JPH11223841A - Liquid crystal device and electronic equipment using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the cell gap of a liquid crystal device uniform over an entire visible image display area by adjusting the film thickness of the panel outer peripheral part of the liquid crystal device where a sealing material is provided. SOLUTION: A liquid crystal device 1 has an element-side substrate 3a having a film for TFD(thin-film diode) elements 7, an opposite-side substrate 3b which has a film for an opposite electrode 8 and faces the element-side substrate 3a, and a sealant 2 which joins the opposite-side substrate 3b and element-side substrate 3a while leaving a specific cell gap. Patterns 11 and 12 for gap adjustment are provided between the sealant 2 and element-side substrate 2a and/or the sealant 2 and opposite-side substrate 3b. Those patterns can be formed at the same time with various films formed on the substrates 3a and 3b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal device that modulates light by controlling a voltage applied to a liquid crystal sealed between a pair of substrates. The present invention also relates to an electronic device including the liquid crystal device.

[0002]

2. Description of the Related Art Conventionally, liquid crystal devices have been widely used in various electronic devices such as digital still cameras, portable telephones, portable information terminals and the like. For example, numbers, letters,
Liquid crystal devices are used to display other visible images. A conventional liquid crystal device generally has a structure in which a pair of substrates are bonded to each other with an annular sealing material.
In many cases, the liquid crystal device is formed in a rectangular shape. In such a case, the sealing material is formed in a rectangular ring shape having four straight sides to join a pair of substrates to each other.

Conventionally, as an active matrix type liquid crystal device, TFD (Thin Film) is provided on one of a pair of substrates.
2. Description of the Related Art There is known a liquid crystal device having a structure in which a non-linear element such as a diode (thin film diode) element and the like and pixel electrodes are arranged in a dot matrix form, and a counter electrode in the form of a stripe is formed on the other substrate. In this liquid crystal device, one pixel for displaying a visible image is formed where each pixel electrode and each counter electrode overlap.

A liquid crystal driving IC for controlling the voltage applied to the liquid crystal is provided on both or one of the pair of substrates constituting the liquid crystal device, either directly on the substrate or by heat sealing, FPC.
(Flexible Printed Circuit)
It is connected to the substrate via a TCP (Tape Carrier Package) or the like.

The stripe-shaped counter electrode formed on the counter substrate must extend outside the visible image display area across the seal material in order to establish connection with the liquid crystal driving IC. Wiring for transmitting signals to the TFD element and the like is formed on the element-side substrate in a stripe shape, and the wiring traverses a sealing material in order to establish connection with a liquid crystal driving IC. It needs to extend outside.

The position where the signal transmission wiring on the element-side substrate crosses the sealing material is a specific one of the four sides of the sealing material. The position where the stripe-shaped electrode on the opposing substrate crosses the sealing material is also a specific one of the four sides of the sealing material.

[0007]

As described above, in the liquid crystal device, the signal transmission wiring on the element-side substrate and the counter electrode on the counter-side substrate cross the sealant from the inside of the visible image display area. It extends outward, but its crossing part is set as a part of the sealing material. Therefore, the thickness of the portion of the sealing material which is traversed by the wiring or the like becomes large, and the thickness of the other portions remains small. In general, a cylindrical spacer is mixed in the sealing material, and the dimension of a gap between a pair of substrates, that is, a so-called cell gap, is often maintained by the cylindrical spacer. If the gap is not uniform, the cylindrical spacer does not work effectively, and as a result, there is a problem that the dimensions of the cell gap become uneven in the visible image display area.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and the size of the cell gap of a liquid crystal device can be adjusted by adjusting the thickness of the outer peripheral portion of the liquid crystal device where a seal member is provided. An object is to make the entire image display area uniform.

[0009]

(1) In order to achieve the above object, a liquid crystal device according to the present invention includes an element-side substrate provided with a film for a non-linear element and a film for a counter electrode. Together with an opposing substrate opposing the element-side substrate, and a sealing material for joining the opposing substrate and the element-side substrate to each other with a predetermined cell gap therebetween, and the sealing material and the element-side substrate And / or between the sealing material and the opposing substrate, a liquid crystal device provided with a gap adjustment pattern for reducing dimensional unevenness of the cell gap, wherein the gap adjustment pattern is at least A part thereof is provided so as to overlap with at least one side of the sealing material, and at least a part of four sides of the sealing material is disposed between the sealing material and the element-side substrate and the opposed-side substrate. The total thickness of the film is characterized by comprising formed to be substantially equal to each other.

According to this liquid crystal device, by providing the gap adjusting pattern in a portion of the liquid crystal device where the sealing material is provided, that is, in an appropriate position on the outer peripheral portion of the liquid crystal device, the film formed on the outer peripheral portion of the liquid crystal device is formed. The thickness of the film can be uniformly adjusted in at least a part of the four sides of the outer peripheral portion thereof. Therefore, the cell gap of the liquid crystal device can be effectively reduced by effectively utilizing the cylindrical spacer mixed in the sealing material. The dimensions can be made uniform over the entire visible image display area.

In the above structure, the non-linear element is an element having a property that the amount of current flowing therethrough when the applied voltage changes is changed not linearly but non-linearly. A TFD (Thin Film Diode) element having a structure in which a pair of electrodes are opposed to each other, or a TFT (Thin
Film Transistor). The element-side substrate and the opposing-side substrate can be formed of a light-transmitting material such as glass, plastic, or the like.

(2) In the liquid crystal device according to the above (1), the gap adjusting pattern can be constituted by a dummy pattern formed by a film provided on the element-side substrate or the opposing-side substrate. This eliminates the need to provide a dedicated process only for forming the gap adjustment pattern, thereby preventing the liquid crystal device from becoming expensive.

The term "dummy pattern" refers to a pattern used for a purpose other than that originally provided. For example, when forming a counter electrode by ITO (Indium Tin Oxide) on the counter substrate, a dummy pattern can be formed by the ITO and the dummy pattern can be used as a gap adjustment pattern. When a color filter is formed on the opposite substrate, R,
A dummy pattern is formed from Cr (chromium), which is a constituent material of a black mask formed around each of the G and B color transmitting portions, and the dummy pattern can be used as a gap adjustment pattern.

The film thickness of the counter electrode is 3000 °, 220
It is often set to about 0 ° or 1500 °, and the thickness of the black mask is often set to about 1000 °. Therefore, if a gap adjusting pattern is formed using these film materials, the cell gap can be adjusted based on the respective film thickness dimensions.

Next, a thin film diode (T
Considering the case of forming an FD) element, a dummy pattern is formed by using at least one of materials constituting each of a first electrode, an insulating layer, and a second electrode of the TFD element,
The dummy pattern can be used as a gap adjustment pattern. As the first electrode and the insulating layer formed thereon, for example, Ta + TaO _x (a laminated structure of tantalum and tantalum oxide) is considered, and the thickness is 18
It is often set to about 00 °. The second electrode may be, for example, Cr, and the thickness of the second electrode is 1600 °.
Often set to about. Therefore, if a gap adjustment pattern is formed using these film materials, the cell gap can be adjusted based on the respective film thickness dimensions.The dot matrix pixel electrodes formed on the element-side substrate are It is formed so as to overlap with the second electrode of the TFD element,
At that time, the same constituent material as that of the pixel electrode may be laminated on the wiring for transmitting a signal to the TFD element. This is for a so-called redundant design, and is intended to ensure overall conduction even if a break occurs in the metal forming the wiring. The pixel electrode and the wiring covering layer are often formed of ITO to a thickness of about 500 °. Therefore, if a gap adjusting pattern is formed using this film material, the cell gap can be adjusted based on the film thickness.

Next, an electronic apparatus according to the present invention is an electronic apparatus including the liquid crystal device having the configuration described above. In many cases, it will be used as a visible image display part of the electronic device, that is, a part for displaying numbers, characters and other information,
The mode of use is not limited to such a visible image display section. Examples of such an electronic device include a digital still camera, a mobile phone, and a portable information terminal.

[0017]

(First Embodiment) FIG. 1 is a plan view showing one embodiment of a liquid crystal device according to the present invention. This diagram is schematically shown in order to clearly show the features of the liquid crystal device according to the present invention, and therefore, the dimensional ratio of each element is different from that of an actual liquid crystal device.

The liquid crystal device 1 shown here has a pair of translucent substrates 3a and 3b joined to each other by a sealing member 2 formed in a rectangular ring shape. Substrate 3a on the back side of the figure
Is a translucent substrate for the element substrate, and the substrate 3 on the near side of the figure is
b is a translucent substrate for the opposite substrate.

As shown in FIG. 3, on the surface of the element-side substrate 3a, linear wirings arranged parallel to each other, that is, stripe-shaped wirings 4, are formed. The pixel electrodes 6 are formed in a dot matrix, and each pixel electrode 6 is connected to each wiring 4 via a TFD element 7. A liquid crystal driving IC 9a is mounted on an IC mounting side of the element side substrate 3a, and each wiring 4 is connected to an output terminal of the IC 9a.

As shown in FIG. 10, the TFD element 7 has a first electrode 7a formed on a substrate 3a and a first electrode 7a.
an anodic oxide film 7b as an insulating layer laminated on
The second electrode 7 laminated on the anodic oxide film 7b
c. The pixel electrode 6 is a second electrode 7c
Are formed so as to overlap. In this embodiment, the first electrode 7a is formed by Ta (tantalum), hence the anodic oxide film 7b is formed by TaO _X (tantalum oxide), and are formed second electrode 7c by Cr (chromium) .

On the other hand, the wiring 4 for transmitting a signal to the TFD element 7 includes a first layer 4a formed on the substrate 3a, a second layer 4b formed on the first layer 4a, Second
And a third layer 4c formed on the layer 4b. The first layer 4a is simultaneously patterned as a dummy pattern when forming the first electrode 7a and the anodic oxide film 7b of the TFD element 7. Therefore, the first layer 4a
Is formed by Ta + TaO _x (laminated structure of tantalum and tantalum oxide), and its thickness is about 1800 °.

The second layer 4b is the second electrode 7 of the TFD element 7.
When forming c, it is simultaneously patterned as its dummy pattern. Therefore, the second layer 4b is formed of Cr and has a thickness of about 1600 °. The third layer 4c is simultaneously patterned as a dummy pattern when the pixel electrode 6 is formed. Therefore, the third
The layer 4c is formed of ITO and has a thickness of 500
It is about. The third layer 4c is used for a so-called redundant design so that even when a disconnection occurs in the second layer 4b, energization of the entire wiring 4 can be ensured.

As shown in FIG. 2, a stripe-shaped counter electrode 8 is formed on the surface of the counter substrate 3b in FIG.
A liquid crystal driving IC 9b is mounted on the IC mounting side of the opposing substrate 3b, and each opposing electrode 8 is connected to an output terminal of the IC 9b. In FIG. 1, one pixel for displaying a visible image is formed in a portion where the pixel electrode 6 on the element-side substrate 3a and the counter electrode 8 on the counter-side substrate 3b face each other.

In FIG. 2, the sealing material 2 is shown on the opposing substrate 3b, and in FIG. 3, the sealing material 2 is also shown on the element side substrate 3a. 2 are not shown, but are shown in order to make the positional relationship of the sealing material 2 easy to understand. Actually, the sealing material 2 is used as the element side substrate 3a.
Alternatively, it is formed on one of the opposing substrates 3b.

When the element-side substrate 3a shown in FIG. 3 and the opposing-side substrate 3b shown in FIG. 2 are bonded to each other, the parts A, B, C, and D of the element-side substrate 3a The portions E, F, G, and H of the opposing substrate 3b are superposed. FIG. 4 is an enlarged view of a portion E in FIG. 2 and shows the portion in an enlarged manner with the opposing substrate 3b omitted.
As shown in the drawing, the tip of the counter electrode 8 enters the sealing material 2.

FIG. 5 is an enlarged view of part A of FIG. As shown, the wiring 4, the pixel electrode 6, and the TFD element 7
Are formed in a region surrounded by the sealing material 2, and the terminal portions 4 d of the respective wirings 4 are guided to the outside across the sealing material 2. Further, a first gap adjusting pattern 11 is formed inside a side region of the sealing material 2 where the terminal portion 4d of the wiring 4 does not exist.

This pattern 11 is simultaneously patterned when the first layer 4a (see FIG. 10) of the wiring 4 is formed on the element-side substrate 3a. That is, it is formed as a dummy pattern of the first layer 4a. Therefore, the pattern 11 is formed of Ta + TaO _X having a thickness of about 1800 °. Further, the pattern 11 is formed at a position where the element-side substrate 3a and the opposing-side substrate 3b (see FIG. 4) are overlapped with the tip end of the opposing electrode 8 when they are bonded to each other.

FIG. 6 is an enlarged view of a portion F in FIG. 2 and shows the portion with the opposing substrate 3b omitted. As shown, the terminal portion 8a of the counter electrode 8 is led to the outside across the sealing material 2.

FIG. 7 is an enlarged view of part B of FIG. As shown, the terminal portion 4 of the wiring 4 in the sealing material 2
The second gap adjusting pattern 12 is formed inside the side region where d does not exist. This pattern 12 is also patterned at the same time as the dummy pattern when the first layer 4a (see FIG. 10) of the wiring 4 is formed on the element-side substrate 3a.
formed by _aO-X. Furthermore, this pattern 12
When the element-side substrate 3a and the opposing-side substrate 3b (see FIG. 6) are bonded to each other, they are formed in positions inside the sealing material 2 so as to overlap the terminal portions 8a of the opposing electrode 8.

FIG. 8 is a sectional view of the liquid crystal device 1 shown in FIG. 1 taken along the line XX. In FIG.
The parts indicated by A, D, E, and H indicate the parts indicated by the same reference numerals in FIGS. As is clear from FIG. 8, the wiring 4 is provided between the sealing material 2 and the element-side substrate 3a on the IC mounting side of the sealing material 2 and on the side opposite thereto.
Exists. Further, for the opposing substrate 3b, a color filter 13 is formed between the opposing electrode 8 and the substrate 3b. As is well known, this color filter 13 has an R
(Red), G (green), and B (blue) light-transmitting portions, and a black matrix surrounding the light-transmitting portions. The black matrix is formed by, for example, a Cr film.

FIG. 9 shows the liquid crystal device 1 shown in FIG. 1 cut along the line YY. In FIG. 9, A,
Each part shown by B, E, and F has shown the part shown using the same code | symbol in FIG.2 and FIG.3. 9, with respect to the element-side substrate 3a, a first gap adjustment pattern 11 is formed between the right side portion of the sealing material 2 and the substrate 3a, and a second gap adjustment pattern 11 is further formed between the left side portion of the sealing material 2 and the substrate 3a. A gap adjustment pattern 12 is formed. Then, with respect to the opposing substrate 3b, opposing electrodes 8 exist between the left and right side portions of the sealing material 2 and the substrate 3b.

Liquid crystal L is sealed in a gap formed between the element-side substrate 3a and the opposite-side substrate 3b, that is, in a cell gap. By changing the voltage applied to the pixel electrode 6 and the counter electrode 8 constituting each pixel in accordance with the ON / OFF voltage control by the TFD element 7, the orientation of the liquid crystal L in the pixel portion is controlled. Is modulated, and as a result, a desired visible image can be displayed outside the opposing substrate 3b or the element-side substrate 3a. The region in which the visible image is displayed is a visible image display region, which is usually a region slightly smaller than the region where both the pixel electrode 6 and the color filter 13 are opposed to each other.

In the liquid crystal device 1 having the above configuration, as shown in FIG. 3, the first gap adjusting pattern 11 is provided on one of the IC non-mounting portions of the sealing member 2 formed in a ring shape on the element side substrate 3a. The second gap adjusting pattern 12 was formed on the other of the IC non-mounted portions. Further, as described with reference to FIGS. 4 and 5, the first gap adjusting pattern 11 is formed at a position overlapping with the tip of the opposing electrode 8. 6 and 7
As described above, the second gap adjusting pattern 12 is formed at a position overlapping with the terminal portion 8a of the opposing electrode 8.

As a result, in FIG. 9, considering the thickness of the sealing material 2 in the Y-Y cross section of the liquid crystal device 1, the film existing in the sealing material 2 on the right side has a thickness of 180.
0 ° first gap adjusting pattern 11 and film thickness 220
Since the counter electrode 8 is 0 °, the total film thickness is 1800 ° + 2200 ° = 4000 °.

On the other hand, in FIG.
Considering the thickness dimension of the sealing material 2 portion with respect to the cross section, the film existing in both the right and left sealing material portions 2 is the wiring 4, and this film 4 is the first layer 4a having a thickness of 1800 °.
A second layer 4b having a thickness of 1600 °, and a thickness of 500
And the third layer 4c of Å, the total thickness is 1800Å + 1600 膜厚 + 500Å = 3900Å.

As a result, in FIG. 1, the outer peripheral portion of the liquid crystal device 1 where the sealing material 2 is formed has a thickness of 3900 ° on the side cut along the XX section.
And the side portion cut by the YY section is 400
0 °, and there is almost no difference between the two. Generally, a cylindrical spacer is mixed into the sealing material 2, and the cell gap is maintained by the cylindrical spacer.
In this case, if the interval between the cylindrical spacers is not uniform, the cell gap in the visible image display area is also uneven, and the display quality is degraded. On the other hand, as described above, if the film thickness of the portion where the sealing material 2 is provided is uniformly adjusted throughout, the cell thickness can be properly controlled by the cylindrical spacers. The dimensions of the cell gap can be made uniform over the entire visual display area. Therefore, high quality display characteristics of the liquid crystal device 1 can be realized.

In the conventional liquid crystal device, the first gap adjustment pattern 11 and the second gap
Since the gap adjustment pattern 12 was not provided,
In the liquid crystal device 1, the gap size in the outer peripheral portion where the seal material 2 is provided becomes non-uniform, and as a result, there is a problem that the size of the cell gap in the visible image display area becomes non-uniform.
On the other hand, as in the present embodiment, by providing the gap adjusting patterns 11 and 12 on the outer peripheral portion of the liquid crystal device 1 to adjust the film thickness of the outer peripheral portion, the dimensions of the cell gap can be made uniform. it can.

As described above, the present invention has been described with reference to the preferred embodiments of the liquid crystal device. However, the liquid crystal device according to the present invention is not limited to the embodiment, but falls within the scope of the invention described in the claims. Various modifications can be made.

For example, in the above embodiment, the first gap adjustment pattern 11 and the second gap adjustment pattern 12
Both are patterned at the same time when the first layer 4a of the wiring 4, that is, the (Ta + TaO _x ) film is formed on the element-side substrate 3a. However, those gap adjustment patterns can also be formed by other various film materials formed on the element-side substrate 3a, for example, the second layer 4b or the third layer 4c of the wiring 4. Alternatively, it can be formed using a film material formed on the opposing substrate 3b, for example, a black mask of a color filter.

The first gap adjusting pattern 11 shown in FIG. 5 and the second gap adjusting pattern 1 shown in FIG.
2 was formed by dividing it into islands in conformity with the shape of the counter electrode 8 because these patterns 11 and 12 were formed using conductive Ta. Are formed of an insulating material, the patterns can be formed as a single pattern that is not divided.

In the above embodiment, the liquid crystal driving I
A structure in which C is directly mounted on a translucent substrate, a so-called C
The present invention is applied to an OG (Chip On Glass) type liquid crystal device, but other various types of liquid crystal devices, for example, TAB
Needless to say, the present invention can be applied to a (Tape Automated Bonding) type liquid crystal device.

In the above embodiment, the present invention is applied to an active matrix type liquid crystal device using a TFD element as a non-linear element. However, the present invention is applied to an active matrix type liquid crystal device using a TFT and other non-linear elements. The invention can also be applied.

(Second Embodiment) FIG. 11 shows an embodiment of an electronic apparatus according to the present invention. This embodiment is
This is an embodiment in which the liquid crystal device according to the present invention is used as a finder of a digital still camera as an electronic apparatus. Whereas a normal camera exposes a photosensitive film with an optical image of a subject, this digital still camera uses a CCD (Charge Coupled Device) to capture the optical image of the subject.
The photoelectric conversion is performed by using an image sensor such as the above to generate an image signal.

This digital still camera includes a light receiving unit 27 disposed on the front side of the casing 26, a shutter button 28 disposed on the upper surface of the casing 26, and the liquid crystal device 1 disposed on the rear side of the casing 26. It consists of. The liquid crystal device 1 functions as a finder for displaying a subject, and can be configured using, for example, a liquid crystal device having the structure shown in FIG. The light receiving unit 27 includes a shutter that opens and closes in conjunction with a shutter button 28, an optical lens, and an image sensor such as a CCD camera.

This digital camera is provided with a video signal output terminal 31 and a data communication input / output terminal 32. A TV monitor 33 is connected to the video signal output terminal 31 as necessary. A personal computer 34 is connected to 32. When the camera photographer points the light receiving unit 27 at the subject, the subject image is displayed on the liquid crystal device 1. When the shutter button 28 is pressed while checking the displayed image, the output terminal of the light receiving unit 27 having a built-in CCD camera is output. An image pickup signal corresponding to the subject is output to a personal computer 34 and a television monitor 33 as necessary.

When a liquid crystal device as shown in FIG. 1 is used as the liquid crystal device 1, a gap adjusting pattern is provided on the outer peripheral portion of the liquid crystal device 1 to adjust the film thickness of the outer peripheral portion. Is uniformly held over the entire visible image display area, so that a good subject image can always be displayed.

[0047]

According to the liquid crystal device and the electronic equipment according to the present invention, the gap adjusting pattern is provided at an appropriate position on the outer peripheral portion of the liquid crystal device where the sealing material is provided, so that the liquid crystal device is formed on the outer peripheral portion of the liquid crystal device. The thickness of the film can be uniformly adjusted over the entire outer peripheral portion, and therefore, the size of the cell gap of the liquid crystal device can be made uniform over the entire visible image display area.

[Brief description of the drawings]

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

FIG. 2 is a plan view showing an opposite substrate of the liquid crystal device shown in FIG.

FIG. 3 is a plan view showing an element-side substrate of the liquid crystal device shown in FIG.

FIG. 4 is an enlarged view showing a portion E in FIG. 2;

FIG. 5 is an enlarged view showing a portion A in FIG. 3;

FIG. 6 is an enlarged view showing a portion F in FIG. 2;

FIG. 7 is an enlarged view showing a portion B in FIG. 3;

FIG. 8 is a sectional view taken along line XX of FIG. 1;

FIG. 9 is a sectional view taken along line YY of FIG. 1;

FIG. 10 is a perspective view showing an example of a nonlinear element.

FIG. 11 is a perspective view illustrating an embodiment of an electronic apparatus according to the invention.

[Explanation of symbols]

 Reference Signs List 1 liquid crystal device 2 sealing material 3a translucent substrate for element-side substrate 3b translucent substrate for opposing substrate 4 wiring 4a first layer of wiring 4b second layer of wiring 4c third layer of wiring 4d terminal part of wiring 6 pixels Electrode 7 TFD element 8 Counter electrode 8a Terminal portion of counter electrode 9a, 9b Liquid crystal drive IC 11 First gap adjustment pattern 12 Second gap adjustment pattern 13 Color filter L Liquid crystal

Claims (5)

[Claims] An element-side substrate provided with a film for a non-linear element, a counter-side substrate provided with a film for a counter electrode and opposed to the element-side substrate, and the opposing substrate and the element-side substrate Having a sealing material bonded to each other with a predetermined cell gap therebetween, and between the sealing material and the element-side substrate and / or between the sealing material and the opposing-side substrate,
A liquid crystal device provided with a gap adjustment pattern for reducing dimensional unevenness of the cell gap, wherein the gap adjustment pattern is provided so that at least a part thereof overlaps at least one side of the sealing material, At least a part of the four sides of the sealing material, the total thickness of the film disposed between the sealing material and the element-side substrate and the counter-side substrate is formed to be substantially equal to each other. Characteristic liquid crystal device. 2. The liquid crystal device according to claim 1, wherein the gap adjustment pattern is a dummy pattern formed by a film provided on the element-side substrate or the counter-side substrate. 3. The liquid crystal device according to claim 1, wherein the gap adjusting pattern is formed by a film for a non-linear element formed on an element-side substrate. . 4. The thin-film diode according to claim 1, wherein the nonlinear element has a structure in which a first electrode, an insulating layer, and a second electrode are sequentially stacked. Wherein the gap adjusting pattern is formed by at least one of the first electrode, the insulating layer, and the second electrode. 5. An electronic apparatus comprising the liquid crystal device according to at least one of claims 1 to 4.