JP2785621B2 - Method of treating alignment film in liquid crystal panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating an alignment film in a liquid crystal panel.

[0002]

2. Description of the Related Art In recent years, liquid crystal panels have been widely used for liquid crystal televisions, personal computer displays, and the like. In general, liquid crystal panels generally include a glass substrate and an alignment film made of polyimide coated on the glass substrate. I have. Conventionally, the molecules of the polyimide of the alignment film are arranged in a predetermined direction, and a rubbing method is known as such a processing method. In this rubbing method, microscopic scratches in a predetermined direction are formed on the surface of the alignment film by rubbing the surface of the alignment film with a buff provided on a rotating roller, and the polyimide molecules are arranged along the microscopic scratches. I have to.

[0003]

However, in the rubbing method described above, the surface of the alignment film is rubbed by the buff, so that the alignment film is charged and dust is generated.

[0004]

[Means for Solving the Problems] In view of such circumstances,
The present invention relates to a liquid crystal panel comprising a glass substrate and an alignment film made of polyimide covering the glass substrate.
Irradiate a laser beam to the alignment film to a required temperature.
Heated, simultaneously with the molecules of the polyimide constituting the alignment film is a state of easy activities, so as to arrange the molecules of the polyimide along the electric field by forming an electric field in the alignment film
And a method for treating an alignment film in a liquid crystal panel.

[0005]

According to such a method, since the polyimide molecules can be arranged without making minute scratches on the surface of the alignment film, the alignment film is not charged and dust is generated. Absent.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention will be described below with reference to the illustrated embodiments. Reference numeral 1 denotes a liquid crystal panel used as a display of a liquid crystal television or the like. A transparent electrode film 3,
Further, an alignment film 4 made of polyimide and covering the transparent electrode film 3 is provided. The alignment film 4 is in a state where molecules of the polyimide p are irregularly scattered in a solidified state at normal temperature. In this embodiment, the alignment film 4
In the state where an electric field is formed, the alignment film 4 is heated by the laser beam L, whereby molecules of the polyimide p constituting the alignment film 4 are arranged along the electric field. That is, in the present embodiment, a pair of electrodes 5 serving as knife edges are located above and separated from the surface of the alignment film 4, and a high voltage is applied to the electrodes 5 from a power source 6 to form the pair of electrodes 5. An electric field E is formed in the alignment film 4 located therebetween (see FIG. 2). Since the molecules of the polyimide p have a large relative dielectric constant of 3 to 8, the electric flux density of the electric field E is high. Further, since the molecules of the polyimide p have dielectric anisotropy, the molecules of the polyimide p are arranged along the electric field E if the molecules of the polyimide p move easily.
In this embodiment, the alignment film 4 in the above-described state is pulsed with a laser beam L from a laser oscillator of an excimer laser (not shown). The surface layer of the alignment film 4 irradiated with the pulse of the laser beam L is instantaneously heated by the laser beam L to be in a semi-molten state, so that the polyimide p molecule is easily activated. Accordingly, the molecules of the polyimide p which are in a state of being easily activated are arranged along the electric field E formed by the pair of electrodes 5 (see FIG. 3). The principle that the molecules of the polyimide p are arranged along the electric field E will be described in comparison with carbon dioxide and water molecules as follows. That is, FIG.
As shown in the figure, the molecules of carbon dioxide are located at the target positions on the left and right sides of one carbon C (positions shifted by 180 degrees from each other).
, Oxygen O is bonded one by one, so that the electric synthetic dipole moment of the carbon dioxide molecule becomes zero because the oxygen O on both the left and right sides cancel each other. In other words, the carbon dioxide molecules do not have a synthetic dipole moment, and therefore remain electrically stable when subjected to an electric field. On the other hand, in the case of a water molecule, two hydrogens H are bonded to one oxygen O, but the two hydrogens H are shifted from each other by 105 degrees around the oxygen O. It is located in. Therefore, the water molecule has a synthetic dipole moment M directed downward in FIG. 5, so that when the water molecule is applied with an electric field, the direction of the synthetic dipole moment M is along the electric field. The direction is changed to be aligned.

Incidentally, the molecules of the polyimide p constituting the alignment film 4 described above are represented by the chemical formulas in FIG. 4. Considering the chemical formulas of the molecules of the polyimide p, the molecules of each polyimide p are As in the case of the water molecule shown in FIG. 5, it has a synthetic dipole moment. Then, on the assumption that the molecule of the polyimide p has a synthetic dipole moment, in this embodiment,
With the electric field E formed in the polyimide p, the polyimide p is heated by the laser beam L. Accordingly, the molecules of the polyimide p are easily activated, so that the molecules of each polyimide p are arranged such that the direction of the above-described composite dipole moment is the same as the direction of the electric field E. The formation of the electric field E and the irradiation of the laser beam L by the pair of electrodes 5 are performed over the entire surface of the liquid crystal panel 2 by the laser oscillator and the pair of electrodes 5.
Is moved, whereby the molecules of the polyimide p in the entire region of the alignment film 4 can be arranged along the electric field E. According to the above-described embodiment, since the electrodes 5 do not contact the alignment film 4 when arranging the molecules of the polyimide p of the alignment film 4, the surface of the alignment film 4 does not have minute scratches. Therefore, no dust is generated, and the alignment film 4 is not charged with static electricity. Therefore, it is possible to prevent the dust from adhering to the alignment film 4. On the other hand, conventionally, the buff provided on the rotating roller is rubbed against the alignment film 4 to arrange the molecules of the polyimide p of the alignment film 4, so that dust is generated and the dust is attached and the dust is attached. The disadvantage of doing so was pointed out. In some cases, the alignment film 4 may be partially broken by the buff. In the above embodiment,
By appropriately changing the wavelength, the output, and the number of shots of the laser beam L, the depth at which the polyimide p of the alignment film 4 is arranged can be changed.

[0008]

As described above, according to the present invention, it is possible to obtain an effect that the alignment film is not charged and no dust is generated.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG. 1;

FIG. 3 is a cross-sectional view of a liquid crystal panel processed according to the present invention.

FIG. 4 shows a chemical formula of polyimide.

FIG. 5 is a diagram showing carbon dioxide and water molecules.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal panel 2 Glass substrate 4 Alignment film p Polyimide L Laser beam

Claims (1)

(57) [Claims] A liquid crystal panel composed of a glass substrate and an alignment film made of polyimide coated on the glass substrate is irradiated with a laser beam to bring the alignment film to a required temperature.
Was heated to, simultaneously with the molecules of the polyimide constituting the alignment film is a state of easy work, the liquid crystal panel, characterized in that aligning the molecules of polyimide along the electric field by forming an electric field in the alignment film Of the alignment film in the above.