Inkjet printing system

Abstract

The application provides an inkjet printing system, comprising: an inkjet printing device comprising a plurality of nozzles, the nozzles containing pixel ink; a display substrate comprising a display area and an under-screen camera area; the nozzles are located above the display substrate; the display substrate comprises a substrate and a pixel definition layer on the surface of the substrate, the pixel definition layer has a first pixel opening and a second pixel opening, the first pixel opening is located in the display area, and the second pixel opening is located in the under-screen camera area; the opening area of the first pixel opening is larger than that of the second pixel opening; and a droplet flow rate control device connected with the nozzles and used for respectively controlling the droplet flow rate of the pixel ink of the nozzles corresponding to the display area and the under-screen camera area; the number of pixel ink droplets flowing out of the nozzles corresponding to the first pixel opening is more than that of the pixel ink flowing out of the nozzles corresponding to the second pixel opening. The inkjet printing system provided by the application can adjust the film thickness.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of inkjet printing technology, and in particular to an inkjet printing system. BACKGROUND

[0002] At present, the organic light emitting diode (OLED) is gradually expanding its market influence with its low power consumption, fast response speed, high contrast, wide color gamut, thin and light LCD, and flexible display. Inkjet printing (IJP) OLED is a new OLED preparation process. Compared with the traditional evaporation process, inkjet printing OLED is printed according to the demand of organic materials, which can achieve more than 90% material utilization rate. Inkjet printing OLED does not need to be carried out in a vacuum, but only needs to control the precision of the nozzle to achieve high-precision printing.

[0003] The current under-screen camera technology mainly relies on reducing the pixel opening to allow more light to enter the camera module to achieve effective imaging. The current pixel arrangement often adopts the SBS (side by side) architecture. Inkjet printing of the SBS architecture needs to print an integer number of ink drops in the pixel to achieve the expected film thickness. The SBS architecture pixel needs to change the size of the pixel opening to achieve the under-screen camera technology, and needs to ensure that the opening area of the R / G / B main pixel and the R / G / B sub-pixel is in a fixed ratio. This ratio must satisfy: S_Main / S_Sub=Drop_Main / Drop_Sub (wherein, S_Main represents the opening area of the main pixel, S_Sub represents the opening area of the sub-pixel, Drop_Main represents the number of ink drops of the main pixel, and Drop_Sub represents the number of ink drops of the sub-pixel). In this way, the film thickness of the main pixel and the film thickness of the sub-pixel can be ensured to be equivalent. At the same time, the number of nozzles that can be used is reduced when the SBS architecture pixel is reduced, the nozzle utilization rate is reduced, and the inkjet printing of the SBS architecture pixel has a high requirement for the landing accuracy in the scanning direction, and there is a risk of printing color mixing. SUMMARY

[0004] Therefore, the present application provides an inkjet printing system which can reduce the risk of printing color mixing, can realize fine film thickness adjustment, and can effectively improve the nozzle utilization rate.

[0005] To solve the above problems, the technical scheme provided by the present application is as follows:

[0006] The present application provides an inkjet printing system, comprising:

[0007] An inkjet printing device, comprising a plurality of nozzles, and a pixel ink in the plurality of nozzles;

[0008] A display substrate includes a display area and an under-display camera area; a plurality of nozzles are located above the display substrate; the display substrate includes a substrate and a pixel definition layer located on the surface of the substrate, the pixel definition layer has a plurality of first pixel openings and a plurality of second pixel openings, the first pixel openings are located in the display area, and the second pixel openings are located in the under-display camera area; the opening area of the first pixel opening is larger than the opening area of the second pixel opening; the plurality of first pixel openings and the plurality of second pixel openings are arranged in multiple rows to form a plurality of adjacent pixel rows; and

[0009] An ink drop flow rate control device is connected to the nozzles and is used to control the ink drop flow rate of the pixel ink of the nozzles corresponding to the display area and the under-display camera area, respectively;

[0010] Wherein, in the same time, the number of ink drops of pixel ink flowing from the nozzles corresponding to the first pixel openings is more than the number of ink drops of pixel ink flowing from the nozzles corresponding to the second pixel openings.

[0011] In an optional embodiment of the present application, the pixel definition layer includes a plurality of first pixel definition blocks and a plurality of second pixel definition blocks;

[0012] Each of the first pixel definition blocks is spaced apart from two adjacent first pixel openings or two adjacent second pixel openings or one first pixel opening and one second pixel opening;

[0013] Each of the second pixel definition blocks is spaced apart from the first pixel openings in adjacent two pixel rows and the second pixel openings in adjacent two pixel rows.

[0014] In an optional embodiment of the present application, the ink drops flowing from the nozzles corresponding to the first pixel definition blocks and the second pixel definition blocks fall on the first pixel definition blocks and the second pixel definition blocks and can flow into the first pixel openings or the second pixel openings adjacent thereto.

[0015] In an optional embodiment of the present application, the surface of the pixel definition layer located in the display area away from the substrate is flush, and the ink drops overflowing from the second pixel openings can flow into the first pixel openings.

[0016] In an optional embodiment of the present application, when defining inkjet printing, a plurality of nozzles are scanned in a first direction; a plurality of first pixel openings and a plurality of second pixel openings are arranged in the first direction, and a plurality of pixel rows are arranged in a second direction perpendicular to the first direction.

[0017] In an optional embodiment of the present application, a portion of the first pixel openings and a portion of the second pixel openings are located in an Nth pixel opening row, another portion of the first pixel openings and another portion of the second pixel openings are located in an (N+1)th pixel opening row, and still another portion of the first pixel openings and still another portion of the second pixel openings are located in an (N+2)th pixel opening row; wherein N is an integer greater than 0.

[0018] The Nth pixel opening row, the (N+1)th pixel opening row, and the (N+2)th pixel opening row are sequentially arranged in the second direction.

[0019] The color of the pixel ink in the first pixel openings and the second pixel openings in the Nth pixel opening row, the color of the pixel ink in the first pixel openings and the second pixel openings in the (N+1)th pixel opening row, and the color of the ink drops in the first pixel openings and the second pixel openings in the (N+2)th pixel opening row are different and are each selected from one of red, green, and blue.

[0020] In an optional embodiment of the present application, the depth of the first pixel opening in a third direction perpendicular to the first direction is equal to the depth of the second pixel opening in the third direction.

[0021] In an optional embodiment of the present application, the surface of the pixel ink located in the first pixel opening away from the substrate is flush with the surface of the pixel ink located in the second pixel opening away from the substrate.

[0022] In an optional embodiment of the present application, the number of ink drops falling in the first pixel opening and / or the second pixel opening is an integer drop or a non-integer drop.

[0023] In an optional embodiment of the present application, all of the nozzles are usable nozzles.

[0024] In an optional embodiment of the present application, in the same pixel row, the ink drops falling in the display area and the under-screen camera area are on or not on the same straight line.

[0025] In an optional embodiment of the present application, each of the first pixel definition blocks located in the display area includes a first sub-pixel block and a second sub-pixel block connected to the first sub-pixel block, and the connection between the surface of the second sub-pixel block and the first sub-pixel block located in the first pixel opening and the second pixel opening and the surface of the first sub-pixel block away from the substrate is a smooth transition connection.

[0026] The inkjet printing system provided in this application, based on a pixel aperture with an LB architecture, reduces the opening area of ​​the second pixel aperture in the under-display camera area. Through an ink droplet flow rate control device, the ink droplet outflow rate of the pixel ink in the nozzles corresponding to the display area and the under-display camera area is controlled respectively. During inkjet printing, the nozzles corresponding to the pixel definition layer can also be used. Due to the leveling property of ink droplets in the pixel aperture of the LB architecture, ink droplets in the nozzles corresponding to the pixel definition layer can flow into adjacent first or second pixel apertures, thereby effectively improving nozzle utilization and enabling precise film thickness adjustment. Because of the leveling property of ink droplets in the pixel aperture of the LB architecture, the number of ink droplets in the pixel ink of the nozzles corresponding to the display area and the under-display camera area can be controlled separately. Therefore, there are no special requirements for S_Main / S_Sub or the droplet impact accuracy in the scanning direction, which can fully meet the transmittance requirements of the under-display camera and reduce the risk of color mixing during printing. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the modules of an inkjet printing system provided in some embodiments of this application.

[0029] Figure 2 for Figure 1 The top view of the display substrate shown.

[0030] Figure 3 for Figure 2 The diagram shows a top view of the display substrate and pixel definition layer, as well as a schematic diagram of the nozzles of an inkjet printing device.

[0031] Figure 4 for Figure 3 A schematic diagram of the nozzle of the inkjet printing device, the substrate of the display substrate with ink droplets, and the pixel definition layer.

[0032] Figure 5 for Figure 4 The diagram shows the distribution of ink droplets in the scanning direction (first direction). Detailed Implementation

[0033] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0034] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly and specifically limited.

[0035] The present application can repeatedly refer to reference numerals and / or reference letters in different embodiments. Such repetition is for the purpose of simplification and clarity, and does not in itself indicate the relationship between the various embodiments and / or arrangements discussed.

[0036] The present application aims at the technical problems of existing inkjet printing systems, which have the risk of printing color mixing, cannot achieve fine film thickness adjustment, and have low nozzle utilization rate when inkjet printing. On the basis of the pixel opening with LB architecture, the opening area of the second pixel opening in the under-screen camera area is reduced, and the ink drop flow rate control device is used to control the ink drop flow rate of the pixel ink of the nozzles corresponding to the display area and the under-screen camera area, respectively, to reduce the risk of printing color mixing, achieve fine film thickness adjustment, and effectively improve the nozzle utilization rate.

[0037] Please refer to Figures 1 to 5The application provides an inkjet printing system 100, which comprises a display substrate 10, an inkjet printing device 20 and a droplet flow rate control device 30. The inkjet printing device 20 comprises a plurality of nozzles 21, and the plurality of nozzles 21 have pixel ink. The display substrate 10 comprises a display area 101 and an under-screen camera area 102, the plurality of nozzles 21 are located above the display substrate 10, the display substrate 10 comprises a substrate 11 and a pixel definition layer 13 located on the surface of the substrate 11, the pixel definition layer 13 has a plurality of first pixel openings 141 and a plurality of second pixel openings 142, the first pixel openings 141 are located in the display area 101, the second pixel openings 142 are located in the under-screen camera area 102, the opening area of the first pixel openings 141 is larger than that of the second pixel openings 142, and the plurality of first pixel openings 141 and the plurality of second pixel openings 142 are arranged in multiple rows to form a plurality of adjacent pixel rows; the droplet flow rate control device 30 is connected with the nozzles 21 and is used for respectively controlling the droplet flow rate of the pixel ink of the nozzles 21 corresponding to the display area 101 and the under-screen camera area 102; wherein the number of the pixel ink droplets flowing out of the nozzles corresponding to the first pixel openings 141 is larger than that of the pixel ink flowing out of the nozzles corresponding to the second pixel openings 142 in the same time.

[0038] The inkjet printing system provided by the application reduces the opening area of the second pixel opening in the under-screen camera area on the basis of the pixel opening with the LB architecture, controls the droplet flow rate of the pixel ink of the nozzles corresponding to the display area and the under-screen camera area by the droplet flow rate control device, the nozzles corresponding to the pixel definition layer can also be used when the inkjet printing system provided by the application is used for inkjet printing, because the droplets in the pixel opening with the LB architecture have the leveling property, the droplets in the nozzles corresponding to the pixel definition layer can flow into the adjacent first pixel opening or second pixel opening, so that the utilization rate of the nozzles can be effectively improved, and the fine film thickness adjustment can be realized. Because the droplets in the pixel opening with the LB architecture have the leveling property, the number of the droplets of the pixel ink of the nozzles corresponding to the display area and the under-screen camera area of the inkjet printing system provided by the application can be controlled respectively, so that there is no special requirement for the S_Main / S_Sub and the landing precision of the droplets in the scanning direction, the required transmittance of the under-screen camera can be fully met, and the risk of printing color mixing can be reduced.

[0039] In an embodiment of the present application, the inkjet printing is defined as that the plurality of nozzles 21 are scanned along a first direction X, the plurality of first pixel openings 141 and the plurality of second pixel openings 142 are arranged along the first direction X, and the plurality of pixel rows are arranged along a second direction Y perpendicular to the first direction X.

[0040] In an embodiment of the present application, the pixel definition layer 13 comprises a plurality of first pixel definition blocks 131 and a plurality of second pixel definition blocks 132. Each of the first pixel definition blocks 131 is spaced apart from two adjacent first pixel openings 141 or two adjacent second pixel openings 142 or one first pixel opening 141 and one second pixel opening 142. Each of the second pixel definition blocks 132 is spaced apart from the first pixel openings 141 in two adjacent pixel rows and spaced apart from the second pixel openings 142 in two adjacent pixel rows.

[0041] In an embodiment of the present application, a part of the first pixel openings 141 and a part of the second pixel openings 142 are located in an Nth pixel opening row, another part of the first pixel openings 141 and another part of the second pixel openings 142 are located in an N+1th pixel opening row, and still another part of the first pixel openings 141 and still another part of the second pixel openings 142 are located in an N+2th pixel opening row. N is an integer greater than 0. The Nth pixel opening row, the N+1th pixel opening row and the N+2th pixel opening row are arranged in sequence along the second direction Y. The color of the ink drops 31 in the first pixel openings 141 and the second pixel openings 142 in the Nth pixel opening row, the color of the ink drops 32 in the first pixel openings 141 and the second pixel openings 142 in the N+1th pixel opening row, and the color of the ink drops 33 in the first pixel openings 141 and the second pixel openings 142 in the N+2th pixel opening row are different and are selected from one of red, green and blue.

[0042] In an optional embodiment of the present application, the Nth pixel opening row, the N+1th pixel opening row and the N+2th pixel opening row are a pixel opening unit, and the display substrate can include a plurality of pixel opening units arranged in sequence in the second direction. In this embodiment, the display substrate includes two pixel opening units, each of which includes the first pixel opening row, the second pixel opening row and the third pixel opening row arranged in sequence in the second direction Y, and the third pixel opening row of one pixel opening unit is adjacent to the first pixel opening row of another pixel opening unit adjacent thereto. The color of the ink drops in the first pixel opening row, the second pixel opening row and the third pixel opening row is one of red, green and blue, respectively.

[0043] Of course, the number of pixel opening rows included in each pixel opening unit is not limited to three, and the color of the ink drops in each pixel opening row is not limited to red, green and blue, and can be set according to the pixel arrangement mode of the OLED display panel.

[0044] In an optional embodiment of the present application, the ink drops flowing out of the nozzles 21 corresponding to the first pixel definition block 131 and the second pixel definition block 132 fall on the first pixel definition block 131 and the second pixel definition block 132 and can flow into the first pixel opening 141 or the second pixel opening 142 adjacent thereto.

[0045] In an optional embodiment of the present application, each first pixel definition block 131 located in the display area 101 includes a first sub-pixel block 1311 extending along the first direction X and a second sub-pixel block 1312 connected with the first sub-pixel block 1311 and extending along the second direction Y. One end of the second pixel definition block 132 located in the display area 101 is connected to one first sub-pixel block 1311, and the other end is connected to the second sub-pixel block 1312 of another first pixel definition block 131 adjacent thereto. Both ends of the second pixel definition block 132 located in the under-screen camera area 102 are connected to two first pixel definition blocks 131, respectively.

[0046] In the present application, the width of the first sub-pixel block 1311 located in the under-screen camera area 102 in the second direction Y is greater than the width of the first sub-pixel block 1311 located in the display area 101 in the second direction Y.

[0047] In an optional embodiment of the present application, the first sub-pixel block 1311 located in the under-screen camera area 102 is connected with the first sub-pixel block 1311 and the second sub-pixel block 1312 located in the display area 101.

[0048] In an optional embodiment of the present application, the first sub-pixel block 1311 is integrally formed with the second sub-pixel block 1312. The first sub-pixel block 1311 located in the under-screen camera area 102 is integrally formed with the first sub-pixel block 1311 and the second sub-pixel block 1312 located in the display area 101.

[0049] In an optional embodiment of the present application, the connection between the surface of the second sub-pixel block 1312 and the surface of the first sub-pixel block 1311 located in the first pixel opening 141 and the second pixel opening 142 and the surface of the first sub-pixel block 1311 facing away from the substrate 11 is a smooth transition connection. In this way, it is beneficial for the ink drops falling on the first sub-pixel block 1311 and the second sub-pixel block 1312 to flow into the first pixel opening 141 and the second pixel opening 142.

[0050] In the present embodiment, the second sub-pixel block 1312 is semicircular. Of course, in other embodiments, the shape of the second sub-pixel block 1312 is not limited to semicircular, but can also be other shapes.

[0051] In an optional embodiment of the present application, the surface of the pixel definition layer 13 located in the display area 101 away from the substrate 11 is flush. The ink drops overflowing from the second pixel opening 142 can flow into the first pixel opening 141.

[0052] In an optional embodiment of the present application, the depth of the first pixel opening 141 in the third direction Z perpendicular to the first direction X is equal to the depth of the second pixel opening 142 in the third direction Z.

[0053] In an optional embodiment of the present application, the surface of the pixel ink located in the first pixel opening 141 away from the substrate 11 is flush with the surface of the pixel ink located in the second pixel opening 142 away from the substrate 11.

[0054] In an optional embodiment of the present application, the number of ink drops falling in the first pixel opening 141 and / or the second pixel opening 142 is an integer drop or a non-integer drop.

[0055] In an optional embodiment of the present application, all the nozzles 21 are usable nozzles.

[0056] In an optional embodiment of the present application, in the same pixel row, the ink drops falling in the display area 101 and the under-screen camera area 102 are on or not on the same straight line.

[0057] The inkjet printing system provided by the application reduces the opening area of the second pixel opening of the under-screen camera area on the basis of the pixel opening with the LB architecture, controls the drop flow rate of the pixel ink of the nozzles corresponding to the display area and the under-screen camera area by the drop flow rate control device respectively, the inkjet printing system provided by the application can also use the nozzles corresponding to the pixel definition layer during inkjet printing, because the drops in the pixel opening with the LB architecture have leveling property, the drops in the nozzles corresponding to the pixel definition layer can flow into the adjacent first pixel opening or second pixel opening, thereby not only effectively improving the nozzle utilization rate, but also realizing fine film thickness adjustment. Because the drops in the pixel opening with the LB architecture have leveling property, the number of drops of the pixel ink of the nozzles corresponding to the display area and the under-screen camera area of the inkjet printing system provided by the application can be controlled respectively, therefore there is no special requirement for the S_Main / S_Sub and the drop landing accuracy in the scanning direction, which can fully meet the transmittance required by the under-screen camera and reduce the risk of printing color mixing.

[0058] The above describes the inkjet printing system provided by the embodiment of the application in detail, the principle and implementation mode of the application are described by applying specific examples in the text, the above embodiment description is only used to help understand the technical solution of the application and the core idea; the person skilled in the art should understand that the technical solution recorded in the foregoing embodiments can be modified or some technical features can be replaced by the equivalent; and the modification or replacement does not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the application.

Claims

1. An inkjet printing system, characterized in that, include: An inkjet printing apparatus includes multiple nozzles, wherein the multiple nozzles contain pixel ink; The display substrate includes a display area and an under-display camera area; a plurality of nozzles are located above the display substrate; the display substrate includes a substrate and a pixel definition layer located on the surface of the substrate, the pixel definition layer having a plurality of first pixel openings and a plurality of second pixel openings, the first pixel openings being located in the display area, and the second pixel openings being located in the under-display camera area; The opening area of ​​the first pixel opening is larger than the opening area of ​​the second pixel opening; Multiple first pixel openings and multiple second pixel openings are arranged in multiple rows to form multiple adjacent pixel rows; the pixel row includes first pixel openings and second pixel openings; and A droplet flow rate control device is connected to the nozzle and is used to control the droplet flow rate of pixel ink of the nozzle corresponding to the display area and the nozzle corresponding to the under-screen camera area respectively; In the same time period, the number of pixel ink droplets flowing out of the nozzle corresponding to the first pixel opening is greater than the number of pixel ink droplets flowing out of the nozzle corresponding to the second pixel opening.

2. The inkjet printing system as described in claim 1, characterized in that, The pixel definition layer includes multiple first pixel definition blocks and multiple second pixel definition blocks; Each first pixel definition block is spaced between two adjacent first pixel openings, or between two adjacent second pixel openings, or between one adjacent first pixel opening and one second pixel opening; Each second pixel definition block is spaced between the first pixel opening within two adjacent pixel rows and the second pixel opening within two adjacent pixel rows.

3. The inkjet printing system as described in claim 2, characterized in that, Ink droplets flowing from the nozzles corresponding to the first pixel definition block and the second pixel definition block fall onto the first pixel definition block and the second pixel definition block and can flow into the adjacent first pixel opening or second pixel opening; and / or Each first pixel definition block located in the display area includes a first sub-pixel block and a second sub-pixel block connected to the first sub-pixel block. The connection between the second sub-pixel block and the surface of the first sub-pixel block located within the first pixel opening and the second pixel opening and the surface of the first sub-pixel block facing away from the substrate is a smooth transition connection.

4. The inkjet printing system as described in claim 1, characterized in that, The surface of the pixel definition layer located in the display area is flush with the surface away from the substrate, and the ink droplets overflowing from the second pixel opening can flow into the first pixel opening.

5. The inkjet printing system according to any one of claims 1-4, characterized in that, During inkjet printing, multiple nozzles scan along a first direction; multiple first pixel openings and multiple second pixel openings are arranged along the first direction, and multiple pixel rows are arranged along a second direction perpendicular to the first direction.

6. The inkjet printing system as described in claim 5, characterized in that, A portion of the first pixel opening and a portion of the second pixel opening are located in the Nth pixel opening row, another portion of the first pixel opening and another portion of the second pixel opening are located in the (N+1)th pixel opening row, and yet another portion of the first pixel opening and yet another portion of the second pixel opening are located in the (N+2)th pixel opening row; where N is an integer greater than 0; The Nth pixel opening row, the N+1th pixel opening row, and the N+2th pixel opening row are arranged sequentially in the second direction; The colors of the pixel inks falling into the first and second pixel openings in the Nth pixel opening row, the colors of the pixel inks falling into the first and second pixel openings in the N+1th pixel opening row, and the colors of the ink droplets falling into the first and second pixel openings in the N+2th pixel opening row are different and are respectively selected from red, green, and blue.

7. The inkjet printing system as described in claim 5, characterized in that, The depth of the first pixel opening in a third direction perpendicular to the first direction is equal to the depth of the second pixel opening in that third direction.

8. The inkjet printing system as described in claim 7, characterized in that, The surface of the pixel ink located in the first pixel opening that is away from the substrate is flush with the surface of the pixel ink located in the second pixel opening that is away from the substrate.

9. The inkjet printing system as described in claim 1, characterized in that, The number of ink droplets falling within the first pixel opening and / or the second pixel opening is an integer or a non-integer number of droplets.

10. The inkjet printing system as claimed in claim 1, characterized in that, All of the nozzles mentioned are usable nozzles; or In the same pixel row, the ink droplets falling on the display area and the under-screen camera area may or may not be on the same straight line.

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