JP2001255524A - Liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active matrix liquid crystal display element having fast response, with a wide viewing angle and with high display luminance. SOLUTION: In the liquid crystal display element, equipped with a pair of substrates (21, 22), an electrically continuous electrode (27) placed on the other substrate (22), a polarizing plate (24) placed on the one substrate (21) and the other polarizing plate (25) placed on the other substrate, the one electrode is provided with a line segment shaped slit (28) intersecting the edges perpendicularly opposed to each other of a number of the electrodes. The optical axis direction of the one polarizing plate forms an angle of about 45 deg. with the direction of the line segment shaped slit and the optic axis direction of the other polarizing plate forms an angle of about 90 deg. with the optic axis direction of the one polarizing plate.

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, and more particularly to an active matrix drive type liquid crystal display device used for office information equipment.

[0002]

2. Description of the Related Art Many liquid crystal display devices have been proposed as display devices for information displays. Conventionally, the TN method (Twisted Nematic) and the STN method (Auper
Twisted Nematic; see JP-A-60-107020)
A liquid crystal display system using a nematic liquid crystal as a representative is widely used. Further, these liquid crystal display systems have an advantage that a display panel which is thin and consumes significantly less power can be realized as compared with a display using a CRT (Cathode Ray Tube). In particular, the TN method uses a TFT
(Thin Film Transistor) It is excellent in compatibility with an active matrix driving method using an element or the like, and is widely used for high definition and high display performance displays.

However, in order to realize bright and dark display, the vertical and horizontal change of the liquid crystal array which is uniform in a plane is used. Therefore, in the case of the intermediate brightness display, the appearance of the liquid crystal array which is obliquely raised (that is, optically visible). The characteristics vary depending on the observation azimuth, which causes a problem (display narrow viewing angle) in which the display brightness and the color specification fluctuate depending on the azimuth.

As a liquid crystal display method having a wide display viewing angle, a display method using no polarizing plate, for example, a guest-host method (Journal of Applied Physics (J.A.
ppl.Phys.), 45, 4718-4723 (197
4 years)) and PDLC (Polymer Dispersed Liqu
id Crysta1; see Japanese Patent Application Laid-Open No. 61-83519). However, display performance is disadvantageous in that the contrast ratio is low, and in the case of the PDLC method, the direct-view transmittance is low. ing. In addition, in combination with the active matrix driving method, the guest / host method has poor pixel potential holding characteristics, and the PDLC method uses the element in a high temperature and intense light irradiation state in a projection method. Therefore, the characteristics of the driving element are likely to be unstable, and have not been put to practical use.

As another liquid crystal display system using a polarizing plate and having a wide display viewing angle, a display system using a ferroelectric liquid crystal material or an antiferroelectric liquid crystal material is known. However, since these materials have a huge spontaneous polarization, the amount of charge to be supplied at the time of driving is large, and the amount of charge to be moved at the time of display switching is also large. Therefore, stable image display by the active matrix driving method is difficult.

As one of the liquid crystal display systems which use a polarizing plate and have a wide display viewing angle and are compatible with an active matrix driving system, an IPS system (In-Plane Switching; Applied Physics Letter (Appl. Phys. Let)
t.), Volume 22, pages 165-167 (1973))
Has been devised. In this system, the display viewing angle is widened by restricting the direction of movement of the liquid crystal array within a substantially plane. For this purpose, a comb-shaped electrode must be provided to generate a driving electric field parallel to the plane of the substrate. For this reason, the problem that the pixel effective area is small (the aperture ratio is low) occurs.

As another liquid crystal display system, a pixel division type VA is used.
(Vertical Alignment) method (Japanese Journal of Applied Physics (Jpn. J. App1.
phys.), volume 31, pages L1603 to L1605 (199).
2)) has been devised.

[0008] The operating principle of the VA system is as follows. As the liquid crystal material, a material having a negative dielectric anisotropy is used. The liquid crystal layer is provided between two orthogonal polarizing plates. When no voltage is applied, the liquid crystal array assumes a vertical alignment state. The light propagates in the liquid crystal layer without changing its polarization state, and is cut off at the time of emission to obtain a dark display. When a vertical electric field is applied, the liquid crystal is oriented in a direction perpendicular to the electric field and assumes a tilted arrangement.
The light changes its polarization state while propagating in the liquid crystal layer, and at the time of emission, a transmission component is generated to obtain a bright display. Further, in the pixel division type VA system, by setting a plurality of orientations at which the liquid crystal array falls and providing means for guiding the liquid crystal molecules to the orientation, various arrangements can be seen from any observation orientation. The optical properties of the liquid crystal layer are compensated at the alignment level. In addition, since this method does not use torsional deformation and relatively low elasticity of the entire nematic liquid crystal, it can quickly return to the initial alignment when the voltage is turned off, and can perform high-speed display. Further, a rubbing treatment is not required for the initial alignment operation of the liquid crystal, and there is no concern about deterioration of the element due to static electricity or reduction in voltage holding characteristics due to contamination of the substrate.

As a technique for controlling the liquid crystal to fall to a predetermined direction, a method of providing alignment layers having different alignment directions in a pixel (see Japanese Patent Application Laid-Open No. 03-150530), a method of providing unevenness on upper and lower interfaces of a pixel portion. A method of inductively aligning liquid crystals in the direction of the slope (see Japanese Patent Application Laid-Open No. 05-173142), and a method of providing slits in upper and lower electrodes of a pixel portion and aligning liquid crystals with an inclined electric field at an electrode end (Japanese Patent Application Laid-Open No. 06-43461). No.), and a combination of these technologies is disclosed.
The latter two methods have been put to practical use from the viewpoint of ease of production.

The relationship between the slits and the unevenness as the alignment region dividing means has the following relationship. Since the slit method is controlled by an electric field, it is possible to divide the alignment region more reliably than the concavo-convex method using the delicate inclination of the vertical arrangement at the interface.However, since the slit needs to be provided on the counter electrode side, a uniform counter electrode can be used. The sheet resistance of the electrode is increased as compared with the case where the electrode is used, and display defects such as flicker and crosstalk are more likely to occur. The concavo-convex method is the opposite, the resistance of the counter electrode is the same as before, but the distribution of the orientation direction and the orientation force is easy to appear in the concavo-convex portion, and the orientation force is weaker than the orientation force due to the electric field near the electrode. Alignment disorder is more likely to occur than in the slit type.

[0011]

The transmission luminance in the bright state by the pixel division type VA method is obtained by the same calculation method as the transmission luminance of the parallel array cells sandwiched between the orthogonal polarizers.
The brightness becomes maximum (25% of the theoretical limit of the maximum transmittance) under the condition that the liquid crystal orientation direction and the optical axis direction of the polarizer make 45 °. For this reason, the prior art aims to control the liquid crystal molecules to fall in four directions forming 45 ° with respect to the optical axis of the orthogonal polarizer with a substantially uniform area ratio.

However, when this system is to be realized on each pixel of the active matrix driving system, an array which deviates from an ideal azimuth of 45 ° from the optical axis of the polarizer is generated, and a bright state is obtained. There is a problem that the luminance is reduced. Two main factors affect this phenomenon.

The first factor is an arrangement disorder at the boundary of the array division area. In the case of the division method using the electrode slits or the substrate interface irregularities, the liquid crystal alignment at the region boundary is destabilized due to the influence of the conflicting orientation control, and as a result, it has fallen along the vertical alignment and the ridgeline of the slits and irregularities. An array having various plane orientations, such as a metastable state with the array or a radial plane array generated when both are relaxed, is generated. These arrangements are recognized as dark lines on the pixels in the bright state, and reduce the luminance according to the total extension of the division boundary. In particular, in the radial arrangement, the extension of the slits and the ridges and depressions is longer, and in the case of the slits, the narrower the width, the more likely it is to generate. Therefore, slits and unevenness have a lower limit of the installation density at which the arrangement can be controlled, and it is not easy to shorten the total length of the destruction. As a region division shape, if a diagonal line slit or unevenness is provided for a pixel, the total extension becomes longer than a case where the pixel is provided in a vertical and horizontal line shape, which is disadvantageous.

[0014] The second factor is the distortion of the arrangement around the pixel electrode. Each pixel of the active matrix driving system is electrically independent, and a signal line electrode, a gate line electrode, an adjacent pixel electrode, and, if necessary, an auxiliary capacitance electrode and the like are provided around or immediately below the pixel, Each of them is in a different potential state. Therefore, in each side of the pixel electrode end, an electric field (Fringe Field) is generated along the electrode side and in the cross section of the electrode in accordance with the potential difference from the adjacent electrode, and the liquid crystal molecules are arranged perpendicular to this electric field. As a result, an array that falls down vertically across the electrode side is likely to occur as a result. Therefore, in the pixel division VA system in which the optical axis direction of the polarizing plate is aligned with the side direction of the pixel and the liquid crystal molecules are tilted in an oblique direction, there is a problem that the periphery of the pixel is darkened and the luminance is reduced. Although the phenomenon is slight, for the same reason, in the pixel division type VA system in which the optical axis of the polarizing plate is inclined and the liquid crystal molecules are tilted to the side of the pixel, the pixel corners are darkened and the luminance is reduced. There is a problem to do. This phenomenon is further emphasized by applying a commonly used driving method of inverting the potential polarity (the relationship of the pixel potential with respect to the counter electrode potential) between adjacent pixels in order to prevent charge bias of the pixels.

For the purpose of suppressing this phenomenon, a technique of disposing an orientation control electrode in the periphery (see Japanese Patent Application Laid-Open No. 07-13164) has been disclosed. However, the manufacturing cost is increased, and the manufacturing process is complicated and the cost is increased. Further, generally, the general planar shape of each pixel of the liquid crystal display element is not a square but a vertically long rectangle. Even if the surrounding electric potential difference can be controlled to be almost the same, the liquid crystal alignment that falls across the side at the electrode end,
It tends to be more likely to occur on the long side where the total amount of falling liquid crystal is large. For this reason, even if the above-described technique aiming at equalizing the area of the divided region in a square pixel is applied to a general active matrix pixel, the viewing angle characteristics are not sufficiently compensated.

Further, in order to compensate for the first cause of the decrease in luminance described above, a driving element and a matrix-like signal electrode are placed immediately below a pixel to improve a pixel aperture ratio (a pixel-mounted type) active matrix liquid crystal. In the display element, the problem that the above-described second luminance reduction phenomenon is greatly enhanced has been discovered. FIG. 1 shows typical phenomena when a problem occurs. FIG.
The horizontal axis represents the value obtained by standardizing the potential difference between adjacent pixels by the potential difference between the black and white binary levels, and the vertical axis represents the element transmitted light luminance in the white display state, normalized by the maximum value. For the counter electrode,
In the case of an element having one cross-shaped slit per pixel, sufficient luminance can be obtained under ideal conditions where there is no potential difference between adjacent pixels. However, when the potential difference exceeds about 1/4 of the threshold voltage of the liquid crystal, the luminance decreases. It drops sharply. This result indicates that even if a driving method in which the pixel potential polarity with respect to the counter electrode potential is the same for all pixels ignoring display defects such as burn-in and the like, if the adjacent pixels display anything other than white, the white luminance is linked. Means lower. Techniques for avoiding this problem are not known.

An object of the present invention is to solve the above-mentioned problems and to provide an active matrix driving type liquid crystal display device having a high speed, a wide viewing angle and a high luminance.

[0018]

In order to solve the above problems and achieve the object, a liquid crystal display device of the present invention is configured as follows.

The liquid crystal display device of the present invention comprises a pair of substrates (a first substrate and a second substrate) and a plurality of electrically independent and grid-like electrodes (pixel electrodes) provided on one of the substrates. And a one-to-one drive element and one electrically continuous electrode (counter electrode) provided on the other substrate
And one polarizing plate (the first polarizing plate) provided on the one substrate.
And the other polarizer (second polarizer) provided on the other substrate, wherein the plurality of electrodes are adjacent to each other, and the driving element is a lower layer than the plurality of electrodes. And the one electrode has a line-shaped slit vertically crossing a pair of sides of the plurality of electrodes, and the one polarizing plate has an optical axis direction substantially equal to that of the line-shaped slit direction. And the optical axis direction of the other polarizing plate forms an angle of approximately 90 ° with the optical axis direction of the one polarizing plate.

The liquid crystal display device of the present invention is easy to manufacture among the pixel division type VA systems capable of high-speed and high viewing angle display.
Taking advantage of the advantage of the electrode slit method that the alignment area division control can be performed stably, the disadvantage that the resistance of the counter electrode is high, compared to the unevenness method, is unique to the active matrix drive type liquid crystal display element. It compensates for this phenomenon.

That is, by aligning the direction in which the liquid crystal molecules fall down defined by the slit with the direction of the higher alignment-induced electric field of the vertical and horizontal inter-electrode electric fields generated around the active matrix pixel, By improving the uniformity of the orientation inside the divided region and setting the orientation at an angle of 45 ° with respect to the optical axis of the polarizer, it is possible to increase the arrangement components satisfying the maximum luminance condition in bright display.

The direction having the higher alignment inducing property is determined in consideration of the pixel shape and the steepness of the potential gradient around the pixel. As for the shape, as described above, generally, a slit shape along the long side of the pixel is desirable. However, when there is an electrode having a large potential difference close to the pixel short side (in a plane or in the stacking direction), a slit shape along the short side may be used.

Further, the total length of the alignment division boundary is equal to the length of one side of the pixel, and can be suppressed to half or less of the case where a slit shape such as a cross or an X character is used. In the prior art, there is a possibility that a disordered arrangement may occur in the middle, even in a narrow and long linear shape, since the division arrangement is stabilized by an electric field around the pixel, stable alignment division can be realized,
The area of the dark line at the boundary can be minimized. Further, since the slit shape is simple and the area ratio with respect to the entire electrode is low, an increase in electrode resistance can be minimized.

In the structure of the present invention, the directions in which the liquid crystal falls are two directions in the left and right directions, and the viewing angle characteristics in all directions are inferior to those of the prior art liquid crystal display element having a structure falling in four directions. However, assuming that the display is used as a display, the vertical direction is easy for the observer to adjust the observation direction, and once the visibility is adjusted, the position of the display characteristics depends on the position even if multiple observers observe in a line. There is little sex. On the other hand, in the left-right azimuth, the display characteristics when a plurality of observers are arranged tend to be position-dependent, and the control of the viewing angle characteristics in this direction is more important.

The liquid crystal display device of the present invention has good viewing angle characteristics in the left and right directions where display characteristics are important, and has higher brightness than conventional products. Furthermore, when the viewing angle characteristics in the vertical direction are to be equivalent to those of the conventional product, a phase compensator may be introduced. Regarding the specifications of the phase compensator and the configuration method in the element,
For example, SID'98 digest, 315 pages (1998)
The described method can be used.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

First, a first embodiment will be described. FIG.
1 is a plan view of a liquid crystal display device according to an example of the present invention. FIG. 2 is a cross-sectional view showing a state where the liquid crystal display element shown in FIG. 3 is cut along line AA ′.

The liquid crystal display device according to the embodiment of the present invention comprises a pair of transparent substrates 21 and 22 facing each other, a liquid crystal layer 23 having a negative dielectric anisotropy sealed between them, and It is composed of an alignment layer (not shown) provided at the interface between the layer 23 and the transparent substrates 21 and 22 and a pair of polarizing plates 24 and 25 disposed with the transparent substrates 21 and 22 interposed therebetween. On the lower transparent substrate 21, a number of pixel electrodes 2
6 are installed. One counter electrode 27 is provided on the upper transparent substrate 22. The slit 28 is provided in the opposite electrode 27 at the same plane cycle as the pixel electrode 26.

The lower transparent substrate 21 has a plurality of gate line electrodes 31 extending in one direction and a plurality of signal line electrodes extending in a direction orthogonal to the one direction via a first insulating layer 32. 33 are formed. A drive element 34 is formed in the lowermost layer near the intersection of the two, and the first insulating layer 32 is removed at the intersection between one terminal 34 a of the drive element 34 and the signal line electrode 33. . Further, an auxiliary capacitance electrode 35 is formed at the same height as the gate line electrode 31. A second insulating layer 36 is formed so as to cover all of them, and the pixel electrodes 26 are further formed thereon in a lattice shape. The other terminal 34b of the pixel electrode 26 and the driving element 34
Is connected via an auxiliary electrode 37 so as not to be short-circuited to an auxiliary capacitance electrode 35 in an intermediate layer. As for the auxiliary capacitance, a capacitance is formed at two places: an overlapping portion of the auxiliary capacitance electrode 35 and the pixel electrode 26, and a laminated portion composed of the auxiliary capacitance electrode and a lower dielectric layer and a semiconductor layer. I have. The auxiliary electrode 37 has the same height as the signal line electrode 33, and the second insulating layer 36 of the connection pad 37 a in the overlapping portion with the pixel electrode 26 and the first insulating pad 36 b in the overlapping portion with the auxiliary capacitance electrode 35. Of the insulating layer 32 is removed. A linear portion connecting the connection pad 37a and the connection pad 37b is disposed immediately below the slit 28.

Note that a transparent material may be used for the second insulating layer 36, or a color filter such as RGB or CMY may be used for each pixel to form a color filter. When a color display element is manufactured using a transparent material, a color filter is separately provided on the upper transparent substrate 22.

A dashed pattern that vertically crosses the pixel shown in FIG. 3 indicates the planar shape of the slit 28 provided in the counter electrode 27 on the upper transparent substrate 22. 3, the dashed arrows outside the margin indicate the optical axis orientation of the lower polarizing plate 24, the solid arrows indicate the optical axis orientation of the upper polarizing plate 25, and the dotted arrow indicates the orientation of the slit 28. That is,
The polarizing plate 25 has an optical axis direction at an angle of approximately 45 degrees with respect to the direction of the slit 28, and the polarizing plate 24 has an optical axis direction at approximately 90 degrees with respect to the optical axis direction of the polarizing plate 25.

Hereinafter, a method for manufacturing a liquid crystal display device according to an embodiment of the present invention will be described. After depositing 50 nm of amorphous silicon on a glass substrate having a thickness of 0.7 mm, the amorphous silicon is patterned, then microcrystallized by laser annealing, and then ion doping is performed on the terminals of the auxiliary capacitance forming region and the driving device region. Was given. After 150 mm of silicon oxide was deposited, the drive element terminal portion and the portion immediately above the connection portion with the pixel electrode were removed by etching. A molybdenum-tungsten alloy is deposited in a thickness of 250 mm, and is patterned into a hatched shape shown in FIG.
The gate line electrode 31 and the auxiliary capacitance electrode 35 were formed.
At this time, the gate line electrode 31 was arranged on the channel portion of the drive element 34 formed at the broken line portion shown in FIG. An ion doping process was performed on a part of the driving element region to complete a terminal portion of the driving element. After 650 nm of silicon oxide was deposited, the drive element terminal portion and the portion immediately above the connection portion with the pixel electrode 26 were removed by etching. A molybdenum, an aluminum-neodymium alloy, and a molybdenum are successively laminated in the order of a 600-mm-thick metal layer, which is patterned into a hatched shape shown in FIG. Was formed. After depositing silicon nitride to a thickness of 450 nm, the portion immediately above the connection with the pixel electrode 26 was removed by etching. Further, an acrylic transparent photosensitive resin CSP-S011 (product name,
(Fuji film, Olin) was formed to a thickness of 3 μm, and the portion immediately above the connection with the pixel electrode 26 was removed by etching. I
100 nm of TO (indium tin oxide) was deposited, and this was patterned into a shape shown in FIG. 4C to form a pixel electrode 26. 3. photosensitive resin CSP-S011
This was formed to a thickness of 1 μm, and this was patterned at a rate of one for every four pixels into the shape of the rope portion shown in FIG. 5 to form a columnar spacer 51. RN-1204 on top
A vertical alignment film (product name, Nissan Chemical Industries, Ltd.) was formed to a thickness of 75 nm.

After another 100 mm of IT0 was deposited on another glass substrate with a color filter having a thickness of 0.7 mm, this was patterned into the shape shown in FIG. 6 to form a slit 28. 75 m vertical alignment film of RN-1204 on the outermost surface
m.

An adhesive layer having a width of 1 mm is formed around the substrate, and the substrates are bonded together such that the slit 28 is located at the position indicated by the broken line in FIG.
LC-2039 (product name, Merck) was enclosed. A pair of polarizing plates 24 and 25 are provided outside the pair of transparent substrates 21 and 22.
Is attached so that the optical axis arrangement on the margin shown in FIG.
A liquid crystal display device according to a first example of the present invention was manufactured.

In order to confirm the performance of this element, a liquid crystal display element shown in a comparative example was manufactured.

Here, Comparative Example 1 will be described. The method of manufacturing the lower substrate with the driving element is the same as that of the first embodiment. After depositing 100 mm of ITO on a 0.7 mm thick glass substrate with a color filter as an upper substrate,
This is patterned into the shape shown in FIG.
8 was formed. A vertical alignment film of RN-1204 was formed on the outermost surface to a thickness of 70 mm. Hereinafter, a liquid crystal display element according to Comparative Example 1 of the present invention was manufactured through the same steps.

Next, Comparative Example 2 will be described. A liquid crystal display device according to Comparative Example 2 of the present invention was manufactured by the same steps as in Comparative Example 1, except that the patterning shape of the slit 28 was as shown in FIG.

The device performance evaluation was performed in the following manner.
A voltage is applied to the gate line electrode, the odd-numbered signal line electrode, the even-numbered signal line electrode, and the counter electrode in accordance with the timing chart shown in FIG. 9 to maintain the same signal potential polarity between adjacent pixels. The checker pattern was displayed. Note that the waveform shown in FIG.
/ 60 seconds corresponds to four field times, that is, two image display times. FIG. 9 shows only the first three gate line electrodes. The waveform of the selection pulse voltage (the state of _VH ) appears sequentially also in the remaining gate line electrodes. For the odd and even signal line electrode potentials, the counter electrode potential V _C (V
_Although a voltage difference of several tens to several hundreds mV may be given between _C and the signal potential median value, the setting is omitted in FIG. 9).
Based on the image signal amplitude V _B of the bright state, repeating a potential state of the image signal amplitude V _D of the dark state, further inversion potential polarity (high or low relationship with respect to the counter electrode potential) for each one field period. The next scan preparation is performed immediately before the end of each field, and the potentials of both signal line electrodes are not always as shown in the figure.

The pixel signal amplitude (V_D) Black level
To the white level (ie, bright state, V _B), Change
The relationship with the transmission luminance in the state pixel was plotted. So
FIG. 10 shows the results. The horizontal axis is the signal amplitude of the dark state pixel,
The vertical axis is the normalized transmission luminance. Trend according to Comparative Example 1
Are the same as those shown in the description of the above-described problem, and the adjacent pixels
A display defect occurred due to the generation of a slight potential difference therebetween.
In the case of Comparative Example 2, the decrease in luminance due to the potential difference between pixels is suppressed.
However, the maximum brightness was low. According to Embodiment 1 of the present invention
In the case of a liquid crystal display device, the luminance may also decrease due to the potential difference
It was not seen and the brightness was high.

Next, a second embodiment will be described. The method of manufacturing the lower substrate with the driving element is the same as that of the first embodiment. After 500 mm of aluminum was deposited on a 0.7 mm-thick glass substrate with a color filter as an upper substrate, this was patterned as shown by a hatched line shape 110 in FIG. Further, after depositing 100 mm of ITO, this was patterned into a hatched portion shape shown in FIG. 11 to form a slit 28. RN-1204 on top
Was formed to a thickness of 70 mm. Less than,
A liquid crystal display device according to Example 2 of the present invention was manufactured through the same steps as in Example 1.

When the same evaluation as in Example 1 was performed,
The same characteristics were obtained within the range of the measurement error. Furthermore, when the electrode resistance of the upper substrate was measured, a resistance value equivalent to that when a uniform ITO electrode was formed was obtained.

Next, a third embodiment will be described. The method of manufacturing the lower substrate with the driving element is the same as that of Example 1 except that the step of forming the columnar spacer was omitted. The method of manufacturing the upper substrate with a color filter is the same as that of the first embodiment.

An adhesive layer having a width of 1 mm was formed around the lower substrate, and micropearls (product name, Sekisui Fine Chemical) having a diameter of 4.0 μm were sprayed on the upper substrate at a density of 100 / square mm. The two substrates were bonded together such that the electrode slit on the substrate was located at the position indicated by the broken line in FIG. Hereinafter, a liquid crystal display device according to Example 3 of the present invention was manufactured through the same steps as in Example 1.

When the same evaluation as in Example 1 was performed,
The same characteristics as in Example 1 were obtained except that the maximum luminance was reduced by about 1%.

Next, a fourth embodiment will be described. The method of manufacturing the lower substrate with the driving element is the same as that of Example 1 up to the step of forming the silicon nitride layer. However, the driving element 34, the gate line electrode 31 and the auxiliary capacitance electrode 35 were formed in the shape shown in FIG. 13A, and the signal line electrode 33 and the auxiliary electrode 37 were formed in the shape shown in FIG.

Photosensitive resin CSP-S mixed with green pigment
011 was formed to a thickness of 3 μm, and this was patterned into the shape of the mask light-transmitting portion 121 shown in FIG. Note that the broken line in FIG.
The mask light-transmitting portion 121 appears repeatedly at a cycle three times as large as the pixel horizontal direction cycle. Photosensitive resin CSP- containing blue pigment
S011 was formed to a thickness of 3 μm, and this was formed as shown in FIG.
In the shape of the mask light-transmitting portion 121. A photosensitive resin CSP-S011 mixed with a red pigment is formed to a thickness of 3 μm, and the photosensitive resin CSP-S011 is formed to a thickness of 3 μm.
1 was patterned.

After depositing 100 mm of ITO, this was patterned into the shape shown in FIG. 4C to form a pixel electrode. The photosensitive resin CSP-S011 is formed to a thickness of 4.1 μm, and the photosensitive resin CSP-S011 is patterned at a rate of one for every four pixels into the shape of a rope portion shown in FIG.
Was formed. A vertical alignment film of RN-1204 was formed on the outermost surface to a thickness of 75 mm.

On another 0.7 mm thick glass substrate, ITO
Was deposited to a thickness of 100 nm and then patterned into the shape shown in FIG. RN-1 on the outermost surface
A vertical alignment film 204 was formed to a thickness of 75 nm.
Hereinafter, a liquid crystal display element according to Example 4 of the present invention was manufactured by the same combination process as in the first example.

When the same evaluation as in Example 1 was performed,
The same characteristics were obtained within the range of the measurement error.

Here, the functions and effects of the liquid crystal display element of the present invention described above will be summarized.

The above-described liquid crystal display device of the present invention eliminates a factor of lowering of luminance which is peculiar to the active matrix liquid crystal display device of the pixel type. In the case of an overlaid type pixel, an auxiliary electrode is required to electrically connect the pixel to a driving element provided in a lower layer, but since this electrode requires high conductivity, it is usually formed as a metal film. Therefore, the area immediately above cannot be used for display. Furthermore, in order to suppress the parasitic capacitance generated around the driving element, it is desirable that the gate line electrode is disposed apart from electrodes (pixel electrodes, auxiliary capacitance electrodes, etc.) other than the signal line electrodes which need to be orthogonal, In that case, there is a possibility that a linear routing portion is generated in the auxiliary electrode. According to the present invention, by providing the linear routing portion directly below the alignment region boundary generated on the pixel, it is possible to avoid the generation of a new non-display region due to the addition of the auxiliary electrode.

Further, according to the liquid crystal display device of the present invention,
The resistance of the counter electrode can be further reduced. Active matrix driving type liquid crystal display elements are provided with driving signal electrodes and auxiliary capacitance electrodes for assisting voltage holding characteristics, and these are usually formed as metal films.
This area directly above cannot be used for display. By forming a material such as a metal having higher conductivity than the light-transmitting electrode material on a position corresponding to the non-pixel region on the counter electrode, an increase in electrode resistance due to slit formation can be avoided.

Further, according to the liquid crystal display device of the present invention, the display luminance can be further increased. A columnar spacer can be selectively formed in a non-pixel portion by using a photoreactive resin or the like, and a new mainstream technology, which always occurs when a method of spraying small spheres of a resin or the like on a substrate, is required. The occurrence of a non-display area is avoided. Furthermore, in the case of the configuration of the present invention, each side of the columnar spacer is set in parallel with the adjacent pixels, and an alignment film for obtaining a vertical alignment of liquid crystal is formed after the columnar spacer is formed in the initial state, whereby the columnar spacer is formed. Can generate a horizontal alignment regulating force with respect to the substrate from each surface, and can further improve the uniformity of arrangement at the periphery of the pixel.

[0054]

According to the present invention, the pixel division type VA system which is high speed and has a wide viewing angle can be applied to an active matrix type liquid crystal display device of a pixel mounted type which has a large pixel area and can be expected to have high luminance and high definition. Becomes Thus, according to the present invention, a liquid crystal display device having excellent display characteristics at low cost can be provided.

[Brief description of the drawings]

FIG. 1 is an element characteristic diagram for explaining a problem when a conventional technique is applied to an active matrix liquid crystal display element on a pixel.

FIG. 2 is a sectional structural view of a pixel portion in the liquid crystal display element according to the embodiment of the present invention.

FIG. 3 is a plan structural view of a liquid crystal display device according to an embodiment of the present invention.

FIG. 4 is a plan view of a lower substrate constituting layer of the liquid crystal display element according to the embodiment of the present invention.

FIG. 5 is a distribution plan view of a spacer of the liquid crystal display element according to the embodiment of the present invention.

FIG. 6 is a plan view of a counter electrode in the liquid crystal display device according to the embodiment of the present invention.

FIG. 7 is a plan view of a counter electrode in a liquid crystal display element according to a comparative example of the present invention.

FIG. 8 is a plan view of a counter electrode in a liquid crystal display element according to another comparative example of the present invention.

FIG. 9 is a timing chart of a driving waveform for a liquid crystal display element according to the present invention.

FIG. 10 is a display characteristic diagram illustrating the performance of the liquid crystal display element according to the present invention.

FIG. 11 is a plan view of a counter electrode in the liquid crystal display element according to the present invention.

FIG. 12 is a plan view of a mask used for manufacturing a liquid crystal display element according to another embodiment of the present invention.

FIG. 13 is a plan view of a lower substrate constituting layer of a liquid crystal display device according to another embodiment of the present invention.

[Explanation of symbols]

 21, 22: transparent substrate 23: liquid crystal layer 24, 25: polarizing plate 26: pixel electrode 27: counter electrode 28: slit 31: gate line electrode 32: first insulating layer 33: signal line electrode 34: driving element 34a, 34b: Terminal of the drive element 35: Auxiliary capacitance electrode 36: Second insulating layer 37: Auxiliary electrode 37a, 37b: Connection pad 51: Spacer 110: Low resistance part 120: Light shielding part 121: Light transmitting part

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasushi Kawada 1-9-1-2 Hara-cho, Fukaya-shi, Saitama F-term in the Toshiba Fukaya Plant (reference) 2H089 LA10 QA14 RA05 RA06 RA10 TA02 TA09 TA15 2H091 FA08X FA08Z FD07 GA02 GA13 HA07 HA08 HA10 LA19 LA30 2H092 GA13 GA17 GA21 JA37 JB69 NA01 NA05 NA28 PA03 PA06 PA11 QA07 QA10

Claims (4)

[Claims] 1. A pair of first and second polarizers disposed to face each other, and a pair of substrates disposed opposite each other between the pair of first and second polarizers, wherein the first polarizer is provided. A first substrate disposed on the side of the second polarizer, a second substrate disposed on the side of the second polarizing plate, and a pair of electrodes disposed opposite to each other between the pair of the first and second substrates. A pixel electrode comprising a large number of electrodes disposed on the first substrate side; a single electrically continuous counter electrode disposed on the second substrate side; and the pixel electrode and the counter electrode. And a liquid crystal layer containing liquid crystal molecules held between the pixel electrode and the counter electrode has a line-shaped slit vertically crossing a pair of sides of the pixel electrode, the second polarizing plate, An optical axis azimuth at an angle of approximately 45 degrees with respect to the azimuth of the line-shaped slit; The liquid crystal display device light plate has an optical axis azimuth of approximately 90 degrees with respect to the optical axis azimuth of the second polarizer, characterized in that. 2. A driving element corresponding to each of a large number of electrodes included in the pixel electrode, and an auxiliary electrode for supplying power from the driving element to the pixel electrode, wherein a part of the auxiliary electrode is directly below the slit. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is installed in a liquid crystal display device. 3. The counter electrode includes a plurality of materials having different conductivity, and a region of the counter electrode that does not face the pixel electrode includes:
2. The liquid crystal display device according to claim 1, comprising a material having relatively high conductivity among the plurality of materials. 4. The liquid crystal display device according to claim 1, further comprising a spacer, which is a columnar resin disposed adjacent to the pixel electrode and maintains a thickness of the liquid crystal layer.