CN1544979A - Thin film transistor liquid crystal display with local multi-domain vertical alignment mode - Google Patents

Abstract

A TFT-LCD with local multi-domain vertical alignment mode, especially a reflective structure and a transflective TFT-LCD structure with local multi-domain vertical alignment mode in the reflective region. The electrically conductive salient point electrodes connected with each other are made on the reflecting plate with salient point structure, or/and a corresponding hole is formed on the transparent electrode of the upper base plate corresponding to each salient point position of the reflecting plate, so that the liquid crystal layer of the vertical alignment reflective TFT-LCD or the reflecting area of the semi-penetration semi-reflective TFT-LCD can form local continuous multi-domain vertical alignment mode (continuous MVA) liquid crystal distribution, thereby having wider visual angle and not influencing the main reflecting and light guiding functions of the salient points.

Description

Thin film transistor liquid crystal display with localized multi-domain vertical alignment mode

technical field

The present invention relates to a reflective thin film transistor liquid crystal display with a localized (local) multi-domain vertical alignment mode (Multi-DomainVertical Alignment Mode; MVA) and a semi-transparent semi-reflective thin film transistor with a localized MVA mode in the reflection area Liquid crystal display, especially refers to a reflective area in the reflective thin film transistor liquid crystal display and in the transflective semi-reflective thin film transistor liquid crystal display, making interconnected conductive bump electrodes, or/and in each corresponding to the reflective plate A structure corresponding to a hole is formed at the transparent electrode of the upper substrate at a bump position.

Background technique

With the rapid progress of thin-film transistor manufacturing technology, liquid crystal displays with the advantages of lightness, lightness, power saving, and radiation-free are widely used in calculators, personal digital assistants (PDAs), watches, notebook computers, digital cameras and In various electronic products such as mobile phones. Coupled with the industry's active investment in research and development and the adoption of large-scale production equipment, the production cost of LCDs has been continuously reduced, and the demand for LCDs has also increased significantly.

Thin film transistor liquid crystal display (TFT-LCD) uses the characteristics of liquid crystal molecules to rotate polarized light direction and birefringence to achieve the effect of displaying light and shade. This characteristic is related to the angle of incident light, so liquid crystal display has the problem of viewing angle in essence. Depending on the viewer's angle, the display quality will be different. The larger the viewing angle, the lower the contrast. With the development of large-scale LCDs, it is more important to improve the contrast and color uniformity of each viewing angle.

In order to further expand the application field and quality of the liquid crystal display, the current research focus of the liquid crystal display mainly focuses on how to increase the viewing angle and shorten the response time of the screen. In order to achieve the above purpose, the existing technology has developed a variety of wide viewing angle technologies, such as in-plane switching technology (In-PlaneSwitching; IPS), boundary field switching technology (Fringe Field Switching; FFS) and multi-domain vertical alignment technology (Multi-Domain Vertical Alignment; MVA).

However, the aforementioned wide viewing angle technology is still limited to be applied to transmissive TFT-LCDs.

Contents of the invention

An object of the present invention is to provide a reflective thin film transistor liquid crystal display (reflective TFT-LCD) with a localized (local) multi-domain vertical alignment mode (MVA) and a transflective semi-transparent TFT-LCD with a localized MVA mode in the reflective region. Reflective thin film transistor liquid crystal display (transflectiveTFT-LCD). By making a plurality of interconnected conductive bump electrodes on the reflector, or/and forming a corresponding electrode hole at the transparent electrode of the upper substrate corresponding to the top position of each bump of the reflector, the The reflective TFT-LCD and the reflective area of the transflective TFT-LCD form a plurality of local continuous multi-domain vertical alignment mode (continuous MVA) liquid crystal distribution, so as to improve gray scale inversion and color shift problems, increase wide viewing angle.

The present invention discloses a reflective thin film transistor liquid crystal display, comprising a transparent lower substrate containing thin film transistors, a transparent insulating layer located on the transparent lower substrate, wherein the upper surface of the transparent insulating layer has a plurality of bumps 1. A reflective plate made on the upper surface of the transparent insulating layer, wherein the reflective plate has a plurality of independently separated (independently separate) conductive bump electrodes connected to each other. When a voltage is applied to the liquid crystal display, each conductive The bump electrode is used to produce a multi-domain vertical alignment mode liquid crystal distribution, a transparent upper substrate with a color filter layer, a transparent upper electrode located on the lower surface of the color filter layer of the transparent upper substrate, and a transparent upper electrode located on the transparent upper substrate. A liquid crystal layer between the upper electrode and the reflector.

In another embodiment of the reflective thin film transistor liquid crystal display of the present invention, the upper surface of the transparent insulating layer has a plurality of first bumps, and the reflector has a plurality of bumps corresponding to the plurality of first bumps. The second bumps, wherein the plurality of second bumps, and the transparent upper electrode has a corresponding hole at a position corresponding to the plurality of second bumps, as an electrode gap, so that when a voltage is applied to In the liquid crystal display, each second bump produces a liquid crystal distribution in a multi-domain vertical alignment mode.

Furthermore, the present invention also discloses a transflective TFT liquid crystal display, which has a reflective area and a transmissive area. The semi-transmissive and semi-reflective thin film transistor liquid crystal display comprises a transparent lower substrate containing thin film transistors, a transparent insulating layer located on the transparent lower substrate in the reflective area, wherein the upper surface of the transparent insulating layer has a plurality of protrusions (bumps), a reflective plate made on the upper surface of the transparent insulating layer, wherein the reflective plate has a plurality of interconnected independently separated (independently separate) conductive bump electrodes, when a voltage is applied to the liquid crystal display, the Each conductive bump electrode is used to generate a liquid crystal distribution in a multi-domain vertical alignment mode, a transparent lower electrode located on the transparent lower substrate in the penetrating region, wherein the transparent lower electrode is electrically connected to the reflector, A transparent upper substrate with a color filter layer, a transparent upper electrode located on the lower surface of the color filter layer of the transparent upper substrate, and a transparent upper electrode located on the transparent upper electrode and the reflector plate and the transparent upper electrode and the transparent lower electrode a liquid crystal layer in between.

In another embodiment of the transflective thin film transistor liquid crystal display of the present invention, the upper surface of the transparent insulating layer has a plurality of first protrusions, and the reflector has a plurality of protrusions corresponding to the plurality of first protrusions. A plurality of second protrusions, wherein the plurality of second protrusions, and the transparent upper electrode has a corresponding hole at a position corresponding to the plurality of second protrusions, as an electrode gap, so that When voltage is applied to the liquid crystal display, each second bump generates a liquid crystal distribution in a multi-domain vertical alignment mode.

Description of drawings

Fig. 1 is the structural sectional schematic diagram that the transflective TFT-LCD unit pixel of the present invention has conductive bump electrode in reflective area;

Fig. 2 is the top view that the unit pixel of the transflective TFT-LCD of the present invention has conductive bump electrodes in the reflective area;

Fig. 3 is the simulation diagram of the arrangement and distribution of the continuous multiple regions that the liquid crystal molecules in the periphery of the conductive bump electrode of the present invention form a non-coplanar toppled continuous multi-area arrangement distribution;

4 is a cross-sectional view of the structure of embodiment 2 in which the unit pixel of the transflective TFT-LCD of the present invention forms a local continuous multi-domain vertical alignment mode in the reflection area;

5 is a top view of Embodiment 2 in which the unit pixel of the transflective TFT-LCD of the present invention forms a local continuous multi-domain vertical alignment mode in the reflective region;

6 is a top view of Embodiment 3 in which the unit pixel of the transflective TFT-LCD of the present invention forms a local continuous multi-domain vertical alignment mode in the reflective region; and

7 is a cross-sectional view of the structure of Embodiment 3 in which the unit pixel of the transflective TFT-LCD of the present invention forms a local continuous multi-domain vertical alignment mode in the reflective region.

Description of figure number

Reflector 13 Upper glass substrate 20

Upper substrate transparent electrode 21 Lower glass substrate 10

Conductive bump electrode 14 Conductive bridging metal 18

Liquid crystal layer 25 Penetration area A

Reflective area B Contour 11, 11’

Holes 22 Scan Lines 100

Signal line 200 TFT 16

Storage capacitor 17 Transparent electrode layer 12

gap, electrode notch 15

Detailed ways

The invention provides a structure of a vertical alignment reflective thin film transistor liquid crystal display capable of widening the viewing angle and a structure capable of widening the viewing angle in the reflection area of the vertical alignment semi-transmissive semi-reflective thin film transistor liquid crystal display. Among them, the whole piece of metal reflector with a plurality of bump structures is used to form conductive bump electrodes that are connected to each other (and outside the conductive bump electrodes, it is like forming a non-conductive mesh. structure), or/and form a corresponding gap (hole) at the transparent electrode of the upper substrate corresponding to the positions of the tops of the bumps, so that not only the reflective TFT-LCD or the semi-transmissive semi-reflective The liquid crystal layer in the reflective area of the type TFT-LCD forms a multi-domain vertical alignment mode (MVA) around each bump (that is, a local area), so that the liquid crystal display has a wider viewing angle without affecting these The main function of the bump is to reflect and guide light.

Hereinafter, the present invention will be described in detail by taking the structure of a vertical alignment transflective TFT-LCD as an example.

Example 1

Fig. 1 shows the cross-sectional structure of a transflective TFT-LCD unit pixel with conductive bump electrodes in the reflective region of the present invention, wherein the liquid crystal display includes a lower glass substrate 10 for making TFT transistors (not shown) , and an upper glass substrate 20 for making a color filter (not shown). There is a liquid crystal layer 25 between the upper and lower glass substrates 20 and 10, so as to change the alignment and arrangement of the liquid crystal molecules according to the applied voltage, and change the light passing through the liquid crystal layer 25 in the transmissive area A and the reflective area B angle. A transparent electrode 21 (ITO electrode) is fabricated on the lower surface of the color filter layer of the upper glass substrate 20 . A transparent electrode layer 12 (such as an ITO layer) is deposited on the lower glass substrate 10 of the penetrating area A as a pixel electrode of the penetrating area A. Referring to FIG.

A transparent organic layer with a plurality of bumps 11 is formed on the lower glass substrate 10 in the reflective area B, and then a whole metal layer is deposited as the reflective plate 13 . Since the reflecting plate 13 is fabricated on the transparent organic layer having a plurality of protrusions 11 , the surface of the reflecting plate 13 also has the protrusion structures 11 ′.

Next, most of the metal conductive layer at the lowest point (the distance between each other is about 3-5 μm) between the bumps 11' and the bumps 11' of the entire metal reflector 13 is etched away to form gaps. 15 of the conductive bump electrodes 14, and form some conductive bridging metal (bridge) 18 (shown in FIG. 2 ) between the bumps, so that each conductive bump electrode 14 can be connected and conducted as a reflection The pixel electrode of area B. In a preferred situation, each conductive bump electrode 14 only contains two conductive bridging metals 18 .

2 is a top view showing that the unit pixel of the semi-transmissive and semi-reflective TFT-LCD of the present invention has a conductive bump electrode, wherein the scanning line 100 and the signal line 200 intersect vertically, and there is a switching element TFT16 and a switching element TFT16 in the unit pixel. The storage capacitor 17 , in the reflective area B, the reflective plate 13 has a plurality of conductive bump electrodes 14 interconnected by conductive bridge metal 18 . The lowest point around each conductive bump electrode 14 (except for the connected conductive bridging metal 18) is a hollow organic dielectric layer, just like forming a slit, so the liquid crystal molecules will flow along each conductive bump electrode. 14, the surrounding trenches are arranged so that each local area forms a multi-domain vertical alignment mode. In fact, the conductive bump electrode structure 14 will cause a strong oblique electric field and a strong change in the equipotential line density, causing the liquid crystal molecules in its surroundings to fall out of coplanarity, resulting in a local continuous multi-domain vertical The effect of alignment mode (continuous MVA) achieves the purpose of increasing the viewing angle.

FIG. 3 is a simulation result of a continuous multi-area arrangement distribution in which the liquid crystal molecules in the periphery of each conductive bump electrode form a non-coplanar dump due to the oblique electric field of the conductive bump electrodes of the present invention. In the present embodiment, when a voltage is applied, the gap 15 between the two conductive bump electrodes 14 is formed into an electrode gap. As can be seen from FIG. 3, the electric field at the electrode gap is small but the liquid crystal layer interval (cell gap) Larger, while the electric field at the conductive bump electrode 14 is large but the distance between the liquid crystal layers is small, so the phase difference values at the two locations are similar, and multiple regions with uniform brightness are formed.

Example 2

Please refer to FIG. 4 and FIG. 5 , which respectively show a cross-sectional structure and a top view of another embodiment in which the unit pixel of the transflective TFT-LCD of the present invention forms a local continuous multi-domain vertical alignment mode in the reflection area.

In this embodiment, a corresponding hole 22 is formed at the transparent electrode 21 of the upper glass substrate 20 corresponding to the top position of each protrusion 11 ′ of the entire metal reflector 13 as an electrode gap. The shape of the hole 22 can be similar to the shape of the protrusion 11 ′, such as a circle or an ellipse. Of course, in order to prevent the color filter material under the upper glass substrate 20 from leaking from the hole 22 to the liquid crystal layer 25, a transparent protective layer can be formed between the transparent electrode 21 and the color filter (not shown). film (not shown). In this way, when a voltage is applied, a local continuous multi-domain vertical alignment mode (continuous MVA) effect can also be formed around each bump 11 ′ on the reflector 13 .

Example 3

6 and 7 respectively show the cross-sectional structure and top view of another embodiment in which the unit pixel of the transflective TFT-LCD of the present invention forms a local continuous multi-domain vertical alignment mode in the reflection area. This embodiment combines the structures of Embodiment 1 and Embodiment 2, that is, the reflection plate 13 in the reflection area B is made of a plurality of conductive bump electrodes 14 interconnected with conductive bridging metal 18, and in the corresponding At the transparent electrode 21 of the upper glass substrate 20 at the top of the plurality of conductive bump electrodes 14, a corresponding electrode hole 22 is formed as an electrode gap to form a local continuous multi-domain vertical alignment mode effect.

As mentioned above, the present invention is described in detail by using the preferred embodiments, rather than limiting the scope of the present invention, and those who are familiar with this kind of art can understand that it is appropriate to make slight changes and adjustments without losing the gist of the present invention. , nor depart from the spirit and scope of the present invention.

Claims (10)

1. A reflective thin film transistor liquid crystal display, characterized in that it comprises: a transparent lower substrate containing thin film transistors; A transparent insulating layer, which is located on the transparent lower substrate, and the upper surface of the transparent insulating layer has a plurality of bumps; A reflection plate, which is made on the upper surface of the transparent insulating layer, and has a plurality of interconnected conductive bump electrodes, wherein when a voltage is applied to the liquid crystal display, each conductive bump electrode is used to generate Liquid crystal distribution in a multi-domain vertical alignment mode; a transparent upper substrate with a color filter layer; a transparent upper electrode located on the lower surface of the color filter layer of the transparent upper substrate; and A liquid crystal layer is located between the transparent upper electrode and the reflection plate. 2. The reflective thin film transistor liquid crystal display as claimed in claim 1, wherein the plurality of conductive bump electrodes are connected to each other by conductive bridging metals, and the conductive bridging metals are located between two conductive bump electrodes the lowest point. 3. The reflective thin film transistor liquid crystal display as claimed in claim 1, wherein the transparent upper electrode has a corresponding electrode hole at a position corresponding to the top of each conductive bump electrode. 4. A reflective thin film transistor liquid crystal display, characterized in that it comprises: a transparent lower substrate containing thin film transistors; a transparent insulating layer, which is located on the transparent lower substrate, and the upper surface of the transparent insulating layer has a plurality of first bumps; A reflection plate, which is made on the upper surface of the transparent insulating layer, and has a plurality of second bumps, wherein the plurality of second bumps correspond to the plurality of first bumps; a transparent upper substrate with a color filter layer; A transparent upper electrode is located on the lower surface of the color filter layer of the transparent upper substrate, and the transparent upper electrode has a corresponding hole at a position corresponding to the plurality of second protrusions as an electrode gap, so that when a voltage is applied to the liquid crystal display, each second bump produces a liquid crystal distribution in a multi-domain vertical alignment mode; and A liquid crystal layer is located between the transparent upper electrode and the reflection plate. 5. The reflective thin film transistor liquid crystal display as claimed in claim 4, wherein the hole in the transparent upper electrode is at a position corresponding to the top of the second bump. 6. A semi-transmissive and semi-reflective thin film transistor liquid crystal display, characterized in that it is divided into a reflective area and a transmissive area and includes: a transparent lower substrate containing thin film transistors; a transparent insulating layer, which is located on the transparent lower substrate of the reflection area, and the upper surface of the transparent insulating layer has a plurality of bumps; A reflection plate, which is made on the upper surface of the transparent insulating layer, and has a plurality of interconnected conductive bump electrodes, wherein when a voltage is applied to the liquid crystal display, each conductive bump electrode is used to generate Liquid crystal distribution in a multi-domain vertical alignment mode; a transparent lower electrode, which is located on the transparent lower substrate in the penetrating region and is electrically connected to the reflector; a transparent upper substrate with a color filter layer; a transparent upper electrode located on the lower surface of the color filter layer of the transparent upper substrate; and A liquid crystal layer is located between the transparent upper electrode and the reflection plate, and the transparent upper electrode and the transparent lower electrode. 7. The semi-transmissive and semi-reflective thin film transistor liquid crystal display as claimed in claim 6, wherein the plurality of conductive bump electrodes are connected to each other by conductive bridging metals, and the conductive bridging metals are located between two conductive bumps. The lowest point between point electrodes. 8. The transflective thin film transistor liquid crystal display according to claim 6, wherein the transparent upper electrode has a corresponding hole at a position corresponding to the top of each conductive bump electrode . 9. A semi-transmissive and semi-reflective thin film transistor liquid crystal display, characterized in that it is divided into a reflective area and a transmissive area and includes: a transparent lower substrate containing thin film transistors; A transparent insulating layer, which is located on the transparent lower substrate of the reflection area, and the upper surface of the transparent insulating layer has a plurality of first bumps; A reflection plate, which is made on the upper surface of the transparent insulating layer, and has a plurality of second bumps, wherein the plurality of second bumps correspond to the plurality of first bumps; a transparent lower electrode, which is located on the transparent lower substrate in the penetrating region and is electrically connected to the reflector; a transparent upper substrate with a color filter layer; A transparent upper electrode is located on the lower surface of the color filter layer of the transparent upper substrate, and the transparent upper electrode has a corresponding hole at a position corresponding to the plurality of second protrusions as an electrode gap, so that when a voltage is applied to the liquid crystal display, each second bump produces a liquid crystal distribution in a multi-domain vertical alignment mode; and A liquid crystal layer is located between the transparent upper electrode and the reflection plate, and the transparent upper electrode and the transparent lower electrode. 10. The transflective thin film transistor liquid crystal display as claimed in claim 9, wherein the hole in the transparent upper electrode is at a position corresponding to the top of the second bump.

Images