Optical Sensor and Display Panel

Abstract

The light sensor and display panel provided by the embodiment of the present application. The light sensor includes: a photosensitive thin-film transistor and a sensing module. The first electrode of the photosensitive thin-film transistor is electrically connected to a first power supply terminal, and the second electrode of the photosensitive thin-film transistor is electrically connected to a second power supply terminal. The sensing module is electrically connected to the photosensitive thin-film transistor. The sensing module is used for sensing light and generating a corresponding sensing signal, and the photosensitive thin-film transistor is used for outputting a sensing current corresponding to the sensing signal. This light sensor can reduce the difficulty of quantifying and detecting ambient light.

Description

Technical Field

[0001] This application relates to the field of display technologies, and particularly to an optical sensor and a display panel. Background Art

[0002] Liquid crystal displays and organic light-emitting displays are commonly used as the screens of electronic devices such as mobile phones, televisions, and computers due to their advantages of being light, thin, low-power consumption, high brightness, and high image quality. Among them, the electronic device detects the intensity of external light at different positions through multiple optical sensors integrated on the liquid crystal display and the organic light-emitting display.

[0003] Current optical sensors include photosensitive thin-film transistors, read thin-film transistors, capacitors, and operational amplifiers. The photosensitive thin-film transistor is connected to a power supply, and the voltage of the power supply is always higher than the voltage of the capacitor. When the photosensitive thin-film transistor senses light, it leaks electricity, and the charge in the power supply flows through the photosensitive thin-film transistor to the capacitor, increasing the voltage of the capacitor. Thus, the intensity of the external light at the position where the photosensitive thin-film transistor is located can be calculated based on the increased value of the voltage of the capacitor. However, there are often residual charges in the capacitor of this optical sensor, and the amount of residual charges is not known during the initial detection process, resulting in inaccurate initial detection results of the intensity of external light by the optical sensor and a slow response speed, making it difficult to quantitatively detect environmental light by the optical sensor. Summary of the Invention

[0004] An object of the embodiments of this application is to provide an optical sensor and a display panel, and this optical sensor can reduce the difficulty of quantitatively detecting environmental light.

[0005] On the one hand, the embodiments of this application provide an optical sensor, including: a photosensitive thin-film transistor and an induction module. The first electrode of the photosensitive thin-film transistor is electrically connected to a first power supply terminal, and the second electrode of the photosensitive thin-film transistor is electrically connected to a second power supply terminal; the induction module is electrically connected to the photosensitive thin-film transistor. The induction module is used to sense light and generate a corresponding induction signal, and the photosensitive thin-film transistor is used to output an induction current corresponding to the induction signal.

[0006] Optionally, in some embodiments of this application, the induction module includes a photoresistor. One end of the photoresistor is electrically connected to the first power supply terminal, and the other end of the photoresistor is electrically connected to the gate of the photosensitive thin-film transistor.

[0007] Optionally, in some embodiments of this application, the induction module further includes a voltage-dividing resistor. One end of the voltage-dividing resistor is electrically connected to the first power supply terminal, and the other end of the voltage-dividing resistor is electrically connected to the first electrode of the photosensitive thin-film transistor.

[0008] Optionally, in some embodiments of the present application, the voltage dividing resistor includes a variable resistor or a photosensitive resistor.

[0009] Optionally, in some embodiments of the present application, the optical sensor further includes a reading module, the reading module is electrically connected to the first node, the second power supply terminal and the ground terminal, and the reading module is configured to calculate the intensity of the light according to the induced current output by the photosensitive thin film transistor.

[0010] Optionally, in some embodiments of the present application, the reading module includes a first resistor and a reading transistor, one end of the first resistor is electrically connected to the ground terminal through the first node, and the other end of the first resistor is electrically connected to the gate of the reading transistor; the first electrode of the reading transistor is electrically connected to the first node, and the second electrode of the reading transistor is electrically connected to the second power supply terminal.

[0011] Optionally, in some embodiments of the present application, the reading transistor is a photosensitive thin film transistor.

[0012] Optionally, in some embodiments of the present application, the reading module further includes a second resistor, one end of the second resistor is electrically connected to the ground terminal through the first node, and the other end of the second resistor is electrically connected to the first electrode of the reading transistor.

[0013] Optionally, in some embodiments of the present application, the first resistor includes a variable resistor or a photosensitive resistor, and the second resistor is a photosensitive resistor.

[0014] On the other hand, an embodiment of the present application further provides a display panel, including a plurality of pixel units arranged in an array and the optical sensor as described above, and at least one of the pixel units is electrically connected to the optical sensor.

[0015] In the optical sensor and the display panel provided by the embodiment of the present application, the optical sensor includes: a photosensitive thin film transistor and an induction module, the first electrode of the photosensitive thin film transistor is electrically connected to the first power supply terminal, and the second electrode of the photosensitive thin film transistor is electrically connected to the second power supply terminal; the induction module is electrically connected to the photosensitive thin film transistor, the induction module is configured to sense light and generate a corresponding induction signal, and the photosensitive thin film transistor is configured to output an induction current corresponding to the induction signal. By electrically connecting the induction module to the gate of the photosensitive thin film transistor, the induction signal output by the induction module is amplified by the photosensitive thin film transistor, that is, the magnitude of the induction current output by the photosensitive thin film transistor is controlled by the induction module, which is beneficial to reducing the quantization detection difficulty of ambient light and improving the detection accuracy. Description of the Drawings

[0016] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0017] Figure 1 The circuit diagram of the optical sensor provided by the first embodiment of the present application;

[0018] Figure 2 One of the circuit diagrams of the optical sensor provided by the second embodiment of the present application;

[0019] Figure 3 Another circuit diagram of the optical sensor provided by the second embodiment of the present application;

[0020] Figure 4 One of the circuit diagrams of the optical sensor provided by the third embodiment of the present application;

[0021] Figure 5 Another circuit diagram of the optical sensor provided by the third embodiment of the present application;

[0022] Figure 6 One of the circuit diagrams of the optical sensor provided by the fourth embodiment of the present application;

[0023] Figure 7 Another circuit diagram of the optical sensor provided by the fourth embodiment of the present application;

[0024] Figure 8 The structural schematic diagram of the display panel provided by the embodiments of the present application. Detailed implementation manners

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0026] The transistors used in all embodiments of the present application can be photosensitive thin-film transistors or field-effect transistors or other devices with the same characteristics. Since the source and drain of the transistors used here are symmetric, their source and drain can be interchanged. In the embodiments of the present application, to distinguish the two poles of the transistor other than the gate, one of the source and drain is called the first electrode, and the other of the source and drain is called the second electrode. According to the form in the drawings, the middle end of the switching transistor is defined as the gate, the signal input end is the first electrode, and the output end is the second electrode.

[0027] Please refer to Figure 1 , Figure 1 which is the circuit diagram of the optical sensor provided by the first embodiment of the present application. As Figure 1 shown, the embodiment of the present application provides an optical sensor 100, including: a photosensitive thin-film transistor T1 and an induction module 10. The first electrode of the photosensitive thin-film transistor T1 is electrically connected to the first power supply terminal VDD, and the second electrode of the photosensitive thin-film transistor T1 is electrically connected to the second power supply terminal VSS; the induction module 10 is electrically connected to the photosensitive thin-film transistor T1. The induction module 10 is used for photosensing and generating a corresponding induction signal, and the photosensitive thin-film transistor T1 is used for outputting an induction current corresponding to the induction signal.

[0028] In the embodiment of the present application, the induction module 10 includes a photosensitive resistor R1. One end of the photosensitive resistor R1 is electrically connected to the first power supply terminal VDD, and the other end of the photosensitive resistor R1 is electrically connected to the gate of the photosensitive thin-film transistor T1. Among them, the material of the photosensitive resistor R1 includes at least one of monocrystalline silicon, polycrystalline silicon or amorphous silicon. The cross-sectional width of the photosensitive resistor R1 is 3 to 500 microns, and the cross-sectional length of the photosensitive resistor R1 is 1 to 10 microns.

[0029] Further, an external reading device 11 can be connected between the second power supply terminal VSS and the second electrode of the photosensitive thin-film transistor T1. The external reading device 11 can calculate the intensity of external light by obtaining the induction current output by the photosensitive thin-film transistor T1.

[0030] By electrically connecting the induction module 10 to the gate of the photosensitive thin-film transistor T1, the induction signal output by the induction module 10 is amplified by the photosensitive thin-film transistor T1. That is, the magnitude of the induction current output by the photosensitive thin-film transistor T1 is controlled by the induction module 10. By adjusting the magnitude of the second power supply voltage, the strength of the output signal can be adjusted, that is, the gain of the optical sensor can be adjusted, which is beneficial to reducing the quantization detection difficulty of ambient light and improving the detection accuracy.

[0031] As a specific implementation manner of the present application, please refer to Figure 2 and Figure 3 , Figure 2 which is one of the circuit diagrams of the optical sensor provided by the second embodiment of the present application; Figure 3 is the second circuit diagram of the optical sensor provided by the second embodiment of the present application. As Figure 2 and Figure 3 shown, the embodiment of the present application provides an optical sensor 200. The difference between the optical sensor 200 and the optical sensor 100 is that: the optical sensor 200 further includes a voltage-dividing resistor R2. One end of the voltage-dividing resistor R2 is electrically connected to the first power supply terminal VDD, and the other end of the voltage-dividing resistor R2 is electrically connected to the first electrode of the photosensitive thin-film transistor T1.

[0032] In an embodiment of the present application, the optical sensor 200 includes a photosensitive thin-film transistor T1 and a photoresistor R1. The first electrode of the photosensitive thin-film transistor T1 is electrically connected to the first power supply terminal VDD, and the second electrode of the photosensitive thin-film transistor T1 is electrically connected to the second power supply terminal VSS. One end of the photoresistor R1 is electrically connected to the first power supply terminal VDD, and the other end of the photoresistor R1 is electrically connected to the gate of the photosensitive thin-film transistor T1. The photoresistor R1 is used for sensing light and generating a corresponding induction signal, that is, converting the optical signal into an electrical signal; the photosensitive thin-film transistor T1 is used for outputting an induction current corresponding to the induction signal.

[0033] In an embodiment of the present application, the voltage-dividing resistor R2 includes a variable resistor or a photoresistor.

[0034] As shown in Figure 2 , the voltage-dividing resistor R2 is a variable resistor, where the resistance value of the voltage-dividing resistor R2 is matched with the resistance value of the photoresistor R1, so that a potential difference is formed in the voltage between the first electrode of the photosensitive thin-film transistor T1 and the gate of the photosensitive thin-film transistor T1, and further amplify the induction signal.

[0035] As shown in Figure 3 , the voltage-dividing resistor R2 is a photoresistor. By setting the light-receiving areas of the voltage-dividing resistor R2 and the photoresistor R1 to be unequal, that is, the sizes are unequal. Since the resistance values of the photoresistors R1 / R2 change with the intensity of the incident light, at a given voltage, the greater the illuminance, the greater the photocurrent. Therefore, the larger the light-receiving area, the greater the corresponding photocurrent within the same illumination time, so that a potential difference is formed in the voltage between the first electrode of the photosensitive thin-film transistor T1 and the gate of the photosensitive thin-film transistor T1, and further amplify the induction signal.

[0036] Furthermore, an external reading device 11 can be connected between the second power supply terminal VSS and the second electrode of the photosensitive thin-film transistor T1. The external reading device 11 can calculate the intensity of the external light by acquiring the induction current output by the photosensitive thin-film transistor T1. Such a design is beneficial to reducing the quantization detection difficulty of the ambient light, improving the response speed, and enhancing the stability and accuracy of the detection.

[0037] As a specific implementation manner of the present application, please refer to Figure 4 and Figure 5 , Figure 4 is one of the circuit diagrams of the optical sensor provided in the third embodiment of the present application; Figure 5 is the second circuit diagram of the optical sensor provided in the third embodiment of the present application. As shown in Figure 4 and Figure 5As shown in the figure, an embodiment of the present application provides a photosensor 300. The difference between the photosensor 300 and the photosensor 100 is that the photosensor 300 further includes a reading module 20. The reading module 20 is electrically connected to the first node E, the second power supply terminal VSS, and the ground terminal. The reading module 20 is configured to calculate the intensity of light according to the induced current output by the photosensitive thin-film transistor T1.

[0038] In the embodiment of the present application, the reading module 20 includes a first resistor R3 and a reading transistor T2. One end of the first resistor R3 is electrically connected to the ground terminal through the first node E, and the other end of the first resistor R3 is electrically connected to the gate of the reading transistor T2; the first electrode of the reading transistor T2 is electrically connected to the first node E, and the second electrode of the reading transistor T2 is electrically connected to the second power supply terminal VSS.

[0039] In the embodiment of the present application, the photosensor 300 further includes a photosensitive thin-film transistor T1 and a photosensitive resistor R1. The first electrode of the photosensitive thin-film transistor T1 is electrically connected to the first power supply terminal VDD, and the second electrode of the photosensitive thin-film transistor T1 is electrically connected to the second power supply terminal VSS; one end of the photosensitive resistor R1 is electrically connected to the first power supply terminal VDD, and the other end of the photosensitive resistor R1 is electrically connected to the gate of the photosensitive thin-film transistor T1.

[0040] As Figure 4 shown, the first resistor R3 is an adjustable resistor, and the reading transistor T2 is a general thin-film transistor. The sensing module 10 is electrically connected to the reading module 20. Further, an external reading device 11 can be connected between the first node E and the ground terminal. The external reading device 11 can calculate the intensity of external light by obtaining the voltage between the sensing module 10 and the reading module 20. Such a design is beneficial to further reduce the difficulty of quantifying and detecting ambient light and improve the accuracy of detection.

[0041] As Figure 5 shown, the first resistor R3 is an adjustable resistor, and the reading transistor T2 is a photosensitive thin-film transistor. Similarly, the sensing module 10 is electrically connected to the reading module 20. Further, an external reading device 11 can be connected between the first node E and the ground terminal. The external reading device 11 can calculate the intensity of external light by obtaining the voltage between the sensing module 10 and the reading module 20. Such a design is beneficial to further reduce the difficulty of quantifying and detecting ambient light and improve the accuracy of detection.

[0042] As a specific embodiment of the present application, please refer to Figure 6 and Figure 7 , Figure 6 which is one of the circuit diagrams of the photosensor provided in the fourth embodiment of the present application; Figure 7 which is the second circuit diagram of the photosensor provided in the fourth embodiment of the present application. As Figure 6 andFigure 7 As shown in the figure, the embodiment of the present application provides an optical sensor 400, and the optical sensor 400 is an improvement based on the above embodiment: the reading module 20 further includes a second resistor R4. One end of the second resistor R4 is electrically connected to the ground terminal via the first node E, and the other end of the second resistor R4 is electrically connected to the first electrode of the reading transistor T2.

[0043] In the embodiment of the present application, the reading module 20 further includes a first resistor R3 and a reading transistor T2. One end of the first resistor R3 is electrically connected to the ground terminal via the first node E, and the other end of the first resistor R3 is electrically connected to the gate of the reading transistor T2; the first electrode of the reading transistor T2 is electrically connected to the first node E, and the second electrode of the reading transistor T2 is electrically connected to the second power supply terminal VSS.

[0044] In the embodiment of the present application, the optical sensor 400 further includes: a photosensitive thin film transistor T1 and a photosensitive resistor R1. The first electrode of the photosensitive thin film transistor T1 is electrically connected to the first power supply terminal VDD, and the second electrode of the photosensitive thin film transistor T1 is electrically connected to the second power supply terminal VSS; one end of the photosensitive resistor R1 is electrically connected to the first power supply terminal VDD, and the other end of the photosensitive resistor R1 is electrically connected to the gate of the photosensitive thin film transistor T1. The photosensitive resistor R1 is used for photosensing and generating a corresponding induction signal, that is, converting the optical signal into an electrical signal.

[0045] In the embodiment of the present application, the first resistor R3 includes a variable resistor or a photosensitive resistor, and the second resistor R4 is a photosensitive resistor.

[0046] As Figure 6 shown, both the first resistor R3 and the second resistor R4 are photosensitive resistors, and the reading transistor T2 is a photosensitive thin film transistor. Further, an external reading device 11 can be connected between the first node E and the ground terminal. The external reading device 11 can calculate the intensity of the external light by obtaining the voltage between the sensing module 10 and the reading module 20. Such a design is beneficial to further reduce the difficulty of quantifying and detecting ambient light, improve the response speed, and enhance the stability and accuracy of detection.

[0047] As Figure 7As shown, the induction module 10 further includes a voltage-dividing resistor R2. The voltage-dividing resistor R2 is an adjustable resistor. One end of the voltage-dividing resistor R2 is electrically connected to the first power supply terminal VDD, and the other end of the voltage-dividing resistor R2 is electrically connected to the first electrode of the photosensitive thin-film transistor T1. Among them, the resistance value of the voltage-dividing resistor R2 is matched with the resistance value of the photosensitive resistor R1, so that a potential difference is formed between the first electrode of the photosensitive thin-film transistor T1 and the gate of the photosensitive thin-film transistor T1, thereby further amplifying the induction signal. In addition, the first resistor R3 and the second resistor R4 are both photosensitive resistors, and the reading transistor T2 is a photosensitive thin-film transistor. The induction module 10 is electrically connected to the reading module 20. Further, an external reading device 11 can be connected between the first node E and the ground terminal. The external reading device 11 can calculate the intensity of the external light by obtaining the voltage between the induction module 10 and the reading module 20. Such a design is beneficial to further reduce the difficulty of quantitative detection of ambient light, improve the response speed, and improve the stability and accuracy of detection.

[0048] Please refer to Figure 8 , Figure 8 which is a schematic structural diagram of the display panel provided by the embodiment of the present application. As Figure 8 shown, the embodiment of the present application further provides a display panel 500, including a plurality of pixel units 510 arranged in an array and the above light sensor 100, and at least one pixel unit 510 is electrically connected to the light sensor 100.

[0049] In the light sensor and the display panel provided by the present application, the light sensor includes: a photosensitive thin-film transistor T1 and an induction module 10. The first electrode of the photosensitive thin-film transistor T1 is electrically connected to the first power supply terminal VDD, and the second electrode of the photosensitive thin-film transistor T1 is electrically connected to the second power supply terminal VSS; the induction module 10 is electrically connected to the photosensitive thin-film transistor T1. The induction module 10 is used for photosensing and generating a corresponding induction signal, and the photosensitive thin-film transistor T1 is used for outputting an induction current corresponding to the induction signal. By electrically connecting the induction module 10 to the gate of the photosensitive thin-film transistor T1, the induction signal output by the induction module 10 is amplified by the photosensitive thin-film transistor T1, that is, the magnitude of the induction current output by the photosensitive thin-film transistor T1 is controlled by the induction module 10, which is beneficial to reducing the difficulty of quantitative detection of ambient light, improving the response speed, and improving the stability and accuracy of detection.

[0050] The above has introduced in detail an optical sensor and a display panel provided by an embodiment of the present application. Specific examples are used herein to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application. At the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A light sensor, characterized in that, it includes: a photosensitive thin-film transistor, the first electrode of the photosensitive thin-film transistor is electrically connected to a first power supply terminal, and the second electrode of the photosensitive thin-film transistor is electrically connected to a second power supply terminal; a sensing module, the sensing module is electrically connected to the photosensitive thin-film transistor, the sensing module is used for photosensing and generating a corresponding sensing signal, and the photosensitive thin-film transistor is used for outputting a sensing current corresponding to the sensing signal; the sensing module includes a photoresistor (R1), one end of the photoresistor (R1) is electrically connected to the first power supply terminal, and the other end of the photoresistor (R1) is electrically connected to the gate of the photosensitive thin-film transistor; the sensing module further includes a voltage-dividing resistor (R2), one end of the voltage-dividing resistor (R2) is electrically connected to the first power supply terminal, and the other end of the voltage-dividing resistor (R2) is electrically connected to the first electrode of the photosensitive thin-film transistor; the voltage-dividing resistor (R2) is a photoresistor; wherein, the light-receiving area of the voltage-dividing resistor (R2) is not equal to the light-receiving area of the photoresistor (R1); the first electrode of the photosensitive thin-film transistor is a source electrode, and the second electrode of the photosensitive thin-film transistor is a drain electrode.

2. The light sensor according to claim 1, characterized in that, the light sensor further includes a reading module, the reading module is electrically connected to a first node, the second power supply terminal and a ground terminal, and the reading module is used for calculating the intensity of the light according to the sensing current output by the photosensitive thin-film transistor; the reading module includes a first resistor and a reading transistor, one end of the first resistor is electrically connected to the ground terminal through the first node, and the other end of the first resistor is electrically connected to the gate of the reading transistor; the first electrode of the reading transistor is electrically connected to the first node, and the second electrode of the reading transistor is electrically connected to the second power supply terminal; wherein, the first node is the second electrode of the photosensitive thin-film transistor.

3. The light sensor according to claim 2, characterized in that, the reading transistor is a photosensitive thin-film transistor.

4. The light sensor according to claim 3, characterized in that, the reading module further includes a second resistor, one end of the second resistor is electrically connected to the ground terminal through the first node, and the other end of the second resistor is electrically connected to the first electrode of the reading transistor.

5. The light sensor according to claim 4, characterized in that, the first resistor includes a variable resistor or a photoresistor, and the second resistor is a photoresistor.

6. A display panel, characterized in that, it includes a plurality of pixel units arranged in an array and the light sensor according to any one of claims 1-5, and at least one of the pixel units is electrically connected to the light sensor.

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