JP2000111955A - Liquid crystal device and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to make an aperture ratio as large as possible without increasing the resistance value of conduction lines of a liquid crystal device. SOLUTION: This liquid crystal display device is constituted by sealing liquid crystals between an element side substrate 3a having continuity lines 4 and TFT elements 7 connected to these continuity lines 4 and a counter substrate disposed to face the element side substrate 3a. The continuity lines 4 have recessed parts 13 in the connecting portions with the TFT elements 7 and the whole or portions of the TFT elements 7 are arranged in these recessed parts 13. Since pixel electrodes 6 may be formed in proximity to the continuity lines 4 in the state of a rectangular shape, openings 22 of a black mask may be formed exactly along the entire area of the outer periphery edges of the pixel electrodes 6 and consequently, the degradation in the aperture ratio may be prevented. In addition, the resistance value of the continuity lines 4 may be maintained at a desired value by increasing the area of the portions 4d held by a pair of the recessed parts 13 among the continuity lines 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal device having a structure in which the orientation of the liquid crystal is controlled by controlling the voltage applied to the liquid crystal, thereby modulating the light passing through the liquid crystal. The present invention relates to a liquid crystal device having a structure including an element-side substrate having a conductive line and a non-linear element connected to the conductive line, and a counter substrate disposed to face the element-side substrate. Further, the present invention relates to an electronic device including the liquid crystal device.

[0002]

2. Description of the Related Art In recent years, liquid crystal devices have been widely used for displays of small computers, displays of digital cameras, image display units of portable telephones, and the like. It is widely known that among these liquid crystal devices, there are a passive matrix type liquid crystal device and an active matrix type liquid crystal device.

In the passive matrix system, each pixel has no active element, the intersection of the scanning electrode and the data electrode corresponds to a pixel or a dot, and a drive signal is directly applied to those electrodes. On the other hand, in the active matrix system, an active element is provided for each pixel or dot, and during the writing period, the active element is turned on to write a data signal, and in other periods, the active element is turned off and written. The retained data signal is retained.

In the active matrix system, a three-terminal TFT (Thin Film Tran) is used depending on the type of active element.
sistor) element or two-terminal TFD (Thin
Film Diode). Now, TFD
Considering a liquid crystal device using a device, conventionally, as shown in FIG. 4, for example, a conductive line 51 used as a data line or a scanning line and a conductive line 51 are formed on an element side substrate constituting the liquid crystal device. MIM (Metal
Insulator Metal) elements 52a and 52b, and a pixel electrode 53 connected to the MIM element 52b on the subsequent stage when viewed from the conduction line 51 are formed. The MIM elements 52a and 52b are examples of a TFD element.

[0005]

In the above-mentioned conventional liquid crystal device, an image is formed with the pixel electrode 53 as one pixel unit. At this time, if light leaks from a portion other than the pixel electrode 53, the contrast of an image formed by the light passing through the pixel electrode 53 may be reduced and the image quality may be reduced. Therefore, in a normal liquid crystal device, the pixel electrode 53
A black matrix having an opening 54 along the outer peripheral edge of is formed. In this black matrix, portions other than the openings 54 have a light-shielding property, so that light leakage from regions other than the pixel electrodes 53 can be prevented.

By the way, in the conventional liquid crystal device, the MIM elements 52a and 52b are formed at positions protruding outside the conduction line 51, so that the MIM elements 52a and 52b
The portion existing at the lateral position of the IM elements 52a and 52b is a narrow portion 53a having a small width. In an old type liquid crystal device, the width W1 of one pixel was relatively large, so there was no particular problem. For example, 7
It is required to be as narrow as about 0 μm.

As described above, when the width W1 of one pixel is reduced, the width W2 of the narrow portion 53a of the pixel electrode 53 is correspondingly reduced. And in that case, the narrow part 5
The width of the opening 54 of the black matrix corresponding to 3a must also be reduced. However, when the width W2 of the narrow portion 53a becomes narrower than the allowable limit dimension, it is difficult to form the corresponding shape of the opening 54 of the black matrix into a shape with sharp corners. Is rounded and a narrow portion 53a of the pixel electrode 53 is formed.
It is difficult to accurately conform to the shape of. As a result, there is a problem that the ratio of the area of the black matrix opening 54 to the pixel area, that is, the opening ratio becomes small, and it becomes difficult to obtain a bright display.

Such a problem is caused by the width W of the conductive line 51.
3 can be reduced by increasing the length of the pixel electrode 53 by that amount. However, in such a case, the resistance value of the conduction line 51 increases and the MIM increases.
Another problem may arise in that desired characteristics cannot be obtained for the elements 52a and 52b and the like.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to increase the aperture ratio as much as possible without increasing the resistance value of a conductive line in a liquid crystal device. .

[0010]

(1) In order to achieve the above object, a liquid crystal device according to the present invention comprises an element-side substrate having a conductive line and a non-linear element connected to the conductive line; A counter substrate disposed opposite to the substrate, and the conductive line has a concave portion at a connection portion with the non-linear element, and further includes the non-linear element or a part thereof in the concave portion. It is characterized by being arranged.

According to this liquid crystal device, since the non-linear element is accommodated in the concave portion of the conductive line, the pixel electrode can be formed close to the conductive line without forming a narrow portion of the pixel electrode. . Since it is not necessary to form a narrow portion in the pixel electrode in this way, even when the width of the pixel electrode is narrowed for higher definition, the black matrix has sharp corners on the outer peripheral edge of the pixel electrode. Therefore, the aperture ratio can be prevented from lowering.

In the above configuration, "the non-linear element or a part thereof is arranged in the concave portion" means that all of the non-linear element is accommodated in the concave portion of the conductive line and that the non-linear element is partially It is meant to include both cases where it fits in the recess.

(2) In the above configuration, the term “non-linear element” means an element having a non-linear voltage-current characteristic, such as a thin film transistor (TFT) or a thin film diode. (T
FD) element or the like can be used. A thin-film diode element is an active element formed in a thin film and having a non-linear current-voltage characteristic. This TFD element is, for example,
It can be constituted by an MIM element formed by sequentially laminating a first electrode, an insulating layer, and a second electrode.

(3) In general, the conduction line formed on the element-side substrate of the liquid crystal device is designed to have a predetermined resistance value. In the liquid crystal device according to the present invention, by adjusting the area of the conductive line in a portion located between one concave portion provided in the conductive line and another concave portion adjacent thereto, the resistance value of the conductive line can be controlled. Can be adjusted to the design value.

(4) Next, the electronic device according to the present invention
An electronic apparatus having a liquid crystal device and a control unit for controlling the liquid crystal device. The liquid crystal device includes an element-side substrate having a conductive line and a non-linear element connected to the conductive line, and a device opposed to the element-side substrate. And a counter substrate provided. The conductive line has a concave portion at a connection portion with the nonlinear element, and the nonlinear element or a part thereof is disposed in the concave portion. According to this electronic device, in the built-in liquid crystal device, the non-linear element is accommodated in the concave portion of the conductive line, so that the pixel electrode is formed close to the conductive line without forming a narrow narrow portion on the pixel electrode. be able to. Since it is not necessary to form a narrow portion in the pixel electrode in this way, even when the width of the pixel electrode is narrowed for higher definition, the black matrix has sharp corners on the outer peripheral edge of the pixel electrode. Therefore, the aperture ratio can be prevented from lowering.

[0016]

(First Embodiment) FIG. 1 is a plan view showing a liquid crystal device according to an embodiment of the present invention, with a part thereof broken away. The liquid crystal device 1 shown here has a pair of translucent substrates 3a and 3b joined to each other by a sealant 2. A gap, a so-called cell gap, is formed between these translucent substrates, and liquid crystal is sealed in a portion of the cell gap surrounded by the sealing material 2.

The light-transmitting substrate 3a on the back side of the figure is an element-side substrate, and on its inner surface, linear conductive lines arranged parallel to each other, that is, stripe-shaped conductive lines 4a.
Are formed, and a plurality of pixel electrodes 6 are formed between the conductive lines 4 in a dot matrix. Further, each pixel electrode 6 and the conductive line 4 are connected via a TFD element 7. A polarizing plate 12 is attached to the outer surface of the element-side substrate 3a.

On the other hand, the light-transmitting substrate 3b on the near side in FIG. 1 is an opposing substrate, and a stripe-shaped opposing electrode 8 is formed on the inner surface thereof. A plurality of pixels arranged in a dot matrix are formed at a portion where the opposing electrode 8 and the pixel electrode 6 on the element-side substrate 3a oppose each other. The polarizing plate 12 is attached to the outer surface of the opposing substrate 3b.

In the element-side substrate 3a, a large number of conductive lines 4 are actually arranged at very narrow intervals.
In FIG. 1, in FIG. 1, in order to clearly show the structure, the spacing dimension of each conductive line 4 is schematically shown in an enlarged manner, and some of those conductive lines 4 are shown and other portions are shown. Is omitted. Further, the pixel electrodes 6 are actually very small in area and are arranged in a dot matrix at fine intervals. However, in FIG. 1, each pixel electrode 6 is enlarged and schematically shown for easy understanding of the structure. And their intervals are also shown enlarged.

In the counter substrate 3b, a large number of counter electrodes 8 are actually formed at very small intervals so as to face the pixel electrodes 6 on the element substrate 3a. In order to show the structure in an easy-to-understand manner, the spacing between the opposing electrodes 8 is schematically shown in an enlarged manner, and a part of the opposing electrodes 8 is omitted.

The element-side substrate 3a on which the pixel electrodes 6 and the like are formed
An alignment film is further formed on the inner surface of the substrate by polyimide or the like, and the alignment film is subjected to a uniaxial alignment process, for example, a rubbing process. In addition, an alignment film is also formed of polyimide or the like on the inner surface of the counter substrate 3b on which the counter electrode 8 is formed, and the alignment film is also subjected to a uniaxial alignment process, for example, a rubbing process.

A color filter and a black mask are further formed on the inner surface of the opposing substrate 3b, if necessary. The black mask is formed in a pattern shape having an opening at a portion corresponding to each of the plurality of pixel electrodes 6 to prevent light from leaking out of a region other than the pixel electrode 6, and thus to prevent light from passing through the pixel region. Improves the contrast of the displayed image.

The liquid crystal device 1 of the present embodiment has a COG (Chip)
An on-glass type liquid crystal device, and therefore, a liquid crystal driving IC 9a is directly mounted on the surface of the element-side substrate 3a, and a liquid crystal driving IC 9b is directly mounted on the surface of the opposing substrate 3b. The conductive line 4 formed on the element-side substrate 3a is connected to the output terminal of the liquid crystal driving IC 9a, while the counter electrode 8 formed on the counter-side substrate 3b is connected.
Is connected to the output terminal of the liquid crystal driving IC 9b. Sign 1
Reference numeral 1 denotes an external connection terminal for connecting the liquid crystal driving ICs 9a and 9b to an external circuit.

When the liquid crystal driving ICs 9a and 9b operate, the pixel electrode 6 corresponding to the selected pixel and the counter electrode 8
A predetermined magnitude of the ON voltage and the OFF voltage is applied between the two, and the voltage control controls the alignment state of the liquid crystal. Then, by modulating the light based on the orientation control, an image such as a character, a numeral, or a picture is displayed outside. The conduction line 4 may be used as a data line or a scanning line.

FIG. 2 is an enlarged view showing the vicinity of one pixel region on the inner surface of the element-side substrate 3a. An area defined by two horizontal lines L1 and two vertical lines L2 corresponds to one pixel area. In this figure, a conduction line 4 includes a first layer 4a formed of a conductive material such as Ta (tantalum) and a second layer 4b formed of an anodic oxide film laminated on the first layer 4a. And a third layer 4c formed of a conductive material such as Cr (chromium) on the second layer 4b.

In the present embodiment, the conductive line 4 is not formed in a simple linear shape having a uniform width, but the recesses 13 are formed at intervals of one pixel, and a pair of adjacent recesses 13 are formed.
A region 4d having a large area is formed therebetween.

The TFD element 7 includes a pair of MIM elements 14a.
And 14b are electrically connected in series in the opposite direction to form an element having a so-called back-to-back structure. With this back-to-back structure, stable switching characteristics can be obtained as compared with the case where one MIM element is used. Of course, a non-linear element can be configured using one MIM element.

Each of the MIM elements 14a and 14b has a first electrode 16 formed of Ta or the like at the same time as the first layer 4a of the conductive line 4, and an anodic oxide film 17 formed on the first electrode 16. And the second electrode 18 formed of Cr or the like at the same time as the third layer 4c of the conduction line 4.

In the present embodiment, almost all of the TFD elements 7, that is, almost all of the MIM elements 14 a and 14 b are provided so as to fit in the recess 13 formed in the conduction line 4.

The second electrode 18 of the MIM element 14b formed on the subsequent stage as viewed from the conduction line 4 has two branch portions 19
Is formed, and ITO (In
The pixel electrode 6 is formed by, for example, dium tin oxide.
In the present embodiment, the TFD element 7 is
3, the pixel electrode 6 is denoted by reference numeral 53 in FIG.
It is formed close to the conductive line 4 with almost a rectangular shape without forming a narrow portion as shown by a.

As described above, since the narrow portion is not formed in the pixel electrode 6, even if the width W1 of one pixel is designed to be narrow, for example, about 70 μm in order to increase the definition of the liquid crystal display, the pixel electrode 6 is not formed. In this case, a narrow portion is not formed, so that the corner of the opening peripheral edge 22 of the black mask can be formed into a sharp pointed shape, so that the opening of the black mask can be accurately positioned on the outer peripheral edge of the pixel electrode 6. Can be formed along the line. As a result, the aperture ratio, that is, the ratio of the aperture area of the black mask to the area of one pixel region can be maintained at a large value.

Moreover, in the present embodiment, by setting the area of the portion 4d of the conductive line 4 located between the pair of adjacent concave portions 13 large, the resistance value of the conductive line 4 becomes excessively large. And the same value as in the case of forming a simple linear shape as shown in FIG. 4 can be maintained.

(Second Embodiment) FIG. 3 shows a portable computer which is an embodiment of an electronic apparatus according to the present invention constituted by using the liquid crystal device shown in FIG. The portable computer 31 includes a keyboard 33 having a plurality of keys 32, a cover 34 that opens and closes and rotates with respect to the keyboard 33 as indicated by an arrow A, and a cover 34.
And a liquid crystal device 30 embedded therein. The liquid crystal device 30 is manufactured by attaching auxiliary equipment such as a backlight to the liquid crystal device 1 of FIG.

Inside the keyboard unit 33, a control unit including a CPU (Central Processing Unit) for executing various calculations for performing the function as a portable computer is stored. Then, the control unit executes an arithmetic process for displaying a predetermined image on the liquid crystal device 30.

In the portable computer according to the present embodiment, as shown in FIG.
Since the liquid crystal device having a pattern structure in which all or a part of the TFD element 7 is accommodated in the pixel electrode 6 is used,
It is not necessary to form a narrow part in
Even when the width W1 of one pixel becomes narrow, the corners of the black mask can be formed in a sharp shape without roundness.
A reduction in the aperture ratio in the liquid crystal device can be prevented. Further, by setting the area of the portion 4d of the conductive line 4 located between the pair of adjacent concave portions 13 large, the resistance value of the conductive line 4 can be maintained at a desired value.

(Other Embodiments) Although the liquid crystal device shown in FIG. 1 is a COG type liquid crystal device, the present invention can be applied to any liquid crystal device having other structures. For example, by using TAB (Tape Automated Bonding) technology, FPC (Flexible Printed Circui
T) formed by bonding an IC chip on t)
The present invention can be applied to a so-called TAB type liquid crystal device having a structure using a CP (Tape Carrier Package).
In addition, I.P.
The so-called COB (Chip On
The present invention can be applied to a liquid crystal device of a (Board) type.

In the above embodiment, the case where a back-to-back type TFD element having a structure in which a pair of MIM elements are connected in series with opposite polarities is used as a non-linear element has been exemplified, but a structure using one MIM element is used. TFD elements can be used, or TFTs can be used instead of TFD elements.
(Thin Film Transistor) elements can also be used.
Further, in FIG. 3, a portable computer is illustrated as an example of the electronic device, but the liquid crystal device according to the present invention can be applied to any other electronic device, for example, a mobile phone.

[0038]

According to the liquid crystal device and the electronic apparatus of the present invention, since the non-linear element such as the TFD element is accommodated in the recess of the conductive line, the pixel electrode can be formed without forming a narrow portion on the pixel electrode. The electrode can be formed close to the conductive line. Since it is not necessary to form a narrow portion in the pixel electrode in this way, even when the width of the pixel electrode is narrowed for higher definition, the black matrix has sharp corners on the outer peripheral edge of the pixel electrode. Therefore, the aperture ratio can be prevented from lowering.

[Brief description of the drawings]

FIG. 1 is a partially cutaway plan view showing an embodiment of a liquid crystal device according to the present invention.

FIG. 2 is an enlarged plan view showing one pixel portion of FIG. 1;

FIG. 3 is a perspective view illustrating an example of an electronic apparatus according to the invention.

FIG. 4 is a plan view showing one pixel portion in a conventional liquid crystal device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal device 2 Sealing material 3a Element side substrate 3b Opposite substrate 4 Conducting line 4a First layer of conducting line 4b Second layer of conducting line 4c Third layer of conducting line 4d Resistance adjusting portion of conducting line 6 Pixel electrode 7 TFD element (non-linear element) 8 Counter electrode 9a, 9b Liquid crystal driving IC 13 Depression 14a, 14b MIM element 16 First electrode 17 Anodized film 18 Second electrode 19 Branch part W1 One pixel width W2 Narrow width W3 Conduction Line width

Continued on the front page F-term (reference) 2H092 JA03 JA07 JA12 JB12 JB44 JB52 KA08 KA16 KA18 KB05 KB14 KB23 MA05 MA14 MA15 MA16 MA18 MA19 MA20 MA24 MA32 MA35 MA37 NA07 NA25 NA27 NA28 NA29 PA09

Claims (4)

[Claims] 1. An element substrate having a conductive line and a non-linear element connected to the conductive line, and a counter substrate disposed to face the element side substrate, wherein the conductive line is a non-linear element. A liquid crystal device having a concave portion at a connection portion with the non-linear element, and the non-linear element or a part thereof is disposed in the concave portion. 2. The method according to claim 1, wherein the nonlinear element includes:
A liquid crystal device comprising a thin film diode element which is an active element having a non-linear current-voltage characteristic and formed in a thin film. 3. The resistance value of the conductive line according to claim 1 or 2, by adjusting the area of a portion between one concave portion and another concave portion adjacent thereto with respect to the conductive line. A liquid crystal device characterized by adjusting. 4. An electronic apparatus having a liquid crystal device and a control unit for controlling the liquid crystal device, wherein the liquid crystal device includes an element-side substrate including a conduction line and a non-linear element connected to the conduction line; An opposing substrate disposed opposite to the conductive line, wherein the conductive line has a concave portion at a connection portion with the non-linear element, and the non-linear element or a part thereof is disposed in the concave portion. And electronic equipment.