TWI383213B - Manufacturing method for liquid crystal display device - Google Patents

Description

Method of manufacturing liquid crystal display device

The present invention relates to a method of fabricating a liquid crystal display device, and more particularly to a method of fabricating a liquid crystal display device that optimizes the contrast of a liquid crystal display device.

Recently, liquid crystal displays have been widely used in a wide variety of electronic products, such as notebook computers and personal digital assistants (PDAs), because of their slimness, low power consumption, and no radiation pollution. Information products. In addition to the liquid crystal type and the internal structure of the panel, the contrast value of the liquid crystal display is closely related to the characteristics of the polarizer outside the liquid crystal panel and the attaching process of the polarizer.

At present, the attaching device of the polarizer is mainly divided into a stage to roller and a roller to roller. Please refer to FIG. 1 and FIG. 2 . FIG. 1 is a schematic view showing a method of attaching a polarizer by a general type of offset machine, and FIG. 2 is a schematic view showing a method of attaching a polarizer by a roller type offset machine. As shown in FIG. 1 , the polarizer is attached to the polarizer carrier 12 by using a general type of offset machine, and the liquid crystal panel 14 is fixed to the bottom of the panel stage 16 , and then the panel is moved. The stage 16 is placed above the polarizer stage 12, and the polarizer stage 12 is lifted and tilted, and the polarizer 10 is attached to the liquid crystal surface by a roller 18. On board 14. As shown in FIG. 2, the liquid crystal panel 14 is placed on the roller stage 20 by the roller type offset machine, and the liquid crystal is rolled by the roller of the roller stage 20 as compared with the general type of offset machine. The panel 14 is moved to the attachment position, and the liquid crystal panel 14 is pressed by the support roller 22 to attach the polarizer 10.

The above two conventional methods align the polarizer 10 with the edge of the liquid crystal panel 14 when attaching, but do not relate to whether the transmission axis of the polarizer 10 is matched with another polarized light that has been attached to the liquid crystal panel 14. The penetration axis of the sheet (not shown) is corrected, so that it is easy to cause a shift in the transmission axis when the polarizer 10 is attached. In the production process of the polarizer, the relative angle between the transmission axis of each polarizer and its appearance is also different. Therefore, when the polarizer is attached, only the appearance of the polarizer and the liquid crystal panel is considered, and The difference in the relative angles of the transmission axes of the two polarizers is not taken into account, which will cause a greater difference in the optical characteristics between the manufactured liquid crystal panels, which not only affects the dark state luminance and the contrast value, but also affects the gamma. Other optical properties such as gamma values.

Therefore, the conventional technique utilizes the angle at which the polarizer penetrates the axis to improve the difference in optical characteristics between the liquid crystal panels. Please refer to FIG. 3, which is a flow chart of a conventional method for attaching a polarizer. As shown in FIG. 3, first, step 30 is performed to measure the direction of the transmission axis of the first polarizer and the second polarizer. Thereafter, in step 32, the first polarizer is attached to one side of the liquid crystal panel. Then proceed to step 34 to invert the liquid crystal panel. Then, in step 36, the second polarizer is attached to the other side of the liquid crystal panel according to the direction of the transmission axis of the first polarizer and the second polarizer, and the first polarizer and the second polarizer are attached. The direction of the transmission axis is perpendicular to each other.

Although the method of the perpendicular direction of the first polarizer and the second polarizer perpendicular to each other allows the liquid crystal panel to have a relatively stable dark state, the liquid crystal molecules in the liquid crystal panel have optical rotation, and the liquid crystal panel is caused by process error. The polarizing plate and the alignment angle cannot be accurately aligned, so that some of the polarized light cannot be extinguished during the passage of the liquid crystal panel, so that the polarized light will penetrate the polarizer with linear polarization, and the original should be dark. The liquid crystal display device has some light ray generation, so that the liquid crystal display device cannot have a true dark state, and the contrast of the liquid crystal display device is relatively reduced.

It is an object of the present invention to provide a method of fabricating a liquid crystal display device for improving the problem of penetration of some of the light rays in the dark state of the liquid crystal panel and improving the contrast of the liquid crystal display device.

According to the scope of the invention of the present invention, the present invention provides a method of manufacturing a liquid crystal display device. First, a liquid crystal panel is provided, wherein the liquid crystal panel has a first surface and a second surface. Next, provide a first a polarizer and attaching the first polarizer to the first surface of the liquid crystal panel. Then, a second polarizer is disposed, and the second polarizer is disposed on one side of the second surface of the liquid crystal panel, and the second polarizer and the first surface and the second surface of the liquid crystal panel are The surface is parallel to a reference plane. Thereafter, a light source is provided, and the light generated by the light source is passed through the second polarizer and the liquid crystal panel, and an optical sensor is used to detect a light passing through the second polarizer and the light of the liquid crystal panel. strength. Then, the second polarizer and the liquid crystal panel are relatively rotated on the reference plane, so that a relative angle is generated between the second polarizer and the liquid crystal panel, and the optical sensor detects that the optical sensor detects The relative angle between the second polarizer and the liquid crystal panel when the light intensity reaches a specific value.

The invention measures the relative angle between the second polarizer and the liquid crystal panel when the light intensity detected by the optical sensor reaches the minimum or maximum value, and then attaches the second polarizer to make the whole The dark state or the bright state of the liquid crystal panel is optimized, thereby improving the contrast of the liquid crystal display device.

Please refer to FIG. 4, which is a flow chart of a method of manufacturing a liquid crystal display device of the present invention. As shown in FIG. 4, the flow of a method for manufacturing a liquid crystal display device includes the following steps: Step 100: providing a liquid crystal panel, wherein the liquid crystal panel has a first surface and a second surface; Step 102: providing a first polarizer and attaching the first polarizer to the first surface of the liquid crystal panel; step 104: providing a second polarizer; and step 106: disposing the second polarizer on the liquid crystal panel One side of the second surface, and the second polarizer and the first surface and the second surface of the liquid crystal panel are parallel to a reference plane; Step 108: providing a light source and passing the light generated by the light source through the second polarizer a liquid crystal panel having a first polarizer; step 110: detecting, by an optical sensor, a light intensity of light passing through the second polarizer and the liquid crystal panel having the first polarizer; and step 112: applying the second polarizer Performing a relative rotation with the liquid crystal panel having the first polarizer on the reference plane to generate a relative angle between the second polarizer and the liquid crystal panel having the first polarizer, and measuring the optical sensor detecting The relative angle between the second polarizer and the liquid crystal panel having the first polarizer when the light intensity reaches a specific value; Step 114: determining that the second polarizer has the light intensity detected by the optical sensor reaching a specific value First If the liquid crystal panel of the polarizer is divorced, if the second polarizer is not divorced from the liquid crystal panel having the first polarizer, step 116 is performed. If the second polarizer and the liquid crystal panel having the first polarizer are divorced, Then proceed to step 118; step 116: according to the second polarizer and the device when the light intensity reaches a certain value Having a relative angle between the liquid crystal panels of the first polarizer, attaching the second polarizer to the second surface of the liquid crystal panel having the first polarizer; and step 118: determining the second polarizer and having the first polarizer The liquid crystal panel is divorced and the attachment of the second polarizer is stopped.

In order to explain in more detail the manufacturing method of the liquid crystal display device of the present invention, please refer to FIG. 5 to FIG. 10, and please refer to FIG. 4 together. 5 to 10 are schematic views showing a manufacturing method of a liquid crystal display device of the present invention. As shown in FIG. 5 , when the step 100 is performed, the liquid crystal panel 150 is fixed to the bottom of a panel stage 152 by a vacuum nozzle (not shown), wherein the first surface 154 of the liquid crystal panel 150 is located on the liquid crystal panel 150 . The other side of the panel stage 152 is opposed to the second surface 156 of the liquid crystal panel 150 facing the panel stage 152. As shown in FIG. 6, when step 102 is performed, the first polarizer 158 is disposed above a polarizer stage 160, and then the polarizer stage 160 is moved below the liquid crystal panel 150, and then for the first polarizer 158. After the alignment with the edge of the liquid crystal panel 150 is performed, the first polarizer 158 is attached to the first surface 154 of the liquid crystal panel 150 by a roller 164 by adjusting the positions of the two. Thereafter, the liquid crystal panel 150 is inverted by a reversing device (not shown), and the liquid crystal panel 150 is fixed to the panel stage 152. At this time, the first surface 154 of the liquid crystal panel 150 faces the panel stage 152. The bottom. As shown in FIG. 7, when step 104 is performed, the second polarizer 166 is placed on the polarizer stage 160. Such as As shown in FIG. 8, when the step 106 is performed, the second polarizer 166 is disposed on one side of the second surface 156 of the liquid crystal panel 150 by the moving polarizer stage 160, and the second polarizer 166 and the liquid crystal panel 150 are disposed. The first surface 154 and the second surface 156 are parallel to a reference plane 168. The central position of the panel stage 152 and the polarizer stage 160 respectively has a first hole 170 and a second hole 172, and the first hole 170 corresponds to the second hole 172. Therefore, when step 108 is performed, the light source 174 is disposed below the polarizer stage 160 and corresponds to the second hole 172, so that the light of the light source 174 can pass through the second polarizer 166 via the second hole 172 and has the first The liquid crystal panel 150 of the polarizer 158. The light source 174 of the present invention uses a HeNe/Ne (Ray) laser of 534 nm, but the present invention is not limited thereto, and the light source 174 may be white light, monochromatic light having any single wavelength, or any two or more wavelengths. Mixed light. In addition, the optical sensor 162 provided in step 110 is disposed above the panel stage 152 and corresponds to the first hole 170, so that the optical sensor 162 can detect that it has passed through the second polarizer 166 and has the first The light of the liquid crystal panel 150 of the polarizer 158 is used to measure the light intensity of the light. It should be noted that the relative position of the light source 174 and the optical sensor 162 is not limited to the above position. For example, the light source 174 may be disposed on one side of the panel stage 152, and the optical sensor 162 may be disposed on the polarizer. One side of the stage 160.

Please refer to Fig. 9, which is a top view along line AA' in Fig. 8. As shown in FIG. 9, in step 112, the step of relatively rotating the second polarizer 166 and the liquid crystal panel 150 on the reference plane 168 is The second polarizer 166 is fixed, and then the liquid crystal panel 150 is rotated on the reference plane 168. However, the present invention is not limited thereto, and the liquid crystal panel 150 may be fixed first, and then the second polarizer 166 may be rotated on the reference plane 168. The direction of rotation can be clockwise, counterclockwise, or both. Since the second polarizer 166 and the liquid crystal panel 150 having the first polarizer 158 have a polarization effect on the light that penetrates the light, the second polarizer 166 and the liquid crystal panel 150 are relatively rotated, and the optical detection is performed. The 162 will measure different light intensities at different relative angles 176. The liquid crystal panel 150 of the present invention is exemplified by a liquid crystal panel of a normally black mode. Please refer to FIG. 10, which is a diagram showing the relationship between the relative angle and the light intensity of the present invention. As shown in FIG. 10, the present invention rotates clockwise and counterclockwise every 0.1 degrees, and the light intensity of each angle is recorded in the system (not shown) of the present invention, and can be obtained through the liquid crystal panel 150. The relationship between the light intensity of the light of the first polarizer 158 and the second polarizer 166 and the relative angle 176 between the liquid crystal panel 150 and the second polarizer 166 is a paraboloid with a notch facing upward, the parabola having a lowest point or The point at which the differential is zero is the minimum value. In the present invention, the specific value of the light intensity detected by the optical sensor 162 reaches the minimum value, which represents the minimum amount of light passing through the liquid crystal panel 150 and the second polarizer 166. Therefore, at the relative angle 176 corresponding to the minimum value, the second polarizer 166 and the liquid crystal panel 150 are attached to obtain an optimum dark state. However, the present invention is not limited to rotating every 0.1 degrees, and the angle of each rotation can be adjusted according to actual needs. It is worth noting that the 0 degree in Fig. 10 represents the vertical of the first polarizer 158. In the second polarizer 166, but the relative angle 176 corresponding to the minimum value is not at 0 degrees, that is, when the first polarizer 158 and the second polarizer 166 are perpendicular to each other, the optimal dark state cannot be obtained. However, the present invention minimizes the problem that the liquid crystal panel 150 is in an optimal dark state by detecting the light intensity to a minimum value, thereby improving the problem that the optimal dark state cannot be achieved. In addition, the liquid crystal panel 150 of the present invention is not limited to the normal black mode, and may be a normally white mode liquid crystal panel, and in the case of the normal white mode, in order to achieve an optimum bright state, a specific value Need to be the maximum. It should be noted that the present invention does not need to measure the transmission axis of the first polarizer 158 before attaching the first polarizer 158, only by measuring the second polarizer 166 before attaching. The combination of the liquid crystal panel 150 having the first polarizer 158 and the transmission axis of the second polarizer 166 optimizes the dark state or the bright state of the entire liquid crystal panel, thereby reducing the conventional measurement of the first polarizer. The step of penetrating the shaft increases the production efficiency.

In addition, in step 114, it is determined whether the second polarizer and the liquid crystal panel are compatible with the standard deviation of the liquid crystal panel. For example, the optical detector can be used to detect the edge of the second polarizer and the liquid crystal panel, and then the system determines whether the edge of the second polarizer exceeds the edge of the liquid crystal panel, and if it exceeds the edge of the liquid crystal panel, the matching is determined. Divorced. Alternatively, the optical detector can be used to detect the relative angle between the second polarizer and the liquid crystal panel. If the relative angle is greater than a reference value, for example, 2 degrees, the optical intensity detected by the optical sensor does not reach a specific level. The value is still judged to be divorced. Due to the polarizer When the time is created, the actual penetration axis does not match the indication. Therefore, the step 118 determines that the second polarizer is divergent from the liquid crystal panel, and emits a warning sound, and stops the attachment of the second polarizer, thereby helping to reduce The additional patch required for divorce after the second polarizer is attached, thereby reducing the cost of wear and tear.

In summary, the method for manufacturing a liquid crystal display device according to the present invention is to measure the relative relationship between the second polarizer and the liquid crystal panel when the intensity of the light detected by the optical sensor reaches a minimum or maximum value. At the angle, the second polarizer is attached to optimize the dark state or the bright state of the entire liquid crystal panel, so that the contrast of the liquid crystal display device is optimized. Moreover, the present invention further provides a warning mechanism to prevent the step of erroneously attaching the second polarizer, which reduces the cost of additional repair and reduces the production cost.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

10‧‧‧ polarizer

12‧‧‧Polarizer stage

14‧‧‧LCD panel

16‧‧‧Board stage

18‧‧‧Roller

20‧‧‧Roller stage

22‧‧‧Support roller

30‧‧‧Steps

32‧‧‧Steps

34‧‧‧Steps

36‧‧‧Steps

100‧‧‧ steps

102‧‧‧Steps

104‧‧‧Steps

106‧‧‧Steps

108‧‧‧Steps

110‧‧‧Steps

112‧‧‧Steps

114‧‧‧Steps

116‧‧‧Steps

118‧‧‧Steps

150‧‧‧LCD panel

152‧‧‧panel stage

154‧‧‧ first surface

156‧‧‧ second surface

158‧‧‧First polarizer

160‧‧‧Polarized film stage

162‧‧‧ optical detector

164‧‧‧Roller

166‧‧‧Second polarizer

168‧‧‧ reference plane

170‧‧‧ first hole

172‧‧‧Second hole

174‧‧‧Light source

176‧‧‧relative angle

Fig. 1 is a schematic view showing a conventional method of attaching a polarizer using a general type of offset machine.

Fig. 2 is a schematic view showing a conventional method of attaching a polarizer by a roller type pasting machine.

Figure 3 is a flow chart of a conventional method of attaching a polarizer.

Fig. 4 is a flow chart showing a method of manufacturing a liquid crystal display device of the present invention.

5 to 10 are schematic views showing a manufacturing method of a liquid crystal display device of the present invention.

100‧‧‧ steps

102‧‧‧Steps

104‧‧‧Steps

106‧‧‧Steps

108‧‧‧Steps

110‧‧‧Steps

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Claims (13)

A method of manufacturing a liquid crystal display device, comprising: providing a liquid crystal panel, wherein the liquid crystal panel has a first surface and a second surface; providing a first polarizer, and attaching the first polarizer to the a second polarizer is disposed on the first surface of the liquid crystal panel; the second polarizer is disposed on one side of the second surface of the liquid crystal panel, and the second polarizer and the liquid crystal panel are a surface and the second surface are parallel to a reference plane; a light source is provided, and the light generated by the light source is passed through the second polarizer and the liquid crystal panel having the first polarizer; using an optical sensor to detect Measure a light intensity of the light passing through the second polarizer and the liquid crystal panel having the first polarizer; and the second polarizer is opposite to the liquid crystal panel having the first polarizer on the reference plane Rotating to generate a relative angle between the second polarizer and the liquid crystal panel having the first polarizer, and measuring the second when the optical intensity detected by the optical sensor reaches a specific value Polarizers and have The relative angle between the liquid crystal panels of the first polarizer; and when the optical sensor detects that the light intensity reaches the specific value, and the edge of the second polarizer exceeds the edge of the liquid crystal panel, It is determined that the second polarizer is divorced from the liquid crystal panel. The manufacturing method of claim 1, wherein when the optical sensor detects that the light intensity reaches the specific value, the edge of the second polarizer does not exceed the edge of the liquid crystal panel. The manufacturing method of claim 2, further comprising attaching the second polarizer to the relative angle between the second polarizer and the liquid crystal panel when the light intensity reaches the specific value The second surface of the liquid crystal panel. The manufacturing method of claim 1, wherein the step of relatively rotating the second polarizer and the liquid crystal panel on the reference plane comprises fixing the liquid crystal panel and rotating the second polarizer. The manufacturing method of claim 1, wherein the step of relatively rotating the second polarizer and the liquid crystal panel on the reference plane comprises fixing the second polarizer and rotating the liquid crystal panel. The manufacturing method according to claim 1, wherein the liquid crystal panel is a normally black mode liquid crystal panel. The manufacturing method of claim 6, wherein the specific value is a minimum value. The manufacturing method according to claim 1, wherein the liquid crystal panel is a normally white mode liquid crystal panel. The manufacturing method of claim 8, wherein the specific value is a maximum value. The manufacturing method of claim 1, further comprising: when the relative angle between the second polarizer and the liquid crystal panel is greater than a reference value, the light intensity detected by the optical sensor is still not When the specific value is reached, it is determined that the second polarizer is divorced from the liquid crystal panel. The manufacturing method of claim 1, wherein the light source is a white light. The manufacturing method of claim 1, wherein the light source is monochromatic light having any single wavelength. The manufacturing method according to claim 1, wherein the light source is a mixed light having any two wavelengths or more.