TWM674193U - Display panel - Google Patents

Abstract

A display panel including a first substrate, a second substrate, a liquid crystal layer, a pixel structure and a filter pattern is provided. The first substrate and the second substrate are arranged opposite to each other. The pixel structure is disposed on the first substrate and is provided with a reflective area and a transmissive area. The pixel structure includes an active device, a pixel electrode and a reflective layer. The pixel electrode is disposed in the transmissive area and electrically connected to the active device. The reflective layer is disposed in the reflective area and overlaps the pixel electrode. The filter pattern is disposed on the second substrate and overlaps the pixel structure. The filter pattern includes a first filter portion and a second filter portion. The first filter portion is located in the reflective area and overlaps the reflective layer. The second filter portion is located in the transmissive area and overlaps the pixel electrode. A first thickness of the first filter portion is different from a second thickness of the second filter portion.

Description

Display Panel

This novel invention relates to a display technology, and in particular to a display panel.

Semi-transflective (or micro-transflective) display panels have gained a significant market share due to their excellent readability both indoors and outdoors and their energy-saving properties. In existing technology architectures, display pixels must have both reflective and transmissive areas to accommodate display requirements in environments with insufficient or excessive ambient light. Typically, both the reflective and transmissive areas are coated with a color resist layer to achieve color display. However, the thickness of the color resist layer cannot meet the display requirements of both the reflective and transmissive areas simultaneously. For example, reducing the color resist layer thickness to increase light transmittance in the transmissive area will reduce the color saturation in the reflective area. Conversely, increasing the color resist layer thickness to increase color saturation in the reflective area will also reduce light transmittance in the transmissive area.

This novel invention provides a display panel whose optical properties in the reflective and transmissive areas can be individually adjusted, helping to enhance the design flexibility of the overall optical performance.

The display panel of the present invention includes a first substrate, a second substrate, a liquid crystal layer, a pixel structure and a filter pattern. The first substrate and the second substrate are arranged opposite to each other. The pixel structure is arranged on the first substrate and is provided with a reflective area and a transmissive area. The pixel structure includes an active element, a pixel electrode and a reflective layer. The pixel electrode is arranged in the transmissive area and is electrically connected to the active element. The reflective layer is arranged in the reflective area and overlaps with the pixel electrode. The filter pattern is arranged on the second substrate and overlaps with the pixel structure. The filter pattern includes a first filter portion and a second filter portion. The first filter portion is located in the reflective area and overlaps with the reflective layer. The second filter portion is located in the transmissive area and overlaps with the pixel electrode. A first thickness of the first filter portion is different from a second thickness of the second filter portion.

In one embodiment of the present invention, the first thickness of the first light filtering portion of the display panel is greater than the second thickness of the second light filtering portion.

In one embodiment of the present invention, the liquid crystal layer of the display panel has a first portion located in the reflective region and a second portion located in the transmissive region. The first portion and the second portion have a first liquid crystal thickness and a second liquid crystal thickness, respectively. The first liquid crystal thickness is less than the second liquid crystal thickness.

In one embodiment of the present invention, the ratio of the second liquid crystal thickness to the first liquid crystal thickness of the display panel is greater than or equal to 1.1 and less than or equal to 2.2.

In one embodiment of the present invention, the display panel further includes a cover layer and a common electrode layer. The cover layer is disposed on the second substrate and is located between the liquid crystal layer and the light filter pattern. The cover layer has an opening within the transmissive region. The common electrode layer is disposed on the cover layer and is located between the cover layer and the liquid crystal layer. The common electrode layer extends into the opening of the cover layer.

In one embodiment of this novel invention, the opening of the display panel passes through the cover layer.

In one embodiment of this novel invention, the pixel electrodes of the display panel are further disposed within the reflective region and are electrically connected to the reflective layer.

In one embodiment of the present invention, the pixel structure of the display panel further includes a capacitor electrode and a common electrode. The capacitor electrode is located within the reflective region and electrically connects the active element and the pixel electrode. The common electrode is also located within the reflective region. The common electrode overlaps the capacitor electrode and is located between the first substrate and the capacitor electrode. The capacitor electrode and the common electrode are electrically coupled to form a storage capacitor.

In one embodiment of the present invention, the display panel further includes a cover layer disposed between the pixel electrode and the first substrate, covering the active element and the capacitor electrode. The cover layer has an opening within the reflective region. The pixel electrode is electrically connected to the capacitor electrode via the opening in the cover layer.

In one embodiment of the present invention, the display panel further includes a first passivation layer and a second passivation layer. The first passivation layer is disposed between the cover layer and the active element. The second passivation layer is disposed between the cover layer and the pixel electrode. The first and second passivation layers have contact holes that overlap with the openings in the cover layer. The pixel electrode is also electrically connected to the capacitor electrode through the contact holes in the first and second passivation layers.

Based on the above, in one embodiment of the display panel of this novel invention, light-filtering patterns are provided in both the reflective and transmissive regions of the pixel structure. The thickness of the first light-filtering portion of the light-filtering pattern in the reflective region is different from the thickness of the second light-filtering portion in the transmissive region. This increases the flexibility of adjusting the optical properties of the display panel independently in the transmissive and reflective regions.

10: Display Panel

100: First substrate

110: Insulating layer

121: First passivation layer

122: Second passivation layer

130, 220: Covering layer

130op, 220op: Opening

200: Second substrate

210: Light filter pattern

210p1: First filter section

210p2: Second filter section

210t1, 210t2: Thickness

AL: Ambient Light

CE: Common Electrode

CEL: Common Electrode Layer

CL: Common electrode connection line

CPE: Capacitor Electrode

Cst: Storage capacitor

DE: Drain

DL: Data Line

GE: Gate

LCL, LCL-A: Liquid Crystal Layer

LCLp1: Part 1

LCLp2: Part 2

LCt1, LCt2: Liquid crystal thickness

PE: Pixel electrode

PX: Pixel structure

RA: Reflex area

RL: Reflective layer

REL: Reflected Light

SC: semiconductor pattern

SE: source

SL: Scan Line

T: Active element

TA: Penetration Zone

TH: Contact hole

TL: Penetrating Light

X, Y, Z: Direction

A-A’: section line

Figure 1 is a schematic front view of a display panel according to the first embodiment of this novel invention.

Figure 2 is a schematic cross-sectional view of the display panel of Figure 1.

Figure 3 is a schematic cross-sectional view of a display panel according to a second embodiment of the present invention.

In the accompanying drawings, the thickness of layers, films, panels, regions, etc., is exaggerated for clarity. It should be understood that when an element, such as a layer, film, region, or substrate, is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. As used herein, "connected" can refer to physical and/or electrical connections. Furthermore, "electrically connected" can mean the presence of other elements between two elements.

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

Figure 1 is a schematic front view of a display panel according to the first embodiment of this novel invention. Figure 2 is a schematic cross-sectional view of the display panel in Figure 1 . Figure 2 corresponds to section line A-A' in Figure 1 . For clarity, Figure 1 only illustrates a portion of the film layers in Figure 2 .

Referring to Figures 1 and 2 , the display panel 10 includes a first substrate 100, a second substrate 200, and a liquid crystal layer (LCL). The liquid crystal layer (LCL) is disposed between the first substrate 100 and the second substrate 200. In other words, the display panel 10 of this embodiment is a liquid crystal display panel.

Furthermore, the first substrate 100 may be provided with a plurality of scan lines SL, a plurality of data lines DL, and a plurality of pixel structures PX. The pixel structure PX is electrically connected to one scan line SL and one data line DL. It should be noted that although FIG1 only illustrates one display unit (including one pixel structure PX) of the display panel 10, the display panel 10 may be composed of a plurality of such display units. For example, the plurality of data lines DL may be arranged along direction X and each extend in direction Y, and the plurality of scan lines SL may be arranged along direction Y and each extend in direction X, wherein direction X is not parallel to direction Y. Direction X may optionally be perpendicular to direction Y, but is not limited thereto. The plurality of pixel structures PX may be arranged in a plurality of rows and a plurality of columns along directions X and Y, respectively.

The pixel structure PX includes an active device T, a common electrode CE, a capacitor electrode CPE, and a pixel electrode PE. The active device T has a source electrode SE, a drain electrode DE, a gate electrode GE, and a semiconductor pattern SC. The semiconductor pattern SC may be made of amorphous silicon, single-crystal silicon, polycrystalline silicon, or a metal oxide semiconductor. The source electrode SE and the drain electrode DE electrically connect two different regions of the semiconductor pattern SC. In some embodiments, ohmic contact layers (not shown) may be provided between the source electrode SE and the semiconductor pattern SC, and between the drain electrode DE and the semiconductor pattern SC. The material of the ohmic contact layers may include, but is not limited to, a doped semiconductor layer.

The source electrode SE is electrically connected to a corresponding data line DL. The drain electrode DE is electrically connected to the capacitor electrode CPE. The gate electrode GE is electrically connected to a corresponding scan line SL. More specifically, in this embodiment, the portion of the scan line SL extending from the pixel structure PX serves as the gate electrode GE of the active device T, while the portion of the data line DL extending from the pixel structure PX serves as the source electrode SE of the active device T. The capacitor electrode CPE extends from the drain electrode DE and is electrically connected to the pixel electrode PE.

The active element T is, for example, an amorphous silicon thin film transistor (a-Si TFT), a polycrystalline silicon thin film transistor (poly-Si TFT), or a metal oxide semiconductor thin film transistor (MTT). In this embodiment, the gate electrode GE may be selectively disposed below the semiconductor pattern SC to form a bottom-gate thin film transistor, but the present invention is not limited thereto. In other embodiments, the gate electrode GE may also be disposed above the semiconductor pattern SC to form a top-gate thin film transistor.

In this embodiment, the pixel electrode PE is a light-transmitting electrode. The material of the light-transmitting electrode includes, for example, a metal oxide, such as indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, or other suitable oxides, or a stack of at least two of the above. Based on conductivity considerations, the scan lines SL, data lines DL, capacitor electrodes CPE, common electrodes CE, and the source SE, drain DE, and gate GE of the active device T are generally made of metal materials, but are not limited to such materials.

The common electrode CE is disposed between the capacitor electrode CPE and the first substrate 100, overlapping the capacitor electrode CPE along direction Z. Unless otherwise specified, the overlapping relationship between the two components is defined along direction Z, and the overlapping direction will not be further discussed. Initially, the common electrode CE can be electrically coupled to the capacitor electrode CPE to form a storage capacitor Cst. More specifically, the storage capacitor Cst is formed by the common electrode CE, the capacitor electrode CPE, and the insulating layer 110 located between the common electrode CE and the capacitor electrode CPE. In this embodiment, the common electrodes CE of two adjacent pixel structures PX arranged along direction X can be electrically connected to each other via a common electrode connection line CL, but this is not limited to this embodiment.

First, it should be noted that in this embodiment, the pixel structure PX may have a reflective area RA and a transmissive area TA. The pixel structure PX may also include a reflective layer RL located within the reflective area RA, overlapping and electrically connected to the pixel electrode PE. Figure 2 illustrates a case where a portion of the pixel electrode PE is located between the reflective layer RL and the first substrate 100, but this is not limiting. In other embodiments, the reflective layer RL may be located between a portion of the pixel electrode PE and the first substrate 100, with the reflective layer RL and the pixel electrode PE being electrically connected to each other. A portion of the pixel electrode PE may overlap with the reflective layer RL in the reflective area RA, while another portion may be located within the transmissive area TA.

From another perspective, the reflective area RA of the pixel structure PX can be defined by the distribution range of the reflective layer RL, while the portion of the pixel electrode PE that does not overlap the reflective layer RL, data lines DL, and scan lines SL defines the transmissive area TA of the pixel structure PX (as shown in Figure 1). When the display panel 10 displays an image, the reflective layer RL located in the reflective area RA reflects ambient light AL to form reflected light REL, thereby displaying the corresponding image. In the event of insufficient ambient light, a backlight module (not shown in Figure 2) can be activated as an auxiliary light source. Light from the backlight module can then pass through the portion of the pixel electrode PE located within the transmissive area TA to form transmitted light TL, thereby displaying the corresponding image. In other words, the display panel 10 of this embodiment can be a semi-transflective display panel.

Specifically, the display panel 10 may further include a first passivation layer 121, a second passivation layer 122, and a capping layer 130. The first passivation layer 121 is disposed between the capacitor electrode CPE and the pixel electrode PE, and covers the capacitor electrode CPE as well as the source SE and drain DE of the active device T. The capping layer 130 is disposed between the first passivation layer 121 and the second passivation layer 122. The cover layer 130 can serve as a planarizing layer to reduce the unevenness of the film layers disposed between the cover layer 130 and the first substrate 100. Specifically, the unevenness of the top surface of the cover layer 130 (i.e., the surface of the cover layer 130 facing away from the first substrate 100) is less than the unevenness of the top surface of the first passivation layer 121 (i.e., the surface of the first passivation layer 121 facing away from the first substrate 100).

The materials of the first passivation layer 121 and the second passivation layer 122 include, but are not limited to, silicon nitride, silicon oxide, or aluminum oxide. The coating layer 130 is, for example, an organic insulating layer, and its material may include polyester, polyolefin, polyacrylic, polycarbonate, polyalkylene oxide, polystyrene, polyether, polyketone, polyol, polyaldehyde, or other suitable materials, or combinations thereof.

In this embodiment, since the cladding layer 130 is made of an organic insulating material, a first passivation layer 121, made of an inorganic insulating material, is placed between the cladding layer 130 and the metal data line DL, capacitor electrode CPE, and source SE and drain DE of the active device T. This prevents separation between the cladding layer 130 and the underlying metal film layer. The pixel electrode PE is disposed on the cladding layer 130, with a second passivation layer 122 positioned between the cladding layer 130 and the pixel electrode PE. The cladding layer 130 has an opening 130op that overlaps the through-area TA. Of particular note, the second passivation layer 122, made of an inorganic insulating material, is positioned between the overcoat layer 130 and the pixel electrode PE, which is made of a transparent conductive material. This further enhances the bonding between the overcoat layer 130 and the pixel electrode PE. However, the present invention is not limited to this. In other embodiments, the display panel may not include the second passivation layer 122.

In this embodiment, the first and second passivation layers 121 and 122 have contact holes TH located within the reflective area RA. The contact holes TH overlap the opening 130op and penetrate the first and second passivation layers 121 and 122 to expose a portion of the capacitor electrode CPE. The pixel electrode PE extends into the opening 130op in the cover layer 130 and is electrically connected to the capacitor electrode CPE through the contact holes TH in the first and second passivation layers 121 and 122.

The display panel 10 further includes a light filter pattern 210, a cover layer 220, and a common electrode layer (CEL) disposed on the second substrate 200. The light filter pattern 210 is located between the second substrate 200 and the liquid crystal layer (LCL), overlapping the pixel structure PX. The cover layer 220 is located between the liquid crystal layer (LCL) and the light filter pattern 210, covering the light filter pattern 210. The common electrode layer (CEL) is located between the second substrate 200 and the liquid crystal layer (LCL), and disposed on the cover layer 220. However, the present invention is not limited to this. In other embodiments not shown, the common electrode layer (CEL) may be disposed on the first substrate 100, between the first substrate 100 and the liquid crystal layer (LCL).

In this embodiment, the common electrode layer (CEL) is located within the reflective area RA and the transmissive area TA, and its material may include a transparent conductive material. Examples of such transparent conductive materials include, but are not limited to, metal oxides (e.g., indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, or other suitable oxides, or a stack of at least two of these). The material of the cover layer 220 includes, for example, polyesters, polyolefins, polyacrylates, polycarbonates, polyalkylene oxides, polystyrenes, polyethers, polyketones, polyols, polyaldehydes, or other suitable materials, or combinations thereof.

For example, the electric field formed between the pixel electrode PE and the common electrode layer CEL can control the orientation of the liquid crystal molecules in the liquid crystal layer LCL to display the corresponding image. In this embodiment, the common electrode layer CEL and the common electrode CE can receive a common voltage, but this is not limited to this.

Furthermore, the light filtering pattern 210 includes a first light filtering portion 210p1 and a second light filtering portion 210p2. The first light filtering portion 210p1 is located within the reflective area RA and overlaps the reflective layer RL. The second light filtering portion 210p2 is located within the transmissive area TA and overlaps the pixel electrode PE. Of particular note, the thickness 210t1 of the first light filtering portion 210p1 of the light filtering pattern 210 along the direction Z may be different from the thickness 210t2 of the second light filtering portion 210p2 along the direction Z.

For example, in this embodiment, the thickness 210t1 of the first filter portion 210p1 can be greater than the thickness 210t2 of the second filter portion 210p2. By increasing the thickness 210t1 of the first filter portion 210p1 of the filter pattern 210, the color saturation of the display panel 10 in the reflective area RA can be increased. Simultaneously, by reducing the thickness 210t2 of the second filter portion 210p2 of the filter pattern 210, the light transmittance of the display panel 10 in the transmissive area TA can be improved.

In other words, the thickness of the filter pattern 210 in the reflective area RA and the transmissive area TA can be individually adjusted according to different optical requirements, helping to enhance the design flexibility of the overall optical performance.

It should be noted that the aforementioned design of the filter pattern 210 having different thicknesses in the reflective area RA and the transmissive area TA can be applied only to a portion of the display units in the display panel. The filter patterns in the remaining display units can still have the same thickness in both the reflective and transmissive areas TA. For example, in one embodiment, the filter pattern adapted to allow blue light to pass can have different thicknesses in the reflective and transmissive areas TA to increase blue saturation in the reflective area RA and blue light transmittance in the transmissive area TA. Other filter patterns adapted to allow red or green light to pass can have the same thickness in both the reflective and transmissive areas TA. This can improve the overall yellowish visual effect of the display panel.

Another embodiment will be cited below to illustrate the present disclosure in detail. Identical components will be designated by the same symbols, and descriptions of identical technical contents will be omitted. For omitted parts, please refer to the previous embodiment and will not be repeated here.

Figure 3 is a schematic cross-sectional view of a display panel according to a second embodiment of the present invention. Referring to Figure 3 , the display panel 10A of this embodiment differs from the display panel 10 of Figure 2 in the thickness design of the liquid crystal layer. Specifically, in the display panel 10A of this embodiment, the cover layer 220A on the second substrate 200 has an opening 220op located within the transmissive area TA, and the opening 220op penetrates the cover layer 220A. The common electrode layer CEL extends into the opening 220op of the cover layer 220A and covers the second filter portion 210p2 of the filter pattern 210 located within the transmissive area TA. However, in another alternative embodiment, the cover layer may not be penetrated by the opening.

In this embodiment, the liquid crystal layer LCL-A has a first portion LCLp1 located within the reflective area RA and a second portion LCLp2 located within the transmissive area TA. The second portion LCLp2 of the liquid crystal layer LCL-A overlaps the opening 220op of the cover layer 220A. More specifically, the liquid crystal thickness LCt1 of the first portion LCLp1 of the liquid crystal layer LCL-A along the Z direction is smaller than the liquid crystal thickness LCt2 of the second portion LCLp2 along the Z direction.

The opening design of the overcoat layer 220A in the transmissive area TA increases the liquid crystal thickness LCt2 of the liquid crystal layer LCL-A in the transmissive area TA, thereby reducing the optical path difference between the reflective area RA and the liquid crystal layer LCL-A in the transmissive area TA, further improving the visual consistency of the display panel 10A in the reflective area RA and the transmissive area TA. Preferably, the ratio of the liquid crystal thickness LCt2 of the second portion LCLp2 of the liquid crystal layer LCL-A to the liquid crystal thickness LCt1 of the first portion LCLp1 is greater than or equal to 1.1 and less than or equal to 2.2.

In summary, in a display panel according to one embodiment of the present invention, light-filtering patterns are provided in both the reflective and transmissive regions of the pixel structure. The thickness of the first light-filtering portion of the light-filtering pattern in the reflective region is different from the thickness of the second light-filtering portion in the transmissive region. This increases the flexibility of adjusting the optical properties of the display panel independently in the transmissive and reflective regions.

10: Display Panel

100: First substrate

110: Insulating layer

121: First passivation layer

122: Second passivation layer

130, 220: Covering layer

130op: Opening

200: Second substrate

210: Light filter pattern

210p1: First filter section

210p2: Second filter section

210t1, 210t2: Thickness

AL: Ambient Light

CE: Common Electrode

CEL: Common Electrode Layer

CPE: Capacitor Electrode

Cst: Storage capacitor

DE: Drain

GE: Gate

LCL: Liquid Crystal Layer

PE: Pixel electrode

PX: Pixel structure

RA: Reflex area

RL: Reflective layer

REL: Reflected Light

SC: semiconductor pattern

SE: Source

T: Active element

TA: Penetration Zone

TH: Contact hole

TL: Penetrating Light

Z: Direction

A-A’: section line

Claims (10)

A display panel includes: a first substrate and a second substrate disposed opposite to each other; a liquid crystal layer disposed between the first substrate and the second substrate; a pixel structure disposed on the first substrate and having a reflective region and a transmissive region, the pixel structure including: an active element; a pixel electrode disposed in the transmissive region and electrically connected to the active element; and a reflective layer disposed in the reflective region and overlapping the reflective region. on the pixel electrode; and a light filtering pattern disposed on the second substrate and overlapping the pixel structure, the light filtering pattern comprising a first light filtering portion and a second light filtering portion, wherein the first light filtering portion is located in the reflective region and overlaps the reflective layer, and the second light filtering portion is located in the transmissive region and overlaps the pixel electrode, and a first thickness of the first light filtering portion is different from a second thickness of the second light filtering portion. A display panel as described in claim 1, wherein the first thickness of the first filter portion is greater than the second thickness of the second filter portion. A display panel as described in claim 1, wherein the liquid crystal layer has a first portion located in the reflective area and a second portion located in the transmissive area, the first portion and the second portion respectively have a first liquid crystal thickness and a second liquid crystal thickness, and the first liquid crystal thickness is less than the second liquid crystal thickness. A display panel as described in claim 3, wherein a ratio of the second liquid crystal thickness to the first liquid crystal thickness is greater than or equal to 1.1 and less than or equal to 2.2. The display panel as described in claim 3 further includes: a covering layer disposed on the second substrate and located between the liquid crystal layer and the filter pattern, wherein the covering layer has an opening located in the transmission area; and a common electrode layer disposed on the covering layer and located between the covering layer and the liquid crystal layer, wherein the common electrode layer extends into the opening of the covering layer. A display panel as described in claim 5, wherein the opening penetrates the cover layer. The display panel as described in claim 1, wherein the pixel electrode is further disposed in the reflective region and electrically connected to the reflective layer. The display panel as described in claim 1, wherein the pixel structure further includes: a capacitor electrode located in the reflective region and electrically connected to the active element and the pixel electrode; and a common electrode located in the reflective region, the common electrode overlapping the capacitor electrode and located between the first substrate and the capacitor electrode, wherein the capacitor electrode and the common electrode are electrically coupled to form a storage capacitor. The display panel as described in claim 8 further includes: a covering layer disposed between the pixel electrode and the first substrate and covering the active element and the capacitor electrode, the covering layer having an opening located in the reflective region, and the pixel electrode being electrically connected to the capacitor electrode through the opening of the covering layer. The display panel as described in claim 9 further includes: a first passivation layer disposed between the cover layer and the active element; and a second passivation layer disposed between the cover layer and the pixel electrode, wherein the first passivation layer and the second passivation layer have a contact hole overlapping the opening of the cover layer, and the pixel electrode is also electrically connected to the capacitor electrode through the contact hole of the first passivation layer and the second passivation layer.