TWI646379B - Display panel - Google Patents

Abstract

A display panel includes a first substrate, a second substrate disposed opposite the first substrate, a display medium located between the first substrate and the second substrate, and a light-shielding pattern disposed on the second substrate. The light-shielding pattern is located between the second substrate and the display medium. The change rate of the resistivity of the light-shielding pattern to a voltage applied to the light-shielding pattern is less than or equal to 3.33 ∙ 10 ¹³ ohm · cm / volt, where the voltage is greater than 0 volts and less than or equal to 30 volts.

Description

Display panel

The present invention relates to a photovoltaic device, and more particularly to a display panel.

Generally speaking, most of today ’s display panels are manufactured using a One Drop Filling (ODF) technology. First, a display medium (such as liquid crystal) is directly dropped on a substrate, and then another piece is taken. The substrates are aligned.

However, when the display medium is dropped on one of the substrates by using the dripping injection method, the properties of the alignment film may be different between the dripped area and the non-drip area due to the influence of the dropped display medium. Therefore, when the display panel is turned on for one to two minutes (for example, at 90 seconds), the white screen displayed on the display panel will appear multiple black dots corresponding to the dripping area, that is, drop mura; After turning on for a period of time (for example, after 10 minutes), the multiple black dots will disappear again. Drop mura seriously affects the quality of the display panel, and a solution that can solve the above problems is urgently needed.

The invention provides a display panel with good display quality.

A display panel of the present invention includes a first substrate, a second substrate disposed opposite to the first substrate, a display medium located between the first substrate and the second substrate, and a light-shielding pattern disposed on the second substrate. The light-shielding pattern is located between the second substrate and the display medium. The change rate of the resistivity of the light-shielding pattern to a voltage applied to the light-shielding pattern is less than or equal to 3.33 ∙ 10 ¹³ ohm · cm / volt, and the voltage applied to the light-shielding pattern is greater than 0 volts and less than or equal to 30 volts.

A display panel of the present invention includes a first substrate, a second substrate disposed opposite to the first substrate, a display medium located between the first substrate and the second substrate, and a light-shielding pattern disposed on the second substrate. The light-shielding pattern is located between the second substrate and the display medium. The change rate of the resistivity of the light-shielding pattern to a voltage applied to the light-shielding pattern is less than or equal to 1.38 · 10 ¹³ ohm · cm / volt, and the voltage applied to the light-shielding pattern is greater than 20 volts and less than or equal to 30 volts.

Based on the above, a display panel according to an embodiment of the present invention includes a first substrate, a second substrate disposed opposite to the first substrate, a display medium located between the first substrate and the second substrate, and a display substrate disposed on the second substrate. Shading pattern. In particular, the change rate of the resistivity of the light-shielding pattern with respect to the voltage applied thereto is small. Therefore, the problem of drop mura can be improved, and the display quality can be improved.

In order to make the above features and advantages of the present invention more comprehensible, embodiments are hereinafter described in detail with reference to the accompanying drawings.

Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.

FIG. 1 is a schematic cross-sectional view of a display panel according to an embodiment of the present invention.

Please refer to FIG. 1, the display panel 10 includes a first substrate 100, a pixel unit 110 disposed on the first substrate 100, a second substrate 180 disposed opposite to the first substrate 100, and located on the first substrate 100 and the second substrate 100. A display medium 160 between the substrates 180 and a light-shielding pattern 170 disposed on the second substrate 180 and located between the second substrate 180 and the display medium 160. The light shielding pattern 170 shields the gaps 114 b between the pixel electrodes 114 of the adjacent pixel units 110. In this embodiment, the display panel 10 further includes a plurality of data lines (not shown) and a plurality of scanning lines (not shown) that are staggered with each other and are electrically connected to the plurality of thin film transistors 112 of the plurality of pixel units 110. ), And the light-shielding pattern 170 also shields the data lines and the scanning lines. In other words, in this embodiment, the light-shielding pattern 170 may be a mesh pattern, and the mesh holes 170 a of the mesh pattern overlap the pixel electrodes 114 of the pixel units 110.

In this embodiment, the display panel 10 further includes a first alignment film PI1 and a second alignment film PI2. The first alignment film PI1 is disposed on the first substrate 100, covers the pixel unit 110, and is located between the display medium 160 and the first substrate 100. The second alignment film PI2 is disposed on the second substrate 180, covers the light-shielding pattern 170, and is located between the second substrate 180 and the display medium 160. For example, in this embodiment, the display medium 160 may be a liquid crystal layer having a plurality of liquid crystal molecules, and the first alignment film PI1 and the second alignment film PI2 are used to fix the liquid crystal molecules when the display panel 10 is not enabled. Pre-tile angle and azimuth angle.

In this embodiment, the pixel unit 110 includes a thin film transistor 112 and a pixel electrode 114. The pixel electrode 114 is electrically connected to the thin film transistor 112. For example, in this embodiment, the display panel 10 further includes an insulating layer 120. The insulating layer 120 covers the thin film transistor 112. The pixel electrode 114 is disposed on the insulating layer 120 and the insulating layer 130 and passes through the opening 120a of the insulating layer 120. The opening 130 a of the insulating layer 130 is electrically connected to the pixel electrode 114. However, the present invention is not limited to this. According to other embodiments, the pixel electrode 114 may be electrically connected to the thin film transistor 112 by other methods.

In this embodiment, the display panel 10 further includes a common electrode 140. The voltage between the common electrode 140 and the pixel electrode 114 is used to drive the display medium 160, so that the display panel 10 displays a picture. For example, in this embodiment, the common electrode 140 and the pixel electrode 114 may be selectively disposed on the first substrate 100, and an insulating layer 130 is sandwiched between the common electrode 140 and the pixel electrode 114. The pixel electrode 114 may have a plurality of slits 114a overlapping the common electrode 140, and an electric field between the edge of the slit 114a and the common electrode 140 is used to drive the display medium 160. In other words, in this embodiment, the display panel 10 is, for example, a fringe field switching (FFS) type liquid crystal display panel. However, the present invention is not limited thereto. In other embodiments, the display panel 10 may also be an in-plane switching (IPS) type, a vertical alignment (VA) type, or a twisted nematic, TN), optically compensated bend (OCB) type or other suitable form of liquid crystal display panel.

2A to 2D illustrate a formation process of a drop mura of a display panel of a comparative example that is estimated.

Please refer to FIG. 2A. FIG. 2A shows a cross-section of a display panel 10A of a comparative example. The display panel 10A of the comparative example is similar to the display panel 10 of an embodiment of the present invention. The difference between the panels 10 is that the material characteristics of the light-shielding pattern 170A of the display panel 10A of the comparative example are different from the material characteristics of the light-shielding pattern 170 of the display panel 10 according to an embodiment of the present invention. The display panel 10A of the comparative example is produced by a dripping injection method. In the dripping injection process, when a display medium material (for example, liquid crystal) is dropped on the first alignment film PI1 on the first substrate 100, the liquid crystal is dropped when the liquid crystal is dropped. Due to the influence of the generated force, the properties of the first alignment film PI1 in the dripping region R1 and the non-dropping region R2 may be different, for example, the charge distribution states are different.

Please refer to FIG. 2B. Next, the display panel 10A is enabled, that is, a voltage V is present between the pixel electrode 114 and the common electrode 140, and the display panel 10A is intended to display a single grayscale picture. At this time, the positive and negative ions in the display medium 160 move toward the first alignment film PI1 or the second alignment film PI2, for example, the negative ions move toward the first alignment film PI1 on the first substrate 100, and the positive ions move toward the first alignment film PI1. The second alignment film PI2 on the second substrate 180 moves. At the same time, the light-shielding pattern 170A located on the second substrate 180 is also affected by the voltage V, which causes the resistance value of the light-shielding pattern 170A to decrease, causing a larger electro-optical effect on the side where the light-shielding pattern 170A is provided, and thus the display medium 160 The separation of positive and negative ions is more obvious. The separation of the positive and negative ions makes the difference between the electric field applied to the portion of the display medium 160 above the dripped region R1 and that applied to the non-drip region R2, which causes the display panel 10A to exhibit a drop mura. At that time, a gray-scale picture displayed on the display will appear multiple black dots corresponding to the dripping area R1.

Next, please refer to FIG. 2C. After the display panel 10A is enabled for a period of time, the free ions in the display medium 160 are attracted by the electric field near the pixel electrodes 114, and the positive and negative ions are respectively directed to the first alignment film PI1 and the second alignment. Membrane PI2 moves. At this time, the positive and negative ions in the display medium 160 moving toward the first alignment film PI1 and the second alignment film PI2, respectively, can reduce the difference in charge distribution between the dripped region R1 and the undrip region R2. Therefore, the phenomenon of dripping halo becomes slight. For example, after the display panel 10A to display a grayscale image is turned on for 10 minutes, the black dot corresponding to the dripping area R1 will fade.

Next, please refer to FIG. 2D. After the display panel 10A is enabled for a long time, the free ions in the display medium 160 are attracted by the electric field near the pixel electrode 114 to gather around the pixel electrode 114, and the first alignment film PI1 is eliminated. The difference in charge distribution between the dripped region R1 and the non-drip region R2. At this time, the phenomenon of dropping the halo disappears. For example, after the display panel 10A to display a grayscale picture is turned on for half a day, the black dot corresponding to the dropping area R1 disappears.

Compared with the display panel 10A of the comparative example, the display panel 10 according to an embodiment of the present invention uses a high-voltage-resistant and high-impedance light-shielding pattern 170. Because the light-shielding pattern 170 has a high-voltage resistance property, when the display panel 10 is enabled and the light-shielding pattern 170 is applied with a voltage, the light-shielding pattern 170 can still maintain a high impedance state, so that the second alignment film PI2 on the same side as the light-shielding pattern 170 The small induced electrical effect causes the difference in electric field between the portion of the display medium 160 applied above the dripped region R1 and the portion of the display medium 160 applied above the non-dropped region R2 not to be enlarged, thereby improving the dripping halo phenomenon.

3 shows the relationship between the applied voltage and resistivity of the light-shielding pattern of the display panel of the comparative example, the relationship between the applied voltage and resistivity of the light-shielding pattern of the display panel of the first embodiment, and the light-shielding pattern of the display panel of the second embodiment. The relationship between the applied voltage and resistivity. The vertical axis (or vertical axis) of FIG. 3 represents the resistivity, and the unit of resistivity is ohm · cm (Ω‧cm), and the horizontal axis (or horizontal axis) of FIG. 3 represents the light-shielding pattern. Voltage in volts (V). The data shown in Figure 3 was measured using the following method:

FIG. 4 shows a process of measuring the resistivity of the material of the light-shielding pattern 170 or 170A.

Please refer to FIG. 4. First, a conductive layer is disposed on the substrate 200 as the first electrode 210. In this embodiment, the substrate 200 is, for example, plain glass, and the material of the first electrode 210 is, for example, chromium. Next, a black matrix BM is arranged on the first electrode 210. The black matrix BM is a material of the light-shielding pattern 170 or 170A according to an embodiment of the present invention. Next, the black matrix BM was heated to 100 ° C. with a hot plate for 90 seconds. Then, a part of the black matrix BM is removed so that the black matrix BM exposes a part 210 a of the first electrode 210. In this embodiment, a method of removing the black matrix BM is, for example, using acetone. In this embodiment, the black matrix BM is then optionally exposed. After the exposure, the black matrix BM is placed in a heating furnace to cure the black matrix BM. The heating furnace system is heated to 230 ° C. and maintained for 20 minutes. In this embodiment, the thickness of the cured black matrix BM is about 3.3 micrometers (μm). Next, the second electrode 220 is arranged on the black matrix BM. In this embodiment, the material of the second electrode 220 is, for example, a silver paste. Next, the first electrode 210 and the second electrode 220 are electrically connected to two ends of a voltage source, respectively, to apply a voltage to the black matrix BM, and measure a current value passing through the black matrix BM. The resistivity of the black matrix BM can be obtained by the voltage value and the current value.

In this embodiment, during the above-mentioned measurement of the resistivity of the material of the black matrix BM, the black matrix BM is exposed, but it is not limited thereto. In other embodiments, if you want to know the black matrix that is not exposed, The resistivity of BM can also omit the above exposure step.

Hereinafter, the composition of the light-shielding pattern 170 according to an embodiment of the present invention will be described more specifically with reference to several experiments. Although the following experiments are described, the materials used, their amounts and ratios, processing details, processing flow, and the like can be appropriately changed without going beyond the scope of the present invention. Therefore, the present invention should not be interpreted restrictively based on the experiments described below. The composition of the light-shielding pattern 170A of the comparative example and the light-shielding pattern 170 of each example is shown in Table 1 below.

<TABLE border = "1" borderColor = "# 000000" width = "85%"> <TBODY> <tr> <td> </ td> <td> First embodiment </ td> <td> Second implementation Example </ td> <td> Comparative example </ td> </ tr> <tr> <td> Carbon black paste </ td> <td> F </ td> <td> F </ td> <td> F </ td> </ tr> <tr> <td> Photoinitiator </ td> <td> D </ td> <td> D </ td> <td> D </ td> </ tr> <tr> <td> Adhesives </ td> <td> F / D </ td> <td> A / F / D </ td> <td> A / F / D </ td> </ tr> <tr> <td> Monomer </ td> <td> M </ td> <td> M </ td> <td> B / D </ td> </ tr> <tr> <td> Additive ( Leveling) </ td> <td> A </ td> <td> A </ td> <td> A </ td> </ tr> <tr> <td> Additive (bond) </ td> < td> E </ td> <td> E </ td> <td> E </ td> </ tr> <tr> <td> Solvent System </ td> <td> A / B / G </ td > <td> A / B / G </ td> <td> A / B / G </ td> </ tr> <tr> <td> Carbon black content (in solid state) </ td> <td> 46 </ td> <td> 46 </ td> <td> 46 </ td> </ tr> <tr> <td> Solid content (110 ° C for 3 hours) </ td> <td> 15% </ td > <td> 15% </ td> <td> 15% </ td> </ tr> </ TBODY> </ TABLE> [表 一]       

In the comparative example, the composition of the light-shielding pattern includes A / F / D as an adhesive and B / D as a monomer.

In the first embodiment of the present invention, the first embodiment adopts a composition similar to that of the comparative example, except that the adhesive is changed to F / D and the monomer is changed to M. In Table 1 of this embodiment, each symbol (such as A to G) represents a material, such as an organic material, a polymer material, an inorganic material, etc. For example, the material of the light-shielding pattern of the first embodiment includes a single material composed of M material, and the material of the light-shielding pattern of the comparative example is composed of B material and D material, which further affects the first embodiment and The difference in the resistance characteristics of the comparative example.

As shown in FIG. 3, when the voltage applied to the light-shielding patterns 170 and 170A is 30 volts, the resistivity of the light-shielding pattern 170 of the first embodiment is greater than 10 ¹³ ohm · cm, while the resistivity of the light-shielding pattern 170A of the comparative example is only 10 ⁶ ohm · cm. In other words, in the case where a high voltage is applied, the light-shielding pattern 170 of the first embodiment still has a high resistivity greater than 10 ¹² ohm · cm.

As shown in FIG. 3, when a voltage is applied to the light-shielding pattern 170 of the first embodiment to be greater than 25 volts and less than or equal to 30 volts, the resistivity of the light-shielding pattern 170 of the first embodiment of the present invention is greater than 10 ¹² ohm · cm The resistivity of the light-shielding pattern 170A of the comparative example is only 10 ⁶ to 10 ⁸ ohm · cm.

Based on the above, when the first embodiment of the present invention uses the light-shielding pattern 170 with a different composition, the light-shielding pattern 170 of the first embodiment can maintain a high impedance state when a high voltage is applied.

In another embodiment of the present invention, the light-shielding pattern 170 of the second embodiment adopts a composition similar to the light-shielding pattern 170A of the comparative example, except that the monomer is changed to M.

In the second embodiment of the present invention, when a voltage of 30 volts is applied to the light-shielding pattern 170, the resistivity of the light-shielding pattern 170 is greater than 10 ¹³ ohm · cm.

In the second embodiment of the present invention, when a voltage is applied to the light-shielding pattern 170 from greater than 25 volts to less than or equal to 30 volts, the resistivity of the light-shielding pattern 170 is greater than 10 ¹² ohm · cm.

Based on the above, when the display panel of the second embodiment of the present invention uses the light-shielding patterns 170 with different compositions, it can maintain a high-impedance state when a high voltage is applied.

From another perspective, the resistivity of the light-shielding pattern 170 according to the first and second embodiments of the present invention is unlikely to be excessively decreased due to a change in applied voltage. As shown in FIG. 3, in the first and second embodiments of the present invention, when a voltage greater than 0 volts and less than or equal to 30 volts is applied to the light-shielding pattern 170, the resistivity of the light-shielding pattern 170 is less than that applied to the light-shielding pattern 170. The rate of change of a voltage is less than or equal to 3.01 ∙ 10 ¹³ ohm · cm / volt. Furthermore, in the first and second embodiments of the present invention, when a voltage greater than 20 volts and less than or equal to 30 volts is applied to the light shielding pattern 170, the resistivity of the light shielding pattern 170 is a voltage applied to the light shielding pattern. The rate of change is less than or equal to 4.06 ∙ 10 ¹² ohm · cm / volt. In other words, after the voltage is applied to the light-shielding pattern 170 of the first and second embodiments, the impedance characteristics of the light-shielding pattern 170 of the first and second embodiments are not easily changed. The effect of external voltage changes. On the other hand, the impedance state of the light-shielding pattern 170A of the comparative example is relatively susceptible to a drastic change due to the influence of an external voltage.

In summary, a display panel according to an embodiment of the present invention includes a first substrate, a second substrate disposed opposite to the first substrate, a display medium located between the first substrate and the second substrate, and a second substrate disposed on the display substrate. Shading pattern. In particular, the light-shielding pattern uses a high-resistance high-resistance material. Therefore, when the display panel is enabled and the light-shielding pattern is applied with a voltage, a high resistivity can be maintained, thereby improving the problem of dripping halo and improving the quality of the display panel.

Although the present invention has been disclosed as above with the examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some modifications and retouching without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be determined by the scope of the attached patent application.

10, 10A‧‧‧ display panel

100‧‧‧first substrate

110‧‧‧ pixel unit

112‧‧‧ thin film transistor

114‧‧‧pixel electrode

114a‧‧‧Slit

114b‧‧‧Gap

120, 130‧‧‧ Insulation

120a, 130a‧‧‧ opening

140‧‧‧Common electrode

160‧‧‧Display media

170, 170A‧‧‧Shading pattern

170a‧‧‧mesh

180‧‧‧second substrate

200‧‧‧ substrate

210‧‧‧first electrode

210a‧‧‧ first electrode

BM‧‧‧Black Matrix

220‧‧‧Second electrode

PI1‧‧‧first alignment film

PI2‧‧‧Second alignment film

R1‧‧‧Drip zone

R2‧‧‧Undrip Zone

V‧‧‧Voltage

FIG. 1 is a schematic cross-sectional view of a display panel according to an embodiment of the present invention. 2A to 2D illustrate a process of forming a drop mura of a display panel of a comparative example. 3 shows the relationship between the applied voltage and resistivity of the light-shielding pattern of the display panel of the comparative example, the relationship between the applied voltage and resistivity of the light-shielding pattern of the display panel of the first embodiment, and the light-shielding pattern of the display panel of the second embodiment. The relationship between the applied voltage and resistivity. FIG. 4 shows the process of measuring the resistivity of the material of the light-shielding pattern.

Claims (7)

A display panel includes: a first substrate; a second substrate disposed opposite to the first substrate; a display medium between the first substrate and the second substrate; and a light-shielding pattern disposed on On the second substrate and between the second substrate and the display medium, a change rate of a resistivity of the light-shielding pattern to a voltage applied to the light-shielding pattern is less than or equal to 3.33 · 10 ¹³ ohm · cm / Volts, and the voltage is greater than 0 volts and less than or equal to 30 volts. A display panel includes: a first substrate; a second substrate disposed opposite to the first substrate; a display medium between the first substrate and the second substrate; and a light-shielding pattern disposed on On the second substrate and between the second substrate and the display medium, a change rate of a resistivity of the light-shielding pattern to a voltage applied to the light-shielding pattern is less than or equal to 1.38 · 10 ¹³ ohm · cm / Volts, and the voltage is greater than 20 volts and less than or equal to 30 volts. The display panel according to item 1 or item 2 of the scope of patent application, further comprising: a plurality of pixel units arranged on the first substrate and located between the display medium and the first substrate, each of which The pixel unit includes a thin film transistor and a pixel electrode electrically connected to the thin film transistor, and the light-shielding pattern shields the gaps between the pixel electrodes of the adjacent pixel units. The display panel according to item 1 or 2 of the scope of patent application, further comprising: a common electrode disposed on the first substrate and between the display medium and the first substrate, wherein the common electrode and each A voltage between the pixel electrodes of a pixel unit is used to drive the display medium. The display panel according to item 1 or item 2 of the patent application scope, wherein the display medium includes a liquid crystal layer. The display panel according to item 1 or item 2 of the scope of patent application, wherein the resistivity of the light-shielding pattern to which the voltage is applied is greater than 10 ¹³ ohm · cm, and the voltage is 30 volts. The display panel according to item 1 or item 2 of the scope of patent application, wherein the resistivity of the light-shielding pattern to which the voltage is applied is greater than 10 ¹² ohm · cm, and the voltage is greater than 25 volts and less than or equal to 30 volts.