquid crystal display device having a size of 4 μm, the area ratio S1: S2 of the regions of the pixels DR and DG corresponding to the red filter 13R and the green filter 13G is set to about 3: 7, and the region of the pixel DB corresponding to the blue filter 13B is set to about 3: 7. The area ratio S1: S2 is about 4: 6.

FIG. 5 is a sectional view of a part of a liquid crystal display element showing a third embodiment of the present invention. In this embodiment, the color filters 13R, 13G, 13B for the respective colors have a thickness of about 1. In the liquid crystal display element having a size of 4 μm, the area ratio S1 of each region of the pixel DR corresponding to the red filter 13R is
: S2 is about 3: 7, the area ratio S1: S2 of each area of the pixel DB corresponding to the blue filter 13B is about 4: 6, and the area ratio S1 of each area of the pixel DG corresponding to the green filter 13G is: S2 is an area ratio in which the difference between S1 and S2 is smaller than that of the pixel DR corresponding to the red filter 13R and the difference between S1 and S2 is larger than that of the pixel DB corresponding to the blue filter 13B.

In the liquid crystal display device shown in FIGS. 4 and 5, the area ratio S1: S2 of the two regions in each of the pixels DR, DG, DB is set to the color filters 13R, 13G, 13.
Although different depending on the color of B, the other configurations are the same as those of the above-described first embodiment, and therefore, duplicate description will be given the same reference numerals in the drawings and omitted.

According to the liquid crystal display element of the second embodiment shown in FIG. 4, the color filters 13R, 13G and 13 of the respective colors are used.
Of the pixels DR, DG, and DB to which B corresponds, the area ratio S1: S of each region of the pixel DB to which the blue filter 13B corresponds.
Since 2 is an area ratio in which the difference between S1 and S2 is smaller than the respective regions of the pixels DR and DG to which the red filter 13R and the green filter 13G correspond, the floor area over a wider viewing angle range than that of the first embodiment described above. A good display without tone reversal can be obtained, and different voltage-transmittance characteristics can be compensated for each pixel of each color, so that the displayed multicolor image is of each color of red, green, and blue. The image has a good color balance in which the difference in the brightness of the pixels is corrected.

According to the liquid crystal display element of the third embodiment shown in FIG. 5, the red filter 13R and the green filter 13G correspond to the area ratio S1: S2 of each region of the pixel DB to which the blue filter 13B corresponds. The area ratio in which the difference between S1 and S2 is smaller than that in each area of the pixels DR and DG, and the area ratio S1: S2 in each area of the pixel DG corresponding to the green filter 13G is corresponded to by the red filter 13R. Since the area ratio in which the difference between S1 and S2 is smaller than that of each region of the pixel DR is set, good display without gradation inversion can be obtained over a wider viewing angle range, and red,
Since the difference in the voltage-transmittance characteristic for each pixel of each color of green and blue is individually corrected, a multicolor image having a better color balance is displayed.

In the first to third embodiments, the color filters 13R, 13G and 13B for the respective colors have a thickness of about 1.4 μm.
The thickness of 13G and 13B may be arbitrary.

However, the color filters 13R, 13G,
If the thickness of 13B is too small, each pixel DR, DG,
The difference between the effective voltages applied to the liquid crystal 16 in the two regions in DB is reduced, the effect of obtaining a wide viewing angle is reduced, and the color filters 13R, 13G, 13 are also reduced.
If the thickness of B is made too large, the light transmission ratio deteriorates and the display becomes dark.
The thickness of 13G and 13B is about 1.2 μm to about 2.0 μm.
It is preferable to be in the range.

Then, for example, the color filter 13 is used.
If the thicknesses of R, 13G, and 13B are increased to some extent, the difference in effective voltage applied to the liquid crystal 16 in the two regions in each pixel DR, DG, and DB becomes large, and the voltage-transmittance in the two regions becomes large. Since the difference in the viewing angle dependence of the characteristics becomes large, the area S1 of the region corresponding to the lower counter electrode 11 of the color filters 13R, 13G, and 13B in each pixel DR, DG, and DB corresponds to the upper counter electrode 12. A wide viewing angle can be obtained even if the area S2 is substantially the same (S1: S2 = about 5: 5).

FIG. 6 is a sectional view of a part of a liquid crystal display device showing a fourth embodiment of the present invention. In this embodiment, the color filters 13R, 13G and 13B for the respective colors have a thickness of about 1.8 μm. , The area ratio S1: S2 of the two regions in each pixel DR, DG, DB is set to about 5: 5.

FIG. 7 is a sectional view of a part of a liquid crystal display device showing a fifth embodiment of the present invention. In this embodiment, the red filter 13R and the green filter 13G have a thickness of about 1.8 μm. The thickness of the blue filter 13B is about 1.
The area ratio S1: S2 of the two regions in each pixel DR, DG, and DB is about 5: 5.

Further, FIG. 8 is a sectional view of a part of a liquid crystal display element showing a sixth embodiment of the present invention. In this embodiment, the red filter 13R has a thickness of about 1.8 μm and the blue filter 13B has a thickness of about 1.8 μm. The thickness of the green filter 13G is thinner than that of the red filter 13R and thicker than that of the blue filter 13B, and each pixel DR,
The area ratio S1: S2 of the two regions in DG and DB is about 5: 5.

In the liquid crystal display element shown in FIGS. 6 to 8, the color filters 13R, 13G and 13B are formed to have the above-mentioned thickness, and the area ratio S1 of the two regions in each of the pixels DR, DG and DB is S1. : S2 is set to S1: S2 = about 5: 5, but other configurations are the same as those of the first embodiment described above, and therefore, duplicate description will be given the same reference numerals in the drawings and omitted. .

According to the liquid crystal display element of the fourth embodiment shown in FIG. 6, the color filters 13R, 13G and 13 of the respective colors are used.
Since B is about 1.8 μm thick, each pixel DR, D
The difference between the effective voltages applied to the liquid crystal 16 in the two regions in G and DB can be increased to increase the difference in the viewing angle dependence of the voltage-transmittance characteristic in the two regions, and thus Even if the area ratio of the two regions in the pixels DR, DG, and DB is about 5: 5, good display without gradation inversion can be obtained over a wide viewing angle range.

Further, as in the liquid crystal display element of the fifth embodiment shown in FIG. 7, the red filter 13R and the green filter 13G are thickened to about 1.8 μm, and the blue filter 13B is compared to about 1.4 μm. If it is made thinner, the fourth
In this embodiment, a good display without gradation inversion can be obtained over a wider viewing angle range than that of the above embodiment, and the displayed multicolor color image can be obtained by comparing the voltage-transmittance characteristic of each pixel of red, green and blue. It is possible to obtain an image in which the difference is corrected and which has a good color balance.

Further, as in the liquid crystal display element of the sixth embodiment shown in FIG. 8, the red filter 13R has a thickness of about 1.8 μm.
If the blue filter 13B is made relatively thick with a thickness of about 1.4 μm and the green filter 13G is made thinner than the red filter 13R and thicker than the blue filter 13B, gradation reversal over a wider viewing angle range will be satisfactory. Since a different display is obtained and the difference in the voltage-transmittance characteristic for each pixel of each color of red, green, and blue is corrected, it is possible to display a multicolor color image with a better color balance.

In the fourth to sixth embodiments, the area ratio S1 of the two regions in each pixel DR, DG, and DB:
S2 is S1: S2 = about 5: 5, but each pixel D
The area ratio S1: S2 in R, DG and DB may be arbitrary.

However, the color filters 13R, 13G,
Area S1 of the region corresponding to the counter electrode 11 on the lower side of 13B
If too small, the effect of the viewing angle dependence of the voltage-transmittance characteristics in this region is almost eliminated, and the effect of obtaining a wide viewing angle becomes small, and the area S2 of the region corresponding to the upper counter electrode 11 is reduced. If it is made too small, the effect of the viewing angle dependence of the voltage-transmittance characteristic in this region is almost eliminated, and the effect of obtaining a wide viewing angle becomes small. Therefore, the area ratio of the two regions in each pixel DR, DG, and DB is reduced. S1: S2 is preferably in the range of about 2: 8 to about 5: 5.

In the first to sixth embodiments, each pixel DR, DG, DB is divided into two regions, and the counter electrode 11 corresponding to one of the regions is divided into color filters 13R, 13G, 13B. The counter electrode 12 corresponding to the other region is provided on the lower side of the color filters 13R, 13G,
Although provided on the upper side of 13B, each of the pixels DR, DG,
Each of the DBs may be divided into three or more regions, a counter electrode corresponding to a predetermined region of the regions may be provided below the color filter, and a counter electrode corresponding to another region may be provided above the color filter. .

Further, in each of the above embodiments, the counter electrode 12 provided above the color filters 13R, 13G and 13B.
Are electrically connected to the lower counter electrode 11 through the light shielding film 14 at the lower end of the portion formed on the side surface of the filter. The upper counter electrode 12 has one end or both ends thereof. To the color filter 13R,
13G and 13B may be covered with a protective film to be formed thereon.

Further, the color filters 13R and 13R
G and 13B may be formed in a dot shape corresponding to each pixel electrode 3, and in that case, the upper counter electrode 12 may be formed on each dot color filter. In addition, the color filters 13R, 13G, 13
The counter electrode 11 on the lower side of B may be formed in a shape corresponding to the pixel region excluding the region corresponding to the upper counter electrode 12.

Further, the color filters 13R, 13
G and 13B may be provided on the substrate 1 side provided with the pixel electrode 3 and the TFT 4, and in that case, the pixel electrode 3 is
The pixel electrodes on the upper and lower sides of the color filter should correspond to the predetermined regions of each pixel, and the pixel electrodes on the lower side of the color filter should correspond to the other regions of each pixel. Good.

Further, the liquid crystal display element of each of the above-mentioned embodiments is
The present invention relates to an active matrix type liquid crystal display element using a two-terminal non-linear resistance element such as MIM or an active matrix type liquid crystal display element having an FT4 as an active element, or a simple matrix type liquid crystal display element. Can also be applied.

[0076]

In the liquid crystal display element of the present invention, the electrodes on the side of the substrate on which the color filters are provided are provided on the lower side and the upper side of the color filters, and the electrodes on the upper side of the color filters are provided in predetermined pixels of each pixel. Since the lower electrode of the color filter is made to correspond to the region and the other region of each of the pixels is made to correspond, the rising alignment state of the liquid crystal molecules is made partially different in each pixel so that the viewing angle is changed. It is possible to improve and obtain a wide viewing angle, and the drive signal applied to the lower electrode and the upper electrode of the color filter in each pixel may be the same signal, and therefore the voltage control method conventionally considered. Since it is not necessary to supply drive signals having different voltage values to the divided electrodes as in the above, display drive can be easily performed.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a liquid crystal display element showing a first embodiment of the present invention.

FIG. 2 is a plan view in which an alignment film of a substrate similarly provided with a color filter is omitted.

FIG. 3 is a diagram showing a change in voltage-transmittance characteristic depending on a viewing angle when the liquid crystal display element of the first embodiment displays eight gradations.

FIG. 4 is a sectional view of a part of a liquid crystal display element showing a second embodiment of the present invention.

FIG. 5 is a partial cross-sectional view of a liquid crystal display element showing a third embodiment of the present invention.

FIG. 6 is a partial cross-sectional view of a liquid crystal display element showing a fourth embodiment of the present invention.

FIG. 7 is a partial cross-sectional view of a liquid crystal display element showing a fifth embodiment of the present invention.

FIG. 8 is a partial cross-sectional view of a liquid crystal display element showing a sixth embodiment of the present invention.

[Explanation of symbols]

 1, 2 ... Substrate 3 ... Pixel electrode 4 ... TFT 10 ... Alignment film 11 ... Lower counter electrode 12 ... Upper counter electrode 13R ... Red filter 13G ... Green filter 13B ... Blue filter 14 ... Shielding film 15 ... Alignment film 16 ... Liquid crystal DR, DG, DB ... Pixel S1 ... Area of region corresponding to lower counter electrode S2 ... Area of region corresponding to upper counter electrode

Claims (8)

[Claims] 1. A liquid crystal is sandwiched between one substrate provided with an electrode and an alignment film, and the other substrate provided with an electrode, a plurality of color filters and an alignment film, and the molecules of the liquid crystal are retained. In a liquid crystal display element in which a twist orientation is provided between both substrates, a substrate side electrode provided with a color filter is provided below and above the color filter, and an electrode above the color filter is provided in a predetermined pixel of each pixel. Corresponding to the area,
A liquid crystal display device, wherein an electrode below the color filter is made to correspond to another region of each pixel. 2. The liquid crystal display element according to claim 1, wherein the lower electrode and the upper electrode of the color filter in each pixel are electrically connected. 3. The liquid crystal display device according to claim 1, wherein the color filter has a thickness of about 1.2 μm to about 2.0 μm. 4. The ratio S1: S2 of the area S1 of the region corresponding to the lower electrode of the color filter to the area S2 of the region corresponding to the upper electrode of each pixel is about 2: 8 to about 5: 5. The liquid crystal display element according to claim 1 or 2, wherein the liquid crystal display element is present. 5. The thickness of the color filter is about 1.4 μm, and the ratio S1 of the area S1 of the region corresponding to the lower electrode of the color filter in each pixel to the area S2 of the region corresponding to the upper electrode of each pixel. : S2 is about 3: 7, The liquid crystal display element according to claim 1 or 2. 6. The color filter is a filter of three colors of red, green and blue, and each color filter has a thickness of about 1.4 μm, and an electrode below the color filter in each pixel corresponds to the color filter. The ratio S1: S2 of the area S1 of the area to the area S2 of the area corresponding to the upper electrode is about 3: in the pixel corresponding to the red filter and the green filter.
7. The liquid crystal display device according to claim 1 or 2, wherein the blue filter has a pixel ratio of about 4: 6. 7. The thickness of the color filter is about 1.8 μm, and the ratio S1 of the area S1 of the region corresponding to the lower electrode of the color filter in each pixel to the area S2 of the region corresponding to the upper electrode of each pixel. : S2 is about 5: 5, The liquid crystal display element according to claim 1 or 2. 8. The color filter is a filter of three colors of red, green and blue. Among these color filters, the red filter and the green filter have a thickness of about 1.8 μm, and the blue filter has a thickness of about 1. The ratio S1: S2 of the area S1 of the region corresponding to the lower electrode of the color filter and the area S2 of the region corresponding to the upper electrode of 4 μm in each pixel.
Is about 5: 5, The liquid crystal display element according to claim 1 or 2.