JP2815238B2 - Liquid crystal display - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a monochrome or color liquid crystal display device which is widely used as a display of a clock, a calculator, a video camera, and other various electronic devices. And especially,
A first electrode and a second electrode are provided on one of two substrates for enclosing liquid crystal, and between the first electrode and the second electrode,
The present invention relates to a configuration of a liquid crystal display device having a nonlinear resistance element having a “metal-insulating film-metal” or “metal-insulating film-transparent conductive film” structure.

BACKGROUND ART In recent years, the display capacity of a liquid crystal display device using a liquid crystal panel has been steadily increasing.

In a system using multiplex driving for a liquid crystal display device having a simple matrix configuration, a reduction in contrast or a reduction in response speed occurs as time division is increased. For this reason, it is difficult to obtain a sufficient contrast when having about 200 scanning lines.

Therefore, in order to eliminate such a drawback, an active matrix type liquid crystal display panel in which a switching element is provided for each pixel is employed.

The active matrix type liquid crystal display panel is roughly classified into a three-terminal system using a thin film transistor as a switching element and a two-terminal system using a non-linear resistance element. The two-terminal system is superior in that the structure and the manufacturing method are simple.

As the two-terminal system, a diode type, a varistor type, a MIM (Metal-Insulator-Metal) type, and the like have been developed.

Among them, the MIM type has a feature that the structure is particularly simple and the manufacturing process is short.

Further, the liquid crystal display panel is required to have high density and high definition, and it is necessary to reduce the area occupied by the switching elements.

As means for achieving higher density and higher definition, there are a photolithography technique and an etching technique, which are fine processing techniques of a semiconductor manufacturing technique. However, even with this semiconductor manufacturing technique, it is very difficult to process a large area and to realize low cost.

Accordingly, FIG. 11 is a plan view showing an example of a conventional liquid crystal display device, and FIG. 12 is a cross-sectional view taken along the line XII-XII, showing a structure of a switching element effective for increasing the area and reducing the cost. This will be described with reference to FIG.

In this liquid crystal display device, as shown in FIG. 12, a first substrate 131 and a second substrate 136 each made of a transparent material are opposed to each other at a predetermined interval via a spacer 142, and a liquid crystal 141 is sealed between them. doing.

On the first substrate 131, a first electrode 132 and a display electrode
As shown in FIG. 11, 135 are provided in a matrix, and a non-linear resistance layer 133 is provided on the first electrode 132. further,
A second electrode 134 is provided on the nonlinear resistance layer 133 so as to overlap with the nonlinear resistance layer 133, thereby forming the nonlinear resistance element 130. As shown in FIG. 11, the second electrode 134 extends from the display electrode 135, and part of the second electrode 134 also serves as the display electrode.

On the other hand, on a surface of the second substrate 136 facing the first substrate 131, in order to prevent light from leaking from gaps between the display electrodes 135 provided on the first substrate 131, as shown in FIG. A black matrix 137 is provided over the entire area indicated by hatching. That is, the black matrix 13 serves as a light-shielding portion in the non-display portion.
7 are provided.

Further, on the second substrate 136, the counter electrode 139 is opposed to the display electrode 135 as shown in FIG. As shown in FIG.

In FIG. 11, the first electrode 132, the display electrode 135, and the second electrode 134 on the first substrate 131 are all shown by broken lines, the nonlinear resistance layer 133 is not shown, and the second electrode 132 is not shown. The black matrix 137 and the counter electrode 139 on the lower surface of the substrate are shown by solid lines.

The first electrode 132 provided on the first substrate 131 is
An overhanging area is provided for providing the nonlinear resistance element 130, and the overhang area 132a overlaps with the second electrode 134 to constitute the nonlinear resistance element 130.

In addition, the first electrode 132 and the display electrode 135 have a gap d of a predetermined size.

The display electrode 135 is arranged so as to overlap with the counter electrode 139 via the liquid crystal 141, so that the display electrode 135 becomes a pixel portion of the liquid crystal display panel.

The black matrix 137 is provided so as to overlap the display electrode 135 formation region by a certain amount,
Has the role of preventing light from leaking from the peripheral area of the light emitting element.

The liquid crystal display device performs a predetermined image display by a change in transmittance of the liquid crystal 141 in a region on the display electrode 135 where the black matrix 137 is not formed.

Further, alignment films 140, 140 are provided on the facing surfaces of the first substrate 131 and the second substrate 136, respectively, as processing layers for regularly arranging the molecules of the liquid crystal 141.

By the way, some nonlinear resistance elements show an asymmetric change depending on the polarity of the applied voltage. An example of the characteristic of the nonlinear resistance element having the asymmetric characteristic will be described with reference to the drawings.

FIG. 13 shows a nonlinear resistance using a tantalum (Ta) film as a first electrode, a tantalum oxide (Ta2O5) film as a nonlinear resistance layer, and an indium tin oxide (ITO) film as a transparent conductive film as a second electrode. FIG. 3 is a diagram showing voltage-current characteristics of the element.

In this diagram, a curve L shows the initial characteristics of the nonlinear resistance element. On the other hand, the curve M shows the characteristic after driving the nonlinear resistance element.

When a positive (+) voltage is applied to the first electrode of the non-linear resistance element, the same voltage is applied to the non-linear resistance element according to the curve L indicating the characteristics after driving with respect to the curve L indicating the initial characteristics. The current value that can be reduced greatly.

Further, when a negative voltage is applied to the first electrode of the nonlinear resistance element, the same voltage can be applied to the nonlinear resistance element by the curve M indicating the characteristics after driving with respect to the curve L indicating the initial characteristics. The current value hardly decreases.

Here, a difference between a curve L indicating initial characteristics when a positive voltage is applied to the tantalum film as the first electrode and a curve M indicating characteristics after driving is indicated by P. Similarly, a curve L indicating initial characteristics when a negative voltage is applied to the first electrode;
The difference from the curve M indicating the characteristics after driving is indicated by Q.

As is apparent from FIG. 13, the differences P and Q are larger when the positive voltage is applied to the first electrode than when the negative voltage is applied to the first electrode. Much larger.

Further, FIG. 14 shows changes in the difference P and the difference Q due to the drive time. A curve R shows a change in the difference P due to the drive time when a positive voltage is applied to the first electrode, and the current value sharply increases as the drive time elapses.

On the other hand, a curve S shows a change in the difference Q due to the driving time when a negative voltage is applied to the first electrode.
Even after the drive time elapses, the current value hardly changes.

This situation can be indicated by a difference U between the curve R and the curve S, and the difference U sharply increases as the drive time elapses.

The difference U varies depending on the amount of current flowing through the nonlinear resistance element, the environment in which the nonlinear resistance element is driven, or the history of the nonlinear resistance element, in addition to the drive time.

Therefore, it is extremely difficult to compensate for the change in the difference U.

Due to the difference U, the voltage applied to the liquid crystal pixel differs between when a positive voltage is applied to the first electrode 132 of the nonlinear resistance element 130 and when a negative voltage is applied.

As a result, a reduction in contrast and a flickering of the image due to flicker, and a burn-in phenomenon of the image, which is an afterimage caused by the bias of ions in the liquid crystal, occur, and the display quality of the liquid crystal display device is significantly reduced.

An object of the present invention is to solve such a problem. That is, the asymmetric characteristic change due to the difference in polarity of the applied voltage of the nonlinear resistance element is suppressed, the direct current application to the liquid crystal is reduced, the bias of the ions in the liquid crystal is eliminated, the contrast is reduced, the flicker phenomenon and the image burn-in phenomenon are caused. And to improve the image display quality of the liquid crystal display device.

DISCLOSURE OF THE INVENTION In order to achieve the above object, the present invention comprises a liquid crystal display device as follows.

In a basic liquid crystal display device according to the present invention, a first substrate and a second substrate made of a transparent material are opposed to each other at a predetermined interval, and a first electrode and a second electrode are formed on the first substrate. A non-linear resistance element is formed in a region where both electrodes overlap, and a black matrix and a counter electrode are provided on the second substrate. Then, liquid crystal is sealed between the first substrate and the second substrate, and a light irradiating unit is provided outside the first substrate.

Further, the black matrix provided on the second substrate has an opening provided in a display pixel portion and a light shielding portion provided in a non-display portion to prevent light leakage.

An opening is provided in a region of the counter electrode facing the non-linear resistance element.

Then, in a region of the counter electrode corresponding to the light shielding portion of the black matrix and facing the non-linear resistance element, light incident from the light irradiation portion through the first substrate does not pass through the counter electrode, and An opening for irradiating the non-linear resistance element by being reflected by the light shielding part is provided.

By providing the opening in the counter electrode, light incident from the light irradiation unit through the first substrate is reflected by the black matrix light-shielding unit through the opening, and the reflected light is efficiently applied to the nonlinear resistance element. Can be done. In addition, it is possible to irradiate the nonlinear resistance element with light while displaying by the liquid crystal display device.

Thereby, the change in the current-voltage characteristics of the nonlinear resistance element can be extremely reduced. That is, a target voltage can be applied to the display electrode (liquid crystal) via the nonlinear resistance element without causing a change in the current-voltage characteristics of the nonlinear resistance element.

For this reason, it is possible to suppress the image flickering phenomenon caused by the change in the current-voltage characteristic of the nonlinear resistance element due to the decrease in contrast and the flicker, and it is possible to almost eliminate the image sticking phenomenon which is an afterimage phenomenon due to the bias of ions in the liquid crystal.

In the above liquid crystal display device, in the case where an insulating film for insulating and separating the black matrix and the counter electrode is provided on the second substrate, the counter electrode and the insulating film correspond to the light shielding portion of the black matrix. In addition, by providing an opening in a region facing the non-linear resistance element, the same effect as described above can be obtained.

In the case of a color liquid crystal display device in which a black matrix, a color filter, and a counter electrode are provided on a second substrate, at least the counter electrode and the color filter correspond to the light-shielding portion of the black matrix and have the nonlinearity. By providing an opening in a region facing the resistance element, the same effect as described above can be obtained.

Furthermore, on the surface facing the non-linear resistance element used as the anti-slope of the light blocking portion of the black matrix in the opening of the counter electrode or the counter electrode and the color filter,
By forming the fine unevenness, the reflected light from the surface of the light shielding portion of the black matrix is converted into diffused light, and the amount of reflected light that can be applied to the nonlinear resistance element can be increased, and the above-described effect can be enhanced.

In the color liquid crystal display device, the second electrode may be an electrode made of a transparent conductive film.

Further, in the case where a black matrix, a color filter, and a counter electrode are provided on the second substrate, and an insulating film for insulating and separating the black matrix and the counter electrode is provided, the color filter, the counter electrode, and the insulating electrode are provided. A similar effect can be obtained by providing an opening in a region of the film facing the non-linear resistance element.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of one display electrode and its peripheral portion of a liquid crystal display device according to a first embodiment of the present invention, and FIG.
It is sectional drawing which follows the II line.

FIG. 3 is a diagram showing the relationship between the current value of the initial characteristics and the characteristics after driving of the nonlinear resistance element in the liquid crystal display device and the amount of light irradiated on the nonlinear resistance element.

FIG. 4 is a diagram showing the relationship between the nonlinear resistance element characteristics and the driving time when light is applied to the nonlinear resistance element in the first embodiment of the present invention.

FIG. 5 is a sectional view corresponding to FIG. 2 of a liquid crystal display device showing a second embodiment of the present invention.

FIG. 6 is a sectional view corresponding to FIG. 2 of a liquid crystal display device showing a third embodiment of the present invention.

FIG. 7 is a plan view corresponding to FIG. 2 of a liquid crystal display device showing a fourth embodiment of the present invention.

FIG. 8 is a sectional view corresponding to FIG. 2 of a liquid crystal display device showing a fifth embodiment of the present invention.

FIG. 9 is a plan view of one display electrode and its peripheral portion of a liquid crystal display device according to a sixth embodiment of the present invention, and FIG.
It is sectional drawing which follows the X-ray.

FIG. 11 is a plan view showing an example of a conventional liquid crystal display device, and FIG.
FIG. 12 is a sectional view taken along the line XII-XII.

FIG. 13 is a diagram showing the voltage-current characteristics of the nonlinear resistance element of the liquid crystal display device, and FIG. 14 is a line showing the relationship between the nonlinear resistance element characteristics and the driving time when the nonlinear resistance element is not irradiated with light. FIG.

BEST MODE FOR CARRYING OUT THE INVENTION In order to explain the contents of the present invention in more detail, embodiments of the present invention will be described with reference to the accompanying drawings.

First Embodiment FIG. 1 is a plan view showing one display electrode and its peripheral portion of a liquid crystal display device according to a first embodiment of the present invention, similarly to FIG. The figure is a cross-sectional view along the line II-II.

In this liquid crystal display device, similarly to the above-described conventional example, as shown in FIG. 2, a first substrate 1 and a second substrate 6 each made of a transparent material are opposed to each other at a predetermined interval via a spacer 12, In the meantime, the liquid crystal 11 is sealed.

A first electrode 2 made of a tantalum (Ta) film is provided on the first substrate 1, and the first electrode 2 is subjected to anodizing treatment to form a non-linear resistance layer 3 made of a tantalum oxide (Ta2O5) film. Is provided.

Further, on the nonlinear resistance layer 3, a second electrode 4 made of an indium tin oxide (ITO) film is provided as a transparent conductive film. The first electrode 2 and the non-linear resistance layer 3
And the second electrode 4, the nonlinear resistance element 1 having the MIM structure
Make up 4.

As shown in FIG. 1, the second electrode 4 extends from a substantially rectangular display electrode 5, and a part of the second electrode 4 also serves as the display electrode 5. The display electrodes 5 are provided on the first substrate 1 in a matrix with an indium tin oxide film.

On the other hand, on the lower surface of the second substrate 6, as a light-shielding portion for preventing light from leaking from a gap between the respective display electrodes 5 provided on the first substrate 1, a black region is shaded entirely. A matrix 7 is provided. The black matrix 7 provided in the non-display portion is made of a chromium (Cr) film.

As shown in FIG. 1, an opening 7a is provided in the black matrix 7 in a region on the lower surface of the second substrate 6 facing the display electrode 5, and no light-shielding portion is provided.

Further, a counter electrode 9 made of an indium tin oxide (ITO) film is provided on the lower surface of the second substrate 6 so as to face the display electrode 5. The counter electrode 9 is provided with the insulating film 8 interposed therebetween so as not to be short-circuited by contact with the black matrix 7.

The counter electrode 9 is provided with an opening 24, and the counter electrode 9 is separated in a plane by the opening 24. In the region facing the nonlinear resistance element 14, the opening
24 opening width is widened.

Further, as shown in FIG. 1, in order to prevent the first electrode 2 and the display electrode 5 from short-circuiting, a gap d having a predetermined size is provided between the two electrodes.

The display electrode 5 is arranged so as to overlap with the counter electrode 9 via the liquid crystal 11, thereby forming a display pixel portion of the liquid crystal display panel.

Then, the liquid crystal display device performs a predetermined image display by changing the transmittance of the liquid crystal 11 in the display pixel portion.

Further, alignment films 10 and 10 are provided on the surfaces of the first substrate 1 and the second substrate 6 facing each other as processing layers for regularly aligning the molecules of the liquid crystal 11, respectively.

Since this liquid crystal display device does not emit light by itself, a light irradiation unit (indicated by a white arrow 16) is required as an external light source.

Therefore, for example, a light irradiator (indicated by a white arrow) 16 composed of a three-wavelength fluorescent tube, a reflector and a diffuser is provided, and the first substrate 1 is arranged on the light irradiator 16 side. Here, the incident paths of light from the light irradiation unit 16 to the nonlinear resistance element 14 are shown by thin lines 17 and 18 with arrows. The thin line 17 indicates the path of light having a larger incident angle than the thin line 18.

As described above, the counter electrode 9 provided in the upper layer of the black matrix 7 has the opening dimension of the opening 24 provided in the region facing the nonlinear resistance element 14 larger than the opening dimension of the opening 24 around the display electrode 5. Therefore, the amount of light reflection on the surface of the black matrix 7 in the region facing the nonlinear resistance element 14 is increased.

As a result, the black matrix 7
The light irradiation can be performed efficiently by utilizing the reflection of light by the light.

The change of the current-voltage characteristic, which is the element characteristic due to the driving of the nonlinear resistance element 14 in this embodiment, will be described with reference to the diagrams of FIGS.

FIG. 3 is a diagram showing the relationship between the current value of the initial characteristics and the characteristics after driving of the nonlinear resistance element of the liquid crystal display device and the amount of light applied to the nonlinear resistance element.

Curve D is a curve L showing initial characteristics when a positive voltage is applied to the tantalum film of the first electrode of the nonlinear resistance element shown in the diagram of FIG. 7 is a curve showing the dependence of P indicating the difference (the amount of change in current) from the curve M showing the characteristic of FIG. Curve E represents Q (the amount of change in current) between curve L in FIG. 13 showing the initial characteristics when a negative voltage is applied to the first electrode and curve M showing the characteristics after driving. 3 is a curve showing the dependence on the amount of light.

As is clear from FIG. 3, the curve D showing the state where a positive voltage is applied to the first electrode 2 shows that the amount of change P in the current increases as the amount of light applied to the nonlinear resistance element 14 becomes larger than 1000 lux. It is rapidly decreasing.

On the other hand, a curve E showing a state in which a negative voltage is applied to the first electrode 2 gradually decreases with an increase in the light amount. The amount of change is very small.

When the difference F between the curve D and the curve E is large, an asymmetric voltage is applied to the liquid crystal 11 depending on the polarity of the voltage applied to the first electrode 2, which causes a decrease in contrast, a flicker phenomenon, or an afterimage phenomenon. Image sticking phenomenon.

However, as is apparent from FIG. 3, by irradiating the non-linear resistance element 14 with a light amount of 5000 lux or more,
The amount of asymmetric current change due to the polarity of the voltage applied to the first electrode 2, that is, the difference F can be extremely small.

Therefore, in the above-described liquid crystal display device according to the present invention, by driving the liquid crystal display device while irradiating the non-linear resistance element 14 with a light amount of 5000 lux or more, the asymmetric characteristic change of the non-linear resistance element 14 is extremely small. can do.

As a result, the application of the DC voltage to the liquid crystal 11 can be reduced, and the quality of the liquid crystal 11 can be prevented from deteriorating, and the contrast, the flicker phenomenon, and the image sticking phenomenon can be prevented. Therefore, the display image quality of the liquid crystal display device can be improved.

FIG. 4 shows the driving time t (min) when the above-mentioned nonlinear resistance element of the liquid crystal display device according to the present invention is driven while irradiating it with a light amount of 5000 lux, and the current change amount P,
FIG. 3 is a diagram showing a relationship with Q. The curve W shown in FIG.
Is a curve showing the dependence of the current variation P on the driving time, which indicates the difference between the initial characteristics when a positive voltage is applied to the first electrode 2 and the characteristics after driving. On the other hand, the curve X is a current variation Q indicating the difference between the initial characteristics when a negative voltage is applied to the first electrode 2 and the characteristics after driving.
5 is a curve showing the dependence of the driving time on the driving time.

As described above, the curve W indicating the characteristic when the positive voltage is applied to the first electrode 2 only slightly increases with the driving time, and the negative voltage is applied to the first electrode 2. In the curve X showing the characteristics in the state, the amount of change Q is extremely small due to the increase in the driving time.

Also, the difference T between the curve W and the curve X remains at a small value even if the drive time increases.

It is easy to obtain a transmittance of 80% or more by using a transparent conductive film for the second electrode 4 constituting the nonlinear resistance element 14.

That is, the light amount of about 5000 lux is the first of the present invention.
As shown in the embodiment, an opening 24 is provided in the counter electrode 9 in a region facing the non-linear resistance element 14, and the reflection of light by the black matrix 7 is used to provide a liquid crystal display device using the light irradiating unit 16. If so, the light amount can be easily applied to the nonlinear resistance element 14 from the light irradiation unit 16.

As described above, by irradiating the nonlinear resistance element 14 with light efficiently, a change in the characteristics of the nonlinear resistance element 14 can be reduced. Further, it is also possible to reduce an asymmetrical non-linear resistance element characteristic change due to a difference in drive voltage polarity in the current-voltage characteristic.

As a result, it is possible to suppress a change in display quality due to driving of the liquid crystal display device, and to reduce a decrease in contrast and a flicker phenomenon due to application of a DC voltage to the liquid crystal 11, and an image burn-in phenomenon.

In the first embodiment of the present invention described above, the nonlinear resistance element
An indium tin oxide (ITO) film is used as a transparent conductive film having a high light transmission characteristic for the second electrode 4 constituting 14, and a metal film made of tantalum having a good light reflection characteristic is used for the first electrode 2. Used. Therefore, it is possible to efficiently irradiate the nonlinear resistance element 14 with light.

Second Embodiment Next, a configuration of a liquid crystal display device according to a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a cross-sectional view similar to FIG. 2 of the liquid crystal display device of the second embodiment, and its basic configuration is the same as that of the above-described first embodiment, and therefore, redundant description will be omitted.

In the second embodiment, a first electrode 2 made of a tantalum (Ta) film containing nitrogen (N) is provided on a first substrate 1. Then, on the first electrode 2, the first electrode 2 is subjected to anodizing treatment to form a tantalum oxide (Ta) containing nitrogen.
A non-linear resistance layer 3 made of a 2O5Nx) film is provided.

Further, a second electrode 4 made of an indium tin oxide (ITO) film is provided as a transparent conductive film on the non-linear resistance layer 3, and the first electrode 2, the non-linear resistance layer 3 and the second electrode 4 , The nonlinear resistance element 14 having the MIM structure.

The second electrode 4 extends from the display electrode 5 as in the first embodiment, and a part of the second electrode 4 also serves as the display electrode 5.

On the other hand, the surface of the second substrate 6 facing the first substrate 1 is provided with a black matrix 7 as a light-shielding portion for preventing light from leaking from the gap between the display electrodes 5 as in the first embodiment. And so as to face the display electrode 5,
A counter electrode 9 made of an indium tin oxide (ITO) film is provided via an insulating film 8.

In the second embodiment, an opening 24 and an opening 25 are provided in regions of the counter electrode 9 and the insulating film 8 facing the nonlinear resistance element 14, respectively. By providing the opening 24, the counter electrode 9 is separated in a plane.

The shape of the opening 24 of the counter electrode 9 and the shape of the opening 25 of the insulating film 8 are substantially the same.

Other configurations are the same as those of the first embodiment described with reference to FIGS. 1 and 2.

Then, for example, illumination light from a light irradiation unit 16 composed of a three-wavelength fluorescent tube, a reflection plate, and a diffusion plate enters from the first substrate 1 side as shown by thin lines 30 and 31 with arrows, and the liquid crystal 11 and the alignment The light is reflected by the lower surface of the black matrix 7 through the film 10 and irradiates the nonlinear resistance element 14.

In this case, the opening 24 and the opening 24 are respectively formed in the region of the counter electrode 9 and the insulating film 8 facing the nonlinear resistance element 14.
Since 25 is formed, the amount of light reflection on the surface of the black matrix 7 in the region facing the nonlinear resistance element 14 increases. As a result, it is possible to irradiate the nonlinear resistance element 14 with light more efficiently than in the first embodiment.

Therefore, also in the second embodiment of the present invention having the non-linear resistance layer 3 made of a tantalum oxide film containing nitrogen, the change in the element characteristics of the non-linear resistance element 14 can be reduced as in the first embodiment.

Therefore, a target display can be always reproduced, a deviation from the target display due to a change in the nonlinear resistance element can be prevented, and a liquid crystal display device with extremely good display quality can be obtained.

Furthermore, the asymmetric change due to the difference in the polarity of the applied voltage of the nonlinear resistance element is suppressed, the DC voltage application to the liquid crystal 11 is reduced, the quality of the liquid crystal 11 is prevented from deteriorating, and the contrast is reduced and the flicker phenomenon is caused. The image sticking phenomenon can be prevented.

Third Embodiment Next, the configuration of a liquid crystal display device according to a third embodiment of the present invention will be described with reference to FIG. This embodiment is a color liquid crystal display device, and FIG. 6 is a sectional view similar to FIG. Since the basic configuration is the same as that of the first embodiment, the duplicate description will be omitted.

In the third embodiment, a first electrode 2 made of a tantalum (Ta) film is provided on a first substrate 1, and the first electrode 2 is anodized thereon to form a tantalum oxide (Ta2O5) film. The provision of the non-linear resistance layer 3 is the same as in the first embodiment.

The first embodiment is characterized in that a second electrode 4 composed of a thin metal film 35 made of a chromium (Cr) film and a transparent conductive film 34 made of an indium tin oxide (ITO) film is provided on the nonlinear resistance layer 3. And different.

The first electrode 2, the non-linear resistance layer 3 and the second electrode 4 constitute a non-linear resistance element 14 having a MIM structure.

The thin film metal film 35 serving as the second electrode 4 and the transparent conductive film
Part of the area 34 also serves as the display electrode 5.

On the other hand, a black matrix 7 is provided on the second substrate 6 in the same manner as in each of the above-described embodiments, and the second substrate 6
Color filter 3 composed of green (G), blue (B), and red (R) over the lower surface of the black matrix 7 and the edge of the black matrix 7.
8,39,40 are provided.

An opening 26 is provided in a region of the color filters 38, 39, 40 facing the nonlinear resistance element 14.

Further, a counter electrode 9 made of an indium tin oxide (ITO) film is provided on the second substrate 6 so as to face the display electrode 5.
Is provided between the color filters 38, 39, 40 and the opposing electrode 9 to protect the color filters 38, 39, 40 and to prevent the opposing electrode 9 from contacting the black matrix 7 and causing a short circuit. An insulating film 8 is provided.

An opening 24 is also provided in a region of the counter electrode 9 facing the nonlinear resistance element 14.

Other configurations are the same as those of the first embodiment described with reference to FIGS. 1 and 2.

Then, illumination light from the light irradiating section 16 composed of, for example, a three-wavelength fluorescent tube, a reflecting plate, and a diffusing plate enters from the first substrate 1 side as shown by a thin line 41 with an arrow, and the liquid crystal 11 and the alignment film 10 are formed.
Then, the light is reflected by the lower surface of the black matrix 7 through the insulating film 8 and irradiates the nonlinear resistance element 14.

Also in the third embodiment, the color filters 38, 39, 40 provided in the upper layer of the black matrix 7 and the counter electrode 9 are provided with the openings 24, 26 in the region opposed to the non-linear resistance element 14. The amount of light reflection on the surface of the black matrix 7 in the region facing the resistance element 14 is increased. As a result, it is possible to efficiently irradiate the nonlinear resistance element 14 with light by utilizing the reflection of light by the black matrix 7.

The liquid crystal display device according to the third embodiment is a color liquid crystal display device having color filters 38, 39, and 40. For this reason, the light irradiating section 16 having a higher luminance is used as compared with a liquid crystal display device of a monochrome display which does not require a color filter. Therefore, it is possible to irradiate the nonlinear resistance element 14 with sufficient light.

Therefore, the same effects as those of the above-described embodiments can be obtained, and the display quality of a color image by the color liquid crystal display device can be improved.

In the description of the third embodiment, the non-linear resistance element is
In order to efficiently irradiate light to 14, a non-linear resistance element 14
Color filters 38, 39, 40 and the counter electrode 9 in the region facing
The case where the openings 24 and 26 are provided respectively has been described.

However, in the case of a color liquid crystal display device, since the high-luminance light irradiation unit 16 is used as described above, even if the openings 26 are provided only in the color filters 38, 39, and 40, the surface of the black matrix 7 does not And the amount of reflected light becomes sufficiently large, so that light irradiation on the nonlinear resistance element 14 can be performed efficiently.

Fourth Embodiment Next, the configuration of a liquid crystal display device according to a fourth embodiment of the present invention will be described with reference to FIG. This embodiment is also a color liquid crystal display device, and FIG. 7 is a sectional view similar to FIGS. 2 and 6.

Most of the configuration is the same as that of the above-described third embodiment, and a duplicate description will be omitted.

In the third embodiment, on a first electrode 2 made of a tantalum (Ta) film provided on a first substrate 1, the first electrode 2 is anodized to form a tantalum oxide (Ta2O5) film. Nonlinear resistance layer having a two-layer structure of a nonlinear resistance layer 3 made of silicon and a nonlinear resistance layer 45 made of silicon nitride (SiNx) film.
46 are provided.

Further, on the composite nonlinear resistance layer 46, a second electrode 4 made of an indium tin oxide (ITO) film as a transparent conductive film is formed.
The first electrode 2, the composite non-linear resistance layer 46 and the second electrode 4 constitute the non-linear resistance element 14 having the MIM structure.

On the other hand, the second substrate 6 is provided with a black matrix 7 and green (G), blue (B), and red (R) color filters 38, 39, and 40, as in the third embodiment. An opening 26 is provided in a region facing the nonlinear resistance element 14.

Further, an opening 24 is also provided in the counter electrode 9 provided so as to face the display electrode 5, and an opening 25 is provided in the insulating film 8 provided between the color filters 38, 39, 40 and the counter electrode 9. ing.

Therefore, for example, illumination light from the high-intensity light irradiator 16 composed of a three-wavelength fluorescent tube, a reflector, a prism sheet, and a diffuser is incident from the first substrate 1 side as shown by a thin line 41 with an arrow, and The amount of light reflected on the surface of the black matrix 7 through the alignment film 11 and the alignment film 10 and irradiating the nonlinear resistance element 14 further increases. Therefore, the nonlinear resistance element
14 can be irradiated with sufficient light.

As described above, in the liquid crystal display device of the fourth embodiment of the present invention having the two-layer film of the tantalum oxide film and the silicon nitride film as the composite non-linear resistance layer 46, the non-linear The change in the element characteristics of the resistance element 14 can be reduced. High quality color image display can be performed.

Fifth Embodiment Next, a liquid crystal display device according to a fifth embodiment of the present invention will be described with reference to FIG. This embodiment is also a color liquid crystal display device, and FIG. 8 is a sectional view similar to FIGS. 2 and 6.

Also in this embodiment, most of the configuration is common to each of the above-described embodiments, and a duplicate description will be omitted.

In this embodiment, a first electrode 2 made of a tantalum (Ta) film is provided on a first substrate 1, and the first electrode 2 is further anodically oxidized thereon to form a tantalum oxide (Ta2O5) film. Is provided.

Further, a titanium (Ti) film is provided as a second electrode 4 on the non-linear resistance layer 3, and a display electrode 5 made of an indium tin oxide (ITO) film, which is a transparent conductive film, is provided separately.

The display electrode 5 and the second electrode 4 are provided so as to overlap at the connection part 51 and are electrically connected.

The first electrode 2, the non-linear resistance layer 3 and the second electrode 4 constitute a non-linear resistance element 14 having a MIM structure.

On the other hand, the configuration on the second substrate 6 side is the third configuration shown in FIG.
The configuration is almost the same as that of the embodiment, but fine irregularities are provided on the surface of the portion facing the nonlinear resistance element 14 used as the reflection surface of the black matrix 7. In the method of forming the irregularities, the openings 26 are formed in the color filters 38, 39, and 40, and fine particles made of silica or ceramic are made to collide with the surface of the black matrix 7 using air pressure.

The point that the opening 26 is provided in the color filters 38, 39 and 40 and the opening 24 is also provided in the counter electrode 9 is the same as the third embodiment of FIG.

The incident optical path of the illumination light by the high-luminance light irradiation unit 16 according to this embodiment is indicated by a thin line 55 with an arrow. According to the third embodiment, incident light from multiple directions is reflected as diffused light by unevenness of the surface of the black matrix 7, and a sufficient amount of light can be uniformly applied to the nonlinear resistance element 14.

Further, in the liquid crystal display device having the second electrode 4 made of a titanium film as in this embodiment, it is possible to efficiently irradiate the nonlinear resistance element 14 with light similarly to the first embodiment.

Therefore, the same operation and effect as those of the above embodiments can be further ensured, and in particular, the display quality of a color image by the color liquid crystal display device can be greatly improved.

Sixth Embodiment Next, a liquid crystal display device according to a sixth embodiment of the present invention will be described with reference to FIGS. In this embodiment, two non-linear resistive elements are provided for each one display electrode, and FIGS. 9 and 10 show the same as in FIGS. 1 and 2, respectively, of a liquid crystal display device. It is a plan view and a cross-sectional view.

In this embodiment, on the first substrate 1, tantalum (Ta)
The first electrode 2 made of a film is formed separately in an island shape.

Further, the first electrode 2 is provided on the first electrode 2.
Is anodized to provide a non-linear resistance layer 3 made of a tantalum oxide (Ta2O5) film.

Then, on the nonlinear resistance layer 3, two second electrodes 6 made of an indium tin oxide (ITO) film as a transparent conductive film are formed.
1 and 62 are provided. The second electrode 61 is connected to a signal electrode 74 for applying a signal from the outside to the first nonlinear resistance element 63, and the other second electrode 62 is connected to the display electrode 5.

These first electrode 2, nonlinear resistance layer 3, and second electrode
61 constitutes a first non-linear resistance element 63.

Further, the first electrode 2, the non-linear resistance layer 3, and the second electrode
62 constitutes the second nonlinear resistance element 64.

The first nonlinear resistance element 63 and the second nonlinear resistance element 64 constitute a nonlinear resistance element section.

This non-linear resistance element section is composed of “signal electrode 74 → second electrode”.
61 → nonlinear resistance layer 3 → first electrode 2 → nonlinear resistance layer 3 →
An electric path from the second electrode 62 to the display electrode 5 is formed.

On the other hand, on the second substrate 6 side, similarly to the first embodiment shown in FIG. 2, a black matrix 7, a counter electrode made of an indium tin oxide (ITO) film, and an insulating film for insulating both. 8 are provided.

The counter electrode 9 is divided into a plurality of portions in a plane by providing an opening 24. The opening 24 of the region facing the nonlinear resistance element portion including the first nonlinear resistance element 63 and the second nonlinear resistance element 64 has a wide opening width as shown in the plan view of FIG. doing.

Further, a gap of a predetermined size is provided between the first electrode 2 and the display electrode 5 in order to prevent a short circuit between them.

Here, light paths from the light irradiation unit 16 to the nonlinear resistance elements 63 and 64 are shown by thin lines 71 and 72 with arrows.

In the sixth embodiment, the light reflected from the black matrix 7 by the thin line 71 irradiates the second nonlinear resistance element 64 with light, and the light reflected by the thin line 72 is irradiated by the first nonlinear resistance element 63.
Shows a situation in which light is radiated to the.

As described above, the opening 24 having a larger opening size than the first nonlinear resistance element 63 and the second nonlinear resistance element 64 is provided in the counter electrode 9 in the upper layer of the black matrix 7. Thereby, the amount of light reflected from the surface of the black matrix 7 facing the first nonlinear resistance element 63 and the second nonlinear resistance element 64 is increased.

As a result, light can be efficiently radiated to the plurality of first nonlinear resistance elements 63 and the second nonlinear resistance elements 64 by utilizing the reflection of light on the surface of the black matrix 7.

As is apparent from the above description, also in the sixth embodiment, the illumination light from the light irradiating section 16 utilizes the reflection of light on the surface of the black matrix 7 to produce a plurality of nonlinear resistance elements 63 and 64. In addition, light can be uniformly and efficiently irradiated.

In addition, by providing a plurality of nonlinear resistance elements for one display electrode in this way, unbalanced characteristics can be made uniform.

Also in this embodiment, the amount of change in the current-voltage characteristic of the nonlinear resistance element due to the magnitude of the voltage applied to the signal electrode 74 can be made extremely small.

As a result, the application of the DC voltage to the liquid crystal 11 can be reduced, and the quality of the liquid crystal 11 can be prevented from deteriorating, and the contrast, the flicker phenomenon, and the image sticking phenomenon can be prevented. Therefore, the image display quality of the liquid crystal display device can be improved.

In the first to sixth embodiments of the present invention described above, in order to form a non-linear resistance element, a non-linear resistance layer 3 made of a tantalum oxide film or a composite non-linear layer made of a tantalum oxide film and a silicon nitride film is formed. The example using the resistance layer 46 has been described. However, as the non-linear resistance layer, the first
An anodic oxide film of the electrode described above, or a silicon oxide film, a silicon nitride film, a silicon carbide film, a tantalum oxide film, an aluminum oxide film, or the like formed by a chemical vapor deposition method or a physical vapor deposition method may be used.

Furthermore, although the embodiment using the chromium film as the black matrix has been described, an aluminum film can also be used as the black matrix.

In the fifth embodiment, the example in which the unevenness is provided on the surface of the black matrix 7 has been described. Therefore, as a method of forming irregularities on the surface by using an aluminum film as a black matrix, air pressure may be used, but it is necessary to control the pressure at the time of film formation to increase the aluminum particle size and form irregularities. Can also.

INDUSTRIAL APPLICABILITY As is apparent from the above description, the liquid crystal display device according to the present invention can always reproduce the intended display by reducing the change in the element characteristics of the nonlinear resistance element. Deviation from the target display due to the change in the element characteristics can be prevented, and good display quality can be obtained.

Furthermore, the asymmetric characteristic change due to the polarity of the voltage applied to the non-linear resistance element is suppressed, the application of the DC voltage to the liquid crystal is reduced, and the deterioration of the quality of the liquid crystal is eliminated. The image sticking phenomenon can be prevented.

Therefore, the display quality of the liquid crystal display device can be improved, and in particular, with respect to the burn-in phenomenon, the characteristics can be improved to a level not inferior to those using a three-terminal switching element.

Therefore, it can be widely used as a display device for various information processing devices, electronic devices, AV devices, industrial devices, and the like.

Claims (6)

(57) [Claims] A first substrate and a second substrate made of a transparent material facing each other at a predetermined interval; a first electrode and a second electrode provided on the first substrate; A non-linear resistance element provided in a region where the electrode and the second electrode overlap each other, a black matrix and a counter electrode provided on the second substrate, and sealed between the first substrate and the second substrate; A liquid crystal; and a light irradiator provided outside the first substrate. The black matrix provided on the second substrate includes an aperture provided in a display pixel portion and a light provided in a non-display portion. And a light-shielding portion for preventing leakage. The light-emitting portion is incident on the counter electrode, in a region corresponding to the light-shielding portion of the black matrix and facing the non-linear resistance element, through the first substrate. Light that does not pass through the counter electrode The liquid crystal display device, characterized in that an opening is provided for being reflected by the light shielding portion of the click matrix so as to irradiate the non-linear resistance element. A first substrate and a second substrate made of a transparent material facing each other at a predetermined interval; a first electrode and a second electrode provided on the first substrate; A non-linear resistance element provided in a region where the electrode and the second electrode overlap, a black matrix and a counter electrode provided on the second substrate, and an insulating film for insulating and separating the black matrix and the counter electrode. A liquid crystal sealed between the first substrate and the second substrate, and a light irradiator provided outside the first substrate; and a black matrix provided on the second substrate, An opening provided in a display pixel portion and a light blocking portion provided in a non-display portion for preventing light leakage, wherein the non-linear resistance of the counter electrode and the insulating film corresponds to the light blocking portion of the black matrix. In the area facing the element, An opening for irradiating the non-linear resistance element with light incident from the irradiation unit through the first substrate being reflected by the light shielding unit of the black matrix without passing through the counter electrode and the insulating film is provided. A liquid crystal display device characterized by the above-mentioned. 3. A first substrate and a second substrate made of a transparent material facing each other at a predetermined interval, a first electrode and a second electrode provided on the first substrate, and a first electrode and a second electrode provided on the first substrate. A non-linear resistance element provided in a region where the electrode and the second electrode overlap each other, a black matrix, a color filter, and a counter electrode provided on the second substrate; and a connection between the first substrate and the second substrate. And a light irradiator provided outside the first substrate. A black matrix provided on the second substrate is provided in an opening provided in a display pixel portion and a non-display portion. A light-shielding portion for preventing light leakage, and a region corresponding to the light-shielding portion of the black matrix of the counter electrode and the color filter and facing the non-linear resistance element. Incident through one substrate The liquid crystal display device, characterized in that light is provided an opening for so as to irradiate the non-linear resistance element is reflected by the light shielding portion of the black matrix without passing through the counter electrode and a color filter. 4. A liquid crystal display device according to claim 1, wherein fine irregularities are formed on a surface of said counter electrode facing said non-linear resistance element, which is used as a reflection surface of a light-shielding portion of said black matrix. A liquid crystal display device characterized by being formed. 5. A first substrate and a second substrate made of a transparent material facing each other at a predetermined interval, and a first electrode and a second electrode made of a transparent conductive film provided on the first substrate. A non-linear resistance element provided in a region where the first electrode and the second electrode overlap each other; a black matrix, a color filter, and a counter electrode provided on the second substrate; An insulating film for insulating and isolating the liquid crystal, a liquid crystal sealed between the first substrate and the second substrate, and a light irradiating unit provided outside the first substrate. The black matrix provided on the substrate has an opening provided in the display pixel portion and a light shielding portion provided in the non-display portion to prevent light leakage, and the color filter and the counter electrode and the insulating film, Black matrix light shield Light incident from the light irradiating section through the first substrate to the corresponding area facing the nonlinear resistance element is reflected by the light shielding section of the black matrix without passing through the color filter, the counter electrode and the insulating film. A liquid crystal display device provided with an opening for irradiating the non-linear resistance element. 6. The liquid crystal display device according to claim 3, wherein fine irregularities are formed on the surface of the counter electrode facing the non-linear resistance element used as a reflection surface of a light-shielding portion of the black matrix in the opening of the counter electrode. A liquid crystal display device characterized by being formed.