CN107121795B - Display device, method and apparatus for manufacturing the same - Google Patents

Abstract

The invention provides a display device, a manufacturing method thereof and a manufacturing device, which can inhibit the reduction of display quality caused by bright point defects. A display device is provided with a light-reducing section (1) which covers a bright point defect section (133) when viewed from the display surface side, in at least one of a first glass substrate (GB1) and a second glass substrate (GB 2). The dimming portion includes: a colored layer (2) having a color different from that of the first glass substrate and the second glass substrate, and a cavity layer (3) including a plurality of cavities.

Description

Display device, method and apparatus for manufacturing the same

Technical Field

The invention relates to a display device, a method and an apparatus for manufacturing the same.

Background

Among various display devices, for example, a liquid crystal display device performs image display by applying an electric field generated between a pixel electrode and a common electrode to a liquid crystal layer sandwiched between a pair of substrates to drive liquid crystal, thereby adjusting the amount of light transmitted through a region between the pixel electrode and the common electrode.

Conventionally, for example, in a liquid crystal display device, a problem of a so-called bright point defect (also referred to as a pixel defect) in which the display luminance of a pixel is higher than a desired luminance is known. The bright defects are generated, for example, by mixing foreign substances between the pair of substrates in the manufacturing process of the liquid crystal display device, causing the alignment of the liquid crystal to be disturbed by the foreign substances, or causing short-circuiting between the pixel electrode and the common electrode.

For example, patent document 1 discloses a method of correcting the above-mentioned bright spot defect. In the method of patent document 1, a laser beam is irradiated into a glass substrate, and a colored layer is formed so as to cover a region where a bright point defect occurs in a plan view, thereby reducing the amount of light transmitted.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication (Kokai) No. 2015-175857

Disclosure of Invention

However, when only a colored layer is used as in the conventional art, coloring may be insufficient, and a defect of a bright point defect may not be sufficiently corrected.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a display device, a method of manufacturing the same, and a manufacturing apparatus for the same, which suppress a decrease in display quality due to a bright point defect.

In order to solve the above problem, a display device according to an aspect of the present invention includes:

a first glass substrate; and

a second glass substrate located on the display surface side opposite to the first glass substrate,

a light-reducing portion that covers the bright point defect portion when viewed from the display surface side is provided in at least one of the first glass substrate and the second glass substrate,

the light reduction portion includes:

a colored layer having a color different from that of the first glass substrate and the second glass substrate, and

a void layer comprising a plurality of voids.

Effects of the invention

According to the aspect of the present invention, it is possible to suppress the reduction of the display quality due to the bright point defect.

Drawings

Fig. 1 is a diagram showing an overall configuration of a liquid crystal display device according to a first embodiment of the present invention.

Fig. 2 is a plan view showing a structure of a part of a display panel of the liquid crystal display device of fig. 1.

FIG. 3 is an end view of the cutting section cut at line A1-A2 of FIG. 2.

Fig. 4 is a cross-sectional view schematically showing an example of a bright point defect in the liquid crystal display device of fig. 1.

Fig. 5 is a cross-sectional view showing the structure of a pixel having a light-reducing section in the liquid crystal display device according to the first embodiment.

FIG. 6 is a schematic illustration of non-bridging oxygen hole center formation in the interior of a glass substrate.

FIG. 7 is a schematic of multiphoton absorption.

Fig. 8 is a diagram showing a processing phenomenon in energy density when an ultrashort pulse laser is condensed inside a glass substrate.

Fig. 9 is a schematic view showing a principle of processing a light reduction portion in the liquid crystal display device of fig. 1.

Fig. 10 is a schematic view of a mode in which the processed laser light is scattered by the cavity.

Fig. 11 is a cross-sectional view showing another structure of a pixel having a light reduction portion in a liquid crystal display device according to a first modification of the first embodiment.

Fig. 12A is a flowchart showing a method of correcting a bright point defect in the liquid crystal display device according to the second embodiment.

Fig. 12B is a block diagram of a manufacturing apparatus of a display device capable of implementing a method of correcting a bright spot defect.

Fig. 13 is a flowchart showing a method of correcting a bright point defect in a liquid crystal display device according to a modification of the second embodiment.

Fig. 14 is a schematic diagram showing the configuration of a manufacturing apparatus of a liquid crystal display device according to a second embodiment.

Fig. 15 is a schematic diagram showing a configuration of a manufacturing apparatus of a liquid crystal display device according to another modification.

Description of the symbols

AF alignment film

BM black matrix

CF color filter

CIT common electrode

CONT contact hole

DL data line

DM drain electrode

DP display panel

GB. GB1, GB2 glass substrate

GSN insulating film

GL gate line

LC liquid crystal layer

LCD liquid crystal display device

OC overcoat layer

PAS insulating film

PIT pixel electrode

POL1 and POL2 polarizing plates

SEM semiconductor layer

SM source electrode

SUB1 TFT substrate

SUB2 CF substrate

UPAS insulating film

1. 1a dimming part

2 coloured layer

3 void layer

4 ultrashort pulse laser

5 refractive index changing layer

6 bright spot defect correcting device

7 ultrashort pulse laser oscillation mechanism

8 high-condensing lens

32 opening part

33. 1000, 1001 foreign matter

34 backlight light

90 inspection device

91 arithmetic unit

92 moving device

93 control device

95 manufacturing device of display device

100 ultraviolet or gamma rays

133 bright spot defective portion

134 backlight source

F focus

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In the following embodiments, a liquid crystal display device is exemplified, and the display device of the present invention is not limited to the liquid crystal display device, and may be, for example, an organic EL display device, a plasma display panel, or the like.

(first embodiment)

Fig. 1 is a plan view showing the entire structure of a liquid crystal display device LCD according to a first embodiment of the present invention.

The liquid crystal display device LCD includes: a display panel DP for displaying an image, a display panel drive circuit (data line drive circuit 30, gate line drive circuit 31) for driving the display panel DP, a control circuit (not shown) for controlling the display panel drive circuit, and a backlight 134 for irradiating light from the back side of the display panel DP with backlight light.

Fig. 2 is a plan view showing a structure of a part of the display panel DP. FIG. 3 is an end view of the cutting section cut at line A1-A2 of FIG. 2. Fig. 2 and 3 show one pixel P.

The display panel DP includes: a thin film transistor substrate SUB1 (hereinafter referred to as a TFT substrate SUB1) (a first substrate) disposed on the back surface side, a color filter substrate SUB2 (hereinafter referred to as a CF substrate SUB2) (a second substrate) disposed on the display surface side and facing the TFT substrate SUB1, and a liquid crystal layer LC sandwiched between the TFT substrate SUB1 and the CF substrate SUB 2.

A plurality of data lines DL extending in the column direction and a plurality of gate lines GL extending in the row direction are formed on the TFT substrate SUB1, and a thin film transistor TFT is formed near each intersection of the plurality of data lines DL and the plurality of gate lines GL. A rectangular region surrounded by two adjacent data lines DL and two adjacent gate lines GL is defined as one pixel P. A plurality of pixels P are arranged in a matrix on the TFT substrate SUB 1.

A pixel electrode PIT (display electrode) made of a transparent (light-transmitting) conductive film such as tin-doped indium oxide (ITO) is formed in the pixel P. As shown in fig. 2, the pixel electrode PIT has an opening 32 (e.g., a notch) and is formed in a stripe shape. The thin film transistor TFT has a semiconductor layer SEM made of amorphous silicon (aSi) formed on a gate insulating film GSN (see fig. 3), and a drain electrode DM and a source electrode SM (see fig. 2) formed on the semiconductor layer SEM. The drain electrode DM is electrically connected to the data line DL. The source electrode SM and the pixel electrode PIT are electrically connected to each other through the contact hole CONT.

The laminated structure of each portion constituting the pixel P is not limited to the structure of fig. 3, and a known structure may be used. For example, in the structure shown in fig. 3, in the TFT substrate SUB1, a gate line GL (see fig. 2) is formed on a first glass substrate GB1, and a gate insulating film GSN is formed so as to cover the gate line GL. Further, the data line DL is formed on the gate insulating film GSN, and the insulating film PAS is formed so as to cover the data line DL. Further, a common electrode CIT (display electrode) is formed on the insulating film PAS, and an upper insulating film UPAS is formed so as to cover the common electrode CIT. Then, a pixel electrode PIT is formed on the upper insulating film UPAS, and an alignment film AF is formed so as to cover the pixel electrode PIT. A polarizing plate POL1 (first polarizing plate) is formed on the back surface side of the first glass substrate GB 1.

In the CF substrate SUB2, a black matrix BM (light-shielding portion) and a color filter CF (for example, a red portion, a green portion, and a blue portion) (light-transmitting portion) are formed on a second glass substrate GB2 (on the lower surface side of the second glass substrate GB2 in fig. 3), and an overcoat layer OC is formed so as to cover these portions. A polarizing plate POL2 (second polarizing plate) is formed on the display surface side of the second glass substrate GB 2. Therefore, the second glass substrate GB2 is located on the display surface side opposite to the first glass substrate GB1, and the liquid crystal layer LC is disposed between the first glass substrate GB1 and the second glass substrate GB 2.

According to the structure shown In fig. 3, the liquid crystal display device LCD has a so-called IPS (In plane switching) type structure, but the liquid crystal display device LCD of the first embodiment is not limited thereto.

Next, a method of driving the liquid crystal display device LCD will be briefly described. The gate line GL is supplied with a gate voltage for scanning output from the gate line driving circuit 31, and the data line DL is supplied with a data voltage for video output from the data line driving circuit 30. When a gate-on voltage is supplied to the gate line GL, the semiconductor layer SEM of the thin film transistor TFT has a low resistance, and the data voltage supplied to the data line DL is supplied to the pixel electrode PIT via the source electrode SM. In addition, a common voltage output from a common electrode driving circuit (not shown) is supplied to the common electrode CIT. Thereby, an electric field (driving electric field) is generated between the pixel electrode PIT and the common electrode CIT, and the liquid crystal layer LC is driven by the electric field, whereby an image is displayed.

In the liquid crystal display device LCD, a bright point defect (pixel defect) may occur in which the display luminance of a pixel is higher than a desired luminance in the manufacturing process thereof. Fig. 4 shows an example of a case where the pixel P becomes the bright point defective portion 133. Fig. 4 illustrates a case where a foreign substance 33 such as an organic substance or a metal is mixed between the TFT substrate SUB1 and the CF substrate SUB2 in the manufacturing process of the liquid crystal display device LCD. In the pixel P shown in fig. 4, since the alignment of the liquid crystal is disturbed by the foreign substance (contaminant) 33, the pixel P becomes a bright point defect portion 133 where the light leakage of the backlight 34 occurs and the bright point defect exists.

The LCD of the first embodiment has a structure for suppressing the bright point defect. Specifically, as shown in fig. 5, a light reduction unit 1 for reducing the amount of transmission of the backlight light 34 is formed inside the second glass substrate GB2 of the CF substrate SUB 2. The dimming portion 1 is formed in a planar arrangement so as to cover the bright point defect portion 133 caused by the hidden foreign substance 33 when viewed from the display surface side of the second glass substrate GB 2. That is, the light reduction portion 10 covering the bright point defective portion 133 when viewed from the display surface side is disposed inside at least one of the first glass substrate GB1 and the second glass substrate GB 2. The dimming portion 1 includes: a colored layer 2 having a color different from that of the first glass substrate GB1 and the second glass substrate GB2, and a cavity layer 3 having a plurality of cavities (void) formed below the colored layer 2. The colored layer 2 is composed of non-bridging oxygen (non-bridging oxygen) hole centers.

Fig. 6 is a schematic view of non-bridge oxygen hole center formation in the interior of the second glass substrate GB 2. FIG. 7 is a schematic of multiphoton absorption. Fig. 8 is a diagram showing a processing phenomenon in energy density when an ultrashort pulse laser is condensed inside a glass substrate. Fig. 9 is a schematic diagram illustrating a processing principle of the dimming part 1. Fig. 10 is an enlarged view showing the vicinity of a converging point of the laser beam after the cavity scattering processing.

As shown in fig. 6, when ultraviolet rays or gamma rays 100 are irradiated to the non-bridge oxygen located inside the glass substrate GB, one electron is emitted to form a non-bridge oxygen hole center. The non-bridging oxygen hole center is absorptive in the ultraviolet region to the visible region and exhibits a chestnut color. The non-bridging oxygen vacancy center is generally formed by irradiation with light having a short wavelength such as ultraviolet light or gamma ray, and can also be formed by irradiation with light having a longer wavelength by utilizing a phenomenon called multiphoton absorption. As shown in fig. 7 (a), light having a short wavelength has a large energy, and non-bridge oxygen emits one electron by absorbing one photon to form a non-bridge oxygen hole center. On the other hand, light of a longer wavelength has a smaller energy, and in one photon, sufficient energy cannot be given to the emitted electron. However, in the case of an ultrashort pulse laser such as a femtosecond laser, since the electric field intensity is very strong, a plurality of photons are sometimes absorbed simultaneously in the condensed region. This is called multiphoton absorption (see fig. 7 b), and the non-bridge oxygen can obtain sufficient energy (energy from the ground state to the excited state) in releasing electrons by the multiphoton absorption, and form non-bridge oxygen hole centers. If the energy density of the light-collecting region is further increased spatially, a phenomenon such as a change in refractive index, formation of voids, or formation of cracks may occur. When the ultrashort pulse laser 4 is condensed inside the glass substrate GB using the high condensing lens, a minute hole having a diameter of 1nm or more and 50 μm or less is formed in the focal point F when the pulse energy of the ultrashort pulse laser 4 is set to an appropriate value (see the hole formation of fig. 8). By relatively moving the positions of the ultrashort pulse laser 4 and the glass substrate GB in the surface direction of the glass substrate GB, as shown in fig. 9, the ultrashort pulse laser 4 is irradiated onto the glass substrate GB while moving the focal point F in the surface direction inside the glass substrate GB, so that a plurality of minute holes having a diameter of 1nm to 50 μm are formed in the surface direction, and the cavity layer 3 is formed. At this time, the energy density is not so high that voids are formed in the glass substrate GB at a position closer to the surface than the focal point F, but there is a region having energy sufficient to form non-bridge oxygen hole centers. By relatively moving the positions of the ultra-short pulse laser 4 and the glass substrate GB in the plane direction, the region expands in the plane direction inside the glass substrate GB, and the colored layer 2 is formed. In the light reduction part 1 including the colored layer 2 and the cavity layer 3, first, the backlight light 34 irradiated from the back surface of the glass substrate GB is finely scattered by the cavity layer 3. Then, the light transmitted while being scattered is absorbed by the coloring layer 2 to be attenuated, and the attenuated light is emitted from the surface of the glass substrate GB, so that the deterioration of the display quality due to the bright point defect can be suppressed. When the positions of the ultra-short pulse laser beam 4 and the glass substrate GB are moved relative to each other in the plane direction, the ultra-short pulse laser beam 4 is focused at the focal point F, and then passes through the glass substrate GB while light not used for processing is expanded, and is irradiated to the color filter CF or the liquid crystal layer LC at the tip thereof. When the distance from the focal point F to the back surface of the glass substrate GB is short, light may impinge on the color filter CF or the liquid crystal layer LC before the energy density is sufficiently expanded to be reduced, possibly causing damage to the color filter CF or the liquid crystal layer LC. However, as shown in fig. 10, the void layer 3 formed by the irradiation has a small amount of light that is not used in the processing and has a low energy density. Accordingly, even if light passing through the glass substrate GB is irradiated on the color filter CF or the liquid crystal layer LC, the color filter CF or the liquid crystal layer LC is less damaged. The ultrashort pulse laser 4 needs to have a pulse width, a wavelength, and a pulse energy that can cause multiphoton absorption in the glass substrate GB, and preferably has a wavelength of 100 to 10000nm, a pulse width of 1fs to 100ps, and a pulse energy of 1 to 20 μ J. Further, the NA (numerical aperture) of the high condensing lens is preferably 0.3 to 0.6, and the high condensing lens preferably has an aberration correction function. By irradiating the glass substrate GB with the laser light 4 under these conditions, the cavity layer 3 including a plurality of voids as shown in fig. 9 is formed at the position of the focal point F, and the colored layer 2 is formed at a position closer to the surface of the glass substrate GB than the position of the focal point F.

According to the first embodiment, the light reduction section 1 that covers the bright point defect 133 when viewed from the display surface side is provided inside at least one of the first glass substrate GB1 and the second glass substrate GB2, and the light reduction section 1 is configured by the colored layer 2 having a color different from that of the first glass substrate GB1 and the second glass substrate GB2, and the cavity layer 3 including a plurality of cavities. With this configuration, it is possible to suppress damage to the color filter CF and the liquid crystal layer LC and to suppress a reduction in display quality due to a bright point defect.

(first modification)

Fig. 11 shows another configuration for suppressing the bright point defect in the liquid crystal display device LCD according to the first modification of the first embodiment. Note that, in fig. 11, for convenience, the following second modification and third modification are also illustrated, but the present invention is not limited to this, and needless to say, only one of the first modification to the third modification may be present in addition to the first embodiment, or any combination of these may be present.

When the light-reducing section 1 is formed, a gap may be formed between the colored layer 2 (first colored layer) and the cavity layer 3 depending on the processing conditions. Since the energy density of light irradiated to the gap is higher than that of light irradiated to the colored layer 2 and is lower when the cavity layer 3 is formed, as shown in fig. 8, the refractive index changing layer 5 (first refractive index changing layer) in which the refractive index (1.4 to 1.6) of the glass substrate GB is increased by 0.02 at maximum is formed. That is, the light reduction part 1 further includes a refractive index changing layer 5 having a refractive index larger than the first glass substrate GB1 and the second glass substrate GB2 between the first colored layer 2 and the cavity layer 3. Since light due to the bright point defect can be shielded with higher accuracy by the refractive index changing layer 5, the display quality of the display device can be further prevented from being degraded.

(second modification)

Next, a second modification of the first embodiment will be described below. The colored layer 2a (second colored layer) may be formed at a position deeper than the focal point F (hollow layer 3) (on the first glass substrate GB1 side). In this case, the cavity layer 3 is located between the first colored layer 2 and the second colored layer 2 a. The second coloring layer 2a is different in color from the first glass substrate GB1 and the second glass substrate GB2, respectively. This is because the energy density of the transmitted light after the formation of the void layer 3 at the focal point F is sufficiently high, and therefore the second colored layer 2a can be formed as a result of coloring caused by the formation of the non-bridge oxygen vacancy center. However, since the coloring concentration of the second colored layer 2a depends on the energy density, the coloring concentration of the second colored layer 2a formed by transmitting light is lower than that of the first colored layer 2 formed by incident light. The light-reducing ability of the light-reducing section 1 is further improved by the second colored layer 2a formed in this manner.

(third modification)

Next, a third modification of the first embodiment will be described below. The light reduction part 1 may further include a second refractive index changing layer 5a which is located between the cavity layer 3 and the second colored layer 2a, is formed by transmitted light after the cavity layer 3 is formed at the focal point F, and has a refractive index larger than that of the first glass substrate GB1 or the second glass substrate GB 2. In this case, since the increase amount of the refractive index depends on the energy density, the refractive index of the second refractive index change layer 5a formed by transmitting light is smaller than the refractive index of the refractive index change layer 5 formed by incident light. The difference in refractive index between the first refractive index changing layer 5 and the first and second glass substrates GB1 and GB2 is at most about 0.015. The second refractive index changing layer 5a is formed at a position closer to the foreign substance 33. Therefore, even when the backlight light 34 expands in an oblique direction due to the influence of the foreign substance 33, the second refractive index changing layer 5a can be refracted, and the expansion angle of the backlight light 34 can be reduced. This suppresses the spread of the backlight light 34, and increases the amount of backlight light 34 entering the cavity layer 3 as compared with the case where the second refractive index changing layer 5a is not formed. Therefore, the dimming capability of the dimming portion 1 is improved.

Here, the second colored layer 2a of the second modification is formed using a laser beam having a wavelength of 200nm to 9000nm inclusive, a pulse width of 2fs to 90ps inclusive, and a pulse energy of 2 μ J to 18 μ J inclusive. The NA of a lens for condensing the laser beam is 0.35 to 0.55.

The second refractive index changing layer 5a of the third modification example is formed using a laser beam having a wavelength of 300nm to 8000nm inclusive, a pulse width of 3fs to 80ps inclusive, and a pulse energy of 3 μ J to 17 μ J inclusive. The NA of a lens for condensing the laser light is 0.4 to 0.5.

(fourth modification)

Next, a fourth modification of the first embodiment will be described below. When the laser light is irradiated with the pulse energy reduced to 1 μ J or more and 4 μ J or less, the cavity layer 3 is formed at the focal point F, but the colored layer 2 is not formed at a position closer to the surface of the glass substrate GB than the focal point F, or the layer is made thin enough to be visually undetectable. That is, only the void layer 3 is formed alone. Even if the void layer 3 alone is present, the backlight 34 is effectively scattered, but the light reduction effect is not obtained. In this state, the pulse energy is increased to 3 μ J or more and 13 μ J, and the laser light is irradiated so as to be condensed at a position closer to the surface of the glass substrate GB than the cavity layer 3 alone, thereby forming the dimming portion 1 of the above-described embodiment and modification. At this time, the light is condensed at the focal point F, and a reaction such as coloring or void formation occurs in the vicinity thereof. The energy not used in this reaction spreads and is irradiated toward the back surface of the glass substrate GB, but since the single hollow layer 3 exists therebetween, the laser light is scattered by a plurality of hollows of the hollow layer 3, and the energy density is lowered. This suppresses damage to the color filter CF and the liquid crystal layer LC located close to the back surface of the glass substrate GB. After the processing, the light reduction part 1 composed of the cavity layer 3 and the colored layer 2 is formed at a position closer to the surface of the glass substrate GB than the cavity layer alone.

(other modification examples)

The dimming part 1 may be formed on the first glass substrate GB1 of the TFT substrate SUB 1. The dimming portion 1 may be formed on both the first glass substrate GB1 and the second glass substrate GB 2. That is, the dimming portion 1 may be formed on at least one of the first glass substrate GB1 of the TFT substrate SUB1 and the second glass substrate GB2 of the CF substrate SUB 2.

When the dimming portion 1 is formed on both of the first glass substrate GB1 and the second glass substrate GB2, the dimming capability can be improved. In this case, when the dimming portions 1 are formed on both sides, the dimming amount of each dimming portion 1 may be smaller than that of the case where the dimming portion is formed only on one of the glass substrates GB. Therefore, the output of the ultrashort pulse laser 4 irradiated on each glass substrate can be reduced, and damage to the lower layer due to the transmitted light is less likely to occur.

When the dimmer 1 is formed only on one of the first glass substrate GB1 and the second glass substrate GB2, the dimmer 1 is preferably formed on the second glass substrate GB 2. This is because the light irradiated by the bright point defect due to the foreign substance 33 is blocked by the foreign substance 33 on the display pixel side, and the display quality can be further improved. In particular, when the display device includes the liquid crystal layer LC located between the first glass substrate GB1 and the second glass substrate GB2 and the bright point defect 133 caused by the foreign substance 33 is included in the liquid crystal layer LC, the dimming portion 1 is preferably formed on the second glass substrate GB2 side. This is to block light caused by the alignment disorder of the liquid crystal molecules due to the foreign substance 33.

In addition, the position inside the first glass substrate GB1 of the dimming portion 1 formed on the first glass substrate GB1 may be the same as or different from the position inside the second glass substrate GB2 of the dimming portion 1 formed on the second glass substrate GB 2. For example, the dimming portion 1 may be formed on the backlight side in the first glass substrate GB1, and the dimming portion 1 may be formed on the liquid crystal layer LC side in the second glass substrate GB 2. However, it is preferable that the dimming portion 1 is formed at a position close to the foreign substance 33 as much as possible. This is because, when the areas of the formed dimmer parts 1 are the same, the formation of the dimmer parts in the areas close to the foreign substances 33 can also dim light spreading in the oblique direction by the foreign substances 33.

According to the above configuration, since the luminance of the pixel which becomes the bright point defect portion 133 can be reduced, the bright point defect (light leakage) can be made inconspicuous. This can suppress a reduction in display quality due to the bright point defect, and can improve the production yield of the liquid crystal display device LCD.

(second embodiment)

Next, as a second embodiment of the present invention, a method for manufacturing a liquid crystal display device LCD according to the first embodiment will be described. This method describes a method for manufacturing a display device including a first glass substrate GB1 and a second glass substrate GB2 located on the display surface side opposite to the first glass substrate GB 1. The method for manufacturing the display device comprises the following steps: the method includes a detection step of detecting a bright point defect of the pixel by lighting inspection of the display device, and an irradiation step of irradiating the first or second glass substrate GB1 or GB2 with laser light 4 so as to cover the bright point defect to form the colored layer 2 and the cavity layer 3. The laser beam 4 irradiated in the irradiation step has a wavelength of 100nm to 10000nm, a pulse width of 1 femtosecond to 100 picoseconds, a pulse energy of 1 muJ to 20 muJ, and is condensed by a lens having an NA of 0.3 to 0.6.

More specifically, the manufacturing method includes: a manufacturing process of the TFT substrate SUB1, a manufacturing process of the CF substrate SUB2, a bonding process of the TFT substrate SUB1 and the CF substrate SUB2, a liquid crystal injection process, a lighting inspection process of the display panel DP, and a bright point defect correction process.

In the above steps, a known method may be used for the manufacturing step of the TFT substrate SUB1, the manufacturing step of the CF substrate SUB2, the bonding step of the TFT substrate SUB1 and the CF substrate SUB2, the liquid crystal injection step, and the lighting inspection step.

For example, the process of manufacturing the TFT substrate SUB1 includes: a process of forming a gate line GL, a data line DL, a pixel electrode PIT, a common electrode CIT, various insulating films, and a polarizing plate POL1 on a first glass substrate GB 1. The pixel P defined in the TFT substrate SUB1 may include a red pixel Pr corresponding to red, a green pixel Pg corresponding to green, and a blue pixel Pb corresponding to blue. The manufacturing process of the CF substrate SUB2 includes a process of forming a black matrix BM, a color filter CF, and a polarizing plate POL2 on a second glass substrate GB 2.

The lighting inspection step and the lighting defect correction step in the present manufacturing method will be described below.

Fig. 12A is a flowchart of a method of correcting a bright spot defect. Fig. 12B is a block diagram of a display device manufacturing apparatus 95 capable of implementing a method of correcting a bright spot defect.

The display device manufacturing apparatus 95 includes at least: an inspection device 90 for inspecting the lighting of the display device and detecting the bright point defect of the pixel, and a bright point defect correction device 6. The manufacturing apparatus 95 may further include a control device 93 and a calculation unit 91. The control device 93 controls the operation of each of the inspection device 90, the arithmetic unit 91, and the bright point defect correction device 6. The calculation unit 91 performs a predetermined calculation as described later.

First, in the lighting inspection step, the inspection device 90 detects a bright point defect. For example, the inspection device 90 turns on the display panel DP all at once or line by line, and measures the luminance of each pixel (step S001).

Next, the inspection device 90 detects the pixel having the luminance exceeding the threshold as the bright point defective portion 133 (pixel defective portion) (step S002). The inspection device 90 outputs the position information of the pixel detected as the bright point defect portion 133 to the bright point defect correction device 6 described later. The detection of the bright point defective portion 133 may be performed by visual observation by an operator. When the bright point defect portion 133 is detected, the process proceeds to a bright point defect correction process (step S030). When the bright point defective portion 133 is not detected, the flow ends.

Fig. 14 shows a schematic configuration of the bright spot defect correction apparatus 6 for performing the bright spot defect correction process (step S030). The bright point defect correction device 6 includes an optical system such as an ultrashort pulse laser oscillation mechanism 7 and a high condensing lens 8.

In the second embodiment, as an example, a laser beam having a 1552nm laser wavelength and a pulse width of 800fs is used as the ultrashort pulse laser oscillation mechanism 7.

The bright point defect correction step (step S030) includes steps S003 to S006.

In the bright point defect correction step (step S030), first, the bright point defect correction device 6 acquires position information and shape information (for example, position, size, shape) of the pixel of the bright point defect from the inspection device 90 (step S003).

Next, based on the acquired shape information, the shape and position information (for example, position, size, shape) of the light reduction portion 1 formed by emitting the ultrashort pulse laser beam 4 are calculated in the calculation portion 91 (step S004).

Next, under the control of the control device 93, the optical system such as the high condensing lens 8 of the bright point defect correction device 6 is aligned based on the position information of the light reduction unit 1 calculated and acquired by the calculation unit 91.

Next, under the control of the control device 93, the bright defect correction device 6 adjusts the position of the focal point F of the ultrashort pulse laser 4 so as to be aligned with a desired position inside the second glass substrate GB 2. The position of the focal point F is adjusted based on, for example, the size of a foreign substance causing a bright point defect or a measured brightness value. For example, as shown in fig. 14, the focal point F of the ultrashort pulse laser 4 is adjusted so as to be aligned with the near side of the foreign substance 33 in the second glass substrate GB 2.

Next, under the control of the control device 93, the bright spot defect correction device 6 emits the ultrashort pulse laser 4 from the ultrashort pulse laser oscillation mechanism 7. Thus, the ultrashort pulse laser beam 4 emitted from the ultrashort pulse laser oscillation mechanism 7 is condensed by the high condensing lens 8 and irradiated at the focal point F inside the second glass substrate GB 2.

Next, the irradiation position of the ultrashort pulse laser 4 is moved by the moving device 92 under the control of the control device 93, and the ultrashort pulse laser 4 is continuously irradiated, so that the dimming portion 1 is formed (step S005), and the bright spot defect correction process (step S030) is completed (step S006).

According to the manufacturing method or manufacturing apparatus of the above embodiment, since inspection can be performed using a conventional inspection apparatus and only a portion having a defect can be made to flow into the correction process, there is an advantage that the overall process tact is not affected.

(modification example)

Fig. 13 is a flowchart showing another method of correcting a bright spot defect as a modification of the second embodiment.

First, the inspection device 90 turns on the display device (step S007), and detects a bright point defect (step S008). In the same manner as in step S002, the inspection device 90 detects the pixel whose luminance is measured to exceed the threshold as the bright point defective portion 133 (pixel defective portion). The inspection device outputs position information of the pixel detected as the bright point defect portion 133 to the bright point defect correction device 6. The detection of the bright point defective portion 133 may be performed by visual observation by an operator. When the bright point defect portion 133 is detected, the process proceeds to a bright point defect correction step (step S040). When the bright point defective portion 133 is not detected, the flow ends.

The bright point defect correction step (step S040) includes steps S009 to S013.

In the bright point defect correction step (step S040), first, the bright point defect correction device 6 acquires position information and shape information (for example, position, size, shape) of the pixel of the bright point defect from the inspection device (step S009).

Next, based on the acquired shape information, the calculation unit 91 calculates the shape and position information (for example, position, size, and shape) of the light reduction unit 1 formed by emitting the ultrashort pulse laser beam 4 (step S010).

Next, under the control of the control device 93, the optical system such as the high condensing lens 8 of the bright point defect correction device 6 is aligned based on the positional information of the light reduction unit 1 calculated and acquired by the calculation unit 91.

Next, under the control of the control device 93, the bright defect correction device 6 adjusts the position of the focal point F of the ultrashort pulse laser 4 so as to be aligned with a desired position inside the second glass substrate GB 2. The position of the focal point F is adjusted based on, for example, the size of a foreign substance causing a bright point defect or a measured brightness value. For example, as shown in fig. 14, the focal point F of the ultra-short pulse laser 4, which is a high-energy beam, is adjusted so as to be aligned with the near side of the foreign substance 33 in the second glass substrate GB 2.

Next, under the control of the control device 93, the bright spot defect correction device 6 emits the ultrashort pulse laser 4 from the ultrashort pulse laser oscillation mechanism 7. Thus, the ultrashort pulse laser beam 4 emitted from the ultrashort pulse laser oscillation mechanism 7 is condensed by the high condensing lens 8 and irradiated at the focal point F inside the second glass substrate GB 2.

Next, the controller 93 moves the irradiation position of the ultrashort pulse laser 4 by the moving device 92 to continuously irradiate the ultrashort pulse laser 4, thereby forming the dimming part 1 (step S011).

After the formation of the light reducing portion 1, the lighting inspection is performed again under the control of the control device 93 (step S012), and the light point defect correction process is completed (step S040) by confirming the disappearance of the light point defect (step S013).

When the bright point defect is detected in the lighting inspection process of the second time or later under the control of the controller 93, the process returns to step S009, and the bright point defect correction is performed again (from step S009 to step S011). In the second and subsequent bright point defect correction, the shape and size of the first formed dimming portion 1 may be different.

As described above, in the bright spot defect correction step (step S030 or S040) of the second embodiment or its modified example, the glass material is colored by irradiating the high-energy beam with the in-focus glass substrate GB, and therefore, the shape of the glass substrate itself is not changed. For example, the inside or the surface of the glass substrate GB is not damaged to change the outer shape. Therefore, for example, the bright point defect correcting process (step S030 or S040) may be performed in a state where the polarizers POL1 and POL2 are formed on the TFT substrate SUB1 and the CF substrate SUB2, that is, after the display panel DP is completed. Further, since the dimming portion 1 is made of the same material as the glass substrate GB, the refractive index does not change.

According to this modification, by performing the inspection again after the correction, it is possible to check whether the correction is sufficient or not and whether the shading is not defective or defective.

(other modification examples)

In the bright point defect correction step (step S030 or S040), the intensity of the ultrashort pulse laser 4 may be adjusted and irradiated according to the color of the pixel corresponding to the bright point defect portion 133 that becomes a bright point defect. Thus, the light reduction portion 1 is formed so as to have different light transmittances depending on the color of the pixel corresponding to the bright point defective portion 133. For example, the light-reducing section 1 covering the bright point defect section 133 corresponding to the green pixel may be formed so that the transmittance of light in the light-reducing section 1 is lower than the transmittance of light in the light-reducing section 1 covering the bright point defect section 133 corresponding to the pixel of another color (for example, red pixel or blue pixel).

In the above description, the bright point defect is shown when the foreign substance 33 is mixed between the TFT substrate SUB1 and the CF substrate SUB2, but the cause of the bright point defect is not limited to this. For example, light leakage due to a defect of the thin film transistor TFT, light leakage due to a spacer disposed between the substrates, or the like can be caused. The bright point defect correction method of the second embodiment or its modified example can also be applied to these bright point defects.

In addition, the mixing position of the foreign substance 33 that can generate the bright point defect is not limited to between the TFT substrate SUB1 and the CF substrate SUB 2. For example, if a foreign substance is mixed between the first glass substrate GB1 and the polarizing plate POL1, a bright point defect may be generated. In this case, the light reduction part 1 may be formed in the vicinity of the foreign matter in the interior of the first glass substrate GB 1. In addition, a bright point defect may be generated even when foreign substances are mixed between the second glass substrate GB2 and the polarizing plate POL 2. In this case, the light reduction part 1 may be formed in the vicinity of the foreign matter in the interior of the second glass substrate GB 2. Thus, foreign substances may be mixed into an unspecified position of the display panel DP. Therefore, for example, as shown in fig. 15, in the case where foreign substances 1001, 1000 causing a bright point defect to occur are mixed between the first glass substrate GB1 and the polarizing plate POL1 (first position) and between the second glass substrate GB2 and the polarizing plate POL2 (second position) in the 1-piece display panel DP, the first dimming portion 1 may be formed in the vicinity of the foreign substance 1000 in the interior of the first glass substrate GB1 in correspondence with the foreign substance 1000 at the first position, and the second dimming portion 1a may be formed in the vicinity of the foreign substance 1001 in the interior of the second glass substrate GB2 in correspondence with the foreign substance 1001 at the second position. In this case, in consideration of the operation efficiency of the bright point defect correcting step, both the first and second dimming portions 1 and 1a may be formed on the display surface side of the second glass substrate GB 2. The first and second light-reducing portions 1 and 1a may be formed to have different transmittances from each other. Specifically, the second dimming portion 1a is disposed at a position shown in fig. 15. In this case, in the pixel P, the foreign substance 1000 is present on the right side of the interface between the second glass substrate GB2 and the polarizing plate POL2, the foreign substance 1001 is present on the left side of the interface between the first glass substrate GB1 and the polarizing plate POL1, and both the foreign substance 1000 and the foreign substance 1001 are smaller than the foreign substance 33 in fig. 15. In order to correct the bright point defect caused by these foreign substances 1000, 1001, as shown in fig. 15, a first light reduction portion 1 is provided on the liquid crystal layer LC side of the foreign substance 1000, and a second light reduction portion 1a is provided on the liquid crystal layer LC side of the foreign substance 1001. This enables more effective correction of the bright point defect.

The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and embodiments appropriately modified by those skilled in the art according to the above embodiments are also included in the technical scope of the present invention within a scope not departing from the gist of the present invention.

In addition, by appropriately combining any of the plurality of embodiments or modifications, the effects of each can be achieved. In addition, combinations between the embodiments or examples or combinations of the embodiments and examples can also be made, and combinations between features in different embodiments or examples can also be made.

The display device, the manufacturing method thereof, and the manufacturing apparatus according to the aspects of the present invention can suppress the reduction of the display quality due to the bright point defect, are particularly useful for a liquid crystal display or an organic EL flat panel display incorporating the display device, and can be widely applied to a display device requiring a display with high luminance, high accuracy, and image quality uniformity, a manufacturing method thereof, a manufacturing apparatus thereof, and the like, and an electric apparatus or a device having the display device.

Claims (9)

1. A display device is provided with:

a first glass substrate, and

a second glass substrate located on the display surface side opposite to the first glass substrate,

a light-reducing portion that covers the bright point defect portion when viewed from the display surface side is provided in at least one of the first glass substrate and the second glass substrate,

the light reduction portion includes:

a colored layer having a color different from that of the first glass substrate and the second glass substrate, and

a void layer comprising a plurality of voids,

the colored layer is composed of non-bridging oxygen vacancy centers,

the diameters of the plurality of cavities are 1nm to 50 [ mu ] m.

2. The display device according to claim 1, wherein the light reduction portion further includes a refractive index changing layer that exhibits a refractive index larger than the first glass substrate and the second glass substrate, between the colored layer and the cavity layer.

3. The display device according to claim 2, wherein the coloring layer is a first coloring layer,

the light reducing portion further includes a second coloring layer having a color different from that of the first glass substrate and the second glass substrate,

the cavity layer is located between the first coloring layer and the second coloring layer.

4. The display device according to claim 3, wherein a coloring concentration of the second coloring layer is lower than a coloring concentration of the first coloring layer.

5. The display device according to claim 2, wherein the refractive index change layer is a first refractive index change layer,

the coloring layer is a first coloring layer,

the light reducing part further includes a second colored layer having a color different from that of the first glass substrate and the second glass substrate, the second colored layer being composed of non-bridging oxygen vacancy centers,

the hollow layer is positioned between the first coloring layer and the second coloring layer,

the light reducing portion further includes a second refractive index changing layer located between the cavity layer and the second colored layer and exhibiting a refractive index greater than that of the first glass substrate or the second glass substrate.

6. The display device according to claim 5, wherein a refractive index of the second refractive index change layer is smaller than a refractive index of the first refractive index change layer.

7. The display device according to any one of claims 1 to 6, further comprising a liquid crystal layer located between the first glass substrate and the second glass substrate and including the bright point defect portion,

the dimming portion is formed in the second glass substrate.

8. A method for manufacturing a display device including a first glass substrate and a second glass substrate located on a display surface side opposite to the first glass substrate,

the method for manufacturing the display device comprises the following steps:

a detection step of performing lighting inspection of the display device and detecting a bright point defect portion of a pixel; and

an irradiation step of irradiating the first glass substrate or the second glass substrate with laser light so as to cover the bright point defect portion, and forming a colored layer and a cavity layer covering the bright point defect portion when viewed from the display surface side in at least one of the first glass substrate and the second glass substrate,

the colored layer is composed of non-bridging oxygen vacancy centers,

the cavity layer includes a plurality of cavities each having a diameter of 1nm or more and 50 μm or less,

the laser light irradiated in the irradiation step has a wavelength of 100nm to 10000nm, a pulse width of 1 femtosecond to 100 picoseconds, and a pulse energy of 1 muJ to 20 muJ, and is condensed by a lens having a numerical aperture of 0.3 to 0.6.

9. A manufacturing apparatus of a display device includes a first glass substrate and a second glass substrate located on a display surface side opposite to the first glass substrate,

the manufacturing device of the display device comprises:

an inspection device that performs lighting inspection of the display device and detects a bright point defect portion of a pixel; and

a bright point defect correction device having an ultrashort pulse laser oscillation mechanism for adjusting the position of a focal point in at least one of the first glass substrate and the second glass substrate and emitting ultrashort pulse laser through an optical system,

the ultrashort pulse laser emitted by the ultrashort pulse laser oscillation mechanism has a wavelength of 100nm to 10000nm, a pulse width of 1 femtosecond to 100 picoseconds, a pulse energy of 1 muJ to 20 muJ, and is condensed by a lens having a numerical aperture of 0.3 to 0.6,

the ultrashort pulse laser oscillation mechanism emits the ultrashort pulse laser through the optical system to a position of the focal point inside at least one of the first glass substrate and the second glass substrate, and forms a colored layer and a cavity layer covering the bright point defect portion when viewed from the display surface side so as to cover the bright point defect portion detected by the inspection device inside at least one of the first glass substrate and the second glass substrate,

the colored layer is composed of non-bridging oxygen vacancy centers,

the cavity layer includes a plurality of cavities each having a diameter of 1nm or more and 50 μm or less.

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