JP2016161803A - Liquid crystal panel and manufacturing method of liquid crystal panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal panel that uniformly increases blackness of an area irradiated with a laser beam irrespective of before or after the generation of bubbles generated in the liquid crystal panel during irradiation with a laser beam, and a manufacturing method of the same.SOLUTION: A manufacturing method of a liquid crystal panel includes the steps of: irradiating a bright spot defective pixel or pixels adjacent to a bright spot defective pixel with a laser beam having a laser peak power density larger than that in a laser irradiation condition when blackening a bright spot defective pixel of a liquid crystal panel to generate bubbles in liquid crystal; and subsequently irradiating the bright spot defective pixel with a laser beam to blacken the bright spot defective pixel.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a liquid crystal panel and a method for manufacturing the same, and more particularly to blackening of bright spot defective pixels generated in a liquid crystal panel.

  In a liquid crystal panel, a defect called a bright spot defect may occur in a pixel due to foreign matter mixed in a manufacturing process. The bright spot defect is a defect that is visually recognized as a bright pixel even when a dark color such as black is displayed on the liquid crystal panel. Since it is conspicuous, a panel generated when a bright spot defect occurs is often discarded as a defective product, which causes a decrease in yield in liquid crystal panel manufacturing.

  Conventionally, as a method of correcting the bright spot defect in such a liquid crystal panel, the color filter colorant corresponding to the bright spot defective pixel of the liquid crystal panel is irradiated with a laser to blacken the bright spot defect. There was a technology to make it inconspicuous.

In this case, the laser irradiation method was as follows.
(1) Continuously irradiating a laser to change the color filter to the middle of white and black, that is, gray to make the bright spot defect inconspicuous (see, for example, Patent Document 1),
(2) The laser device is used from the upper side of the upper substrate to irradiate the laser light with the laser light focused on the boundary surface between the color filter and the upper substrate, whereby the transmittance of the color filter changes, and the light source unit (3) for irradiating a color filter included in a bright spot defective pixel with a laser so that the light transmittance of the color filter is reduced. It is changed to minimize the influence on adjacent cells (for example, see Patent Document 3).

JP-A-3-21928 JP 2006-227621 A JP 2008-170938 A

As described above, when the bright spot defect of the liquid crystal panel is corrected by laser irradiation, that is, when the laser beam is scanned, the color material of the color filter is heated to thermally denature and blacken. Blacken the pixel. A part of the heat generated by the laser irradiation diffuses to the surrounding members, and the temperature of the color filter coloring material or the like rises due to the remaining part.
During the laser beam scan for blackening, bubbles are generated in the liquid crystal, and if the thermal diffusion near the laser irradiation part changes in the middle, there is a problem that a spatial distribution is generated according to the degree of blackening.

  The present invention has been made to solve such a problem, and its purpose is to make the degree of blackening of the laser irradiated region uniform and high regardless of the occurrence of bubbles generated in the liquid crystal panel during laser beam irradiation. The object is to provide a liquid crystal panel and a method of manufacturing the same.

  In order to achieve the above object, the liquid crystal panel according to the present invention irradiates the bright spot defect pixel with a laser beam having a laser peak power density equal to or higher than a laser irradiation condition when blackening the bright spot defect pixel of the liquid crystal panel. The bubbles generated in this manner are included in the liquid crystal, and the bright spot defective pixels are blackened by irradiating the bright spot defective pixels with a laser beam.

  Further, the liquid crystal panel according to the present invention irradiates a pixel adjacent to the bright spot defective pixel with a laser beam having a laser peak power density equal to or higher than a laser irradiation condition for blackening the bright spot defective pixel of the liquid crystal panel. It has the generated bubble in the liquid crystal and has the bright spot defective pixel blackened by irradiating the bright spot defective pixel with a laser beam.

  In addition, according to the present invention, a laser beam having a laser peak power density equal to or higher than a laser irradiation condition for blackening a bright spot defective pixel of a liquid crystal panel is irradiated on the bright spot defective pixel to generate bubbles in the liquid crystal. There is provided a method of manufacturing a liquid crystal panel in which the bright spot defective pixels are irradiated with a laser beam to blacken the bright spot defective pixels.

  Further, according to the present invention, a liquid crystal is irradiated with a laser beam having a laser peak power density equal to or higher than a laser irradiation condition when blackening a bright spot defective pixel of a liquid crystal panel on a pixel adjacent to the bright spot defective pixel. There is provided a method of manufacturing a liquid crystal panel in which bubbles are generated and the bright spot defective pixels are irradiated with a laser beam to blacken the bright spot defective pixels.

  The inventor noticed that the area irradiated with laser before the generation of liquid crystal bubbles had a low degree of blackening, and that the area irradiated with laser after the generation of liquid crystal bubbles had a high degree of blackening, generated bubbles in the liquid crystal. Therefore, since the blackening of the color material is performed, thermal diffusion to the liquid crystal is suppressed, and a high and uniform blackening degree can be obtained.

It is a schematic sectional drawing of the liquid crystal module containing the liquid crystal panel used by each embodiment of this invention. It is a schematic block diagram of the laser irradiation apparatus used as a blackening apparatus of a bright spot defect pixel in the liquid crystal panel by each embodiment of this invention, and its manufacturing method. It is process drawing for demonstrating the liquid crystal panel which concerns on Embodiment 1 of this invention, and its manufacturing method. It is process drawing for demonstrating the liquid crystal panel which concerns on Embodiment 2 of this invention, and its manufacturing method.

  FIG. 1 shows a schematic cross-sectional view of a liquid crystal module 16 including a liquid crystal panel 15. In FIG. 1, the thickness of each element in the liquid crystal module 16 is illustrated to be significantly different from the actual ratio for the sake of explanation.

  The liquid crystal module 16 includes a liquid crystal panel 15, a backlight 12, a liquid crystal panel drive control device 17, and the like. The backlight 12 is disposed on the back side of the liquid crystal panel 15, that is, the surface (back side) opposite to the front side when the liquid crystal panel 15 is viewed, and below the liquid crystal panel 15 in FIG. 1. The liquid crystal panel 15 and the backlight 12 are further electrically connected to the lower liquid crystal panel drive control device 17 in FIG. 1, and the operation is controlled by the liquid crystal panel drive control device 17.

  The liquid crystal panel 15 has a structure in which the liquid crystal 7 is sandwiched between the color filter substrate 13 and the TFT substrate 14. The color filter substrate 13 is formed on the color filter substrate side glass substrate 3 and transmits the transmitted light in a specific wavelength range corresponding to red, green, and blue to express the color, and adjacent pixels. It has a black matrix 4 disposed between them to block transmitted light, a counter electrode 5 for applying a voltage to the liquid crystal 7, and a color filter substrate side alignment film 6 for aligning the liquid crystal 7 in a specified direction.

  The black matrix 4, the counter electrode 5, and the alignment film 6 are provided on the surface of the color filter substrate side glass substrate 3 on the liquid crystal 7 side, but are opposite to the surface of the color filter substrate side glass substrate 3 on the liquid crystal 7 side. The color filter substrate side polarizing plate 2 is provided on the surface.

  A TFT substrate 14 (TFT: Thin Film Transistor) is provided on the back surface of the liquid crystal 7. The TFT substrate 14 is provided on the TFT substrate-side alignment film 8 for aligning the liquid crystal 7 in a specified direction, and on the liquid crystal 7. It comprises a TFT array 9 for controlling the voltage to be applied, a TFT substrate side glass substrate 10, and a TFT substrate side polarizing plate 11. The TFT substrate side alignment film 8 and the TFT array 9 are formed on the surface of the TFT substrate side glass substrate 10 on the liquid crystal 7 side, and the TFT substrate side polarizing plate 11 is provided on the opposite surface.

The bright spot defect blackening process in the liquid crystal panel and the manufacturing method thereof according to the present invention targets the liquid crystal panel 15 and blackens it by irradiating the color filter color material 1 of the bright spot defective pixel with laser. This is for shielding the bright spot defect on the liquid crystal panel 15, that is, making it inconspicuous.
First, an apparatus used for blackening a bright spot defect of the liquid crystal panel 15 as a laser irradiation apparatus will be described below with reference to FIG.

  This blackening device is roughly divided into a laser irradiation / observation unit 18 and a liquid crystal panel installation unit 19 as shown in the figure. A laser beam generated, shaped, and condensed by the laser irradiation / observation unit 18, that is, a laser beam, is applied to the liquid crystal panel 15 installed in the liquid crystal panel installation unit 19, and the color in which the bright spot defective pixels of the liquid crystal panel 15 exist The filter color material 1 and the like are laser processed.

  The liquid crystal panel installation unit 19 includes an XY stage 28, a panel installation unit 29, and an observation light source 30. The panel installation unit 29 on which the liquid crystal panel 15 is mounted is driven by an XY stage 28 having two axes substantially orthogonal to each other on a plane perpendicular to the optical axis of the laser beam incident from the laser irradiation / observation unit 18. By driving the XY stage 28, it is possible to irradiate a laser beam to an arbitrary place on the liquid crystal panel 15. In addition, a transmission hole 31 is provided in the panel installation part 29 so that the liquid crystal panel 15 can be observed by illuminating the liquid crystal panel 15 with the observation light source 30.

The laser irradiation / observation unit 18 includes a first part that generates a laser beam, a second part that adjusts and collects the laser beam, and a third part that observes the liquid crystal panel.
The first part that generates the laser beam of the laser irradiation / observation unit 18 is constituted by a laser oscillator 20 and a laser drive power source 21. A laser beam is generated from a laser oscillator 20 driven by a laser driving power source 21. As the laser oscillator 20, a solid laser, a gas laser, a laser diode (LD), a fiber laser, or the like can be used.

  The second part that adjusts and condenses the laser beam of the laser irradiation / observation unit 18 includes a laser beam adjustment optical system 22, a transfer mask 23, and an objective lens 24. The laser beam formed by the transfer mask 23 is reduced and transferred onto the liquid crystal panel 15 by the objective lens 24.

  The transfer mask 23 is a substantially circular or substantially rectangular opening, and has a mechanism for changing the size of the opening. An iris diaphragm can be used for a circle, and a slit can be used for a rectangle. The iris diaphragm can adjust the aperture diameter by adjusting the degree of overlap of the wings. The slit is composed of two pairs of slits substantially orthogonal to each other, and the opening width can be adjusted by adjusting the distance between the slits.

  The laser beam spot on the liquid crystal panel 15 is determined by the shape of the opening of the transfer mask 23 and the magnification of the objective lens 24. For example, if the size of the opening of the transfer mask 23 is 200 μm in length × 200 μm in width and the magnification of the objective lens 24 is 40 times, the image is transferred at a ratio of 200 μm in length × 200 μm in width at 1/40 times. The laser beam spot is 200 μm long × 200 μm wide × 1/40 = 5 μm long × 5 μm wide. The diameter of the laser beam spot on the liquid crystal panel 15 can be controlled by adjusting the size of the opening of the transfer mask 23.

  The beam profile on the transfer mask 23 is adjusted by the laser beam adjusting optical system 22. The laser beam adjusting optical system 22 includes a lens, a prism, a diffractive optical element, and the like.

  The third part for observing the liquid crystal panel being processed by the laser irradiation / observation unit 18 is constituted by a mirror 25 and a camera 26. Part of the light that illuminates the liquid crystal panel 15 is reflected by the mirror 25 toward the camera 26, and the camera 26 can observe the state of the liquid crystal panel.

  The laser irradiation / observation unit 18 is installed on the Z stage 27, and the relative distance between the objective lens 24 and the liquid crystal panel 15 is adjusted for laser and observation focusing by driving the Z stage 27.

Next, a blackening process step for bright spot defective pixels will be described.
The blackened region of the liquid crystal panel is a pixel of the liquid crystal panel or a part of the pixel, and is a rectangle having a side of several tens to several hundreds of μm or a shape close to a rectangle. The color filter colorant 1 and the alignment films 6 and 8 of the liquid crystal panel 15 are blackened by the laser irradiation. In any case, the composition to be blackened is a thin film having a thickness of several μm or less. When the laser is irradiated, these thin films are heated by the absorption of the laser to be thermally denatured and blackened.

  In laser processing of such a thin film, if the laser output at the processing point is too large, the film is damaged. This is because the film is rapidly heated by laser irradiation and rapidly expands, and stress is generated on the film. When the film is broken in the liquid crystal panel 15, impurities and foreign matters are scattered in the liquid crystal, and new defects may occur in pixels around the blackened pixels.

  On the other hand, if the laser output at the processing point is reduced, damage to the film can be suppressed. However, if the laser output is too small, the energy given to the composition to be blackened is insufficient and the bright spot defect is shielded. A sufficient degree of blackening cannot be obtained.

  In order to obtain a sufficient degree of blackening while suppressing damage to the film, it is necessary to optimize the laser output at the processing point and the size of the laser beam spot at the processing point. The optimum size of the laser beam spot at the processing point is about several μm to several tens of μm. Here, the size of the laser beam spot is a typical length of the outer shape of the laser beam spot having a two-dimensional spread, and is a diameter when the laser beam spot is circular, or a side length when the laser beam spot is rectangular. . The laser output at the processing point can be adjusted by the laser output generated by the laser oscillator 20 and the size of the laser beam spot at the processing point.

  The laser beam spot is scanned relative to the liquid crystal panel 15 in order to blacken an area of a pixel having a side of several tens of μm to several hundreds of μm with a laser beam spot of several μm to several tens of μm without any gap. This scanning operation is performed by driving the XY stage 28 of the panel installation unit 29 on which the liquid crystal panel 15 is installed.

  If the blackening process by laser irradiation can be performed with the color filter substrate side polarizing plate 2 and the TFT substrate side polarizing plate 11 of the liquid crystal panel 15 attached, the repair relief effect is great. However, when damage to the polarizing plates 2 and 11 due to laser irradiation is not torn or when it is difficult to observe the blackening target, the blackening treatment may be performed after removing one or both polarizing plates.

Embodiment 1 FIG.
FIG. 3 shows a process flow and a cross-sectional view of a liquid crystal panel when the present invention corrects a bright spot defect existing in a B (blue) pixel among RGB pixels. As shown in FIG. 5A, a liquid crystal bubble 40 is irradiated by irradiating a laser on a liquid crystal panel 15 for a short time under a condition where the peak power density is higher than that of a laser irradiation condition for blackening such as a color filter. Is generated. Thereafter, the blackening process shown in FIG.
In addition, these processes can also be called the process of manufacturing a liquid crystal panel.

  In laser irradiation for generating the liquid crystal bubble 40, the spot of the laser beam is determined by the size and shape of the transfer mask 23. When the laser beam spot is large, the surface shape change to the color filter coloring material described later becomes large. Therefore, the laser beam spot should be as small as possible, and preferably about 1 μm to 3 μm. The shape of the laser beam spot may be square or round. If the laser to be used is the same as that of the black material such as the color filter color material, the apparatus configuration is simple.

  Further, one pulse is sufficient for laser irradiation for generating the liquid crystal bubble 40, and it is desirable that one pulse be used in order to minimize a damaged area of a member such as a color filter color material. As the pulsed laser, a pulsed laser such as a Q-switched laser or a mode-locked laser may be used, or a driving current may be pulsed by a pulse shape using a continuous wave laser such as a laser diode. In the latter case, the liquid crystal bubble 40 can be sufficiently generated even with an irradiation time of 1 msec or less. When the laser is irradiated for a longer time, the surface shape change of the color filter color material and the like becomes larger, so the irradiation time is desirably 1 msec or less.

  On the other hand, the laser irradiation for generating the laser liquid crystal bubble 40 may cause cracks in the color filter color material 1 in the vicinity of the laser irradiation portion, or disturb the liquid crystal alignment due to the surface shape of the color filter color material or the like. For this reason, a new display defect may occur. When the display defect is remarkable, it is visually recognized as another defect and repair failure occurs. However, if the display defect is not remarkable, it can be said that it is a more preferable state of blackening.

That is, as shown in FIG. 3A, the B pixel portion is irradiated on the liquid crystal panel 15 for a short time under a condition where the peak power density is higher than the laser irradiation condition for blackening such as a color filter. As a result, the liquid crystal bubble 40 is generated. At this time, the color filter color material 1 may be cracked 41 as illustrated. However, even if the crack 41 occurs in this way, the B pixel has not reached the blackened state because the peak power density is high.
Therefore, as shown in FIG. 5B, the B pixel is irradiated with laser for blackening, and the blackened state is obtained.

Embodiment 2. FIG.
The above repair failure problem does not pose a major problem if the pixel where the bright spot defect exists is a B pixel among the RGB pixels as in the example of FIG. 3, but the bright spot defect occurs in the G pixel or the R pixel. It becomes noticeable when there is. This is because the wavelength range of the G (green) and R (red) pixels is highly sensitive to the human eye, so even if the liquid crystal orientation is disturbed to the same extent, it is easier to see compared to the B (blue) pixels.

FIG. 4 shows a process diagram and a liquid crystal panel sectional view in blackening of the G pixel or the R pixel according to the second embodiment of the present invention. In the blackening of the G pixel or the R pixel, as shown in FIG. 5A, prior to the laser scan for blackening the target pixel, the B pixel adjacent to the target pixel is irradiated with a laser, and the liquid crystal Bubble 40 is generated. The liquid crystal bubble 40 spreads over several tens of pixels around the pixel irradiated with the laser. By irradiating the adjacent pixel with laser to generate the liquid crystal bubble 40, it is possible to obtain the effect of reducing the diffusion of heat generated by the laser irradiation to the liquid crystal 7, similar to the case where the liquid crystal bubble 40 is generated at the target pixel. .
At this time, a crack 41 may occur in the B pixel, but the crack 41 does not cause a significant display defect.

  After irradiating the B pixel with the laser to generate the liquid crystal bubble 40, the laser beam spot is moved to the blackening target pixel to blacken the target pixel as shown in FIG. Since the liquid crystal bubble 40 extending to the target pixel suppresses the diffusion of heat generated by laser irradiation into the liquid crystal, a uniform and sufficient blackened state can be obtained. In addition, by generating the liquid crystal bubble 40 by irradiating the inconspicuous B pixel, even if a display defect such as a crack 41 caused by the liquid crystal bubble occurs, it does not lead to a repair failure because it is not a significant display defect. It is possible to improve the success probability of blackening repair.

If the bubble generation step is not provided before the blackening step, liquid crystal bubbles may be generated during the blackening step. In this case, before the liquid crystal bubble 40 is generated, the energy of the laser irradiated for blackening is diffused into the liquid crystal 7, so that blackening does not progress relatively.
Since the blackening further progresses after the liquid crystal bubble 40 is generated, a spatial distribution occurs in the degree of blackening. Since light leaks from an area where the degree of blackening is low, the black spot repair fails without shielding the bright spot defect.

  As described above, according to the present invention, it is possible to prevent the laser energy for blackening from diffusing into the liquid crystal and to obtain a remarkable effect that a uniform and sufficient blackening state can be obtained.

  1 color filter color material, 2 color filter substrate side polarizing plate, 3 color filter substrate side glass substrate, 4 black matrix, 5 counter electrode, 6 color filter substrate side alignment film, 7 liquid crystal, 8 TFT substrate side alignment film, 9 TFT Array, 10 TFT substrate side glass substrate, 11 TFT substrate side polarizing plate, 12 backlight, 13 color filter substrate, 14 TFT substrate, 15 liquid crystal panel, 16 liquid crystal module, 17 liquid crystal panel drive control device, 18 laser irradiation / observation section , 19 Liquid crystal panel installation section, 20 Laser oscillator, 21 Laser drive power supply, 22 Laser beam adjustment optical system, 23 Transfer mask, 24 Objective lens, 25 Mirror, 26 Camera, 27 Z stage, 28 XY stage, 29 Panel installation section, 30 Light source for observation, 31 through Hole, 40 liquid crystal bubble, 41 crack.

Claims (10)

The liquid crystal panel has bubbles generated by irradiating a laser beam having a laser peak power density equal to or higher than a laser irradiation condition when blackening the bright spot defective pixel of the liquid crystal panel on the bright spot defective pixel, and the bright spot A liquid crystal panel having the bright spot defective pixel blackened by irradiating the defective pixel with a laser beam. The liquid crystal has bubbles generated by irradiating a pixel adjacent to the bright spot defective pixel with a laser beam having a laser peak power density equal to or higher than the laser irradiation condition when blackening the bright spot defective pixel of the liquid crystal panel. A liquid crystal panel having the bright spot defective pixels blackened by irradiating the bright spot defective pixels with a laser beam. The liquid crystal panel according to claim 1, wherein the laser beam for generating the bubble is a single energy pulse of a laser. The liquid crystal panel according to claim 1, wherein, when the bright spot defective pixel is a B pixel among RGB pixels, the bubble is generated by irradiating the B pixel with a laser beam. When the bright spot defective pixel is an R pixel or a G pixel among RGB pixels, the bubble is generated by irradiating a B pixel adjacent to the R pixel or the G pixel with a laser beam. The liquid crystal panel according to claim 2. A laser beam having a laser peak power density equal to or higher than the laser irradiation condition when blackening the bright spot defective pixel of the liquid crystal panel is irradiated on the bright spot defective pixel to generate bubbles in the liquid crystal,
A method of manufacturing a liquid crystal panel, wherein the bright spot defective pixel is irradiated with a laser beam to blacken the bright spot defective pixel. A laser beam having a laser peak power density equal to or higher than the laser irradiation condition when blackening the bright spot defective pixel of the liquid crystal panel is irradiated on a pixel adjacent to the bright spot defective pixel to generate bubbles in the liquid crystal,
A method of manufacturing a liquid crystal panel, wherein the bright spot defective pixel is irradiated with a laser beam to blacken the bright spot defective pixel. The method for manufacturing a liquid crystal panel according to claim 6, wherein the laser beam for generating the bubble is a single energy pulse of a laser. The method of manufacturing a liquid crystal panel according to claim 6, wherein when the bright spot defective pixel is a B pixel among RGB pixels, the bubble is generated by irradiating the B pixel with a laser beam. The bubble is generated by irradiating a B pixel adjacent to the R pixel or the G pixel with a laser beam when the bright spot defective pixel is an R pixel or a G pixel among RGB pixels. Liquid crystal panel manufacturing method.

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