JP3229823B2 - Liquid crystal display device and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audiovisual (AV) device and an office automation (OA).
The present invention relates to a direct-view type liquid crystal display device that can be used for equipment and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, home televisions used as AV equipment and display devices used for OA equipment have been reduced in weight.
There is a demand for thinner, lower power consumption, higher definition, and larger screens. For this reason, CRT (Cathode R)
a Tube, a liquid crystal display (LCD (Liquid)
d Crystal Display), plasma display device (PDP (Plasma Display Pan)
el)), EL (Electro Luminescence)
nce) display device, LED (Light Emitti)
A display device such as an ng diode display device is also being developed and put into practical use to have a large screen.

[0003] Among them, the liquid crystal display device has the advantages that the thickness (depth) can be remarkably reduced, the power consumption is small, and the full color display is easy, compared with other display devices. It is being used in various fields, and there is great expectation for larger screens.

On the other hand, when the size of the screen of the liquid crystal display device is increased, a defective rate due to disconnection of a signal line, a pixel defect, or the like in a manufacturing process sharply increases, and further, the price of the liquid crystal display device increases. Such a problem arises. In order to solve this problem, a plurality of liquid crystal display panels are connected to form a single liquid crystal display device that constitutes one screen as a whole, and the size of the screen is increased. At this time, in order to obtain a natural large-screen image, a technique for making the seams between the display screens inconspicuous is required. The present applicant has disclosed in Japanese Patent Application Laid-Open No. 8-122767 a new multi A panel type liquid crystal display device is proposed.

A multi-panel type liquid crystal display device will be described with reference to FIGS.

FIG. 5 is a sectional view showing the structure of an example of a liquid crystal display device proposed in Japanese Patent Application Laid-Open No. 8-122770. FIG. 6 is a diagram showing a pixel arrangement when the liquid crystal display device shown in FIG. 5 is viewed from directly above.

[0007] The multi-panel type liquid crystal display device 14 comprises:
Two active matrix type liquid crystal panels 1 are arranged adjacent to one large substrate 15 on the same plane, and are connected by an adhesive 16 at a connection region 5 of the two liquid crystal panels 1 to form a large panel. It is schematically configured by disposing a polarizer 17 (polarizing plate) on almost the entire surface of each of the front and back surfaces in a direction in which the polarization axes are orthogonal to each other. Note that a backlight and a driving circuit required for display are omitted in the drawing. Further, the two liquid crystal panels 1 are configured by sealing a liquid crystal 18 with a sealant 19 between a pair of substrates. Here, as the substrate, a scanning electrode (gate electrode),
Data electrode (source electrode), thin film transistor arranged at the intersection of these electrodes, TF on which pixel electrode is formed
A T substrate 6 and a counter substrate 20 on which a common electrode is formed are used. Further, when performing color display, R (red), G (green), and B (blue) color filters 4 corresponding to each pixel 21 and a black matrix 10 for separating each pixel 21 are provided on the substrate. Formed, R (red), G (green), B
(Blue) constitutes one pixel unit 22.

[0008]

However, the conventional liquid crystal display device described above has the following problems.

The above-mentioned liquid crystal display device is designed such that two liquid crystal panels are connected, and at this time, the pixel pitch of the connection region and the pixel pitch of the other region are almost equalized to obtain a natural image without a sense of discomfort. Have been. For example, as shown in FIG. 7, the connection area between the two liquid crystal panels is R (red),
The two liquid crystal panels on which the G (green) and B (blue) color filters 4 and the black matrix 10 are formed are connected by an adhesive 16 at a connection side 13 of the liquid crystal panel.
The pixel pitch M including this connection region is determined by the distance A between the pixel 21 of the two liquid crystal panels and the connection side 13 of the liquid crystal panel, and the width B of the gap (joining portion) generated when the two liquid crystal panels are joined. And R (red), G (green), and B (blue) color filter regions C. In order to make this approximately the same as the pixel pitch N of the other regions, the connection side of the liquid crystal panel is 13 needs to be provided in a place close to the pixel 21. For this reason, the quality of the processing accuracy of the connection side 13 of the liquid crystal panel affects the display performance.

Therefore, the connection side 13 of the liquid crystal panel is formed by precisely cutting one side of one liquid crystal panel formed by an ordinary method in the vicinity of the pixel 21 by a dicing method or the like. At this time, the accuracy of the division position was determined by observing with a loupe or a microscope and checking and confirming the accuracy. For example, as shown in FIG.
On the color filter substrate 8 side of the liquid crystal panel constituted by the substrate 6 and the color filter substrate 8, the interval between the connection side 13 and the pixel 21 adjacent to the connection side 13 (corresponding to the interval A in FIG. 7) is marked. The distance was read with a magnifying loupe or microscope 9 and measured at a plurality of locations on the liquid crystal panel for confirmation.

However, in this method, although the focus can be well focused on the pixel 21 of the color filter and the position can be specified, a predetermined position (the same height as the pixel 21 of the color filter) Position of)
It was difficult to focus on, and it was difficult to specify the position.

This is because the dividing plane 11 exists in a direction perpendicular to the observation loupe or microscope 9.
That is, when focusing on the pixel 21 of the color filter, the pixel 2 of the color filter is in spite of being in focus on the pixel 21 of the color filter in the division plane 11.
The connection side 13 is blurred due to the depth of focus of the loupe or the microscope 9 because the dividing plane 11 has a width in the direction of observation with the loupe or the microscope 9 from the position 1. Therefore, when observed with a loupe or a microscope 9, the connection side 13 overlaps with the connection side 13 having the same height as the pixel 21 of the focused color filter and the blurred connection side 13. Is not clear, it has been difficult to specify the position of the connection side 13. Therefore, it is difficult to measure the exact position of the divided part, which hinders the inspection in the manufacturing process.

The present invention solves the above problems,
It is an object of the present invention to provide a liquid crystal display device in which a plurality of liquid crystal panels are connected so that the processing accuracy of a connection portion of the liquid crystal panel can be easily inspected, and a method for manufacturing the same.

[0014]

According to the present invention, there is provided a liquid crystal display device for displaying a large screen by arranging a plurality of liquid crystal panels adjacent to each other on the same plane. Is provided with a marker that can measure the positional accuracy of the connection side between the adjacent liquid crystal panels, so that the above object can be achieved.

The marker can measure the distance between a connection side between adjacent liquid crystal panels and a pixel closest to the connection side, thereby achieving the above object.

Further, since the marker is formed on a part of the substrate which is provided on the periphery of the liquid crystal panel and is exposed for taking out terminals, the above object can be achieved. .

The method of manufacturing a liquid crystal display device according to the present invention is directed to a method of manufacturing a liquid crystal display device for displaying a large screen by arranging a plurality of liquid crystal panels adjacent to each other on the same plane.
When the wiring pattern of the liquid crystal panel is formed, a marker that can measure the positional accuracy of the connection side of the adjacent liquid crystal panels is formed in the same step, thereby achieving the above object.

The operation of the above configuration will be described below.

In the liquid crystal display device of the present invention, since a plurality of liquid crystal panels are provided with a marker capable of measuring the positional accuracy of the connection side between adjacent liquid crystal panels, when the connection side is observed with a loupe or a microscope, The position of the connection side of the liquid crystal panel can be adjusted by focusing on the marker without worrying about blurring of the connection side (partition line) due to the loupe or the depth of focus of the microscope caused by the width of the division plane in the observation direction. Accuracy can be measured.

Further, since the distance between the connection side between adjacent liquid crystal panels and the pixel closest to the connection side can be measured, the marker is focused only on the marker, so that the end of the pixel of the color filter can be measured. The distance from to the connection side (divided line) can be easily measured at a glance. Therefore, as compared with a method of measuring with a loupe or a microscope having a scale, it is possible to save labor and time for positioning the marker and the scale of the loupe or the microscope. In addition, the marker also has the scale function of a conventional loupe or microscope, so that measurement errors due to parallax caused by the misalignment of the observer with the conventional marker and loupe or microscope can be eliminated. it can.

Further, since the marker is formed on a part of the substrate which is provided in the peripheral portion of the liquid crystal panel and is exposed for taking out the terminal, when the marker is focused, a loupe or a microscope and the marker are used. Since there is no substrate between them, the marker can be read easily and accurately. Furthermore, in the past, it was necessary to observe with a loupe or microscope system having a focal length larger than the thickness of the substrate in the observation direction of the loupe or microscope from the measurement position, but the marker is part of the exposed part of the substrate. Since it is formed, measurement can be performed even with a loupe or microscope system having a short focal length, a high-powered lens having a short focal length can be applied, and a marker can be easily and accurately read.

Further, according to the method of manufacturing a liquid crystal display device of the present invention, when forming a wiring pattern of a liquid crystal panel, a marker capable of measuring the positional accuracy of a connection side between adjacent liquid crystal panels is formed. When a marker is formed on the TFT, the TFT or its wiring material is used to form the TF.
Since a marker can be provided at the same time as patterning the T or the wiring material, the manufacturing process can be simplified.

[0023]

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

A feature of the present invention is that, in the liquid crystal display device for increasing the screen size by connecting two liquid crystal panels shown in the conventional example of FIGS. 5 to 7, each liquid crystal panel is divided along a dividing line. After that, a marker (scale) that can easily measure the positional accuracy of the connection side in the dividing step is provided.

FIGS. 1A and 1B are views for explaining a part of the manufacturing process of the liquid crystal display device of the present invention. FIG.
(A), (b) is the perspective view and top view of one liquid crystal panel before a connection.

As shown in the liquid crystal panel 1 before connection in FIG. 1A, the marker 2 is applied to one liquid crystal panel so as to cross the dividing line 3 of the liquid crystal panel which is a connection side in the joining step. At least two places.

Next, the dividing, inspecting, and joining steps, which are part of the manufacturing process of the liquid crystal display device, will be described, and the role of the marker will be described.

First, as shown in FIG. 1A, in the dividing step, the dividing lines are formed along the edges of the display area on the sides connected to each other of the two liquid crystal panels 1 on which the markers 2 are formed. 3 (which will become the connection side 13 in a later step). At this time, division is performed so as to cross the marker 2. Since the division needs to be performed accurately at a position of about 100 to 200 μm from the end pixel of the color filter 4, it is performed using a dicing device or a wire saw. Further, in order to improve the flatness of the divided section (which becomes a connection surface in a later step), the divided section may be further polished.

Next, the liquid crystal panel 1 on which the marker 2 is formed
The position accuracy of the connection side is confirmed by the division. The marker 2 is focused on with a loupe or a microscope, and the length of the marker 2 left on the substrate at the time of the division is measured.
This measurement is performed at least at two points on the marker 2 formed on the liquid crystal panel 1, and based on the measurement result, the positional accuracy of the connection side due to the division of the liquid crystal panel 1 is confirmed.

At this time, if the processing accuracy of the division of the connection side of the liquid crystal panel 1 is poor, the seam of the liquid crystal panel becomes thicker or thinner. As a result, the connection area 5 of the liquid crystal panel
Is deviated from the design value, thereby deteriorating the image display performance. Therefore, when producing the liquid crystal display device, it is necessary to check the positional accuracy of the connection side before connecting the liquid crystal panel.
Just by focusing on the marker 2, the positional accuracy of the connection side can be easily confirmed. As in the conventional method shown in FIG. 4A, it is possible to focus on the pixel 21. However, at the connection side 13 formed by dividing the liquid crystal panel, a sectional plane is taken in a direction perpendicular to the observation direction. Because of the presence of 11, the connection side 13 formed by dividing is difficult to identify even if an attempt is made to focus on the same height as the pixel 21, and the connection side 13 can be specified. As a result, it does not occur that it is difficult to confirm the positional accuracy of the connection side 13.

Next, as shown in FIG. 1 (b), in the joining step, the divided and processed liquid crystal panel 1 is set so that the pixel pitch of the connection region 5 of the liquid crystal panel and the pixel pitch of the other regions are substantially equal. So that the connection side 1 of the two liquid crystal panels
3 are connected to each other with an adhesive.

Further, the markers formed on the liquid crystal panel will be described in detail.

As shown in FIGS. 2A and 2B, the marker 2 is formed on the same substrate surface as the terminal extraction region 7 provided to be exposed on the periphery of the TFT substrate 6. Usually, in an active matrix type liquid crystal panel,
A terminal extraction region 7 is provided in a peripheral portion of the TFT substrate 6 on which the TFT is formed so that an image display signal can be input.
m) or the CF substrate 8 is not covered so that the drive LSI can be mounted by COG (Chip On Glass) method. The marker 2 is formed at a predetermined position in this area.

As a method for forming the marker 2, T
Although it can be newly added as a separate step when manufacturing the FT substrate 6, a bus line or a T
When the FT is formed, it can be formed by patterning a metal film or an insulating film by photolithography at the same time. In this case, since a new process is not added, productivity can be improved.

FIG. 4B shows a method for confirming the positional accuracy of the connection side of the liquid crystal panel when the marker 2 is formed on a part of the TFT substrate 6 exposed for taking out a terminal. Show. T exposed for terminal removal
A loupe or a microscope 9 is focused on the marker 2 formed on a part of the FT substrate 6, and the length of the marker 2 left by the division is measured. At this time, since the marker 2 is provided in a region where the surface of the TFT substrate 6 is exposed, it is easy to focus on the marker 2 without disturbing focusing on the color filter substrate 8 with a loupe or a microscope 9. Can be combined. Therefore,
The position accuracy of the connection side can be measured accurately and easily.

Further, specific markers will be described with reference to FIG.

FIG. 3 is an enlarged perspective view of the marker forming area when the liquid crystal panel is divided.

As shown in FIG. 3, a TFT substrate 6 on which a scanning electrode (gate electrode), a data electrode (source electrode), a thin film transistor arranged at the intersection of these electrodes, and a pixel electrode are formed on an insulating substrate. , R corresponding to each pixel
A marker 2 is formed on a liquid crystal panel including a (red), G (green), B (blue) color filter 4 and a color filter substrate 8 on which a black matrix 10 for separating each pixel is formed. ing.

The marker 2 is formed on a part of the surface of the TFT substrate 6 in a region where the color filter substrate 8 is not covered for taking out terminals provided on the periphery of the TFT substrate 6.

The marker 2 is constituted by line segments arranged at equal intervals with numerical values.

Further, the position of the marker 2 is
With the end 12 of the pixel of the color filter 4 closest to (to be a connection surface in a later step) as a reference (0), a marker 2 (scale) from which the distance to the division plane 11 can be measured at a glance ) Are formed in the direction of the section plane 11.

For example, in the case of FIG. 3, it is possible to easily confirm that the positional accuracy of the connection side 13 due to the division is a value of 150 only by focusing the marker 2 with a loupe or a microscope. Note that the marker 2 is continuously formed up to the portion of the liquid crystal panel that has been divided and dropped.

By making such a marker 2, only by focusing on the marker 2 with a loupe or a microscope,
Since the position accuracy of the connection side 13 due to the division can be easily specified, the position accuracy of the connection side 13 can be easily inspected, and the measurement can be quickly performed and confirmed.
Production efficiency can be improved.

The same effect can be obtained with other markers (scales) as long as the positional accuracy of the connection side due to the division can be determined.

[0045]

According to the liquid crystal display device of the present invention, since a plurality of liquid crystal panels are provided with a marker capable of measuring the positional accuracy of the connection side between adjacent liquid crystal panels, when the connection side is observed with a loupe or a microscope. In addition, the connection side of the liquid crystal panel can be obtained simply by focusing on the marker without worrying about blurring of the connection side (partition line) due to the loupe or the depth of focus of the microscope caused by the width of the division plane in the observation direction. Position accuracy can be measured. This makes it possible to easily inspect the processing accuracy of the connection portion of the liquid crystal panel, improve the production efficiency, prevent inspection errors, and provide a multi-panel excellent in display quality with no noticeable joints. A liquid crystal display device of a system can be provided.

The marker can measure the distance between a connection side between adjacent liquid crystal panels and a pixel closest to the connection side. Therefore, focusing only on the marker allows the end of the pixel of the color filter to be focused. The distance from to the connection side (divided line) can be easily measured at a glance. Therefore, as compared with a method of measuring with a loupe or a microscope having a scale, it is possible to save labor and time for positioning the marker and the scale of the loupe or the microscope. In addition, the marker also has the scale function of a conventional loupe or microscope, so that measurement errors due to parallax caused by the misalignment of the observer with the conventional marker and loupe or microscope can be eliminated. it can.
This makes it possible to easily inspect the processing accuracy of the connection portion of the liquid crystal panel, improve the production efficiency, prevent inspection errors, and provide a multi-panel excellent in display quality with no noticeable joints. A liquid crystal display device of a system can be provided.

Further, since the marker is formed on a part of the substrate which is provided at the periphery of the liquid crystal panel and is exposed for taking out the terminal, when the marker is focused, a loupe or a microscope and the marker are used. Since there is no substrate between them, the marker can be read easily and accurately. Furthermore, in the past, it was necessary to observe with a loupe or microscope system having a focal length larger than the thickness of the substrate in the observation direction of the loupe or microscope from the measurement position, but the marker is part of the exposed part of the substrate. Since it is formed, it is possible to measure even with a loupe or microscope system having a short focal length, a high-power one having a short focal length can be used, and the marker can be easily and accurately read. This allows
A multi-panel type liquid crystal display that can easily inspect the processing accuracy of the connection part of the liquid crystal panel, improve production efficiency, prevent inspection errors, and have excellent display quality with no noticeable joints An apparatus can be provided.

In the method of manufacturing a liquid crystal display device according to the present invention, when forming a wiring pattern of a liquid crystal panel, a marker capable of measuring the positional accuracy of a connection side between adjacent liquid crystal panels is formed in the same step. When a marker is formed on the TFT substrate, the marker can be provided at the same time as the patterning of the TFT or the wiring material using the TFT or its wiring material, so that the manufacturing process can be simplified. Thereby, the production efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a part of a manufacturing process of a liquid crystal display device of the present invention.

FIG. 2A is a perspective view of one liquid crystal panel before connection of the liquid crystal display device of the present invention. (B) is a plan view of one liquid crystal panel before connection of the liquid crystal display device of the present invention.

FIG. 3 is a diagram showing a specific example of a marker used in the present invention.

FIG. 4A is a diagram showing a conventional method for confirming the positional accuracy of a connection side of a liquid crystal panel. (B) is a diagram showing a method for confirming the positional accuracy of the liquid crystal panel connection side when the marker of the present invention is used.

FIG. 5 is a structural sectional view of an example of a liquid crystal display device proposed in Japanese Patent Application Laid-Open No. 8-122770.

FIG. 6 is a diagram showing a pixel arrangement when the conventional liquid crystal display device shown in FIG. 5 is viewed from directly above.

FIG. 7 is an enlarged plan view of a liquid crystal panel connection region of the conventional liquid crystal display device shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal panel 2 Marker 3 Dividing line 4 Color filter 5 Liquid crystal panel connection area 6 TFT substrate 7 Terminal take-out area 8 Color filter substrate 9 Loupe or microscope 10 Black matrix 11 Cross section 12 Pixel end 13 Connection edge

Claims (4)

(57) [Claims] 1. A liquid crystal display device that performs a large-screen display by arranging a plurality of liquid crystal panels adjacent to each other on the same plane, wherein the plurality of liquid crystal panels include a position of a connection side between adjacent liquid crystal panels. A liquid crystal display device comprising a marker capable of measuring accuracy. 2. The liquid crystal display device according to claim 1, wherein the marker can measure a distance between a connection side between adjacent liquid crystal panels and a pixel closest to the connection side. 3. The marker according to claim 1, wherein the marker is formed on a part of a substrate provided at a peripheral portion of the liquid crystal panel and exposed for taking out a terminal. Liquid crystal display. 4. A method for manufacturing a liquid crystal display device for displaying a large screen by arranging a plurality of liquid crystal panels adjacently on the same plane. A method for manufacturing a liquid crystal display device, wherein a marker capable of measuring the positional accuracy of a connection side between panels is formed in the same step.