Patent Application
20230307426
This application claims priority to Chinese Patent Application No. 202211740543.8 filed Dec. 30, 2022, the disclosure of which is incorporated herein by reference in its entirety.
The present invention relates to the field of display technology and, in particular, to a display panel, a method for preparing a display panel, and a display device.
With the development of science and technology, more and more electronic devices with a display function are widely applied to and bring great convenience for people's daily life and work. Such devices have now become indispensable and important tools for people.
In the field of active matrix display, a thin-film transistor, as a switch for pixels, plays an irreplaceable role. High-resolution and large-size display has become a new direction for the development of display technology. Therefore, higher requirements are put forward for the thin-film transistor. However, the active layer of the thin-film transistor is sensitive to light, and the activity of carriers in the active layer is easily affected by the light. Thus, the thin-film transistor cannot accurately provide a corresponding signal, thereby affecting the light-emitting accuracy of the display panel, and then affecting the display effect of the display panel.
The present invention provides a display panel, a method for preparing the display panel, and a display device to improve the light-emitting accuracy of a light-emitting element, thereby improving the display effect of the display panel.
According to one aspect of the present invention, a display panel is provided. The display panel includes a substrate; a plurality of driver circuits located on one side of the substrate, where the plurality of driver circuits include a thin-film transistor; a plurality of light-emitting elements located on the side of the plurality of driver circuits facing away from the substrate, where at least one of the plurality of light-emitting elements are electrically connected to the plurality of driver circuits; and a light-shielding structure, where at least part of the light-shielding structure is at least located between a light-emitting element and the thin-film transistor, and the light-shielding structure covers at least an active layer of the thin-film transistor in the direction perpendicular to the plane in which the substrate is located.
According to another aspect of the present invention, a method for preparing a display panel is provided. The method includes providing a substrate; forming a driver circuit on one side of the substrate, where the driver circuit includes a thin-film transistor; disposing a light-emitting element on one side of the driver circuit, where the light-emitting element is electrically connected to the driver circuit; and forming a light-shielding structure at least between the thin-film transistor and the light-emitting element.
According to another aspect of the present invention, a display device is provided. The display device includes the preceding display panel.
To illustrate technical solutions in embodiments of the present invention more clearly, drawings used in description of the embodiments are briefly described below. Apparently, the drawings described below merely illustrate part of the embodiments of the present invention, and those of ordinary skill in the art may obtain other drawings based on the drawings on the premise that no creative work is done.
The technical solutions in the embodiments of the present invention are described clearly and completely in conjunction with the drawings in the embodiments of the present invention from which the solutions of the present invention are better understood by those skilled in the art. Apparently, the embodiments described below are part, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art on the premise that no creative work is done are within the scope of the present invention.
It is to be noted that the terms “first”, “second”, and the like in the description, claims, and drawings of the present invention are used for distinguishing between similar objects and are not necessarily used for describing a particular order or sequence. It is to be understood that the data used in this way is interchangeable where appropriate so that the embodiments of the present invention described herein may also be implemented in a sequence not illustrated or described herein. In addition, the terms “including”, “having”, or any other variations thereof described herein are intended to encompass a non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units may include not only the expressly listed steps or units but also other steps or units that are not expressly listed or are inherent to such a process, method, system, product, or device.
As described in the background, the activity of carriers in the active layer in the thin-film transistor in a display panel is easily affected by the light.
In addition, with the development of technology, the number of pixels per unit area in a display panel is increasing. For a high-resolution display panel, the traditional technology of defining light-emitting elements in a pixel defining layer needs to use the opening technique and mask technologies, so it is difficult to implement too many and too small openings. Therefore, this arrangement manner is not advantageous to the high resolution of the display panel. The LED mass transfer technology can implement the high resolution of a display panel. However, based on the requirements of the LED bonding technique, a certain space needs to be reserved around the light-emitting element 01. This results light entering from this space and propagating to the active layer 0214 of the thin-film transistor 021. Especially when the light-emitting element 01 is in a highlight state, the leakage current of the thin-film transistor 021 is more serious, and even the brightness of high-profile light (100%) is lower than that of low-profile light (20%).
To solve the preceding technical problems, the embodiments of the present invention provide a display panel. The display panel includes a substrate; multiple driver circuits located on one side of the substrate, where a driver circuit includes a thin-film transistor; multiple light-emitting elements located on the side of the multiple driver circuits facing away from the substrate, where the multiple light-emitting elements are electrically connected to the multiple driver circuits; and a light-shielding structure located at least between a light-emitting element and the thin-film transistor, where the light-shielding structure covers at least an active layer of the thin-film transistor in the direction perpendicular to the plane in which the substrate is located.
According to the preceding technical solutions, the light-shielding structure is disposed at least between the light-emitting element and the thin-film transistor. Thus, the light emitted from the light-emitting element and/or at least part of the light propagating to the side of the thin-film transistor in the external ambient light can be blocked from propagating to the position in which the active layer of the thin-film transistor is located, thereby improving the influence caused by the light on the channel carrier of the thin-film transistor. Moreover, the driver circuit including the thin-film transistor can accurately provide a drive signal for the light-emitting element, thereby improving the light-emitting accuracy of the light-emitting element driven by the driver circuit, and improving the display effect of the display panel. Further, the light-blocking structure is disposed between at least the thin-film transistor and the light-emitting element to block at least part of light emitted from the light-emitting element and/or external ambient light. Thus, the part of the light can be prevented from reaching the driver circuit and being reflected by the metal structure or the like in the thin-film transistor, thereby reducing unnecessary reflection in the display panel and improving the display brightness and the display contrast.
The preceding is the core idea of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art are within the scope of the present invention on the premise that no creative work is done. Technical solutions in the embodiments of the present invention are described clearly and completely hereinafter in conjunction with the drawings in the embodiments of the present invention.
It is to be noted that a thin-film transistor 201 may include an active layer 205, a gate 202, a source 203, and a drain 204. The active layer 205 may include a source region, a drain region, and a channel region located between the source region and the drain region. In the direction perpendicular to the plane in which the substrate 100 is located, the gate 202 generally covers the channel region of the active layer 205. The source 203 is electrically connected to the source region by a via. The drain 204 is electrically connected to the drain region by the via. By applying a corresponding electrical signal to the gate 202, the activity of carriers in the channel region in the active layer 205 can be controlled to control the on-off of the source 203 electrically connected to the source region and the drain 204 electrically connected to the drain region. The thin-film transistor 201 may be a device directly or indirectly electrically connected to a light-emitting element 300. Exemplarily, the thin-film transistor 201 is a device indirectly electrically connected to the light-emitting element 300. The display panel 10 may also include a lap join structure 210 and a bonding electrode 230. The source 203 or drain 204 of the thin-film transistor 201 is electrically connected to the light-emitting element 300 via the lap join structure 210 and the bonding electrode 230 in turn.
It is also to be noted that in addition to including the thin-film transistor 201, the driver circuit 200 may also include other active and/or passive devices. For example, the active device may be a device including three or four terminals, such as a control terminal, an input terminal, and an output terminal. The passive device may be a two-terminal device, such as a capacitor, a resistor, or an inductor. In an example embodiment, as shown in
It is to be understood that the light-emitting element 300 may be, for example, a submillimeter light-emitting diode (Mini LED) or a micro light-emitting diode (Micro LED). The type of the light-emitting element 300 is not specifically limited in this embodiment. The multiple light-emitting elements 300 may each be a blue light-emitting element or a white light-emitting element for emitting blue light or white light. Alternatively, the multiple light-emitting elements 300 may also include light-emitting elements emitting light of different colors, for example, include a red light-emitting element, a green light-emitting element, and a blue light-emitting element. The red light-emitting element can emit red light. The green light-emitting element can emit green light. The blue light-emitting element can emit blue light. The light of different colors is combined with each other to enable the display panel to implement color display.
It is also to be understood that the substrate 100 may be transparent, translucent, or opaque. The substrate 100 may be a rigid substrate, such as a glass substrate or a silicon substrate. The substrate 100 may also be a flexible substrate, for example, a flexible resin-based material, or formed of a polymer with a thinner thickness. Specific materials may include polyimide (PI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and the like.
In addition, with continued reference to
Specifically, the light emitted from the light-emitting element 300 propagates in all directions. That is, the light emitted from the light-emitting element 300 not only propagates towards the side facing away from the substrate 100, but also part of the light propagates towards the side facing the substrate 100. Therefore, when the light propagating to the side facing the substrate 100 reaches the position in which the thin-film transistor 201 of the driver circuit 200 is located without blocking, the activity of carriers in the active layer 205 in the thin-film transistor 201 is affected. Thus, electric leakage occurs in the thin-film transistor 201, and threshold drift occurs in the thin-film transistor 201, thereby affecting the thin-film transistor 201 to provide a drive signal for the light-emitting element 300. The light-shielding structure 400 is disposed at least between the light-emitting element 300 and the driver circuit 200. That is, the light-shielding structure 400 is located on the side of the light-emitting element 300 facing the thin-film transistor 201. In the direction perpendicular to the plane in which the substrate 100 is located, the light-shielding structure 400 covers at least the active layer 205 of the thin-film transistor 201. Thus, the light-shielding structure 400 can block at least part of light emitted from the light-emitting element 300 and propagating to the side facing the substrate 100 to prevent the part of light from reaching the active layer of the thin-film transistor 201 to influence the activity of carriers in the active layer of the thin-film transistor 201. Moreover, the electric leakage generated by the light can be reduced so that the thin-film transistor 201 can accurately provide a drive signal for the light-emitting element 300, thereby enabling the light-emitting element 300 to emit light accurately. In addition, the light-shielding structure 400 located at least between the light-emitting element 300 and the driver circuit 200 can also block the enter of at least part of external ambient light to effectively reduce the light propagating to the active layer 205 in the thin-film transistor 201. Thus, the electric leakage of the thin-film transistor 201 is reduced in the case where the light-emitting element 300 is highlighted and/or the external ambient light is brighter so that the thin-film transistor 201 can provide an accurate drive signal for the light-emitting element 300, thereby improving the light-emitting accuracy of the light-emitting element 300.
In addition, with continued reference to
It is to be understood that the preceding description of the film layer structure of the display panel is only for example. The film layer structure of the display panel includes but is not limited to the preceding description. For example, in an optional embodiment, as shown in
According to the embodiments of the present invention, the light-shielding structure is disposed at least between the light-emitting element and the thin-film transistor. Thus, the light emitted from the light-emitting element and/or at least part of the light propagating to the side of the thin-film transistor in the external ambient light can be blocked from propagating to the position in which the active layer of the thin-film transistor is located, thereby improving the influence caused by the light on the channel carrier of the thin-film transistor. Moreover, the driver circuit including the thin-film transistor can accurately provide a drive signal for the light-emitting element, thereby improving the light-emitting accuracy of the light-emitting element driven by the driver circuit, and improving the display effect of the display panel. Further, the light-blocking structure is disposed between at least the thin-film transistor and the light-emitting element to block at least part of light emitted from the light-emitting element and/or external ambient light. Thus, the part of the light can be prevented from reaching the driver circuit and being reflected by the metal structure or the like in the thin-film transistor, thereby reducing unnecessary reflection in the display panel and improving the display brightness and the display contrast.
In the embodiments of the present invention, the light-shielding structure is located at least between the light-emitting element and the thin-film transistor. The light-shielding structure may be disposed before the light-emitting element is disposed. Alternatively, the light-shielding structure may be disposed after the light-emitting element is disposed. This is not specifically limited in the embodiments of the present invention.
In an embodiment,
In S101, a substrate is provided.
As shown in
In S102, a driver circuit is formed on one side of the substrate.
Specifically, with continued reference to
In S103, a light-emitting element is disposed on one side of the driver circuit.
Specifically, with continued reference to
In S104, a light-shielding structure is formed at least between the thin-film transistor and the light-emitting element.
Specifically, with continuing reference to
In addition, after the light-emitting element 300 is disposed on one side of the driver circuit 200 so that the light-emitting element 300 is electrically connected to the driver circuit 200, the light-shielding structure 400 is formed at least between the thin-film transistor 201 and the light-emitting element 300. An opening for disposing the light-emitting element 300 is not required in the light-shielding structure 400, thereby facilitating the simplification of the technique preparation process of the display panel. At the same time, since an opening for disposing the light-emitting element 300 is not required in the light-shielding structure 400, the resolution of the display panel 10 is not affected by a technique preparation process such as setting the opening. When the light-emitting element 300 is a Mini LED or a Micro LED, the light-emitting element 300 has a smaller size, thereby facilitating the high resolution of the display panel 10.
It is to be understood that the preceding is only exemplary description of the technique preparation process of the display panel in the embodiments of the present invention. On the premise that the core invention points of the embodiments of the present invention can be implemented, the technique preparation process of the display panel is not specifically limited in the embodiments of the present invention.
It is also to be understood that the light-shielding structure is located at least between the thin-film transistor and the light-emitting element in the embodiments of the present invention. That is, the light-shielding structure can fill all the gap between the light-emitting element and the thin-film transistor or can fill part of the gap between the light-emitting element and the thin-film transistor. This is not specifically limited in the embodiments of the present invention. At the same time, materials of the light-shielding structure include, but are not limited to, a photoresist having fluidity. When the materials of the light-shielding structure include a photoresist, the material of the light-shielding structure may include a black photoresist. That is, a black dye is doped into a material such as a photosensitive resin. Thus, the light-shielding structure can have a high light-shielding capability. Alternatively, the light-shielding structure may be a titanium dioxide-doped photoresist. In this case, titanium dioxide particles can be doped into a material such as a photosensitive resin. Thus, the titanium dioxide-doped photoresist has a certain light-shielding capability.
In an optional embodiment, in order that the light-shielding structure 400 has a sufficient light-blocking capability, the value range of the thickness T1 of the light-shielding structure 400 in the direction perpendicular to the plane in which the substrate 100 is located is T1≥1/OD. OD denotes an optical density value of the light-shielding structure 400.
The optical density value is the logarithm of the ratio of incident light to transmitted light or the logarithm of the reciprocal of light transmittance. When the optical density value of the light-shielding structure 400 is larger, the light flux of the light-shielding structure 400 per unit size is smaller. Most of the light can be shielded without superimposing a thick material of the light-shielding structure 400. Therefore, the light-shielding structure 400 can have a smaller thickness T1 in the direction perpendicular to the plane in which the substrate 100 is located. However, when the optical density value of the light-shielding structure 400 is small, the light flux of the light-shielding structure 400 per unit size is larger. A thick material of the light-shielding structure 400 is required to superimpose so that more light can be shielded. Therefore, the light-shielding structure 400 needs to have a larger thickness T1 in the direction perpendicular to the plane in which the substrate 100 is located. Thus, the minimum thickness of the light-shielding structure 400 is defined according to the optical density value of the light-shielding structure 400. This can ensure that the light-shielding structure 400 has a sufficiently large light-shielding capability.
In an optional embodiment, when the value range of the thickness T1 of the light-shielding structure 400 is T1≥1/OD, the thickness of the light-shielding structure 400 is thinned as much as possible to ensure that the light-shielding structure 400 has a sufficiently large light-shielding capability, and the light and thinning of the display panel 10 are facilitated. In this case, the value range of the optical density value of the light-shielding structure 400 is OD≥1.0.
It is to be understood that the optical density (OD) value of the light-shielding structure 400 may be less than 1.0. In this case, the thickness T1 of the light-shielding structure 400 in the direction perpendicular to the plane in which the substrate 100 is located is appropriately increased so that T1≥1/OD can satisfy the light-shielding requirement.
It is to be noted that the preceding only exemplarily uses the case where the light-shielding structure 400 is located between the thin-film transistor 201 and the light-emitting element 300 as an example for the description of the technical solutions in the embodiments of the present invention. The light-shielding structure 400 may be located at other positions in the embodiments of the present invention. The following exemplarily describes the technical solutions in the embodiments of the present invention for typical examples.
In an embodiment,
Exemplarily, the first light-shielding portion 410 and the second light-shielding portion 420 may be made of the same material and are prepared and integrally formed in the same process. The first light-shielding portion 410 is located at least between a light-emitting element 300 and a thin-film transistor 201 and can block at least part of the light from propagating to the position in which the active layer 205 of the thin-film transistor 201 is located. The first light-shielding portion 410 can also block at least part of the light from reaching a driver circuit and being reflected by a metal structure or the like in the thin-film transistor 201. The second light-shielding portion 420 is located between two adjacent light-emitting elements 300 and can block at least part of the light emitted from a light-emitting element 300 to the adjacent light-emitting element 300. In this manner, the mutual crosstalk of the light emitted from adjacent light-emitting elements 300 can be reduced, and the contrast ratio of a display panel 10 can be improved.
It is to be noted that patterns filled in figures are used only for distinguishing different film layer structures. Pattern types are not used for distinguishing film layer materials. The same pattern type may be different film layer materials and different film layer structures. The same film layer material may be different filling patterns. The first light-shielding portion 410 and the second light-shielding portion 420 may be of the same material or different materials. This is not specifically limited in the embodiments of the present invention.
In an embodiment, with continued reference to
Specifically, the second light-shielding portion 420 may be disposed around the light-emitting element 300 and is in contact with the light-emitting element 300. That is, no gap is disposed between the second light-shielding portion 420 and the light-emitting element 300. Light cannot enter the film layer in which the active layer in the thin-film transistor 201 is located from the gap between two adjacent light-emitting elements 300. In this manner, the light emitted from the light emitting element 300 and/or the external ambient light entering the film layer in which the active layer of the thin film transistor 201 is located can be reduced as much as possible, thereby preventing light from affecting the activity of carriers in the active layer of the thin-film transistor 201, further enabling the thin-film transistor 201 to provide an accurate drive signal for the light-emitting element 300 to accurately drive the light-emitting element 300 to emit light. At the same time, when the light-shielding structure 400 has a high light-shielding capability, light emitted from the light-emitting element 300 and/or the external ambient light cannot pass through the light-shielding structure 400 to the film layer having a reflection function in a driver circuit 200. Thus, light reflection in the display panel can be reduced, further improving the display brightness and display contrast of the display panel.
In an embodiment,
When the distance between the first surface 11 and the substrate 100 is a first distance, and the distance between the surface of the side of the light-emitting layer 330 facing the substrate 100 and the substrate 100 is a second distance, the first surface 11 is flush with the surface of the side of the light-emitting layer 330 facing the substrate 100. It is to be understood that the first distance is equal to the second distance. In this case, the surface height of the first surface 11 is the same as the surface height of the surface of the side of the light-emitting layer 330 facing the substrate 100 with the plane in which the substrate 100 is located as a reference plane. Accordingly, the first surface 11 is located on the side of the light-emitting layer 330 facing the substrate 100. It is to be understood that the first distance is less than the second distance. That is, the surface height of the first surface 11 is less than the surface height of the surface of the side of the light-emitting layer 330 facing the substrate 100 with the plane in which the substrate 100 is located as a reference plane.
According to the embodiments, the surface height of the first surface 11 is less than or equal to the surface height of the surface of the side of the light-emitting layer 330 facing the substrate 100. This can ensure that the light emitted from the side of the light-emitting layer 330 is not blocked by the second light-shielding portion 420. In this manner, the light can be emitted from the side of the light-emitting layer 330. Thus, the light utilization rate of the light-emitting element 300 is improved, thereby facilitating the improvement of the display brightness of the display panel 10. Moreover, when the light utilization rate of the light-emitting element 300 is improved, and when the display panel 10 needs a higher display brightness, a higher display brightness can be implemented only by providing a smaller drive signal for the light-emitting element 300, thereby facilitating the low power consumption of the display panel 10.
In other optional embodiments,
The at least part of the first surfaces 11 located on the side of the second surface 12 facing away from the substrate 100 can be understood that when the distance between the first surface 11 and the substrate 100 is a first distance, and the distance between the second surface 12 and the substrate 100 is a second distance, the first distance may be greater than the second distance. That is, the surface height of the first surface 11 may be greater than the surface height of the second surface with the plane in which the substrate 100 is located as a reference plane.
Specifically, the surface height of the first surface 11 of the second light-shielding portion 420 disposed between two adjacent light-emitting elements 300 is set to be greater than the surface height of the second surface 12 of a light-emitting element 300. Thus, the second light-shielding portion 420 can block at least part of light emitted from the light-emitting element 300 that propagates toward one side of an another light-emitting element 300 adjacent to the light-emitting element 300. Moreover, the mutual crosstalk between the light emitted from adjacent light-emitting elements 300 can be minimized, the contrast ratio of a display panel 10 can be improved, and the display effect can be improved. In this case, since the second light-shielding portion 420 is located between two adjacent light-emitting elements 300, the second light-shielding portion 420 does not block light emitted from a light-emitting element 300 toward the side facing away from the substrate 100. Thus, normal display light emission of the light-emitting element 300 is not affected.
In an optional embodiment, referring to
It is to be understood that the preparation process of the light-shielding structure is after the preparation process of the light-emitting element. When the light-shielding structure is formed, the material of part of the light-shielding structure is located on the side of the light-emitting element facing away from the substrate, thereby affecting the normal display light emission of the light-emitting element. In this case, after the light-shielding structure is formed, the light-shielding structure on the side of the light-emitting element facing away from the substrate can be removed by patterning the light-shielding structure.
In an embodiment,
In S201, a light-shielding material layer covering a light-emitting element and a driver circuit is formed.
In S202, the light-shielding material layer is patterned to remove at least the light-shielding material layer located on the side of the light-emitting element facing away from the substrate to form a first light-shielding portion of the light-shielding structure and a second light-shielding portion of the light-shielding structure.
Specifically, referring to
It is to be understood that, when the light-shielding material layer includes a photoresist, the photoresist may be irradiated or radiated by the ultraviolet light, the electron beam, the ion beam, the X-ray, or the like, to change the solubility of the photoresist. Thus, the corresponding solution can be used to develop the photoresist, and the patterning of the light-shielding material layer can be implemented. The photoresist may include a positive photoresist or a negative photoresist.
In an embodiment, the light-shielding material layer includes a positive photoresist as an example. Patterning the light-shielding material layer includes patterning the light-shielding material layer by using a photolithography technique.
Specifically, with continued reference to
It is to be noted that the preceding only exemplarily shows that the light-shielding material layer 401 is patterned by performing photolithography on the light-shielding material layer 401. After the light-shielding material layer 401 is patterned by using the photolithography technique, part of the light-shielding material layer 401 may still remain on the side of the light-emitting elements 300 facing away from the substrate. In this case, after the light-shielding structure is formed at least between thin-film transistors and the light-emitting elements, the light-shielding material layer remaining on the surface of the side of the light-emitting elements facing away from the substrate may be removed by using an ashing technique.
Specifically, the light-shielding material layer has a certain non-light-transmissive property. At the time of exposure, the light-shielding material layer directly above the side of the light-emitting elements facing away from the substrate may not be completely degraded. At the time of developing, there is part of the remaining light-shielding material layer. The remaining organic matter in the light-shielding material layer directly above the side of the light-emitting elements facing away from the substrate may be removed by high temperature. The remaining part may be dissolved by acid to remove the remaining light-shielding material layer directly above the side of the light-emitting elements facing away from the substrate.
In an embodiment,
The bonding electrodes 230 may be used for bonding light-emitting elements 300 transferred through mass transfer. After the light-emitting elements are transferred through mass transfer, the light-emitting elements 300 cannot normally display and emit light due to the influence of internal or external factors. In this case, the light-emitting elements 300 need to be repaired. Generally, redundant electrodes 240 are reserved in the display panel. Thus, light-emitting elements 300 can be disposed on the redundant electrodes 240 when the light-emitting elements 300 bonding on the bonding electrodes 230 cannot normally display and emit light, thereby ensuring that the display panel can normally display and emit light at this position. The redundant electrodes 240 and the bonding electrodes 230 have the same or similar structure. The redundant electrodes 240 and the bonding electrodes 230 are disposed in the same layer in the electrode layer 121.
It is to be understood that, in the preparation process of the display panel, light-emitting elements 300 are usually not disposed on the redundant electrodes 240 but only bonded on the bonding electrodes 230. After a light-emitting element 300 is disposed on one side of a driver circuit 200, a light-shielding material layer 401 is prepared on the side of the driver circuit 200 facing away from the substrate 100 by a technique such as coating. Due to the fluidity of the light-shielding material layer 401, the surface of the side of a redundant electrode 240 facing away from the substrate 100 forms an uneven structure such as a concave structure or a concave-convex structure. That is, the light-shielding material layer 401 at other positions flows to the redundant electrode 240. This can increase the thickness of the light-shielding material layer 401 at the position of the redundant electrode 240 to a certain extent. Although a concave structure or a concave-convex structure may be formed at the position of the redundant electrode 240 due to the influence of the technique, the light-shielding structure 400 covered the side of the redundant electrode 240 facing away from the substrate 100 can still have a high light-shielding capability. This can block light from propagating to the redundant electrode 240 and prevent unnecessary reflection.
In an embodiment,
L0 is the size of a light-emitting element 300 in any direction parallel to the plane in which the substrate 100 is located. For example, when light-emitting elements 300 are arranged in an array, L0 may be the size of a light-emitting element 300 in the row direction or the size of a light-emitting element 300 in the column direction. This is not specifically limited in the embodiments of the present invention.
Specifically, the bank structure 500 has a certain light-blocking capability to block at least part of the light emitted from a light-emitting element 300 toward the side of the adjacent light-emitting element 300, reduce the mutual crosstalk between the light emitted from adjacent light-emitting elements 300, and improve the display contrast of the display panel 10. At the same time, the bank structure 500 may also have a certain reflection capability. Thus, at least part of light can be reflected by the bank structure 500 when reaching a position in which the bank structure 500 is located. In addition, since a first gap 501 exists between a light-emitting element 300 and a bank structure 500, the light emitted from the light-emitting element 300 facing the side of the bank structure 500 can change the optical path propagation direction after being reflected on the surface of the side of the bank structure 500 facing the light-emitting element 300. Thus, the reflected light can be emitted from the first gap 501 and propagated toward the side facing away from the substrate 100, thereby improving the light utilization rate of the light-emitting element 300 and facilitating the low power consumption of the display panel 10.
In an optional embodiment, the bank structure 500 and the light-shielding structure 400 may be made of the same material. Moreover, the bank structure 500 may be integrated with the light-shielding structure 400. At this time, corresponding light-shielding materials can be filled in a gap between a light-emitting element 300 and a thin-film transistor 201 and a gap between two adjacent light-emitting elements 300. Then, the filled light-shielding materials are patterned to form the light-shielding structure 400 and the bank structure 500, respectively. The first gap 501 is formed between the bank structure 500 and the light-emitting element 300. In this manner, the light-shielding structure 400 and the bank structure 500 are integrally formed, thereby facilitating the simplification of the technique preparation process and reducing the preparation cost of the display panel 10.
It is to be understood that when the material of the bank structure 500 is the same as the material of the light-shielding structure 400, the bank structure 500 and the light-shielding structure 400 may have the same optical density value and reflectance. In this case, both the bank structure 500 and the light-shielding structure 400 may include a photoresist material, for example, a black photoresist or a photoresist doped with titanium dioxide.
In other optional embodiment, as shown in
In an optional embodiment, when the bank structure 500 and the light-shielding structure 400 are made of different materials, the light-shielding structure 400 and the bank structure 500 may be formed in steps. That is, after the light-shielding structure 400 is disposed at least between light-emitting elements 300 and thin-film transistors 201, the bank structure 500 is disposed between two adjacent light-emitting elements 300.
It is to be understood that since the material of the bank structure 500 is different from the material of the light-shielding structure 400, the bank structure 500 may include a material having a larger reflectance, and the light-shielding structure 400 may include a material having a larger light-shielding capability. For example, the bank structure 500 may include a photoresist doped with titanium dioxide. The light-shielding structure 400 may include a black photoresist.
In an embodiment, referring to
The third surface 13 of the bank structure 500 flush with the second surface 12 of the light-emitting element 300 can be understood that when the distance between the third surface 13 of the bank structure 500 and the substrate 100 is a first distance, and the distance between the second surface 12 of the light-emitting element 300 and the substrate 100 is a second distance, the first distance is equivalent to the second distance. That is, the third surface 13 of the bank structure 500 and the second surface 12 of the light-emitting element 300 have the same surface height with the plane in which the substrate 100 is located as a reference plane.
Specifically, the third surface 13 of the bank structure 500 is flush with the second surface 12 of the light-emitting element 300. Thus, the display panel 10 has an even upper surface after the light-emitting element 300 and the bank structure 500 are prepared. Moreover, the subsequent film layer can be prepared based on the even surface. Alternatively, the subsequent assembly structure can be assembled based on the even surface, thereby facilitating the simplification of the subsequent film layer preparation process or the assembly of the assembly structure. At the same time, a bank structure 500 can block the light emitted from a light-emitting element 300 to propagate toward the side of a light-emitting element 300 adjacent to the light-emitting element 300. When the third surface 13 of the bank structure 500 is flush with the second surface of the light-emitting element 300, the light emitted from the light-emitting element 300 can be prevented from propagating through the bank structure 500 to the position in which a light-emitting element 300 adjacent to the light-emitting element 300 is located. Thus, the mutual crosstalk between the light emitted from adjacent light-emitting elements 300 can be minimized, and the display contrast of the display panel 10 can be improved. Further, the display effect of the display panel 10 can be improved.
In other optional embodiment, as shown in
It is to be noted that at least part of the third surfaces 13 is flush with the second surface 12. Moreover/alternatively, at least part of the third surfaces 13 is located on the side of the second surface 12 facing away from the substrate 100. It may be that the surface height of all of the third surface 13 is greater than or equal to the surface height of the second surface 12 with the plane in which the substrate 100 is located as a reference plane. Alternatively, the surface height of part of the third surface 13 is greater than or equal to the surface height of the second surface 12. This is not specifically limited in the embodiments of the present invention. Those skilled in the art may set according to actual situations.
In an embodiment, a bank structure includes a first bank portion and a second bank portion. The second bank portion is located on the side of the first bank portion facing away from the substrate. The size of the second bank portion is less than or equal to the size of the first bank portion in the direction parallel to the plane in which the substrate is located.
In an example embodiment, as shown in
In another example embodiment, as shown in
It is to be understood that the section of the bank structure 500 may also be in the shape of a structure having a straight edge such as a triangle or a structure having an arc edge. The main function of the bank structure 500 is to prevent the light emitted from two adjacent light-emitting elements 300 from generating crosstalk and to reflect the light emitted from the side surface of a light-emitting element 300 to improve the light utilization rate. On the premise that this condition is satisfied, the shape of the section of the bank structure 500 is not specifically limited in the embodiments of the present invention. For ease of description, without otherwise specified, the technical solutions in the embodiments of the present invention are described in the following by taking the shape of the section of the bank structure 500 as an isosceles trapezoid as an example.
In an embodiment, referring to
In an embodiment,
It is to be understood that the light-shielding structure 400 and the bank structure 500 have a certain reflection capability for light. To prevent a case in which the display contrast of the display panel 10 is affected by reflection of the external ambient light by the light-shielding structure 400 and/or the bank structure 500, an anti-reflective structure such as a polarizer may be disposed on the side of the light-emitting element 300 facing away from the substrate 100.
In an optional embodiment,
The multiple light-emitting elements 30 may include multiple light-emitting elements of different colors, including, for example, a red light-emitting element 310, a green light-emitting element 320, and a blue light-emitting element 330. The red light-emitting element 310, the green light-emitting element 320, and the blue light-emitting element 330 emit red light, green light, and blue light, respectively, to implement the display of a color image.
Specifically, when the external ambient light enters the display panel 10 through the gap between two adjacent light-emitting elements 300, the external ambient light is reflected on the structure having the reflection capability. Thus, an obvious light-dark contrast cannot be formed between the two adjacent light-emitting elements 300, thereby affecting the display contrast of the display panel 10. A color resist structure 601 overlaps the gap between two adjacent light-emitting elements 300. The color resist structure 601 blocks at least part of the light passing through. Thus, the external ambient light entering the display panel 10 can be reduced, further reducing the reflection of the external ambient light by the structure having the reflection capability in the display panel 10. Moreover, the light emitted from the two adjacent light-emitting elements 300 has a high light-dark contrast, thereby improving the display effect of the display panel. At the same time, when the color resist structure 601 overlaps the gap between the two adjacent light-emitting elements 300, the color resist structure 601 can block the light emitted from the two adjacent light-emitting elements 300 to reduce the mutual crosstalk between the light emitted from the adjacent light-emitting elements 300 and increase the contrast ratio of the display panel 10. In addition, the color resist structure 601 can reduce the external ambient light entering through the gap between two adjacent light-emitting elements 300. Further, the light reaching a thin-film transistor 201 can be reduced. Thus, the leakage current of the thin-film transistor 201 can be reduced. Further, the accuracy of the drive signal provided by the thin-film transistor 201 can be improved so that the light-emitting element 300 can emit light accurately. The color resist structure 601 may include a black color resist to be able to block light of different colors. Alternatively, the color resist structure 601 may also include color resists of different colors. In this case, the color resist structure 601 can transmit light of the corresponding color while blocking light of other colors.
In an embodiment,
The red color resist can transmit red light while blocking light of other colors. The green color resist can transmit green light while blocking light of other colors. The yellow color resist can transmit yellow and orange light while blocking light of other colors. The blue color resist can transmit blue light while blocking light of other colors.
Specifically, when the first color resist structure 610 includes a red color resist or a yellow color resist, the first color resist structure 610 can transmit red light emitted from the red light-emitting element 310 while blocking light of other colors. Thus, display light close to the light emitted from the red light-emitting element 310 is displayed at the position in which the red light-emitting element 310 is located, thereby improving the accuracy of display light emission at the position in which the red light-emitting element 310 is located. Similarly, when the second color resist structure 630 includes a blue color resist, the second color resist structure 630 can transmit blue light emitted from the blue light-emitting element 330 while blocking light of other colors. Thus, blue light is displayed at a position in which the blue light-emitting element 330 is located, thereby improving the accuracy of light emission at the position in which the blue light-emitting element 330 is located. Accordingly, when the third color resist structure 620 includes a green color resist or a yellow color resist, the third color resist structure 620 can transmit green light emitted from the green light-emitting element 320 while blocking light of other colors. Thus, the accuracy of light emission at the position in which the green light-emitting element 320 is located can be improved. Thus, the first color resist structure 610, the second color resist structure 630, and the third color resist structure 620 are disposed. Unnecessary reflected light in the display panel 10 can be further reduced, and the display contrast of the display panel 10 can be improved.
In an embodiment,
A first signal line 131 may be a signal line electrically connected to the source or drain of a thin-film transistor 201 to provide a corresponding electrical signal for the source or drain of the thin-film transistor 201. Thus, the thin-film transistor 201 can transmit the electrical signal to other devices electrically connected to the thin-film transistor 201. Alternatively, a first signal line 131 may be a signal line electrically connected to the gate of a thin-film transistor 201 to provide a corresponding electrical signal for the gate of the thin-film transistor 201 to control the turn-on or turn-off of the thin-film transistor 201. The specific connection mode of a first signal line 131 and the type of the electrical signal transmitted by the first signal line 131 are not specifically limited in the embodiments of the present invention.
Specifically, since the first signal line 131 is used for transmitting an electrical signal, the first signal line 131 should have a certain conductive capability. In this case, the material of the first signal line 131 may include a material having a conductive function, such as a metal, so that the first signal line has a certain reflection capability. Generally, the light reflected by the first signal line includes yellow and orange light. The second color resist structure 630 can cover the side of the first signal line facing away from the substrate so that the second color resist structure 630 can prevent light excluding blue light from reaching the first signal line 131. Moreover, the yellow and orange light reflected by the first signal line 131 cannot be transmitted through the second color resist structure 630, thereby reducing unnecessary reflection due to the first signal line 131. In addition, since the second color resist structure 630 covering at least part of the first signal lines 131 can be prepared in the same process as the second color resist structure 630 overlapping the blue light-emitting element 330, the technique preparation process can be reduced, and the preparation cost can be reduced.
It is to be understood that the preceding only takes the light-shielding structure located between driver circuits and light-emitting elements as an example. In the embodiments of the present invention, the metal and other structures in a driver circuit also have a certain light-shielding capability. In this case, at least part of structure in a driver circuit can be reused as at least part of the light-shielding structure to simplify the technique preparation process.
In an embodiment,
The first metal structure 211 may be any structure located between the active layer of the thin-film transistor 201 and a light-emitting element 300. Exemplarily, the first metal structure 211 may be a lap join structure 210. In this case, at least part of the light-shielding structure 400 and the first metal structure 211 are disposed in the same layer. The at least part of the light-shielding structure 400 may be integrated with the first metal structure 211. That is, part of the first metal structure 211 is reused as at least part of the light-shielding structure 400. Thus, the light-shielding action can be implemented without additional arrangement of the part of the light-shielding structure 400. This facilitates the simplification of the technique preparation process of the display panel 10 and reduces the film layer structure of the display panel 10, further facilitating the low cost and light and thinning of the display panel 10.
It is to be understood that the material of the first metal structure 211 is a metal material and may include, for example, a metal material such as Ti/Al/Ti or Mo/Al/Mo. In this case, when the first metal structure 211 is reused as at least part of the light-shielding structure 400, light emitted from the side of the light-emitting element 300 facing the substrate 100 can be reflected, thereby effectively improving the light utilization rate.
In an embodiment,
Specifically, the first metal structure 211 has a certain reflection capability. When the first light-shielding structure 401 and the first metal structure 211 are disposed in the same layer, the first light-shielding structure 401 also has a certain reflection capability. The second light-shielding structure 402 is disposed on the side of the first light-shielding structure 401 facing away from the active layer of a thin-film transistor 201. Thus, the second light-shielding structure 402 can prevent the light reflected by the first light-shielding structure 401 from being emitted toward the side facing away from the substrate 100, thereby effectively reducing the reflected light in the display panel 10. At the same time, in the direction perpendicular to the plane in which the substrate 100 is located, both the first light-shielding structure 401 and the second light-shielding structure 402 overlap the active layer of the thin-film transistor 201. Thus, the first light-shielding structure 401 and the second light-shielding structure 402 can simultaneously block at least part of light propagating to the active layer of the thin-film transistor 201. That is, the light passing through the second light-shielding structure 402 can be shielded by the first light-shielding structure 401, thereby further reducing the light propagating to the active layer of the thin-film transistor 201. Moreover, the active layer of the thin-film transistor 201 is prevented from being affected by the light, and thus unable to provide an accurate drive signal to a light-emitting element. In addition, the second light-shielding structure 402 has a small reflectance. The emission of ambient light entering from the outside and reaching the light-shielding structure 400 can be reduced by covering the first light-shielding structure 401 with the second light-shielding structure 402. After passing through the second light-shielding structure 402 to reach the first light-shielding structure 401 and being reflected by the first light-shielding structure 401, a small portion of the light can be blocked by the first light-shielding structure 401. Thus, the reflected light in the display panel can be reduced, and the influence of the reflected light on the display light emission of the display panel 10 can be avoided, thereby facilitating the improvement of the display contrast and display effect of the display panel 10.
In an embodiment,
A light-transmissive hole region 80 can be used for providing a photosensitive element such as a camera, an infrared sensor, or a fingerprint recognition element. Alternatively, a light-transmissive hole region 80 may be a transparent display region with a high transmittance. In this case, the display panel 10 may be a transparent display panel. Thus, the display panel may be applied to a display device such as an in-vehicle heads-up display or a window display.
Specifically, by disposing driver circuits 200 and light-emitting elements 300 in the pixel region 70, the driver circuits 200 can drive the light-emitting elements 300 to emit light. When the light-emitting elements 300 emit light, the light emitted from the light-emitting elements 300 can be radiated to light-transmissive hole regions 80. Thus, the light-transmissive hole regions 80 can also display an image of a corresponding content. At the same time, a driver circuit 200 includes a semiconductor layer, a conductive layer, an insulation layer, and the like. Thus, part of the film structure in the driver circuit 200 has a certain blocking action for light. At least part of the film layer of the driver circuit having the light-blocking action in the light-transmissive hole region 80 can be removed after each structure of the driver circuit 200 is formed. Only the film layer having a high light transmittance is retained to form a light-transmissive hole 81 penetrating through at least part of the film layer of the driver circuit 200.
In an optional embodiment, film layers of all driver circuits 200 in the light-transmissive hole region 80 can be removed to form light-transmissive holes 81 penetrating through the film layers of the driver circuits 200. Thus, the light-transmissive hole region 80 can have a high light transmittance.
In addition, a light-transmissive hole 81 may be provided with a transparent structure 82. The transparent structure 82 includes, but is not limited to, a transparent optically clear adhesive or a pixel-level transparent encapsulating adhesive. Thus, the light-transmissive hole provided with the transparent structure 82 can still have a high light transmittance. At the same time, by disposing transparent structures 82 in at least part of light-transmissive holes 81, the support property of the light-transmissive hole region 80 can be increased. Thus, the display panel 10 in the light-transmissive hole region 80 is not easily damaged by external impact.
In an embodiment, with continued reference to
400. Thus, no gap is left between the transparent structure 82 and the light-shielding structure 400. Moreover, the light-shielding structure 400 and the transparent structure 82 can cooperate with each other to form a protective structure for a driver circuit 200, thereby preventing the driver circuit 200 from being exposed and corroded by water and oxygen in the atmosphere. Thus, the service life of the driver circuit 200 can be prolonged, that is, the service life of the display panel can be prolonged.
In an embodiment,
The transparent structure 82 is filled in at least part of a light-transmissive hole 81. That is, the transparent structure 82 may be filled in the entire light-transmissive hole 80. Alternatively, the transparent structure 82 may be filled in part of the light-transmissive hole 81. When the transparent structure 82 is filled only in part of a light-transmissive hole 81, a second gap 801 may be disposed between the transparent structure 82 and the pixel region 70. By filling the second gap 801 with the material of the light-shielding structure 400, the light-shielding structure 400 can cover the side wall of the light-transmissive hole 81, that is, the surface of the side of a driver circuit 200 facing a light-transmissive hole region 80. Thus, this part of the light-shielding structure 400 can shield the light entering from the light-transmissive hole 81, thereby avoiding the light from affecting the activity of carriers in the active layer of a thin-film transistor 201. Moreover, the accuracy of a drive signal provided by the thin-film transistor 201 is improved, and the accuracy of the light emission of a light-emitting element 300 is improved.
In an optional embodiment, the value range of the size d2 of the second gap 801 may be 0.5 μm≤d2≤15 μm. In this manner, it is possible to ensure that the light-shielding structure 400 has a sufficiently large light-shielding capability at the second gap 801, and that the light-shielding structure 400 does not occupy a large size of the light-transmissive hole region 80. Thus, the light-transmissive hole region 80 has a sufficiently large light-transmissive size, thereby ensuring that the light-transmissive hole region 80 has a sufficient light flux to satisfy the photosensitive requirement of a photosensitive element or satisfy the display requirement of the transparent display.
It is to be understood that the process of disposing the transparent structure in the light-transmissive hole region may be before or after disposing the light-shielding structure. This is not specifically limited in the embodiments of the present invention. When the transparent structure in the light-transmissive hole region is located before the light-shielding structure is disposed, the transparent structure may serve as a template for the light-shielding structure.
In an embodiment, for example, a transparent structure is formed before a light-shielding structure is formed at least between a thin-film transistor and a light-emitting element.
In S301, a sacrificial layer covering a driver circuit, a light-emitting element, and a light-transmissive hole is formed.
The sacrificial layer may include silicon oxide, polysilicon, photoresist and other materials that can be etched off by a chemical etchant.
In S302, the sacrificial layer is patterned to remove at least part of the sacrificial layer located in the light-transmissive hole.
The manner of patterning the sacrificial layer may include, but is not limited to, etching or photolithography. After the sacrificial layer is patterned, only at least part of the sacrificial layer in the light-transmissive hole may be removed, while the sacrificial layer at other locations is retained. Thus, the sacrificial layer can be used as a mask plate with an opening.
In S303, the sacrificial layer is used as a mask to form a transparent structure in the light-transmissive hole.
Specifically, referring to
In S304, after the transparent structure is formed, the sacrificial layer is removed.
Specifically, with continued reference to
Thus, by using the sacrificial layer as a mask, the transparent structure with the opposite pattern to the sacrificial layer is formed. The transparent structure does not need to be patterned. Thus, the aging and damage of the transparent structure in the patterning process can be avoided, thereby avoiding affecting the light-transmissive property of the transparent structure.
It is to be understood that the formation manner of the transparent structure is only the exemplary formation manner of the transparent structure in the embodiments of the present invention. In other embodiments of the present invention, the transparent structure may be formed by patterning the material of the transparent structure.
In an embodiment,
In S401, a transparent material layer covering a driver circuit, a light-emitting element, and a light-transmissive hole is formed.
The formation manner of the transparent material layer includes, but is not limited to, a preparation technique such as coating or deposition.
In S402, the transparent material layer is patterned. The transparent material layer excluding at least part of the transparent material layer in the light-transmissive hole is removed to form a transparent structure in the light-transmissive hole.
Specifically, referring to
In an embodiment, the transparent structure is prepared before the light-shielding structure. In this case, the manner of forming the light-shielding structure at least between the thin-film transistor and the light-emitting element may include filling a light-shielding material in a gap of the transparent structure to form the light-shielding structure. In this manner, the transparent structure can be used as a mask to prepare the light-shielding structure to prevent the light-shielding structure from entering the light-transmissive hole and affecting the light transmittance of the light-transmissive hole. At the same time, when the transparent structure is used as a mask to prepare the light-shielding structure, no additional mask plate is required. The case that the light-shielding structure having fluidity enters the light-transmissive hole, resulting in that the thickness of the light-shielding structure facing the light-transmissive hole is different from that of the light-shielding structure facing away from the light-transmissive hole, which affects the light-shielding effect, does not occur due to the existence of the light-transmitting hole.
It is to be noted that the preceding only takes the transparent structure disposed in the light-transmissive hole as an example to exemplarily describe the preparation technique and structure of the display panel. In the embodiments of the present invention, the transparent structure in the light-transmissive hole may be removed after the light-shielding structure is formed. In this case, the structure of a display panel is shown in
It is to be understood that in the embodiments of the present invention, a display panel includes at least one light-transmissive hole region. That is, the number of light-transmissive hole regions may be one or more. When multiple light-transmissive hole regions are included, driver circuits in pixel regions located on opposite sides of the light-transmissive hole regions need to be connected by corresponding signal lines. In this case, the display panel may also include a wire region.
In an embodiment,
The wire region 90 and the pixel region 70 are located on different sides of the light-transmissive hole region 80. That is, the wire region 90 and the pixel region 70 may be located on two sides adjacent to the light-transmissive hole region 80. At this time, the signal line 910 in the wire region 90 can be electrically connected to driver circuits 200 in pixel regions 70 located on opposite sides of the light-transmissive hole region 80. Thus, the driver circuits 200 in the pixel regions 70 located on opposite sides of the light-transmissive hole region 80 can share the signal line 910, thereby reducing the number of signal lines 910 disposed in the display panel 10. At the same time, since the signal line 910 is used for transmitting an electrical signal, the signal line 910 can be made of a conductive material such as a metal. In this case, the signal line 910 generally has a certain reflection capability. By forming the light-shielding structure 400 on the side of the signal line 910 in the wire region 90 facing away from the substrate 100, light can be blocked from reaching the signal line 910, and the reflection of the light by the signal line 910 can be reduced, thereby improving the display effect.
In other optional embodiments, a corresponding light-shielding structure may not be disposed in the wire region. In this case, referring to
Thus, by forming the transparent structure 82 on the side of the signal line 910 in the wire region 90 facing away from the substrate 100, the step between the wire region 90 and the pixel region 70 can be reduced. Thus, the wire region 90 and the pixel region 70 are relatively flat. At the same time, covering the transparent structure 82 on the side of the signal line 910 facing away from the substrate 100 can increase the light-transmissive property of the display panel 10, thereby facilitating transparent display.
In an embodiment, with continued reference to
In an embodiment, the wire region may also be provided with a photoresistor structure. The photoresistor structure is located on the side of a light-transmissive structure in the wire region facing away from the substrate. The photoresistor structure is configured to block transmission of at least part of visible light. In this manner, the light entering the wire region can be reduced, and the reflection of the light display by the signal line in the wire region can be reduced, thereby facilitating the improvement of the display contrast of the display panel.
In an example embodiment,
In another example embodiment,
Based on the same inventive concept, the embodiments of the present invention also provide a display device.
It is to be understood that the display device 011 provided in the embodiments of the present invention may be the phone shown in
It is to be noted that the preceding are only preferred embodiments of the present invention and the technical principles used therein. It is to be understood by those skilled in the art that the present invention is not limited to the embodiments described herein. Those skilled in the art can make various apparent modifications, adaptations, and substitutions without departing from the scope of the present invention. Therefore, while the present invention has been described in detail through the preceding embodiments, the present invention is not limited to the preceding embodiments and may include more other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202211740543.8 | Dec 2022 | CN | national |
