JP6214197B2 - Method of darkening a bright spot defect in a liquid crystal panel - Google Patents

Description

  The present invention relates to a method for darkening a bright spot defect generated in a pixel of a liquid crystal panel by irradiating a laser beam.

  In the liquid crystal panel, a defect called a bright spot defect may occur due to contamination of foreign matters in the 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. Since such bright spot defects are easily visible to human eyes, the liquid crystal panel in which the bright spot defect has occurred is often discarded as a defective product, which causes a decrease in yield in the manufacture of liquid crystal panels.

  As a method of correcting the bright spot defect in such a liquid crystal panel, the bright spot defect has been conspicuous by irradiating the color filter color material of the pixel in which the bright spot defect has occurred with a laser to darken the pixel. There is a technique to eliminate (for example, Patent Documents 1 to 3).

JP-A-3-21928 JP 2006-227621 A JP2008-170938A

  In the above-described dark spot defect of a liquid crystal panel or so-called laser repair, a color filter coloring material included in the liquid crystal panel is heated by laser irradiation, and the reaction of blackening by heat denaturation is used. . This prevents light from the backlight from being transmitted through pixels having bright spot defects. At this time, the thickness of the blackened material obtained by heating by laser irradiation may become non-uniform.

  And the place where a black thing is thin becomes an area | region (henceforth a low dark spotting degree area | region) where a dark spotting degree is locally low. When this low dark spot degree region occurs, light from the backlight leaks from the region, and thus there is a problem that the bright spot defect cannot be shielded.

  An object of the present invention was made to solve the above-described problems, and a method for darkening a bright spot defect in a liquid crystal panel so that the bright spot defect in the liquid crystal panel can be surely made a dark spot. Is to provide.

  In order to achieve the above object, a dark spot defect darkening method for a liquid crystal panel according to the present invention includes a color filter substrate in which a plurality of pixels are arranged, and a thin film transistor array for driving a pixel electrode corresponding to each pixel. This is a method for darkening a bright spot defect of a liquid crystal panel including a substrate and a liquid crystal sealed between a color filter substrate and a thin film transistor array substrate. This method irradiates a luminescent spot defective pixel having a luminescent spot defect with a laser beam with a spot size smaller than that of the luminescent spot defective pixel, and alters at least a part of the color filter substrate to lower the light transmittance. The first laser irradiation step to be performed, and the bright spot defect pixel is irradiated with laser light under laser processing conditions different from the first laser irradiation step, and the thickness of the region altered in the first laser irradiation step is made uniform. 2 laser irradiation processes. In the first laser irradiation step and the second laser irradiation step, the laser light is moved relative to the liquid crystal panel, and the laser light is scanned in the bright spot defective pixel.

  By making the thickness of the region altered in the first laser irradiation process uniform in the second laser irradiation process, the bright spot defects of the liquid crystal panel can be surely darkened.

It is a schematic sectional drawing which shows the liquid crystal module by Embodiment 1 of this invention. It is a schematic block diagram which shows the dark spot darkening apparatus of the bright spot defect of a liquid crystal panel. It is explanatory drawing which shows the flow of a laser irradiation process. (A) and (B) show dark spot target pixels before and after the dark spotting process, and (C) and (D) show dark spot target pixels before and after the uniformization process. (A) is the top view which looked at the pixel for darkening from the main surface side of a liquid crystal panel, (b) shows the c-c 'sectional view taken on the line of (a). It is a partial schematic sectional drawing which shows the modification of the liquid crystal panel by Embodiment 1 of this invention. It is explanatory drawing which shows the production | generation method of the scanning path | route of the laser spot by Embodiment 2 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or similar components are denoted by the same reference numerals. Note that some drawings may be exaggerated for easy understanding. For example, the thickness of each element in the illustrated liquid crystal module is greatly different from the actual ratio.

Embodiment 1 FIG.
FIG. 1 is a schematic cross-sectional view of the liquid crystal module according to the first embodiment.
The liquid crystal module 16 includes a liquid crystal panel 15, a backlight 12, a liquid crystal panel drive control board 17, and the like. The backlight 12 is arranged on the back side of the liquid crystal panel 15 (the surface opposite to the surface facing the eyes when viewing the liquid crystal panel, the lower side in FIG. 1). The liquid crystal panel 15 and the backlight 12 are electrically connected to a liquid crystal panel drive control device 17 that controls these operations.

  The liquid crystal panel 15 includes a liquid crystal 7 sealed between a color filter substrate 13 and a thin film transistor substrate (hereinafter referred to as a TFT (TFT: Thin Film Transistor) substrate) 14.

  The color filter substrate 13 transmits light in a specific wavelength range corresponding to red, green, blue, and the like from the color filter substrate side polarizing plate 2, the color filter substrate side glass substrate 3 from the front side of the liquid crystal panel 15. A color filter color material 1 that expresses color, a black matrix 4 that is disposed between adjacent pixels and blocks transmitted light, a counter electrode 5 for applying a voltage to the liquid crystal 7, and molecules of the liquid crystal 7 in a predetermined direction. And a color filter substrate side alignment film 6 for aligning.

  As the color filter color material 1, for example, a colored one such as polyimide, acrylic, or epoxy resin is used, and the film thickness is about 1 μm by way of example. In the color filter color material 1, red, green, and blue are arranged in order without the same color being continuous. The black matrix 4 is a film having excellent light shielding properties, and a black resin to which carbon is added, a metal chromium film, or the like is used. The metal chromium film can be made as thin as about 0.1 μm. The counter electrode 5 is formed of a transparent conductive film such as ITO (Indium Tin Oxide), for example, and has a thickness of about 50 to 150 nm. The color filter substrate-side alignment film 6 is made of, for example, polyimide and has a film thickness of about several tens of nm.

  The TFT substrate 14 includes, from the back side of the liquid crystal panel 15, a TFT substrate side polarizing plate 11, a TFT substrate side glass substrate 10, a TFT array 9 for controlling the voltage applied to the liquid crystal 7 for each color pixel unit, and a liquid crystal And a TFT substrate side alignment film 8 for aligning 7 molecules in a predetermined direction. As the TFT substrate side alignment film 8, the same film as the color filter substrate side alignment film 6 can be used. The TFT array 9 includes pixel electrodes (not shown) for applying a voltage corresponding to each pixel of the liquid crystal 7, TFTs arranged in an array, and the like.

  As the backlight 12, for example, a point light source such as a light emitting diode or a fluorescent tube or a surface light source formed by using a linear light source and a light guide, or a surface light source using an electroluminescence element is used.

  The drive control board 17 includes a control IC and the like, and is electrically connected to the TFT array 9 and the backlight 12, and drives the liquid crystal 7 by controlling the operation of the TFT array 9 of the liquid crystal panel 15. The operation of the backlight 12 is also controlled.

  In the liquid crystal module 16 as described above, a bright spot defect may occur in the liquid crystal panel 15 due to contamination of foreign matters during the production of the liquid crystal panel 15. The bright spot defect darkening method according to the present embodiment targets the liquid crystal panel 15 in which such a bright spot defect has occurred, and has a bright spot defect in the color filter color material 1 constituting the liquid crystal panel 15. The color filter colorant formed on the pixel (hereinafter referred to as a bright spot defective pixel) is irradiated with a laser to darken the bright spot defective pixel and shield the bright spot defect on the liquid crystal panel 15.

Next, the bright spot defect darkening device 100 of the liquid crystal panel will be described.
Here, “darkening of bright spot defects” is not only to completely darken the bright spot defective pixels, but also to reduce the light transmittance of the bright spot defective pixels to a certain extent to darken the brightness of the pixels. This also includes making it inconspicuous.

FIG. 2 is a schematic configuration diagram showing an apparatus for darkening a bright spot defect of a liquid crystal panel.
The dark spotting device 100 includes a laser irradiation / observation unit 18 and a liquid crystal panel installation unit 19. The laser irradiation / observation unit 18 has functions such as generation, shaping (adjustment), and focusing of laser light, and a function of observing the liquid crystal panel 15. The liquid crystal panel installation unit 19 is a part on which the liquid crystal panel 15 to be irradiated with laser light is installed, and moves the liquid crystal panel 15 in the X and Y directions substantially orthogonal to each other with respect to the laser irradiation / observation unit 18. It has a function. In this apparatus 100, the laser beam generated by the laser irradiation / observation unit 18 is irradiated toward the bright spot defective pixels on the liquid crystal panel 15 installed in the liquid crystal panel installation unit 19, thereby causing the color of the bright spot defective pixels to be increased. The filter coloring material 1 and the like are altered by laser processing.

First, the laser irradiation / observation unit 18 will be described.
Of the laser irradiation / observation unit 18, a part that generates laser light includes a laser oscillator 20, a laser drive power supply 21, and the like, and power is supplied from the laser drive power supply 21 to the laser oscillator 20 to generate laser light. As the laser oscillator 20, a light source such as a solid-state laser, a gas laser, a laser diode (LD), or a fiber laser can be used.

  Of the laser irradiation / observation unit 18, a part for adjusting and condensing the laser beam is constituted by a laser beam adjusting optical system 22, a transfer mask 23, an objective lens 24, and the like. The laser beam adjusting optical system 22 is composed of a lens such as a spherical lens or a cylindrical lens, a prism, a diffractive optical element, and the like, and adjusts the laser beam to a beam profile suitable for dark spot of a bright spot defective pixel.

  The transfer mask 23 has an opening shape such as a substantially circular shape or a substantially rectangular shape, and has a mechanism for changing the size of the opening. As an example of the transfer mask 23, an iris diaphragm can be used in the case of a circle, and a slit can be used in the case of a rectangle. In the iris diaphragm, the aperture diameter can be adjusted by adjusting the overlapping degree of the diaphragm blades. The slit is composed of two pairs of slits that are substantially orthogonal, and the opening width can be adjusted by adjusting the distance between the slits. When the laser beam adjusted to a suitable beam profile by the laser beam adjusting optical system 22 passes through the transfer mask 23, it is shaped into an opening shape (for example, a circle, a rectangle, etc.) of the transfer mask 23.

  The objective lens 24 reduces and transfers the laser beam shaped by the transfer mask 23 onto the liquid crystal panel 15 with a predetermined spot size. Here, the “spot size” is a typical length of the outer shape of a laser spot having a two-dimensional extent, and is a diameter when the laser spot is circular, or a side length when the laser spot is rectangular. be able to. The laser output at the processing point can be adjusted by the laser output generated by the laser oscillator 20, the spot size at the processing point, and the like.

  The spot size on the liquid crystal panel 15 is determined by the opening shape 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 and the magnification of the objective lens 24 is 40 times, 200 μm is transferred at 1/40 times, so the spot size on the liquid crystal panel 15 is 200 μm × 1/40 = 5 μm.

  Here, if the spot size is too large, the color filter color material 1 and the like are not deteriorated, and the probability of damaging the color filter substrate 13 increases. On the other hand, if the spot size is too small, it is not possible to obtain a dark spot level sufficient for shielding bright spot defects. Therefore, by adjusting the opening shape of the transfer mask 23 as a processing parameter, or by changing the transfer magnification of the objective lens 24, the spot size is adjusted according to the type of the liquid crystal panel 15 and the type of the color filter color material 1. Optimize.

  Of the laser irradiation / observation unit 18, the part for observing the laser beam is constituted by a mirror 25, a camera 26, and the like. The camera 26 is a CCD camera, for example, and corresponds to an example of an “imaging device” in the claims. Part of the light that illuminates the liquid crystal panel 15 is reflected by the mirror 25 in the direction of the camera 26, so that the state of the liquid crystal panel 15 can be observed by the camera 26.

  The laser irradiation / observation unit 18 is provided with a Z stage 27 having an actuator, a motor and the like as a drive unit. When irradiating a laser beam for darkening a bright spot defective pixel or observing the liquid crystal panel 15, it is necessary to focus on the liquid crystal panel 15. The Z stage 27 is configured to be movable in the vertical direction in FIG. As a result, the distance between the laser irradiation / observation unit 18 and the liquid crystal panel 15 is adjusted to adjust the focus.

  Here, when the spot size on the liquid crystal panel 15 is as small as several μm, for example, when the distance between the objective lens 24 and the liquid crystal panel 15 fluctuates due to the inclination of the liquid crystal panel 15 or the like, The shape of the laser spot changes, which makes laser processing unstable. For stable processing, it is effective to maintain the distance between the objective lens 24 and the liquid crystal panel 15 at a predetermined value. This can be done, for example, by calculating the distance between the objective lens 24 and the liquid crystal panel 15 by image processing by the processing unit 200 described later, and automatically controlling the Z stage 27 based on this distance.

Next, the liquid crystal panel installation unit 19 will be described.
The liquid crystal panel installation unit 19 includes an XY stage 28 having an actuator, a motor and the like as a drive unit, a panel installation unit 29 for installing the liquid crystal panel 15, an observation light source 30 installed on the back side of the XY stage 28, and the like. Is done. As the observation light source 30, a light emitting diode, a lamp, or the like can be used. The panel installation unit 29 is installed on the front side of the XY stage 28 and can move in two directions substantially orthogonal to each other in a plane substantially perpendicular to the laser light incident on the liquid crystal panel 15. The panel installation unit 29 is positioned so that the laser beam can be irradiated to an arbitrary place on the liquid crystal panel 15 by the movement of the XY stage 28.

  If the laser irradiation / observation unit 18 moves relative to the liquid crystal panel 15, the panel installation unit 29 can be positioned. Therefore, the laser irradiation / observation unit 18 side is not the XY stage 28 but the X, Y You may be comprised so that it can move to a direction.

  Further, the panel installation portion 29 is provided with a transmission hole 31, and light emitted from the observation light source 30 is irradiated to the liquid crystal panel 15 through the transmission hole 31, thereby observing the liquid crystal panel 15 being processed. It can be done. The emitted light can be observed by a camera 26 provided in the objective lens 24 of the laser irradiation / observation unit 18. In order to condense the light emitted from the observation light source 30, it is preferable to provide a condensing lens or the like between the light source 30 and the panel installation part 29.

  In addition to the above configuration, the dark spotting device 100 includes a processing unit 200 having a CPU (Central Processing Unit), a memory, and an input unit such as a mouse or a touch panel. The processing unit 200 is connected to the camera 26 by a cable, and is connected to the driving units of the Z stage 27 and the XY stage 28 by cables via A / D converters (not shown).

  The processing unit 200 automatically generates an image processing unit 210 that processes an image captured by the camera 26 and calculates a luminance value for each pixel and a luminance value distribution within one pixel, and a scanning path of the laser spot. Scanning path generation means 220. The image processing unit 210 also has a function of calculating the distance between the objective lens 24 and the liquid crystal panel 15 based on the captured image, for example, using the pixel size as a reference.

  Further, the processing unit 200 determines the luminance value of each pixel calculated by the image processing unit 210, the calculation result of the distribution of the luminance value within one pixel, or the automatically generated scanning path. A control signal can be transmitted to the drive unit. Similarly, a control signal can be transmitted to the drive unit of the Z stage 27 so that the distance between the objective lens 24 calculated by the image processing unit 210 and the liquid crystal panel 15 becomes a predetermined value.

  Next, a method for darkening a bright spot defective pixel will be described.

  Here, the region to be darkened is a pixel of the liquid crystal panel 15 or a part of the pixel, and has a rectangle with one side of several tens to several hundreds of μm or a shape close to a rectangle. It is the color filter color material 1 and the alignment films 6 and 8 of the liquid crystal panel 15 that are altered by laser irradiation. These are thin films having a thickness of several μm or less. When the laser beam is irradiated, these thin films absorb the laser beam and are heated, and are thermally denatured to become dark spots. However, it is not necessary for all of these thin films to be heat-denatured, and it is sufficient that at least one of them is heat-denatured to reduce the light transmittance.

  In laser processing of such a thin film, if the laser output at the processing point is too large, rapid heating due to laser irradiation may cause stress on the thin film due to rapid thermal expansion, and the thin film may be damaged. As described above, when the color filter color material 1 or the like is damaged in the liquid crystal panel, impurities and foreign matters are scattered in the liquid crystal, and new defects are generated in pixels around the darkened pixels.

  On the other hand, if the laser output at the processing point is reduced, damage to the thin film can be suppressed. However, if the laser output is too small, the energy applied to the thin film to be darkened is insufficient, and the bright spot defects are shielded. It is not possible to obtain a sufficient dark spot level.

  Therefore, in order to obtain a sufficient degree of dark spot while suppressing damage to the thin film, it is necessary to optimize the laser output at the processing point and the spot size at the processing point. In this embodiment, the optimum spot size at the processing point is about several μm to several tens of μm. In order to darken a bright spot defect pixel with a side of several tens of μm to several hundreds of μm without gaps using a laser spot having the spot size, in the present embodiment, the laser spot is relative to the liquid crystal panel. To scan.

  As described above, the dark spot of the bright spot defective pixel is caused by the color filter color material 1 and the like being thermally denatured and blackened due to a temperature rise due to laser irradiation. By the way, a low dark spot degree region having a low dark spot degree may occur locally in a region to be dark spotted during or after dark spotting. This phenomenon is particularly noticeable when the area of the pixel is large and, therefore, the area of the region to be darkened is large. Since the light transmittance is high in the low dark spot area, if the low dark spot area occurs at a predetermined ratio or more with respect to the area of the dark spot target area, the bright spot defect is sufficiently shielded. Cannot be done, thus leading to laser repair failure.

  According to the investigation by the present inventor, it has been found that the material darkened in the thin film (hereinafter, blackened material) is thinned in the low dark spot region. This is considered to be because the darkened material is locally thinned when the material darkened by heating by laser irradiation is cooled and contracts.

  Therefore, the present invention has been made in order to suppress the occurrence of a local low dark spot region, which occurs when the color filter color material 1 and the like are deteriorated by laser irradiation, and to increase the success probability of laser repair. Is.

Based on the above consideration, each process included in the dark spot darkening method of the bright spot defective pixel will be described.
First, the liquid crystal panel 15 is installed on the XY stage 28. At this time, the liquid crystal panel 15 is installed on the transmission hole 31 of the XY stage 28 so that the observation light emitted from the observation light source 30 is irradiated onto the liquid crystal panel 15.

  Next, an all black display signal is sent from the liquid crystal panel drive control device 17 to the liquid crystal panel 15 to place the liquid crystal panel 15 in an all black display state. Thus, when observing the liquid crystal panel 15, it is preferable to display all black. By displaying all black, the portion other than the bright spot defect is displayed in black, while in the bright spot defect portion, the observation light emitted from the observation light source 30 leaks to become a bright spot, and is determined as a bright spot defect. It becomes easy to do.

  Next, the observation light source 30 emits observation light to the liquid crystal panel 15, and the light leaking from the liquid crystal panel 15 is received by the camera 26 to observe the bright spot defect of the liquid crystal panel 15. Next, the XY stage 28 is moved and positioned so that laser light can be irradiated toward the dark spot target pixel 40 (see FIG. 3) of the liquid crystal panel 15.

  Next, a laser irradiation process is performed. Here, if the dark spot processing by laser irradiation can be performed in a state where the color filter substrate side polarizing plate 2 and the TFT substrate side polarizing plate 10 of the liquid crystal panel 15 are attached, the repair effect of laser repair is increased. However, if the damage to the polarizing plate due to laser irradiation is not torn or it is difficult to observe the dark spot object, remove one or both polarizing plates and perform the dark spot treatment. Also good.

  FIG. 3 is an explanatory diagram showing a flow of the laser irradiation process. 3A and 3B show the dark spot target pixels before and after the dark spotting process, and FIGS. 3C and 3D show the dark spot target pixels before and after the uniformization process. 3A is a plan view of the darkening target pixel viewed from the main surface side of the liquid crystal panel, and FIG. 3B is a cross-sectional view taken along the line c-c ′ in FIG. FIG. 3 shows a case where only the color filter color material 1 is blackened.

  In the dark spotting method according to the present embodiment, as a laser irradiation step, a substance in a thin film such as the color filter color material 1 is thermally denatured by laser irradiation to blacken, and a dark spot target area is darkened. It includes two processes, a dark spot process and a uniform process for making the thickness of the blackened material uniform. The homogenization step is performed twice or more as necessary. The dark spot forming step and the uniformizing step correspond to “first laser irradiation step” and “second laser irradiation step” in the claims, respectively.

First, the dark spot forming step will be described.
In the dark spotting step, the laser beam is irradiated while scanning along the scanning path indicated by the arrow in FIG. The laser light emitted from the laser oscillator 20 is shaped and condensed through the laser beam adjusting optical system 22, the transfer mask 23, and the objective lens 24, and directed toward the dark spot target pixel (bright spot defect pixel) 40 on the liquid crystal panel 15. Is irradiated. As a result, a part of the color filter substrate 13 is altered to reduce the light transmittance, thereby darkening the bright spot defect.

  The laser beam scanning is performed by driving the XY stage 28 of the panel installation unit 29 on which the liquid crystal panel 15 is installed. When the laser irradiation / observation unit 18 side can be moved in the X and Y directions, scanning may be performed by moving the laser irradiation / observation unit 18 side in the X and Y directions.

  In this dark spotting step, it is necessary to scan the laser spot without any gap in the area to be dark spotted. As shown in FIG. 3A, the laser spot is scanned back and forth in a zigzag manner along the scanning path from one corner of the dark spot target pixel 40, and the corner is different from the corner near the processing start point. The scanning is terminated when reaching. This scanning path is not limited to that shown in FIG. 3A, and any path may be used as long as it scans the area to be darkened without gaps. In FIG. 3A, the laser spot is a square region, but a rectangular region or the like may be used.

  The spot size is desirably relatively small in order to suppress damage to thin films such as the color filter color material 1 and the alignment films 6 and 8, and is illustratively 3 μm.

  In the dark spotting process, the laser light is continuously used (CW: Continuous Wave) to reduce the thermal effect on the surroundings of the dark spot area and obtain the temperature rise of the color filter colorant 1 and the like necessary for dark spotting. It is effective to generate oscillation or quasi-continuous wave (QCW). In particular, by using quasi-continuous oscillation, it is possible to reduce the thermal influence around the dark spot region.

Next, the uniformizing process will be described.
After the dark spotting step, as shown in FIG. 3B, the thickness of the blackened material becomes non-uniform, and a low dark spot level region 42 may be generated locally. Therefore, the darkening process is followed by a homogenization process, and the thickness of the blackened material is made uniform by laser irradiation again. However, in the dark spot forming step, a sufficient temperature increase of the thin film or the like was necessary for the thermal denaturation of the thin film such as the color filter coloring material 1, but in the uniformizing step, the thin film was irradiated by laser irradiation. It is necessary not to increase the temperature but to move the resulting blackened material. Therefore, in the uniformizing process, laser irradiation is performed under laser processing conditions different from those in the dark spot forming process.

  “Laser processing conditions” include laser output at a processing point, laser pulse waveform, laser wavelength, laser spot shape (including spot size), scanning path, scanning speed, and the like. In consideration of the laser processing conditions in the dark spotting process, the laser processing conditions are selected in the homogenizing process so that the movement of the blackened material occurs appropriately.

  For example, a pulsed laser is preferably used in the homogenization process. Therefore, conditions where the laser peak output is high and the laser average output is low tend to be optimal. In order to obtain such high peak output and low average output laser light, for example, LD, Q-switched laser, mode-locked laser, etc. can be used. In particular, the Q-switched laser can adjust the frequency of laser light relatively freely, and it is easy to obtain laser light with high peak output and low average output. As described above, by processing with laser light having a low laser average output and a high laser peak output, it is possible to efficiently uniformize the thickness of the blackened product while suppressing the thermal effect.

  Further, in the homogenization process, a larger spot size is optimal compared to the dark spotting process for more efficient homogenization. However, as in the dark spotting step, if the spot size is too large, the color filter color material 1, the alignment films 6 and 8, and the like may be damaged. Therefore, by using a highly anisotropic rectangular region as shown in FIG. 3C, for example, a laser spot of 2 μm × 10 μm or the like, both efficient uniformization and suppression of damage to the thin film can be achieved.

  In addition, as in the scanning process in the darkening process even in the uniformization process, if laser irradiation is performed on the entire dark spotting target pixel 40 without a gap, the blackening object is black regardless of where the thinned area is generated. The thickness of the compound can be made uniform. However, the area to be processed in the homogenization process is around the area where the blackened material is thinned, and the area where the blackened material tends to be thinned in the darkening process is the scanning path, the laser spot, and the liquid crystal panel 15. It can be predicted to some extent depending on the configuration.

  Therefore, for example, before the dark spotting process, an area where the blackened material is likely to become thin in the dark spotting process is input to the processing unit in advance, and the scanning path generation unit 220 generates the scanning path. Then, the laser spot is scanned only around the area in accordance with the generated scanning path as indicated by an arrow in FIG. By limiting the laser irradiation in the uniformization process to only a part of the dark spot area, the processing time can be shortened and productivity can be improved.Furthermore, laser repair failure due to application of excess heat can be avoided. Can be suppressed.

  As described above, according to the first embodiment, in addition to the dark spotting process, the bright spot defects of the liquid crystal panel 15 are surely eliminated by performing the uniformizing process under the laser processing conditions different from the dark spotting process. Can darken.

FIG. 4 is a partial schematic cross-sectional view showing a modification of the liquid crystal panel according to Embodiment 1 of the present invention.
The configuration of FIG. 4 is different from the configuration of FIG. 1 in that an overcoat (protective film) 50 is provided on the liquid crystal 7 side of the color filter color material 1. For the overcoat 50, for example, an acrylic resin is used.

  As described above, for example, if the laser output at the processing point is too large, the thin film may be damaged. When the thin film is broken in the liquid crystal panel 15 in this way, impurities and foreign matters are scattered in the liquid crystal 7 and there is a possibility that a new defect may occur in the pixels around the darkened pixels.

  As in this modification, in the liquid crystal panel 15 provided with the overcoat 50, the blackened color filter color material 1 is confined in the overcoat 50, so that diffusion of impurities and foreign matters can be prevented. The failure probability of the resulting laser repair is relatively low. Therefore, by applying the present invention to the liquid crystal panel according to this modified example, the effect of increasing the success probability of laser repair appears more remarkably.

Embodiment 2. FIG.
Hereinafter, only differences from the first embodiment will be described.
In the first embodiment, the scanning path of the uniformization process is generated in advance regardless of the result of the dark spotting process. In the second embodiment, the scanning path is generated according to the result of the dark spotting process. Further, in order to generate the scanning path, a darkened object is thin in the darkening target pixel 40, and accordingly, an area where the degree of decrease in light transmittance due to the darkening process is small, that is, a low darkening degree area is detected. The process to perform is implemented.

  Here, in Embodiment 1, in the homogenization process, the homogenization process was performed only on the periphery of the place where the blackened product tends to be thin. However, depending on the LCD panel model and the laser processing conditions of the dark spot process, there is no specific place where the blackened product is likely to be thinned. It may not be known before. At this time, as described in the first embodiment, it is conceivable to perform laser irradiation with no gap toward the entire dark spot target pixel 40, but there is a problem that the processing time becomes long. Therefore, in the second embodiment, even in the case where the low dark spot degree region is randomly generated as described above, the uniformization process can be performed efficiently.

  First, in the processing unit 200, a uniformization process execution region 60 including the region is specified. The uniformization process execution area | region 60 is comprised by the combination of a rectangle or an ellipse, for example. For example, the operator recognizes (manually detects) a low dark spot degree area on the observation image of the dark spot target pixel 40, and the position of the recognized area is pointed to the input unit of the processing unit 200 using, for example, a mouse. Or by performing a touch operation on the touch panel for input.

  Alternatively, the image processing unit 210 of the processing unit 200 automatically detects a region where the luminance value is less than a certain value (low dark spot region), and automatically approximates the detected region with a combination of a rectangle or an ellipse. You may do it.

  After designating the uniformization process execution region 60 as described above, the scanning path generation unit 220 generates a scanning path for the laser spot.

  FIG. 5 is an explanatory diagram of a method for generating a scanning path of a laser spot according to the second embodiment of the present invention. The arrows shown in FIG. 5 represent automatically generated scanning paths. In order to suitably equalize the thickness of the blackened material, it is preferable to generate a scanning path that reciprocally scans in a zigzag manner without gaps as shown in FIG. The angle formed by the zigzag is basically 90 degrees. However, as shown by the symbol X in FIG. 5, for example, when an overlap occurs in a rectangular area in the uniformization process execution area 60, the angle is appropriately changed. To generate a scanning path.

  As described above, according to the second embodiment, after the dark spotting step, the low dark spot degree area is detected, and the scan path is generated based on the detected area, thereby making the low dark spot degree area randomly. Even when it is difficult to predict a region where the blackened material is likely to be thinned in the dark spot target pixel 40 before the dark spot process, the brightness of the liquid crystal panel 15 is surely reduced while shortening the processing time. Point defects can be darkened.

  As described in the second embodiment, the detection of the low dark spot degree region in the uniformizing process is not only performed by the operator's recognition, but also the luminance value by the image processing unit 210 of the processing unit 200. This can be done automatically by calculating the distribution. This may be applied to the positioning of the XY stage 28 in the darkening process described in the first embodiment. That is, the luminance of each pixel is calculated by the image processing unit 210, and the XY stage 28 can be positioned with the pixel having a luminance value less than a certain value as the dark spot target pixel 40.

  DESCRIPTION OF SYMBOLS 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 orientation film, 7 Liquid crystal, 8 TFT substrate side orientation 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 unit 19 liquid crystal panel installation section, 20 laser oscillator, 21 laser drive power supply, 22 laser light adjusting optical system, 23 transfer mask, 24 objective lens, 25 mirror, 26 camera, 27 Z stage, 28 XY stage, 29 panel installation section,0 observation light source, 31 transmission hole, 40 dark spot target pixel, 41 laser spot, 42 low dark spot area, 43 blackened product, 50 overcoat, 60 uniformization process execution area, 61 automatically generated scanning path , 100 dark spotting device, 200 processing unit, 210 image processing means, 220 scanning path generation means.

Claims (5)

A color filter substrate in which a plurality of pixels are arranged;
A thin film transistor array substrate for driving a pixel electrode corresponding to each pixel;
A method of darkening a bright spot defect of a liquid crystal panel comprising a liquid crystal sealed between a color filter substrate and a thin film transistor array substrate,
A first laser that irradiates a luminescent spot defective pixel having a luminescent spot defect with a laser beam with a spot size smaller than that of the luminescent spot defective pixel and alters at least a part of the color filter substrate to reduce light transmittance. Irradiation process;
Compared with the first laser irradiation process, the bright spot defect pixel is irradiated with laser light having a low average output as a temporal characteristic and a high peak output as a temporal characteristic, and is altered in the first laser irradiation process. A second laser irradiation step for making the thickness of the region made uniform,
In the first laser irradiation step and the second laser irradiation step, the laser beam is moved relative to the liquid crystal panel, and the laser beam is scanned within the bright spot defective pixels. A method for darkening point defects. A color filter substrate in which a plurality of pixels are arranged;
A thin film transistor array substrate for driving a pixel electrode corresponding to each pixel;
A method of darkening a bright spot defect of a liquid crystal panel comprising a liquid crystal sealed between a color filter substrate and a thin film transistor array substrate,
A first laser that irradiates a luminescent spot defective pixel having a luminescent spot defect with a laser beam with a spot size smaller than that of the luminescent spot defective pixel and alters at least a part of the color filter substrate to reduce light transmittance. Irradiation process;
A second laser irradiation step of irradiating the bright spot defect pixel with a laser beam under a laser processing condition different from that of the first laser irradiation step, and uniformizing a thickness of a region altered in the first laser irradiation step;
In order to generate a laser beam scanning path in the second laser irradiation step, after the first laser irradiation step, a low dark spot degree region detection for detecting a region where the degree of decrease in light transmittance is small in the bright spot defective pixel Process,
In the first laser irradiation step and the second laser irradiation step, the laser beam is moved relative to the liquid crystal panel, and the laser beam is scanned within the bright spot defective pixels. A method for darkening point defects.   The laser processing condition is selected from the group consisting of a laser output at a processing point, a laser pulse waveform, a laser wavelength, a laser spot shape, a scanning path, and a scanning speed. A method of darkening a bright spot defect in a liquid crystal panel.   In the low dark spot area detection step, the bright spot defect pixel is imaged using an image sensor, and an area where the degree of decrease in the light transmittance is small is detected based on a luminance value of the captured image. The method of darkening a bright spot defect of a liquid crystal panel according to claim 2. The liquid crystal panel has a color filter color material as a part of the color filter substrate that is altered by irradiation with laser light,
The method for darkening a bright spot defect in a liquid crystal panel according to any one of claims 1 to 4, wherein a protective film is provided between the color filter colorant and the liquid crystal.