JP3075050B2 - Rubbing treatment method and device for liquid crystal display element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display (hereinafter referred to as L
(Hereinafter referred to as CD) rubbing method and an improvement of the apparatus.

[0002]

2. Description of the Related Art Conventionally, there is a rubbing method as one of methods for aligning liquid crystal molecules in an LCD cell in a specific direction.
This rubbing method comprises forming an alignment film covering a transparent electrode on a glass substrate, and then rotating a cylindrical rubbing roll formed by winding a rubbing material such as a brushed cloth at a high speed, whereby the rubbing material is used. Rubbing the alignment film,
Thus, the long axis of the liquid crystal molecules is oriented in a direction parallel to the rubbing direction. Incidentally, in such a rubbing process, poor alignment may be caused due to abrasion of the rubbing material, variation in the distance or parallelism between the rubbing material and the glass substrate, or adhesion of foreign matter. Therefore, conventionally, a sampling inspection was performed by dropping liquid crystal onto an arbitrary glass substrate having completed the rubbing treatment and examining the alignment state, and when an alignment defect was found, the rubbing process was immediately interrupted, and the rubbing material was replaced or replaced. Necessary measures such as removal of foreign substances were taken.

[0003]

However, in the conventional process management in which a defective alignment is found by a sampling inspection, if the inspection interval is long, there is a danger that defective products will be mass-produced. If the sampling inspection is frequently performed, the work becomes complicated and more glass substrates are wasted for the inspection, so that there is a problem that productivity is significantly impaired. The present invention has been made in view of the above circumstances, and is not based on a sampling inspection of a glass substrate, but is based on abrasion of a rubbing material, a variation in the distance and parallelism between the rubbing material and the glass substrate, or an abnormality caused by adhesion of a foreign substance or the like. It is an object of the present invention to provide a method and a device capable of easily and reliably detecting the presence or absence.

[0004]

In order to achieve the above object, a rubbing method for a liquid crystal display device according to the present invention is characterized in that a rubbing roll formed by winding a rubbing material is rotationally driven by a driving motor. In a rubbing method for a liquid crystal display element, in which an alignment film on a glass substrate is rubbed with a rubbing material, the glass substrate is set on a table having a lower thermal conductivity than the glass substrate, rubbing is performed, and the glass immediately after the rubbing is processed. The substrate surface is photographed by an infrared vidicon camera to output an image signal, and the image signal is processed to detect a temperature distribution pattern on the glass substrate surface, and the detected measured temperature distribution pattern and a preset target temperature It is characterized in that the distribution pattern is compared with the distribution pattern, and the presence or absence of the abnormality is determined based on the comparison result.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1 which is a schematic front view, a rubbing roll 3 wrapped with a rubbing material 2 is rotatable at a high speed in a vertical plane via a drive motor (not shown) at an upper left position of the base 1. It is arranged. Further, an infrared vidicon camera 4 for photographing the temperature distribution on the glass substrate surface after the rubbing process and outputting an image signal is disposed at the upper right position of the base 1. An image processing apparatus 5 for image-processing an image signal from the infrared vidicon camera 4 and detecting a temperature distribution pattern on the glass substrate surface after the rubbing processing is electrically connected.

Further, a control panel 6 is electrically connected to the image processing apparatus 5, and the control panel 6 has a storage means for storing a target temperature distribution pattern on the surface of the glass substrate immediately after the rubbing process. 7 and a determination means for comparing the measured temperature distribution pattern detected by the image processing by the image processing device 5 with a preset target temperature distribution pattern to determine whether or not the glass substrate surface after the rubbing processing is abnormal. The storage means 7 and the determination means 8 are constituted by a microcomputer. A monitor 9 is electrically connected to the control panel 6.

On the base 1, a carriage 10 on which the glass substrate G is placed and moved in the direction of the arrow is provided movably in the left-right direction. The carriage 10 is shown in FIG. Bogie body 11 having recess 11a on the upper surface
And a ceramic table 12 mounted on the carriage body 11 and having a lower thermal conductivity and air permeability than the glass substrate G. The reason why the thermal conductivity of the table 12 is smaller than that of the glass substrate G is as follows.
This is for preventing the heat of the glass substrate heated by the rubbing treatment from escaping in a short time. The hollow chamber defined by the recess 11a of the bogie main body 11 and the table 12 is communicated with a vacuum pump (not shown), and the pressure in the hollow chamber is reduced, so that the glass substrate G placed on the table 12 is reduced. It can be fixed by suction with a pressure difference from the atmospheric pressure.

[0008] In the apparatus configured as described above, after the glass substrate G to be rubbed is placed on the table 12 of the carriage 10, the hollow chamber of the carriage 10 is depressurized and the glass substrate G on the table 12 is moved to the table 12. The glass substrate G is rubbed by moving the glass substrate G rightward at a low speed via the carriage 10 while rotating the rubbing roll 3 at a high speed. Next, the rubbed glass substrate G is moved to a position directly below the infrared vidicon camera 4 with the carriage 10 and immediately after the processed surface of the glass substrate G is photographed by the infrared vidicon camera 4, the image is processed by the image processing device 5. After the processing, the temperature distribution pattern on the processing surface of the glass substrate G is detected.

The rubbing treatment generates frictional heat on the processing surface of the glass substrate G. The amount and distribution of the frictional heat depends on the contact state between the rubbing material 2 and the glass substrate G, the pressing force of the rubbing material 2, and the like. It depends on the contact speed and contact time of the rubbing material 2 and the frictional heat forms a spectrum depending on the temperature, and this spectrum forms a temperature distribution pattern.

Therefore, the measured temperature distribution pattern is input from the image processing device 5 to the control panel 6 and compared with a preset target temperature distribution pattern, and it is determined whether there is any abnormality based on the comparison result. become. Then, the result can be visually observed on the monitor 9. As a result, it is possible to easily and reliably determine the presence or absence of an abnormality due to wear of the rubbing material 2, variation in the distance and parallelism between the rubbing material 2 and the glass substrate G, or adhesion of foreign matter. In the above embodiment, the table 12
Is moved horizontally, but it goes without saying that the infrared vidicon camera 4 may be moved horizontally.

[0011]

As is apparent from the above description, according to the present invention, a glass substrate is set on a table having a lower thermal conductivity than this glass substrate, rubbed, and the surface of the glass substrate immediately after the rubbing is processed by an infrared vidicon camera. And outputs an image signal, processes the image signal to detect a temperature distribution pattern on the surface of the glass substrate, and compares the detected measured temperature distribution pattern with a preset target temperature distribution pattern. Since the presence or absence of an abnormality is determined based on the comparison result, it is easy and reliable to determine the presence or absence of an abnormality due to wear of the rubbing material, variation in the distance and parallelism between the rubbing material and the glass substrate, or adhesion of foreign matter. It has an excellent effect such that it is possible to detect in a short time.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a bogie used for carrying out the present invention.

[Explanation of symbols]

 4 Infrared vidicon camera 5 Image processing device 7 Storage means 8 Judgment means 12 Table

Claims (2)

(57) [Claims] 1. A rubbing treatment method for a liquid crystal display element, wherein a rubbing roll formed by winding a rubbing material is rotatively driven by a driving motor to rub an alignment film on a glass substrate with the rubbing material. Is set on a table having a smaller thermal conductivity than this glass substrate and subjected to rubbing treatment, an image signal is output by photographing the surface of the glass substrate immediately after the rubbing treatment with an infrared vidicon camera, and the image signal is processed. Detecting a temperature distribution pattern on the surface of the glass substrate, comparing the detected temperature distribution pattern with a preset target temperature distribution pattern, and determining whether there is an abnormality based on the comparison result. Rubbing treatment method for liquid crystal display element. 2. A rubbing treatment apparatus for a liquid crystal display element, wherein a rubbing material wound around a rubbing material is rotatively driven by a drive motor to rub the alignment film on a glass substrate with the rubbing material. A table 9 on which a glass substrate to be mounted can be placed horizontally and having a lower thermal conductivity than the glass substrate; an infrared vidicon camera 4 for photographing the glass substrate surface after the rubbing process and outputting an image signal; An image processing device 5 for processing a signal to detect a temperature distribution pattern on the glass substrate surface after the rubbing process, and a storage unit 7 for storing a target temperature distribution pattern on the glass substrate surface immediately after the rubbing process.
And a determining means 8 for comparing the measured temperature distribution pattern detected by the image processing device 5 with the target temperature distribution pattern in the storage means 7 to determine the presence or absence of an abnormality. Rubbing processing device for display element.