CN110989871B

CN110989871B - Array substrate, display panel and display device

Info

Publication number: CN110989871B
Application number: CN201911319337.8A
Authority: CN
Inventors: 王婷; 周洪波; 伍黄尧; 周秀峰
Original assignee: Xiamen Tianma Microelectronics Co Ltd
Current assignee: Xiamen Tianma Microelectronics Co Ltd
Priority date: 2019-12-19
Filing date: 2019-12-19
Publication date: 2022-10-25
Anticipated expiration: 2039-12-19
Also published as: CN110989871A

Abstract

The embodiment of the invention discloses an array substrate, a display panel and a display device, wherein the array substrate comprises at least one fingerprint identification area, the fingerprint identification area is positioned in the display area, and the display area also comprises a touch sensor and a touch switch unit; the non-display area comprises a touch shift register circuit; in the fingerprint identification area, the touch sensor is electrically connected with the integrated circuit through a third wire; in the display area and the non-fingerprint identification area, at least part of the touch sensors are electrically connected with the first wires and the second wires through touch switch units, each touch shift register unit is used for driving at least part of the touch sensors in one row through the first wires, the control ends of the touch switch units are electrically connected to the first wires, the input ends of the touch switch units are electrically connected to the second wires, and the output ends of the touch switch units are electrically connected to the touch sensors. Therefore, the number of touch related signal lines can be reduced, the lower frame of the array substrate can be reduced, and a narrow frame can be realized.

Description

Array substrate, display panel and display device

Technical Field

The invention relates to the technical field of display, in particular to an array substrate, a display panel and a display device.

Background

With the development of display technologies, in order to improve user experience, electronic products with a display function generally integrate a touch function; meanwhile, in order to improve the use safety of the electronic product, the electronic product also integrates a fingerprint identification function. On the basis, in line with the thinning development of electronic products, the structural component with the touch function and the structural component with the fingerprint identification function are usually integrated in the film layer structure inside the display panel.

However, when the structural component with the touch function and the structural component with the fingerprint identification function are integrally arranged in the film layer structure inside the display panel, the signal routing lines are arranged for receiving and sending the touch signal and the fingerprint identification signal, so that the number of the routing lines inside the display panel is increased, the reserved area of the lower frame is increased, and the narrow frame design of the display panel and the display device is not facilitated.

Disclosure of Invention

The embodiment of the invention provides an array substrate, a display panel and a display device, which are used for reducing the number of touch related signal routing wires, thereby being beneficial to reducing the lower frame area of the array substrate and further being beneficial to realizing the narrow frame design of the display panel and the display device.

In a first aspect, an embodiment of the present invention provides an array substrate, which is provided with a display area and a non-display area surrounding the display area; the touch screen comprises a display area, a fingerprint identification area and a touch sensor, wherein the fingerprint identification area is positioned in the display area, the display area comprises the touch sensor, the touch sensor is arranged in an array along a first direction and a second direction, the first direction and the second direction are crossed, and part of the touch sensor is positioned in the fingerprint identification area;

the array substrate further comprises an integrated circuit, a touch shift register circuit, a touch switch circuit, a first wire, a second wire and a third wire; the integrated circuit and the touch shift register circuit are both arranged in the non-display area, the touch shift register circuit comprises a plurality of cascade-arranged touch shift register units, and each touch shift register unit is used for driving at least part of the touch sensors in one row through the first routing; the touch switch circuit is arranged in the display area and comprises a plurality of touch switch units which are arranged in an array, and part of single touch sensors are electrically connected with the output end of at least one touch switch unit; the first routing lines and the third routing lines are arranged along the first direction, extend along the second direction, and extend from the display area to the non-display area, and the second routing lines extend along the first direction and are arranged along the second direction;

in the fingerprint identification area, the touch sensor is electrically connected with the integrated circuit through the third routing;

in the display area and in the non-fingerprint identification area, at least part of the touch sensors are electrically connected with the first wires and the second wires through the touch switch unit, the control end of the touch switch unit is electrically connected to the first wires, the input end of the touch switch unit is electrically connected to the second wires, and the output end of the touch switch unit is electrically connected to the touch sensors.

In a second aspect, an embodiment of the present invention further provides a display panel, including any one of the array substrates provided in the first aspect.

In a third aspect, an embodiment of the present invention further provides a display device, including any one of the display panels provided in the second aspect.

In the array substrate provided by the embodiment of the invention, the touch shift register circuit and the touch switch circuit are arranged, and the touch shift register circuit comprises a plurality of touch shift register units which are arranged in a cascade manner, the touch switch circuit comprises a plurality of touch switch units which are arranged in an array manner, at least part of touch sensors in the touch sensors are electrically connected with the first routing and the second routing through the touch switch units in the display area and the non-fingerprint identification area, the control ends of the touch switch units are electrically connected to the first routing, the input ends of the touch switch units are electrically connected to the second routing, and the output ends of the touch switch units are electrically connected to the touch sensors; in the fingerprint identification area, the touch sensor is electrically connected with the integrated circuit through a third wire; therefore, at least part of the touch sensors in one row can be driven by the touch shift register unit through the first routing, namely, at least part of the touch sensors can be driven in a cascade mode in the non-fingerprint identification area of the display area; therefore, the number of touch related signal wires can be reduced, the area of a lower frame area reserved for the signal wires can be reduced, and the narrow frame design of the array substrate, the display panel comprising the array substrate and the display device comprising the display panel can be realized.

Drawings

Fig. 1 is a schematic structural diagram of an array substrate provided in the prior art;

fig. 2 is a schematic structural diagram of an array substrate according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of another array substrate according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of another array substrate according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of another array substrate according to an embodiment of the present invention;

fig. 6 is a schematic partial structure diagram of another array substrate according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of another array substrate according to an embodiment of the present invention;

fig. 8 is a schematic structural view of another array substrate according to an embodiment of the present invention;

fig. 9 is a schematic structural view of another array substrate according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of another array substrate according to an embodiment of the present invention;

fig. 11 is a schematic structural view of another array substrate according to an embodiment of the present invention;

fig. 12 is a schematic cross-sectional view of an array substrate according to an embodiment of the invention;

fig. 13 is a schematic cross-sectional view of a display panel according to an embodiment of the disclosure;

fig. 14 is a schematic view of a partial plan structure of a display panel according to an embodiment of the invention;

fig. 15 is a schematic cross-sectional view illustrating a display device according to an embodiment of the invention;

fig. 16 is a schematic plan view illustrating a display device according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention. It should be further noted that, for the convenience of description, only some but not all of the features relevant to the present invention are shown in the drawings.

Fig. 1 is a schematic structural diagram of an array substrate provided in the prior art, which illustrates an electrical connection relationship and a related structure between a touch-related signal trace and a touch sensor in the array substrate integrated with a touch function and a fingerprint identification function. Referring to fig. 1, the array substrate 01 includes a display area 011 and a non-display area 012 surrounding the display area 011, a fingerprint identification area 013 is disposed in the display area 011, and touch sensors 014 are disposed in the display area 011 and arranged in an array; such that a portion of the touch sensor 014 is located in the fingerprint identification region 013. In the present array substrate 01 structure, fingerprint identification district 013 limits to the subregion in the display area 011, and because of directly integrating capacitanc touch sensor 014 in array substrate 01, because touch sensor 014's quantity is more, and its touch-control relevant signal line is more, leads to the lower frame reserved area great to the lower frame broad is unfavorable for realizing display panel and display device's narrow frame design. Meanwhile, a fingerprint identification sensor is further arranged in the fingerprint identification area 013 of the array substrate 01, correspondingly, fingerprint identification related signal wiring needs to be arranged, the signal wiring is usually made of shading materials, and therefore the whole light-transmitting area of the array substrate 01 is small due to the fact that the number of touch control and fingerprint identification signal wiring is large, and the opening ratio of the display panel comprising the array substrate 01 and the display device is greatly reduced. Accordingly, in order to ensure that the uniformity of the luminance of the non-fingerprint identification region of the fingerprint identification region 013 and the display region 011 is good, the light shielding structure is also formed using the light shielding material in the non-fingerprint identification region, so that the aperture ratio of the entire display panel is low, and the power consumption of the display panel and the display device including the array substrate is high compared to the array substrate having a high aperture ratio when used to display the same luminance.

In view of the above problems, embodiments of the present invention provide an array substrate to solve at least one of the above technical problems. Specifically, by arranging the touch shift register circuit and the touch switch circuit, at least part of touch sensors in the non-fingerprint identification area of the display area can be driven in a cascade mode; in the fingerprint identification district, the line is walked in touch-control sensor czochralski to under the prerequisite of realizing touch-control, fingerprint identification and display function, the quantity of the relevant signal line of reducible touch-control is walked, is favorable to reducing the area of the lower frame of reserving for the touch-control signal line, thereby is favorable to realizing the display panel including this array substrate and display device's narrow frame design. Meanwhile, the number of signal wires is reduced, and the shielding of light can be reduced, so that the aperture opening ratio is improved, and the overall power consumption of the display panel and the display device is reduced.

The array substrate, the display panel and the display device provided by the embodiment of the invention are exemplarily described below with reference to fig. 2 to 16.

Fig. 2 is a schematic structural diagram of an array substrate according to an embodiment of the present invention. Referring to fig. 2, the array substrate 10 is provided with a display region 101 and a non-display region 102 surrounding the display region 101; the array substrate 10 further includes at least one fingerprint identification area 103, the fingerprint identification area 103 is located in the display area 101, the display area 101 includes touch sensors 110, the touch sensors 110 are arranged in an array along a first direction X and a second direction Y, the first direction X is crossed with the second direction Y, and a part of the touch sensors 110 are located in the fingerprint identification area 103; the array substrate 10 further includes an integrated circuit 120, a touch shift register circuit 130, a touch switch circuit 140, a first trace 151, a second trace 152, and a third trace 160; the integrated circuit 120 and the touch shift register circuit 130 are both disposed in the non-display area 102, the touch shift register circuit 130 includes a plurality of cascade-connected touch shift register units 132, and each touch shift register unit 132 is configured to drive at least a portion of the touch sensors 110 in a row through the first routing 151; the touch switch circuit 140 is disposed in the display area 101, the touch switch circuit 140 includes a plurality of touch switch units 142 arranged in an array, and a part of the individual touch sensors 110 is electrically connected to an output terminal of at least one of the touch switch units 142; the first traces 151 and the third traces 160 are arranged along the first direction X, extend along the second direction Y, and extend from the display region 101 to the non-display region 102, and the second traces 152 extend along the first direction X and are arranged along the second direction Y; in the fingerprint identification area 103, the touch sensor 110 is electrically connected to the integrated circuit 120 through the third trace 160; in the display area 101 and in the non (non) fingerprint identification area 103, at least a portion of the touch sensor 110 is electrically connected to the first trace 151 and the second trace 152 through the touch switch unit 142, a control terminal of the touch switch unit 142 is electrically connected to the first trace 151, an input terminal of the touch switch unit 142 is electrically connected to the second trace 152, and an output terminal of the touch switch unit 142 is electrically connected to the touch sensor 110.

The display area 101 is used for transmitting light or emitting light to display an image to be displayed. The non-display area 102 is used for disposing a scan driving circuit (or "scan shift register circuit"), an anti-static circuit, an integrated circuit, a data driving circuit (or "multiplexer circuit", "data selection circuit", or "DEMUX circuit"), and other circuit structures known to those skilled in the art, which is not limited in the embodiment of the present invention.

Illustratively, the non-display area 102 is only exemplarily shown in fig. 2 to be disposed around the display area 101. In other embodiments, the non-display area 102 may be disposed to partially surround the display area 101, or the non-display area 102 and the display area 101 are adjacent to each other vertically, horizontally, or otherwise, a space for disposing the peripheral circuit area may be reserved by using other relative positional relationships known to those skilled in the art.

The fingerprint identification area 103 is used for setting a fingerprint identification sensor for realizing a fingerprint identification function. The fingerprint sensor may be externally attached to the array substrate 10, or integrated in a film structure inside the array substrate 10, and may be configured according to actual requirements of the array substrate 10, the display panel, and the display device, which is not limited in the embodiment of the present invention. Through setting up fingerprint identification district 103 in display area 101, be about to part display area 101 multiplexing for fingerprint identification district 103, so, can avoid fingerprint identification district 103 to occupy the area of non-display area 102 to be favorable to improving the display area 101 at the shared area proportion of display surface, thereby be favorable to improving the screen ratio of taking up.

The touch sensor 110 is configured to implement a touch function, and by setting the touch sensor 110 to be located not only in the non-fingerprint identification area of the display area 101 but also in the fingerprint identification area 103 of the display area 101, a full display area touch can be implemented. For example, the touch sensor 110 may be a capacitive touch sensor, or a touch sensor based on other principles known to those skilled in the art, and the film structure thereof may be any structure known to those skilled in the art, which is neither described nor limited in the embodiments of the present invention.

The touch sensors 110 are arranged in an array along the first direction X and the second direction Y, so that the touch sensors 110 are distributed uniformly in the array substrate 10. Illustratively, the array arrangement of the touch sensors 110 is 18 columns and 36 rows. In other embodiments, the touch sensor 110 may also adopt other array arrangements known to those skilled in the art, and the array arrangement may be set according to actual requirements of the array substrate 10, the display panel and the display device, which is not limited in the embodiments of the present invention.

Taking the orientation shown in fig. 2 as an example, the integrated circuit 120 is disposed in the lower frame area of the array substrate 10, the touch shift register circuit 130 is disposed in the left and right frame areas of the array substrate 10, and the touch switch circuit 140 is disposed in the display area 101 of the array substrate 10 and is electrically connected to at least a portion of the touch sensor 110. In the touch shift register circuit 130, each touch shift register unit 132 can output a trigger signal of the touch sensor 110 in the current row and output a shift signal to the next touch shift register unit 132; the trigger signal of the current-stage touch shift register unit 132 can turn on the touch switch unit 142 electrically connected to the current-row touch sensor 110, i.e., the touch switch unit is in a state of allowing the touch driving signal on the second trace 152 to be transmitted to the corresponding touch sensor 110, and allowing the touch sensing signal sensed by the touch sensor 110 to be transmitted to the integrated circuit 120 through the first trace 151. Each row of touch sensors 110 is sequentially triggered according to the cascade relationship of the touch shift register units 132, receives the touch driving signal, and feeds back the touch sensing signal, so as to realize the touch identification process of the non-fingerprint identification area in the display area 101. Meanwhile, the touch sensor 110 in the fingerprint identification area 103 receives the touch driving signal sent by the integrated circuit 120 through the third trace 160 (i.e., "straight pull trace"), and transmits the sensed touch sensing signal to the integrated circuit 120, so as to implement the touch identification process of the fingerprint identification area 103 in the display area 101.

In the array substrate 10 provided in the embodiment of the present invention, the touch sensor 110 disposed in the fingerprint identification area 103 in the display area 101 is electrically connected to the integrated circuit 120 in a straight pull manner, and at least a portion of the touch sensor 110 in the non-fingerprint identification area in the display area 101 is electrically connected in a cascade manner and is triggered step by step, so that the number of signal traces related to the touch function can be reduced while the touch function and the fingerprint identification function are implemented, thereby facilitating reduction of an area of a lower bezel area reserved for the signal traces related to touch, and further facilitating implementation of a narrow bezel design of a display panel and a display device including the array substrate.

For example, taking the array arrangement of the touch sensors 110 as 18 × 36, when 2 × 4 touch sensors 110 close to the upper frame area are located in the fingerprint identification area 103, the number of signal traces pulled down to the lower frame area may be: 18+2 + 4=26 roots; the number of the 18 first wires 151 of the touch sensor 110 in the cascade connection mode is 18, and each column of the touch sensor 110 is provided with one first wire 151 correspondingly; 2 x 4 are straight pull traces in the fingerprint identification area 103, i.e. the number of third traces 160, requiring a total of 26 signal traces. In the prior art, the number of the signal traces is equal to the number of the touch sensors 110, that is, the number of the signal traces is 18 × 36 =648. Therefore, compared with the prior art, in the array substrate 10 provided by the embodiment of the present invention, the number of signal traces related to touch in the lower bezel region is greatly reduced, thereby facilitating the implementation of a narrow bezel design.

In other embodiments, when the touch sensors 110 are arranged in other arrays and the distribution of the touch sensors 110 in the fingerprint identification area 103 is in other manners, the number of signal traces related to touch may also be other values, which is not repeated nor limited in the embodiment of the present invention.

It should be noted that fig. 2 only shows that the boundary between the display area 101 and the non-display area 102 is a rounded rectangle and the outer boundary of the non-display area 102 is a right-angled rectangle, but the outer boundary of the non-display area 102 is not limited to the array substrate 10 provided in the embodiment of the present invention, and in other embodiments, the outline shapes of the display area 101 and the non-display area 102 may also be set according to the actual requirements of the array substrate 10, the display panel, and the display device, which is not limited in the embodiment of the present invention.

Next, it should be noted that fig. 2 only illustrates the outline shape of the touch sensor 110 in a square shape and the outline shape of the touch shift register unit 132 in a rectangle shape by way of example, in an actual product structure, the outline shape of the touch sensor 110 may be set according to actual requirements of the array substrate 10, the display panel and the display device, which is not limited in the embodiment of the invention.

Again, it should be noted that fig. 2 only exemplarily shows that 1 row of touch sensors 110 is connected to one second trace 152, and 1 column of touch sensors 110 is connected to 3 first traces 151, but these do not limit the array substrate 10 provided in the embodiment of the present invention. In other embodiments, the corresponding relationship between the first traces 151 and the second traces 152 and the touch sensor 110 can be set according to actual requirements of the array substrate 10, the display panel and the display device, which is not limited in the embodiments of the invention.

It should be noted that the structure of the touch shift register circuit 130 may be any shift register circuit structure known to those skilled in the art, and the structure of the touch switch unit 142 may be any control switch structure known to those skilled in the art, which is not repeated and is not limited in the embodiments of the present invention.

Finally, it should be noted that the first direction X and the second direction Y may intersect perpendicularly or not, which is not limited in the embodiment of the present invention.

Illustratively, the first direction X is a row direction and the second direction Y is a column direction.

Optionally, referring to fig. 3, the array substrate 10 further includes a substrate 100 and pixel electrodes 201, and the pixel electrodes 201 are arranged in an array; in the fingerprint identification area 103, when the vertical projection of a touch sensor 110 on the substrate 100 covers the vertical projection of M1 rows of pixel electrodes 201 on the substrate 100, the touch sensor 100 is electrically connected to the integrated circuit 120 through M1 connection points on the third trace 160; wherein M1 is a positive integer.

One pixel electrode 201 corresponds to one sub-pixel, and thus, the above arrangement is that: in the fingerprint identification area 103, the number of connection points of the third trace 160 and the touch sensor 110 is equal to the number of rows of sub-pixels covered by the touch sensor 110.

With such an arrangement, the touch driving signals on the same touch sensor 110 are more uniform in the column direction, thereby being beneficial to ensuring higher touch uniformity and touch sensitivity.

Illustratively, the partial enlarged portion in fig. 3 shows that a touch sensor 110 covers 4 rows of pixel electrodes 201, and based on this, the number of connection points between the touch sensor 110 and the third trace 160 is 4, i.e., M1=4. In other embodiments, the number of rows of the pixel electrodes 201 covered by one touch sensor 110 may be other numbers known to those skilled in the art, and may be set according to the actual requirements of the array substrate 10, the display panel and the display device, depending on the relevant factors known to those skilled in the art, such as the resolution, which is not limited in the embodiment of the invention.

Optionally, referring to fig. 4 or fig. 5, the first trace 151 includes a first main line 1511 and a plurality of first branch lines 1512 electrically connected to the first main line 1511, a first end of the first main line 1511 is electrically connected to a data output end of the integrated circuit 120, and a plurality of second ends of the first main line 1511 are electrically connected to the plurality of first branch lines 1512 in a one-to-one correspondence; the second wire 152 includes a second main wire 1521 and a plurality of second branch wires 1522 electrically connected to the second main wire 1521, a first end of the second main wire 1521 is electrically connected to the output end of the touch shift register unit 132, and a plurality of second ends of the second main wire 1521 are electrically connected to the plurality of second branch wires 1522 in a one-to-one correspondence manner. "multi" in this paragraph is understood to mean "greater than or equal to 2".

With such a configuration, while the first main line 1511 and the second main line 1521 are fewer, the first branch line 1512 and the second branch line 1522 are more; the number of touch pins of the integrated circuit 120 may be equal to the number of the first main lines 1511, the number of the touch shift register units 132 may be equal to the number of the second main lines 1521, and the touch switch units 142 may be disposed at the intersection of the first branch lines 1512 and the second branch lines 1522.

Thereby: on the first hand, by setting the first main lines 1511 with a smaller number, the number of signal routing lines in the lower frame is favorably reduced, so that the lower frame is favorably reduced; meanwhile, the number of the touch pins of the integrated circuit 120 is reduced, so that the difficulty of alignment connection is reduced, the cost of the integrated circuit 120 and the flexible printed circuit board electrically connected with the integrated circuit 120 is reduced, and the overall cost of the display panel and the display device comprising the array substrate is reduced. In a second aspect, the number of the touch shift register units 132 is reduced by providing the second branch lines 1521 with a smaller number, so that the structure of the touch shift register circuit 130 is simplified, the area of the non-display area 102 of the array substrate 10 occupied by the touch shift register circuit is reduced, and the left and right frames are reduced. In the third aspect, by arranging the first branch lines 1512 and the second branch lines 1522 in a larger number, more setting positions of the touch switch units 142 can be reserved, so that flexible setting of the touch switch units 142 is facilitated, and the touch switch units 142 in a larger number are facilitated to be arranged, so that higher touch uniformity and higher touch sensitivity are realized.

It is noted that only one first trace 151 shown in fig. 4 and 5 as exemplary includes three first branches 1512 and one second trace 152 includes three second branches 1522. In other embodiments, the number of the first branches 1512 included in each first trace 152 and the number of the second branches 1522 included in each second trace 152 can also be other numbers as known by those skilled in the art, and the numbers of the first branches 1512 and the second branches 1522 can be equal to or different from each other, and can be set according to actual requirements of the array substrate 10, the display panel, and the display device, which is not limited by the embodiment of the present invention.

Optionally, with continued reference to fig. 5, both the first main line 1511 and the second main line 1521 extend into the display area 101 from the non-display area 102, and both the first branch line 1512 and the second branch line 1522 are located in the display area 101.

With such a configuration, the first branch lines 1512 and the second branch lines 1512 are only disposed in the display area 101, and the first main line 1511 and the second main line 1521 are disposed in the non-display area 102, so that the number of signal traces in the non-display area 102 is small, which is beneficial for implementing a narrow bezel design.

Optionally, with reference to fig. 4 or fig. 5, the control terminals of the touch switch units 142 in the same row are electrically connected to the same second branch line 1522; the input terminals of the touch switch units 142 in the same column are electrically connected to the same first branch line 1512.

So configured, the first branch 1512 extends in the column direction and the second branch 1522 extends in the row direction; therefore, the first branch lines 1512 and the second branch lines 1522 are arranged in a simple manner, and the difficulty of the forming process is low.

For example, each row of the touch sensors 110 may be connected to a plurality of rows of the touch switch units 142; meanwhile, each row of the touch sensors 110 may correspond to one touch shift register unit 142, so that the number of the touch shift register units 132 in the touch shift register circuit 130 may be equal to the number of rows of the touch sensors 110, and thus the touch shift register circuit 130 has a simpler circuit structure and a smaller area, which is beneficial to realizing a narrow frame design.

Optionally, referring to fig. 5 and 6, the array substrate 10 further includes a substrate 100 and pixel electrodes 201, and the pixel electrodes 201 are arranged in an array; when a vertical projection of a touch sensor 110 on the substrate 100 covers a vertical projection of M2 pixel electrodes 201 on the substrate 100 in the display area 101 and in the non-fingerprint identification area 103, the touch sensor 110 is electrically connected to the first branch line 1512 and the second branch line 1522 through M2 touch switch units 142; wherein M2 is a positive integer.

With such an arrangement, connection points between the touch sensor 110 and the first branch line 1512 and the second branch line 1522 can be increased, thereby facilitating improvement of uniformity of touch signals.

Illustratively, when each pixel electrode 201 is covered by the touch sensor 110, the number of touch switch units 142 is equal to the number of pixel electrodes 201 in the non-fingerprint identification area 103 (not in) of the display area 101. Based on the number of pixel electrodes 201 being equal to the number of pixel driving circuits 202, the number of touch switch units 142 in the non-fingerprint identification area 103 of the display area 101 may be equal to the number of pixel driving circuits 202.

For example, fig. 5 exemplarily shows that a touch sensor 110 covers 3 × 3 pixel electrodes 201, and in this case, the touch sensor 110 is electrically connected to the first branch 1512 and the second branch 1522 through 3 × 3 (i.e., 9) touch switch units 142, that is, 9 connection points are formed.

In other embodiments, the number of the pixel electrodes 201 covered by the touch sensor 110 and the arrangement of the pixel electrodes 201 may also be set according to actual requirements of the array substrate 10, the display panel and the display device, which is not limited in the embodiments of the present invention.

The following describes an arrangement manner of the touch shift register circuit 130 by taking a position of the fingerprint identification area 103 in the display area 101 as an example.

Alternatively, referring to fig. 7 or 8, along the first direction X, the display area 101 includes a first display area 1011 and a second display area 1012 located at opposite sides of the fingerprint identification area 103; the non-display area 102 includes a first non-display area 1021 and a second non-display area 1022, the first non-display area 1021 is located on a side of the first display area 1011 facing away from the fingerprint identification area 103, and the second non-display area 1022 is located on a side of the second display area 1012 facing away from the fingerprint identification area 103; the touch shift register unit 132 includes a first touch shift register unit 1321 and a second touch shift register unit 1322, the first touch shift register unit 1321 is disposed in the first non-display area 1021, and the second touch shift register unit 1322 is disposed in the second non-display area 1022; the first touch shift register unit 1321 is configured to provide a first driving signal to the touch sensor 110 disposed in the first display area 1011, and the second touch shift register unit 1322 is configured to provide a second driving signal to the touch sensor 110 disposed in the second display area 1012. The "first driving signal" and the "second driving signal" in this paragraph are both touch signals, and they are only named for distinguishing whether they are provided by the first touch shift register unit 1321 or the second touch shift register unit 1322.

With such a configuration, the touch sensors 110 in the first display area 1011 and the second display area 1012 directly opposite to the fingerprint identification area 103 along the first direction X are driven in a double-sided manner; wherein, first line 151 of walking is disconnected by fingerprint identification district 103 to no longer set up extra first line 151 in the fingerprint identification district 103, and the upper and lower adjacent area of fingerprint identification district 103 also need not the wire winding, is favorable to making wiring mode simple in the display area 101, and the technology degree of difficulty is lower. Meanwhile, the redundant first routing wires 151 or the winding wires are not arranged by occupying extra area, so that the smaller shading area is favorably ensured, and the higher aperture opening ratio is ensured.

For example, taking the orientations shown in fig. 7 and fig. 8 as an example, in order from top to bottom and from left to right, the fingerprint identification area 103 covers the first and second rows of touch sensors 110, then the touch sensor 110 in the first display area 1011 on the left side of the fingerprint identification area 103 is triggered by the first touch shift register unit 1031 in the first non-display area 1021, and the touch sensor 110 in the second display area 1021 on the right side of the fingerprint identification area 103 is triggered by the second touch shift register unit 1032 in the second non-display area 1022, thereby implementing the dual-side driving touch shift register circuit 130.

In other embodiments, the number of the fingerprint identification areas 103 may also be 2 or more, when one fingerprint identification area 103 cuts the display area into a left display area and a right display area along the first direction X, the touch sensor 110 in the left display area may be triggered by the touch shift register unit 132 in the left non-display area, and the touch sensor 110 in the right display area may be triggered by the touch shift register unit 132 in the right non-display area.

Optionally, with continued reference to fig. 7 or 8, along the first direction X, the display area 101 further includes a third display area 1013 offset from the fingerprint identification area 103, and the non-display area 102 further includes a third non-display area 1023 and a fourth non-display area 1024 on opposite sides of the third display area 1013; the touch shift register unit 132 further comprises a third touch shift register unit 1323, the third touch shift register unit 1323 is disposed in the third non-display area 1023 and/or the fourth non-display area 1024; the third touch shift register unit 1323 is configured to provide a third driving signal for the touch sensor 110 disposed in the third display area 1013.

The second traces 152 in the third display area 1013 can penetrate through the third display area 1013 along the first direction X, so that the same row of touch sensors 110 in the third display area 1013 can be triggered by the same level of touch shift register unit 132, thereby implementing dual-side driving and single-side driving.

For example, in fig. 7, the touch shift register circuit 130 is disposed in the third non-display area 1023, but the touch shift register circuit 130 is not disposed in the fourth non-display area 1024, and the left-side single-side driving can be realized by taking the orientation in fig. 7 as an example.

In other embodiments, a right side single sided drive may also be implemented.

For example, in fig. 8, the touch shift register circuits 130 are disposed in the third non-display area 1023 and the fourth non-display area 1024, and the second traces 152 corresponding to the same row of touch sensors 110 can be simultaneously connected to the third touch shift register units 1323 on the left and right sides, so as to implement dual-edge driving. Therefore, the uniformity of the touch signal is better in the row direction.

In other embodiments, in the structure where the touch shift register circuit 130 is disposed in both the third non-display area 1023 and the fourth non-display area 1024, the second trace 152 corresponding to the same row of touch sensors 110 may be further connected to the third touch shift register unit 1323 only on the left side or only on the right side, so as to implement dual-sided single driving. Thus, the number of the third touch shift register units 1323 in the touch shift register circuit 130 is small, so that the area is small, which is beneficial to implementing a narrow frame design.

In other embodiments, the driving may be performed in other manners known to those skilled in the art, which are not described or limited in this embodiment of the present invention.

It should be noted that, in fig. 7 and 8, the display area 101 is exemplarily shown only by taking the two-dot chain line A1A2 as a boundary line and includes a first display area 1011, a second display area 1012 and a third display area 1013, and correspondingly, the non-display area 102 includes a first non-display area 1021, a second non-display area 1022, a third non-display area 1023 and a fourth non-display area 1024. In other embodiments, according to the shapes and relative positions of the display area 101, the non-display area 102, and the fingerprint identification area 103, the boundary lines of the display area 101 and the non-display area 102 may also be a broken line type, a curved line type, or other line type shapes known to those skilled in the art, which may be set according to the actual requirements of the array substrate 10, and this is not limited by the embodiments of the present invention.

Optionally, referring to fig. 9, 10 and 11, the non-display area 102 further includes a scan shift register circuit 170; the scan shift register circuit 170 is disposed between the display area 101 and the touch shift register circuit 130; or the touch shift register circuit 130 is disposed between the display area 101 and the scan shift register circuit 170; or the scanning shift register circuit 170 includes a plurality of scanning shift register units 172 arranged in cascade, and M3 scanning shift register units 132 are arranged between two adjacent touch shift register units 172 along the second direction Y; wherein M3 is a positive integer.

The scan shift register circuit 170 is configured to implement shift register of the scan trigger signal, so as to implement gradual refresh of the display data signal, and implement refresh of the display screen of the display panel and the display device including the array substrate 10. In the scan shift register circuit 170, the cascade relationship of the scan shift register units 172 may be any one known by those skilled in the art, and the circuit structure of the scan shift register units 172 may be any one known by those skilled in the art.

The position relationship between the scanning shift register circuit 170 and the touch shift register circuit 130 relative to the display area 101 can be flexibly set according to the requirement of the array substrate 10.

For example, referring to fig. 9, in the same side of the display area 101, the touch shift register circuit 130 and the scan shift register circuit 170 are in a line, and the touch shift register circuit 130 may be located on a side of the scan shift register circuit 170 close to the display area 101; alternatively, referring to fig. 10, in the same side of the display area 101, the touch shift register circuit 130 and the scan shift register circuit 170 are respectively in a row, and the touch shift register circuit 130 may be located on a side of the scan shift register circuit 170 away from the display area 101; alternatively, referring to fig. 11, in the same side of the display area 101, the touch shift register circuits 130 and the scan shift register circuits 170 are combined into a row, and since the number of the touch shift register units 132 is less than the number of the shift register units 172, M3 scan shift register units 132 can be arranged between two adjacent touch shift register units 172; for example, in fig. 11, M3 is 3, which is only a partial structure of the array substrate 10, and in other partial structures of the array substrate, M3 may also be 1, 2, 4 or other values known to those skilled in the art, which is not limited in the embodiment of the present invention.

In other embodiments, the touch shift register circuit 130 and the scan shift register circuit 170 may also be disposed at different sides of the display area 101, and may be flexibly disposed according to the requirement of the array substrate 10, which is neither described nor limited in this embodiment of the present invention.

It should be noted that the touch shift register circuit 130 and the scan shift register circuit 170 can be formed synchronously by using the same process flow, and the process flow is different from the prior art only in that the patterning shape of a part of the film layer needs to be adjusted; therefore, additional process flow and additional process equipment are not required to be added, and the method is favorable for fusing with the existing process and simultaneously is favorable for ensuring lower manufacturing cost.

Referring to fig. 12, a longitudinal (i.e., a direction perpendicular to a plane defined by the first direction X and the second direction Y, which is shown as a third direction Z in fig. 12) film structure of the array substrate 10 according to an embodiment of the present invention is exemplarily described.

Optionally, referring to fig. 12, the array substrate 10 further includes a substrate 100, and a driving circuit layer 210, a first insulating layer 220, a metal wire layer 230, a planarization layer 240, a first transparent electrode layer 250, a second insulating layer 260, a second transparent electrode layer 270, and a third insulating layer 280, which are sequentially stacked on one side of the substrate 100; the first wire 151 and the third wire 160 are disposed on the metal wire layer 230, and the second wire 152 is disposed in a metal wire layer of the driving circuit layer 210; the touch sensor 110 includes a touch electrode block 112, and the touch electrode block 112 is disposed in the first transparent electrode layer 250.

The substrate 100 may be a rigid substrate, such as a glass substrate; but also flexible substrates such as polyimide substrates; the substrate may also be a substrate with other properties or materials known to those skilled in the art, and the embodiment of the present invention is not described or limited herein.

In conjunction with fig. 2 and fig. 9, the film layer structure in the driving circuit layer 210 is used to form the touch shift register circuit 130 and the touch switch circuit 140, and is used to form the scan shift register circuit 170. The driving circuit layer 210 is used to form a thin film transistor (T) and a capacitor (C), i.e., to form a multi-T multi-C circuit.

For example, the driving circuit layer 210 may include a buffer layer (buffer), an active layer (poly), a gate insulating layer (GI), a gate metal layer (M1), an interlayer dielectric layer (IMD), an intermediate metal layer (Mc), an insulating Interlayer (ILD), a source/drain metal layer (M2), and a passivation layer (PV) sequentially stacked from the substrate 100 along the third direction Z. This is a top gate structure, in which the function, material and manufacturing process of each film layer can be any one known to those skilled in the art, and this is not limited by the embodiment of the present invention.

In other embodiments, the film structure of the driving circuit layer 210 may also be other film structures known to those skilled in the art, which is not repeated nor limited in this embodiment of the present invention.

The driving circuit layer 210 includes a plurality of patterned film layers to form a thin film transistor and a capacitor. Based on this, the second wire 152 is used as a touch scan line, and the second wire 152 can be formed in the gate metal layer in the driving circuit layer 210, so that the electrical connection manner between the second wire 152 and the touch switch unit 142 can be set in a manner similar to the electrical connection manner between the display scan line and the pixel driving circuit, and thus the design manner is simpler, the process flow can be integrated, and the process difficulty is lower.

The scan data lines may be disposed on the source-drain metal layer, and the touch data lines (including the first trace 151 and the third trace 160) may be disposed on the metal wire layer 230 (M3), so that the touch data lines and the scan data lines are disposed in different metal film layers, which may reduce coupling between the scan data and the touch data, i.e., reduce mutual influence therebetween, thereby facilitating to ensure higher display accuracy and higher touch accuracy.

The driving circuit layer 220 includes a plurality of patterned film layers, and the metal wire layer 230 also includes a patterned metal wire, so that the surface of the metal wire layer 230 away from the substrate 100 has a concave-convex shape. The planarization layer 240 is used to planarize the concave-convex surface formed by overlapping the driving circuit layer 220 and the metal wire layer 230, i.e. the surface of the metal wire layer 230 away from the substrate 100, so that the planarization degree of the film layer deposited thereafter is higher, which is beneficial to the precise control of the display effect.

The first transparent electrode layer 250 and the second transparent electrode layer 260 may be used as a common electrode layer and a pixel electrode layer, respectively, and transparent electrodes in the common electrode layer are arranged in different regions to form the touch electrode block 112; through the time-sharing multiplexing of the touch electrode block 112, the display can be realized in the display stage, and the touch control can be realized in the touch control stage.

In the above arrangement, the second trace 152, the touch scan shift register circuit 130, the scan shift register circuit 170, and the touch switch circuit 140 can be synchronously formed in the driving circuit layer 210; the first trace 151 and the third trace 160 may be simultaneously formed in the metal wire layer 230; and multiplexing the time division multiplexing of the touch electrode blocks 112 in the first transparent electrode layer 250 to realize touch control and display. Therefore, the array substrate 10 has fewer film layer structures and simpler preparation process flow, and the manufacturing process is simple and the manufacturing cost is low while the thin design of the array substrate 10 and the display panel and the display device comprising the array substrate 10 is realized.

In other embodiments, the array substrate 10 may further include other film structures known to those skilled in the art, and the film layers in the array substrate 10 may also be set to have other relative position relationships known to those skilled in the art, which is neither described nor limited in this embodiment of the present invention.

On the basis of the foregoing embodiments, an embodiment of the present invention further provides a display panel, and referring to fig. 13, the display panel 30 includes any one of the array substrates 10 provided in the foregoing embodiments, so that the display panel 30 also has the beneficial effects of the array substrate 10 provided in the foregoing embodiments, which can be understood with reference to the foregoing, and is not described herein again.

Illustratively, the Display panel 30 is exemplarily shown in fig. 13 as a Liquid Crystal Display (LCD) panel; in other embodiments, the display panel 30 may also be an Organic Light Emitting Diode (OLED) display panel or other types of display panels known to those skilled in the art, which is not limited by the embodiments of the invention.

The structure of the display panel 30 will be described below by taking the display panel 30 as an example of an LCD panel.

For example, referring to fig. 13 and 14, the display panel 30 further includes a color filter substrate 310 and a liquid crystal layer 320 filled between the array substrate 10 and the color filter substrate 310; a black matrix 312, a color resist block 314 and a covering layer 316 are arranged on one side of the color film substrate 310 facing the array substrate 10; the black matrix 312 includes a plurality of hollow areas 3121, the color block 314 is disposed in the hollow areas 3121, and the cover layer 316 is disposed on a side of the black matrix 312 and the color block 314 facing the array substrate 10; in the display area 101 and the non-fingerprint identification area 103 (not shown), vertical projections of the first traces 151, the second traces 152 and the third traces on the color filter substrate 310 are all located in the non-hollow area 3122 of the black matrix 314.

The black matrix 312 is a black matrix layer having pixel openings (i.e., hollow areas 3121). On one hand, the black matrix 312 is used to space the materials (i.e., the color resist blocks 314) filled in the different pixel openings, so that the mutual influence between the color resist blocks 314 of different colors is small, and an algorithm can be used to perform color mixing, i.e., to realize controllable adjustment of the color; on the other hand, the metal traces are used for shielding the metal traces on the side of the light emitting surface of the black matrix 312 away from the display panel 30, so as to prevent the metal traces from reflecting ambient light to generate visible influence on the display effect of the display panel 30, thereby improving the display effect of the display panel 30.

The color block 314 is used to determine the transmission color of the sub-pixels of the display panel 30 at the position. For example, the transparent color of the color block 314 may be red, green, blue or other colors known to those skilled in the art, so that a white display or a color display of the display panel 30 can be realized.

The color block 314 is not only disposed in the display region 101, but also disposed in the non-display region 102, and the color block 314 in the non-display region 102 is used to balance the height difference of the surface of the color block 314 on the side away from the color filter substrate 310, so as to facilitate the surface leveling of the side of the cover layer 316 away from the color filter substrate 310. For example, the covering layer 316 may be a transparent optical adhesive layer or other transparent covering layers known to those skilled in the art, which is not described or limited in the embodiments of the present invention.

The vertical projections of the first traces 151, the second traces 152 and the third traces on the color film substrate 310 are all located in the non-hollowed-out region 3122 of the black matrix 314, and the signal traces related to touch can be shielded by using the original light shielding structure in the display panel 30, so that an additional light shielding structure is not required to be provided, an additional light shielding area is not formed, and the display panel 30 is further ensured to have a higher aperture ratio.

In other embodiments, the display panel 30 may further include other structures known to those skilled in the art, such as other optical components, electrical components, and supporting structures, which are not described or limited in this embodiment of the present invention.

On the basis of the foregoing embodiments, an embodiment of the present invention further provides a display device, where the display device includes any one of the display panels provided in the foregoing embodiments, and the display panel includes any one of the array substrates provided in the foregoing embodiments, so that the display device also has the technical effects of the display panel and the array substrate provided in the foregoing embodiments, which can be understood with reference to the foregoing, and are not described herein again.

Exemplarily, referring to fig. 15 and 16, the display device 50 further includes a backlight module 520; the light emitting surface of the backlight module 520 faces the display panel 30.

The backlight module 520 is used for providing backlight for the display panel 30, and the display panel 30 modulates the light emitted from the backlight module 520 to realize that the display device 50 displays a to-be-displayed picture.

For example, the backlight module 520 may be a whole backlight or a partitioned backlight, and may be configured according to actual requirements of the display device 50, which is not limited in the embodiment of the invention.

In combination with the above explanation of the array substrate and the display panel 30, the aperture ratio of the display panel 30 is higher, and when the same required brightness value needs to be achieved, the brightness of the backlight module 520 required by the display panel 30 is lower compared to the display panel with the lower aperture ratio, so that the power consumption of the backlight module 520 is lower, and the reduction of the overall power consumption of the display device 50 is facilitated.

It should be noted that fig. 16 only shows that the display device 50 is a mobile phone by way of example, in other embodiments, the display device 50 may also be a tablet computer, a smart wearable device, a vehicle-mounted display screen, or other types of devices, or components with display functions or integrated display functions known to those skilled in the art, and this is neither described nor limited in the embodiment of the present invention.

It is to be noted that the foregoing description is only exemplary of the invention and that the principles of the technology may be employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An array substrate is provided with a display area and a non-display area surrounding the display area, and is characterized by further comprising at least one fingerprint identification area, wherein the fingerprint identification area is located in the display area, the display area comprises touch sensors, the touch sensors are arranged in an array mode along a first direction and a second direction, the first direction and the second direction are crossed, and part of the touch sensors are located in the fingerprint identification area;

the array substrate further comprises an integrated circuit, a touch shift register circuit, a touch switch circuit, a first wire, a second wire and a third wire; the integrated circuit and the touch shift register circuit are both arranged in the non-display area, the touch shift register circuit comprises a plurality of cascade-arranged touch shift register units, and each touch shift register unit is used for driving at least part of the touch sensors in one row through the first routing; the touch switch circuit is arranged in the display area and comprises a plurality of touch switch units which are arranged in an array, and part of the single touch sensors are electrically connected with the output end of at least one touch switch unit; the first routing lines and the third routing lines are arranged along the first direction, extend along the second direction, and extend from the display area to the non-display area, and the second routing lines extend along the first direction and are arranged along the second direction;

in the fingerprint identification area, the touch sensor is electrically connected with the integrated circuit through the third routing wire; in the display area and in the non-fingerprint identification area, at least part of the touch sensors are electrically connected with the first wire and the second wire through the touch switch unit, the control end of the touch switch unit is electrically connected to the first wire, the input end of the touch switch unit is electrically connected to the second wire, and the output end of the touch switch unit is electrically connected to the touch sensors.

2. The array substrate of claim 1, further comprising a substrate and pixel electrodes, wherein the pixel electrodes are arranged in an array;

in the fingerprint identification area, when the vertical projection of one touch sensor on the substrate base plate covers the vertical projection of M1 rows of the pixel electrodes on the substrate base plate, the touch sensor is electrically connected with the integrated circuit through M1 connecting points on the third wiring;

wherein M1 is a positive integer.

3. The array substrate of claim 1, wherein the first trace includes a first main line and a plurality of first branch lines electrically connected to the first main line, a first end of the first main line is electrically connected to a data output terminal of the integrated circuit, and a plurality of second ends of the first main line are electrically connected to the plurality of first branch lines in a one-to-one correspondence; the second routing line includes a second main line and a plurality of second branch lines electrically connected to the second main line, a first end of the second main line is electrically connected to an output end of the touch shift register unit, and a plurality of second ends of the second main line are electrically connected to the plurality of second branch lines in a one-to-one correspondence manner.

4. The array substrate of claim 3, wherein the first main line and the second main line both extend into the non-display area and the first branch line and the second branch line are both located in the display area.

5. The array substrate of claim 3, wherein the control terminals of the touch switch units in the same row are electrically connected to the same second branch line; the input ends of the touch switch units positioned in the same column are electrically connected to the same first branch line.

6. The array substrate of claim 3, further comprising a substrate and pixel electrodes, wherein the pixel electrodes are arranged in an array;

when the vertical projection of one touch sensor on the substrate base plate covers the vertical projection of M2 pixel electrodes on the substrate base plate in the display area and in the non-fingerprint identification area, the touch sensor is electrically connected with the first branch line and the second branch line through M2 touch switch units;

wherein M2 is a positive integer.

7. The array substrate of claim 3, wherein along the first direction, the display area comprises a first display area and a second display area on opposite sides of the fingerprint identification area; the non-display area comprises a first non-display area and a second non-display area, the first non-display area is positioned on one side, away from the fingerprint identification area, of the first display area, and the second non-display area is positioned on one side, away from the fingerprint identification area, of the second display area;

the touch shift register unit comprises a first touch shift register unit and a second touch shift register unit, the first touch shift register unit is arranged in the first non-display area, and the second touch shift register unit is arranged in the second non-display area;

the first touch shift register unit is used for providing a first driving signal for the touch sensor arranged in the first display area, and the second touch shift register unit is used for providing a second driving signal for the touch sensor arranged in the second display area.

8. The array substrate of claim 7, wherein along the first direction, the display area further comprises a third display area staggered from the fingerprint identification area, and the non-display area further comprises a third non-display area and a fourth non-display area located on opposite sides of the third display area;

the touch shift register unit further comprises a third touch shift register unit, and the third touch shift register unit is arranged in the third non-display area and/or the fourth non-display area;

the third touch shift register unit is configured to provide a third driving signal for the touch sensor disposed in the third display area.

9. The array substrate of claim 1, wherein the non-display region further comprises a scan shift register circuit;

the scanning shift register circuit is arranged between the display area and the touch shift register circuit; or alternatively

The touch shift register circuit is arranged between the display area and the scanning shift register circuit; or

The scanning shift register circuit comprises a plurality of scanning shift register units which are arranged in a cascade mode, and M3 scanning shift register units are arranged between every two adjacent touch shift register units along the second direction;

wherein M3 is a positive integer.

10. The array substrate of claim 1, further comprising a substrate, and a driving circuit layer, a first insulating layer, a metal wire layer, a planarization layer, a first transparent electrode layer, a second insulating layer, a second transparent electrode layer, and a third insulating layer sequentially stacked on one side of the substrate;

the first wire and the third wire are arranged on the metal wire layer, and the second wire is arranged in one metal wire layer in the driving circuit layer;

the touch sensor comprises a touch electrode block, and the touch electrode block is arranged in the first transparent electrode layer.

11. A display panel comprising the array substrate according to any one of claims 1 to 10.

12. The display panel according to claim 11, further comprising a color film substrate and a liquid crystal layer filled between the array substrate and the color film substrate;

a black matrix, a color resistance block and a covering layer are arranged on one side, facing the array substrate, of the color film substrate; the black matrix comprises a plurality of hollow areas, the color resistance blocks are arranged in the hollow areas, and the covering layer is arranged on one side, facing the array substrate, of the black matrix and the color resistance blocks;

in the display area and the non-fingerprint identification area, the vertical projections of the first routing lines, the second routing lines and the third routing lines on the color film substrate are all located in the non-hollow area of the black matrix.

13. A display device characterized by comprising the display panel according to any one of claims 11 to 12.

14. The display device according to claim 13, further comprising a backlight module;

the light emitting surface of the backlight module faces the display panel.