Display substrate, preparation method thereof, and display device

Abstract

An embodiment of the present invention provides a display substrate, a preparation method thereof, and a display device. The display substrate includes a substrate, the substrate includes a pixel region and a light-shielding region surrounding the pixel region on all sides. A barrier wall is formed on the light-shielding region, the barrier wall surrounds the periphery of at least one of the pixel regions, a piezoelectric functional layer covering at least one of the pixel regions is formed on the barrier wall, a transducer chamber is formed between the piezoelectric functional layer and at least one of the pixel regions, and the transducer chamber and the piezoelectric functional layer form an ultrasonic transducer unit for ultrasonic gesture recognition; it can realize the integration of the gesture recognition unit and the display substrate.

Description

Technical Field

[0001] The present invention relates to the field of display technologies, and particularly to a display substrate, a preparation method thereof, and a display device. Background Art

[0002] Organic Light Emitting Diode (OLED) display devices are the development trend of future display products, and have a series of advantages such as wide viewing angles, fast response speeds, high brightness, high contrast ratios, vivid colors, light weight, thin thickness, and low power consumption. Currently, organic light emitting diode display devices have begun to be applied to mobile phone screens.

[0003] In computer science, gesture recognition is a topic of recognizing human gestures through mathematical algorithms. Gesture recognition can come from the movements of various parts of a person's body. Existing optical gesture recognition units are large in volume and cannot be integrated with a display substrate. Summary of the Invention

[0004] The technical problem to be solved by the embodiments of the present invention is to provide a display substrate, a preparation method thereof, and a display device, which can integrate a gesture recognition unit with the display substrate.

[0005] To solve the above technical problem, an embodiment of the present invention provides a display substrate, including a substrate, the substrate including a pixel region and a light-shielding region surrounding the pixel region on all four sides, a retaining wall being formed on the light-shielding region, the retaining wall surrounding the perimeter of at least one of the pixel regions, a piezoelectric functional layer being formed on the retaining wall and covering at least one of the pixel regions, a transducer chamber being formed between the piezoelectric functional layer and at least one of the pixel regions, and the transducer chamber and the piezoelectric functional layer forming an ultrasonic transducer unit for ultrasonic gesture recognition.

[0006] In an exemplary embodiment, a light-emitting unit is provided on the pixel region, the retaining wall including a first portion that is higher than the light-emitting unit and a second portion that is lower than the first portion, the first portion surrounding the perimeter of at least two of the pixel regions, the second portion being located between at least two adjacent pixel regions within the first portion, and the piezoelectric functional layer being formed on the first portion.

[0007] In an exemplary embodiment, the retaining wall is made of a light-shielding material.

[0008] In an exemplary embodiment, the transducer chamber includes at least two chambers, the areas of the vertical projections of the at least two chambers on the substrate being different, and the at least two chambers being configured to emit ultrasonic waves of different frequency bands.

[0009] In an exemplary embodiment, the transducer chamber includes a first chamber, a second chamber, and a third chamber. The area of the vertical projection of the first chamber on the substrate is greater than the area of the vertical projection of the second chamber on the substrate, and the area of the vertical projection of the second chamber on the substrate is greater than the area of the vertical projection of the third chamber on the substrate. The first chamber is configured as a low-frequency chamber, the second chamber is configured as a medium-frequency chamber, and the third chamber is configured as a high-frequency chamber.

[0010] In an exemplary embodiment, the piezoelectric functional layer includes a stacked first electrode layer, a second electrode layer, and a piezoelectric layer located between the first electrode layer and the second electrode layer, and the first electrode layer is located on the side of the piezoelectric layer close to the substrate.

[0011] In an exemplary embodiment, an adhesive layer is provided between the piezoelectric functional layer and the retaining wall.

[0012] In an exemplary embodiment, the vertical projection of the transducer chamber on the substrate is square, rhombic, rectangular, or circular.

[0013] An embodiment of the present invention further provides a display device, including the foregoing display substrate.

[0014] An embodiment of the present invention further provides a method for manufacturing a display substrate, including:

[0015] Forming a pixel region and a light-shielding region surrounding the pixel region on the substrate;

[0016] Forming a retaining wall on the light-shielding region so that the retaining wall surrounds the periphery of at least one of the pixel regions;

[0017] Forming a piezoelectric functional layer covering at least one of the pixel regions on the retaining wall. A transducer chamber is formed between the piezoelectric functional layer and at least one of the pixel regions. The transducer chamber and the piezoelectric functional layer form an ultrasonic transducer unit for ultrasonic gesture recognition.

[0018] The present invention provides a display substrate, a method for manufacturing the same, and a display device. By forming a piezoelectric functional layer on the retaining wall, a transducer chamber is formed between the piezoelectric functional layer and the pixel region, so that the transducer chamber and the piezoelectric functional layer form an ultrasonic transducer unit for ultrasonic gesture recognition, realizing the integration of the gesture recognition unit and the display substrate.

[0019] In the display substrate according to an embodiment of the present invention, by dividing the transducer chamber into at least two chambers with different sizes, at least two chambers are respectively configured to emit ultrasonic waves of different high and low frequency bands, so that the chamber with the low frequency band is used for long-distance ultrasonic gesture recognition to increase the detection distance of the display substrate; the chamber with the high frequency band is used for short-distance ultrasonic gesture recognition to improve the detection accuracy of the display substrate.

[0020] Of course, it is not necessary for any product or method implementing the present invention to achieve all the above advantages simultaneously. Other features and advantages of the present invention will be described in the embodiments of the following specification, and, in part, will become apparent from the embodiments of the specification or will be understood by implementing the present invention. The objectives and other advantages of the embodiments of the present invention can be achieved and obtained through the structures specifically pointed out in the specification, claims, and drawings. Description of the Drawings

[0021] The drawings are used to provide a further understanding of the technical solutions of the present invention, and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solutions of the present invention and do not constitute a limitation to the technical solutions of the present invention. The shapes and sizes of the components in the drawings do not reflect the true proportions, and the purpose is only to schematically illustrate the content of the present invention.

[0022] Figure 1 It is a cross-sectional view of the display substrate according to an embodiment of the present invention;

[0023] Figure 2 It is a schematic structural diagram of the display substrate according to an embodiment of the present invention;

[0024] Figure 3 It is a schematic diagram of the display substrate according to an embodiment of the present invention after forming the dam material film;

[0025] Figure 4 It is a schematic diagram of the display substrate according to an embodiment of the present invention after the photoresist is developed;

[0026] Figure 5 It is a schematic diagram of the display substrate according to an embodiment of the present invention after forming the dam;

[0027] Figure 6 It is a schematic diagram of the display substrate according to an embodiment of the present invention after forming the adhesive layer. Detailed Embodiments

[0028] The following further describes in detail the specific embodiments of the present invention in conjunction with the drawings and embodiments. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other arbitrarily.

[0029] Figure 1A cross-sectional view of the display substrate according to an embodiment of the present invention; Figure 2 A schematic structural diagram of the display substrate according to an embodiment of the present invention. As Figure 1 and Figure 2 shown, the display substrate includes a substrate 10, the substrate 10 includes a plurality of pixel regions 20 arranged in an array and a light-shielding region 30 surrounding the pixel regions 20 on all sides, and the light-shielding region 30 separates adjacent pixel regions 20. Three (such as red, green, and blue) or four (such as red, green, blue, and white) light-emitting units 40 that emit light of different colors can be provided on the pixel region 20. The light-emitting unit 40 includes a driving structure layer provided on the pixel region 20 and a light-emitting structure layer provided on the driving structure layer. The driving structure layer mainly includes a plurality of thin film transistors (TFTs) for controlling the light-emitting structure layer to emit light. The light-emitting structure layer mainly includes an anode layer, a light-emitting layer provided on the anode, and a cathode layer provided on the light-emitting layer, and the light-emitting structure layer is used to emit display light. A retaining wall 50 is formed on the light-shielding region 30, and the retaining wall 50 forms a closed ring structure surrounding the perimeter of at least one pixel region 20. A piezoelectric functional layer 60 is formed on the retaining wall 50, and the piezoelectric functional layer 60 covers at least one pixel region 20 located within the retaining wall 50, that is, the area of the piezoelectric functional layer 60 projected vertically onto the substrate 10 overlaps at least the area of at least one pixel region 20 projected vertically onto the substrate 10 within the retaining wall 50. A transducer chamber 70 is formed between the piezoelectric functional layer 60 and at least one pixel region 20 located within the retaining wall 50, and the transducer chamber 70 and the piezoelectric functional layer 60 form an ultrasonic transducer unit for ultrasonic gesture recognition, thus integrating the gesture recognition unit with the display substrate.

[0030] In an exemplary embodiment, the retaining wall 50 can be made of a light-shielding material. For example, the retaining wall 50 can be made of light-shielding materials such as printing ink, light-shielding resin, and polystyrene-based plastics. By using a light-shielding material for the retaining wall 50 in the display substrate according to the embodiment of the present invention, the retaining wall 50 solves the problem of pixel crosstalk between pixel regions 20.

[0031] In an exemplary embodiment, the transducer chamber 70 includes at least two chambers, and the areas of the at least two chambers projected vertically onto the substrate 10 are different, that is, the sizes of the at least two chambers are different, so that the at least two chambers can be configured to emit ultrasonic waves of different frequency bands.

[0032] By dividing the transducer chamber 70 into at least two chambers with different sizes in the display substrate according to the embodiment of the present invention, the at least two chambers are respectively configured to emit ultrasonic waves of different high and low frequency bands, so that the chamber with the low frequency band is used for long-distance ultrasonic gesture recognition to increase the detection distance of the display substrate; the chamber with the high frequency band is used for short-distance ultrasonic gesture recognition to improve the detection accuracy of the display substrate.

[0033] In the embodiment of the present invention, the low-frequency chamber of the display substrate emits short pulses for rough measurement, and the high-frequency chamber continuously emits ultrasonic waves for precise measurement, thereby saving system resources and achieving fast and high-precision measurement.

[0034] The display substrate in the embodiment of the present invention is described by taking the transducer chamber 70 being divided into three chambers as an example. As Figure 2 shown, the transducer chamber 70 includes a first chamber 701, a second chamber 702, and a third chamber 703. The area of the vertical projection of the first chamber 701 on the substrate 10 is larger than the area of the vertical projection of the second chamber 702 on the substrate 10, and the area of the vertical projection of the second chamber 702 on the substrate 10 is larger than the area of the vertical projection of the third chamber 703 on the substrate 10. That is, the size of the first chamber 701 is larger than the size of the second chamber 702, and the size of the second chamber 702 is larger than the size of the third chamber 703. The first chamber 701 is configured as a low-frequency chamber, the second chamber 702 is configured as an intermediate-frequency chamber, and the third chamber 703 is configured as a high-frequency chamber.

[0035] The chambers with different sizes in the transducer chamber 70 emit ultrasonic waves of different high and low frequencies, which can be used to detect different distance ranges and identify different precisions. For example, when the transducer chamber 70 emits a frequency of 20 Hz, the minimum recognizable distance that can be detected is 8.5 mm, the maximum recognizable distance that can be detected is 4 m, and the recognition precision is 8.5 mm; when the transducer chamber 70 emits a frequency of 40 Hz, the minimum recognizable distance that can be detected is 4.25 mm, the maximum recognizable distance that can be detected is 2 m, and the recognition precision is 4.25 mm; when the transducer chamber 70 emits a frequency of 100 Hz, the minimum recognizable distance that can be detected is 1.7 mm, the maximum recognizable distance that can be detected is 1 m, and the recognition precision is 1.7 mm; when the transducer chamber 70 emits a frequency of 200 Hz, the minimum recognizable distance that can be detected is 0.85 mm, the maximum recognizable distance that can be detected is 0.5 m, and the recognition precision is 0.85 mm.

[0036] In an exemplary embodiment, the vertical projection of the transducer chamber 70 on the substrate 10 is not limited. For example, the vertical projection of the transducer chamber 70 on the substrate 10 can be square, rhombus, rectangular, or circular.

[0037] In an exemplary embodiment, as Figure 1 and Figure 2As shown, the retaining wall 50 includes a first part 501 that is higher than the light-emitting unit 40 and a second part 502 that is lower than the first part 501. Among them, the height of the first part 501 can be 10um higher than the height of the light-emitting unit 40. The first part 501 forms a closed annular structure that surrounds the peripheries of at least two pixel regions 20. The second part 502 is located between at least two adjacent pixel regions 20 within the first part 501, so that the surface of the second part 502 away from the substrate 10 is higher than the surface of the light-emitting unit 402 away from the substrate 10 within the second part 502 and the surface of the second part 502 away from the substrate 10 within the second part 502. A piezoelectric functional layer 60 is formed on the first part 501, and the piezoelectric functional layer 60 covers the pixel region 20 within the first part 501, so that a transducer chamber 70 is formed between the piezoelectric functional layer 60 and the light-emitting unit 40 and the second part 502 within the first part 501.

[0038] In an exemplary embodiment, an adhesive layer 80 is provided between the piezoelectric functional layer 60 and the retaining wall 50, and the adhesive layer 80 is used to bond the piezoelectric functional layer 60 and the retaining wall 50. Among them, the material of the adhesive layer 80 can be 3M double-sided tape.

[0039] In an exemplary embodiment, the piezoelectric functional layer 60 includes a stacked first electrode layer 601, a second electrode layer 602, and a piezoelectric layer 603 located between the first electrode layer 601 and the second electrode layer 602, and the first electrode layer 601 is located on the side of the piezoelectric layer 603 close to the substrate 10. Among them, the first electrode layer 601 and the second electrode layer 602 adopt transparent electrodes, such as ITO electrodes or other transparent materials. The material of the piezoelectric layer 603 can adopt transparent polyvinylidene fluoride. The first electrode layer 601, the second electrode layer 602, and the piezoelectric layer 603 all adopt transparent materials, so that the piezoelectric functional layer 60 does not affect the display effect of the display substrate.

[0040] The display substrate according to the embodiment of the present invention further includes a gesture recognition driving unit, a receiving circuit module connected to the gesture recognition driving unit, and a transmitting circuit module. The gesture recognition driving unit includes an excitation signal module, a timing adjustment module, a data processing module, and a gesture comparison module.

[0041] The ultrasonic gesture recognition method for the display substrate in the embodiments of the present invention is as follows: The excitation signal module generates a driving signal with a frequency f and gives it to the transmitting circuit module. After the transmitting circuit module performs a boosting process, it drives the ultrasonic transducer unit to emit ultrasonic waves. After the ultrasonic waves encounter a target object and reflect an echo, the reflected echo is received by the ultrasonic transducer unit, and after signal processing by the receiving circuit module, it is sent to the data processing module. The data processing module determines whether to use the high-frequency chamber in the ultrasonic transducer unit to achieve high-precision detection of the ultrasonic transducer unit. If necessary, the data processing module sends a signal to the timing adjustment module, and the timing adjustment module adjusts the frequency of the excitation signal generated by the excitation signal module and performs detection again. If not, the data processing module sends the signal to the gesture comparison module, and the gesture comparison module performs gesture comparison to complete gesture detection. Among them, the receiving circuit module includes a filtering circuit module, an amplifying circuit module, etc.

[0042] The display substrate in the embodiments of the present invention has a MEMS PVDF structure. The size of the transducer chamber 70, the laminated material, and the thickness determine its optimal operating resonance frequency, and the size of the transducer chamber 70 is the main influencing factor. The display substrate in the embodiments of the present invention can also achieve its optimal operating resonance frequency by adjusting the laminated thickness in different regions.

[0043] Figures 3 to 6 It is a schematic diagram of the preparation process of the display substrate in the embodiments of the present invention. The preparation process of the display substrate in this embodiment includes:

[0044] 1) Form a light-emitting unit 40 on the pixel area 20 of the substrate 10, and deposit or coat a damascene material thin film 90 covering the substrate 10, such as Figure 3 shown. Among them, the damascene material thin film 90 can use light-shielding materials such as printing ink, light-shielding resin, and polystyrene-based plastics.

[0045] 2) Coat a layer of photoresist thin film on the damascene material thin film 90, use a mask plate to expose it through ultraviolet light, and only the photoresist 100 pattern remains at the light-shielding area 30 position after development, exposing the damascene material thin film 90 at the pixel area 20 position, as Figure 4 shown.

[0046] 3) Etch the damascene material thin film at the pixel area 20 position to expose the light-emitting unit 40 on the pixel area 20. Subsequently, remove the photoresist pattern at the second part position of the damascene to expose the damascene material thin film at the second part position of the damascene, etch the damascene material thin film at the second part position of the damascene to form the second part 502 of the damascene 50. Finally, remove the photoresist pattern at the first part position of the damascene to form the first part 501 of the damascene 50, as Figure 5 shown.

[0047] 4) Bond the adhesive layer 80 onto the first part 501 of the retaining wall 50, as Figure 6 shown. The material of the adhesive layer 80 can be double-sided tape.

[0048] 5) Bond the piezoelectric functional layer 60 onto the adhesive layer 80, so as to form a transducer chamber 70 between the piezoelectric functional layer 60 and the pixel region 20 located in the first part 501 of the retaining wall 50. The transducer chamber 70 and the piezoelectric functional layer 60 form an ultrasonic transducer unit for ultrasonic gesture recognition, as Figure 1 shown.

[0049] An embodiment of the present invention further provides a display device, including the display substrate of the foregoing embodiment. The display device can be: any product or component with a display function such as a mobile phone, a tablet computer, a television, a monitor, a notebook computer, a digital photo frame, a navigator, etc.

[0050] An embodiment of the present invention further provides a method for manufacturing a display substrate, including:

[0051] Form a pixel region and a light-shielding region surrounding the pixel region on a substrate;

[0052] Form a retaining wall on the light-shielding region, so that the retaining wall surrounds the periphery of at least one of the pixel regions;

[0053] Form a piezoelectric functional layer covering at least one of the pixel regions on the retaining wall. A transducer chamber is formed between the piezoelectric functional layer and at least one of the pixel regions. The transducer chamber and the piezoelectric functional layer form an ultrasonic transducer unit for ultrasonic gesture recognition.

[0054] In the description of the embodiments of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "middle part", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0055] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "mount", "connect", and "couple" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0056] Although the embodiments disclosed in the present invention are as described above, the content described is only an embodiment adopted for facilitating the understanding of the present invention and is not intended to limit the present invention. Any person skilled in the art within the scope of the present invention may make any modifications and changes in the form of implementation and details without departing from the spirit and scope disclosed in the present invention. However, the scope of patent protection of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. A display substrate, characterized in that, it includes a substrate, the substrate includes a pixel region and a light-shielding region surrounding the pixel region, a barrier wall is formed on the light-shielding region, the barrier wall surrounds the periphery of at least one of the pixel regions, a piezoelectric functional layer covering at least one of the pixel regions is formed on the barrier wall, a transducer chamber is formed between the piezoelectric functional layer and at least one of the pixel regions, and the transducer chamber and the piezoelectric functional layer form an ultrasonic transducer unit for ultrasonic gesture recognition; a light-emitting unit is disposed on the pixel region, the barrier wall includes a first portion higher than the light-emitting unit and a second portion lower than the first portion, the first portion surrounds the periphery of at least two of the pixel regions, the second portion is located between at least two adjacent pixel regions within the first portion, and the piezoelectric functional layer is formed on the first portion.

2. The display substrate according to claim 1, characterized in that, the barrier wall is made of a light-shielding material.

3. The display substrate according to claim 1, characterized in that, the transducer chamber includes at least two chambers, the areas of the at least two chambers projected vertically onto the substrate are different, and the at least two chambers are configured to emit ultrasonic waves of different frequency bands.

4. The display substrate according to claim 3, characterized in that, the transducer chamber includes a first chamber, a second chamber and a third chamber, the area of the first chamber projected vertically onto the substrate is larger than the area of the second chamber projected vertically onto the substrate, the area of the second chamber projected vertically onto the substrate is larger than the area of the third chamber projected vertically onto the substrate, the first chamber is configured as a low-frequency chamber, the second chamber is configured as a medium-frequency chamber, and the third chamber is configured as a high-frequency chamber.

5. The display substrate according to claim 1, characterized in that, the piezoelectric functional layer includes a stacked first electrode layer, a second electrode layer and a piezoelectric layer located between the first electrode layer and the second electrode layer, and the first electrode layer is located on the side of the piezoelectric layer close to the substrate.

6. The display substrate according to claim 1, characterized in that, an adhesive layer is provided between the piezoelectric functional layer and the barrier wall.

7. The display substrate according to claim 1, characterized in that, the vertical projection of the transducer chamber onto the substrate is square, rhombic, rectangular or circular.

8. A display device, characterized in that, it includes the display substrate according to any one of claims 1-7.

9. A method for manufacturing a display substrate, characterized in that, it includes: forming a pixel region and a light-shielding region surrounding the pixel region on a substrate; forming a barrier wall on the light-shielding region so that the barrier wall surrounds the periphery of at least one of the pixel regions; wherein, a light-emitting unit is disposed on the pixel region, the barrier wall includes a first portion higher than the light-emitting unit and a second portion lower than the first portion, the first portion surrounds the periphery of at least two of the pixel regions, the second portion is located between at least two adjacent pixel regions within the first portion, and the piezoelectric functional layer is formed on the first portion. A piezoelectric functional layer covering at least one of the pixel regions is formed on the retaining wall, a transducer chamber is formed between the piezoelectric functional layer and at least one of the pixel regions, and the transducer chamber and the piezoelectric functional layer form an ultrasonic transducer unit for ultrasonic gesture recognition.

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