JPH05273507A - Method for assembling liquid crystal panel - Google Patents

Abstract

PURPOSE:To provide the method for production of the liquid crystal panel which stabilizes the quality of products and production capacity and further improves the production capacity by shortening tact time. CONSTITUTION:Substrates 1a, 1b are so disposed that the sealing materials 3 on one side thereof face each other. The pressurization is stopped under 0kg pressurizing force between stages 5a and 5b. The relative positions between two sheets of the substrates 1a, 1b are subjected to image recognition, by which the positions of the substrates are confirmed. The substrates on the stages 5a, 5b are fixed and the substrates of the stages 5a, 5b are set as a moving side. The correction of X-Y-theta is executed and simultaneously the pressurization up to the primary pressurizing force is executed by an imaging recognizing device. The pressurization until the pressurizing force of the primary pressure +akg is executed. The accuracy of the relative positions between two sheets of the substrates 1a, 1b is checked at the point of the time when the final pressurization ends. The relative positions between two sheets of the substrates 1a, 1b before and after the pressurization of the respective steps in the previous time are stored. These positions are offset and corrected at the time of the correction of X-Y-theta before the pressurization in the respective steps.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of assembling a liquid crystal panel with improved accuracy.

[0002]

2. Description of the Related Art Generally, in a liquid crystal cell that constitutes a liquid crystal panel, as shown in FIGS. 2 to 4, two substrates 1a and 1b are made to face each other with their processing surfaces facing each other, and a liquid crystal 2 is placed between the substrates 1a and 1b. While sandwiching the liquid crystal 2, a sealing material 3 is provided around the liquid crystal 2 to hold the liquid crystal 2 between the substrates 1a and 1b.

Then, a conventional assembling operation will be described with reference to a flow chart shown in FIG.

On one of the substrates 1a and 1b of the liquid crystal display cell, a seal material 3 is applied on a pre-processed surface, and the surface on which the seal material 3 is applied and the pre-processed surface are not in contact with each other. Face each other. Then, with the substrates 1a and 1b facing each other, the substrates 1a and 1b are mounted on the stage 5a,
Each of the 5b is held by vacuum adsorption or the like, and as shown in FIG.
The sealing material 3 on one of the substrates 1a and 1b comes into contact with the opposing substrates 1a and 1b, or stops at a pressing force of 0 kg between the stages 5a and 5b, which is just before the contact (step 1). At this time, pores (not shown) are formed in a part of the sealing material 3 so that the liquid crystal 2 can leak out in response to the pressure.

When the applied pressure is 0 kg, the two substrates 1
Image confirmation of the relative position between a and 1b (step 2), for example, with the upper stage 5a fixed and the lower stage 5b as the moving side, the X-axis of the relative position between the two substrates 1a and 1b,
XY- [theta] of the twist angle [theta] between the Y-axis and the substrates 1a and 1b is corrected (step 3). However, after performing the correction once, it is confirmed again by image processing whether the relative position between the two substrates 1a and 1b has been moved to the normal position, and the like.
This operation is repeated until the movement to the regular relative position is completed (step 4).

Then, when the relative position of the substrates 1a and 1b is completely moved to the normal position, a force such as an air cylinder is used to reach a primary pressurizing force by a predetermined air pressure of the first pressure reducing valve or the like. Pressure of up to 50kg, 2
The sealing material 3 between the substrates 1a and 1b is pressed (step 5).

Further, at this point, again as in the previous time, 2
The relative position between the two substrates 1a and 1b is image-recognized (step 6), and the relative position correction of XY-θ between the two substrates 1a and 1b is repeated (step 7). When the movement to the normal relative position is completed (step 8), the pressure of the air transmitted to the cylinder is applied from the second pressure reducing valve so that the final 100 kg of secondary pressure is applied to the sealing material 3 between the two substrates 1a and 1b. After supplying (step 9) and holding for a predetermined time (step 1)
0) The total pressure applied to the seal material 3 between the two substrates 1a and 1b is released, and the assembly is completed.

In the liquid crystal display cell, the relative positional deviation amount between the two substrates 1a and 1b after assembling is about several microns, which is a highly accurate positional precision.
The parallelism between 1a and 1b is 0. Since several microns are required, two substrates 1a,
The parallelism between 1b becomes very important.

Therefore, the upper stage 5a of the assembly apparatus
Also, the parallelism between the lower stage 5b, the parallelism between the pressure axis at the time of pressurization and the axis of the camera of the image processing apparatus are important points.

However, in the case of the method shown in FIGS. 2 to 5, the XY position of the relative position between the two substrates 1a and 1b is used.
In order to easily correct θ, the stage of the assembling apparatus is used for the purpose of softening the sealing material 3 between the two substrates 1a and 1b.
5a and 5b perform heating at about 30 ° C to 50 ° C.

Because of this temperature, the stages 5a and 5b made of ordinary mechanical materials have stages 5a and 5b.
, The parallelism between the stages 5a and 5b, the axis of the camera of the image processing apparatus, and the pressure axis of the stages 5a and 5b are likely to be misaligned.

Further, since the substrates 1a and 1b are increased in size to improve productivity, it is necessary to apply a pressure of several hundreds of kg in order to keep the distance between the two substrates 1a and 1b at several microns. is doing. And this pressing force is also a factor which easily causes the deviation of the axial center.

Further, XY-θ of the relative position between the two substrates 1a and 1b is corrected at the point of step pressurization, but between the stages 5a and 5b at the time of XY-θ correction. There is a slight deviation in parallelism and a slight deviation between the axis of the camera of the image processing device and the axis of pressure between the stages 5a and 5b.
It is extremely unlikely that the number of times of correction will fall within the accuracy of the regular relative position.

Then, the correction of the substrates 1a and 1b is repeated until the accuracy is within the normal relative position,
The tact time as an apparatus varies between products, which leads to variations in manufacturing conditions among products and within products, which leads to unstable product quality and unstable manufacturing capability.

[0015]

As described above, the relative assembly accuracy of several microns, which is the required assembly accuracy of the two substrates 1a and 1b as the liquid crystal display cell, and 0. In order to secure parallelism of several microns, the relative position correction by image processing between the two substrates 1a and 1b is repeated several times each time the pressure is applied, but this number varies from substrate to substrate 1a and 1b. In addition, there is a problem that a tact time shift occurs, which causes a variation in manufacturing conditions on products, and further leads to instability in product quality and manufacturing capability.

The present invention has been made in view of the above problems, and a liquid crystal panel capable of improving the production quality by stabilizing the quality of the product, stabilizing the production capacity, and shortening the takt time. It is intended to provide a manufacturing method.

[0017]

SUMMARY OF THE INVENTION The present invention provides a method for assembling a liquid crystal panel, which is constructed by stacking the processed surfaces of two substrates so as to face each other with a gap therebetween and injecting liquid crystal between the substrates. Stepwise pressurization for stepwise pressurizing the superposing pressure when superposing two substrates, and during each step pressurization, the alignment between the substrates is corrected to superpose one set of two substrates. At the end of the alignment, the relationship between the position correction amount for each step pressurization, the next step pressurization, and the actual position at the end of the position correction between the two substrates is stored, and is stored when the next substrate is superposed. This offsets the corrected position amount between the substrates.

[0018]

According to the present invention, stepwise pressurization for stepwise pressurizing the superposing force when superposing two substrates,
Position adjustment between the substrates during each step pressurization, and the position correction amount for each step pressurization at the end of the superposition of the substrates,
The relationship with the actual position at the end of the next step pressurization and the position correction between the two substrates is stored, and is offset to the corrected position amount between the two substrates when the next substrate is superposed.
The history of the relative position accuracy between the points of each step pressurization is stored and offset at the time of the next superposition, so the quality of the product is stabilized, the manufacturing capacity is stabilized, and the manufacturing capacity is reduced by shortening the takt time. It is possible to improve.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for assembling a liquid crystal panel according to the present invention will be described below with reference to the drawings. 2 to 4
Since the liquid crystal panel shown in FIG. 1 is the same as the conventional one, it will be described with reference to FIGS. 2 to 4 used in the description of the conventional example.

On one of the substrates 1a and 1b of the liquid crystal display cell, the seal material 3 is applied on the pre-processed surface, and the surfaces to which the seal material 3 is applied are pre-processed surfaces. Face each other. Then, with the substrates 1a and 1b facing each other, the substrates 1a and 1b are mounted on the stage of the assembly apparatus.
The substrates 1a and 1b are held by vacuum suction or the like, respectively, and as shown in FIG.
Stages 5a, 5 that are in contact with a, 1b, or just before contact
It stops when the applied pressure between b is 0 kg (step 11).

In the state shown in FIG. 2, the two substrates 1a and 1b are
The positions of the substrates 1a and 1b are confirmed by image-recognizing the relative position between them (step 12), for example, the substrate 1a of the upper stage 5a is fixed, and the substrate 1b of the lower stage 5b is set as the moving side. Then, the substrate 1b is moved in the X-axis direction by the value from the image recognition device,
X-Y-θ of twist angle θ with respect to Y-axis direction and substrate 1a
At the same time, the pressure is increased to the primary pressure (step 13). At this time, it is confirmed whether or not the pressurization is completed up to a predetermined pressing force, and the process proceeds to the next step. In the next step, image recognition is performed again to correct XY-θ, and at the same time, as shown in FIG.
Pressurization is performed until the pressure of kg is reached (step 14).
This operation is repeated n times, and the pressurization is sequentially repeated step by step until the final pressure is reached (step 15).

At the end of the final pressurization, the accuracy of the relative position between the two substrates 1a and 1b is confirmed by image recognition again (step 16), and the positions of the substrates 1a and 1b are within the standard. Whether or not it is detected (step 17), as shown in FIG. 4, if it is within the standard, it is held for a predetermined time (step 1).
8), release and complete.

However, when the positions of the substrates 1a and 1b are out of the standard, the pressing force and the number of times are set to -bkg (step 19), and when the pressing force becomes -bkg (step 20), that is, -m. Return to the previous position (step 21), step
Returning to step 12, the image is recognized again, XY-θ correction and stepwise pressurization are performed.

In this case, the relative positions between the two substrates 1a and 1b before and after the previous step pressurization are stored, and an offset is applied at the time of correcting XY-θ at each step pressurization. And make corrections (step 22).

Furthermore, when the assembly of the liquid crystal cells of one set of liquid crystal panels is completed and the next liquid crystal cell is assembled, the two substrates before and after the pressurization of each step in the previous assembly of the liquid crystal cells are performed. According to the relative position of 1a and 1b, the movement amount to be actually corrected is offset and corrected.

By assembling the liquid crystal cell as described above, it is possible to minimize the amount of increase in the step pressing force immediately before the completion of the final assembly, and to increase the pressure of the two substrates 1a, It is also possible to minimize the amount of movement of the gap between 1b.

Further, the relative position between the two substrates 1a and 1b before the step pressurization at each step pressurization in the previous assembly and the moved relative position after the step pressurization are stored, and the next assembly is carried out. 2 substrates 1a and 1b for feedback of
It is possible to set the amount of step pressurization such that the relative position is corrected once, which is the minimum number of times, and the number of step pressurization can be suppressed to the minimum number. Therefore, the assembly accuracy can be improved, and the total number of times of image recognition and the number of times of correcting the relative position accuracy between the two substrates 1a and 1b can be reduced.

Furthermore, not only the tact time can be shortened, but also the number of times of image processing and relative position correction can be fixed,
It is possible to stabilize the tact time, the production conditions, and the productivity.

[0029]

According to the method of assembling the liquid crystal panel of the present invention, the pressing force of the superposition of the two substrates is set to the step pressurization, and the alignment correction between the substrates is corrected during each step pressurization. Then, the relationship between the position correction amount for each step pressurization, the next step pressurization, and the actual position at the end of the position correction between the two substrates is stored at the end of superposition of the substrates,
Since offset to the corrected position amount between the two substrates when the next substrate is stacked, the history of relative position accuracy between each step pressure point is stored and offset at the time of the next stack. It is possible to improve the production capacity by stabilizing the quality, stabilizing the production capacity, and shortening the takt time.

[Brief description of drawings]

FIG. 1 is a flowchart showing an assembling operation of a liquid crystal panel according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing one step of assembling the above liquid crystal panel.

FIG. 3 is a cross-sectional view showing the next step shown in FIG. 2 in assembling the above liquid crystal panel.

FIG. 4 is a sectional view showing a next step shown in FIG. 3 for assembling the liquid crystal panel.

FIG. 5 is a flowchart showing an assembling operation of a conventional liquid crystal panel.

[Explanation of symbols]

 1a, 1b substrate

Claims (1)

[Claims] 1. A method for assembling a liquid crystal panel, which comprises stacking two substrates with their processed surfaces facing each other with a gap therebetween and injecting a liquid crystal between these substrates. The pressure applied in the stacking is set to stepwise pressurization, and the alignment between the substrates is corrected during each step pressurization. At the end of the superposition of one set of two substrates, each step is applied. The relationship between the position correction amount for each pressure, the next step pressurization, and the actual position at the end of position correction between the two substrates is stored, and the corrected position amount between the two substrates when stacking the next substrate is stored. A method for assembling a liquid crystal panel, which is characterized by offsetting to.