Display module and display apparatus

Abstract

The present disclosure relates to the technical field of display, and provides a display module and a display apparatus. The display module comprises a measurement circuit and a sampling circuit; the display module comprises a sensing circuit and a processing circuit; the sensing circuit comprises a photosensitive transistor; a drain of the photosensitive transistor is electrically connected to a first voltage end; a source of the photosensitive transistor is electrically connected to a second voltage end; a gate of the photosensitive transistor is electrically connected to a third voltage end; the photosensitive transistor is configured to change the magnitude of a current between the drain and the source on the basis of the intensity of received light, wherein the potential of the first voltage end is greater than the potential of the second voltage end, and the potential of the second voltage end is constant; and the processing circuit is electrically connected to the sensing circuit, and the processing circuit is configured to generate a control signal on the basis of a current and / or potential in the sensing circuit. The accuracy of light intensity measurement is improved.

Description

Display modules and display devices

[0001] Cross-reference to related applications

[0002] This disclosure claims priority to Chinese Patent Application No. 202410705658.6, filed with the Chinese Patent Office on May 31, 2024, entitled “Display Module and Display Device”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of display technology, and more particularly to a display module and a display device. Background Technology

[0004] Some display devices incorporate photosensitive transistors that detect the ambient light intensity, thereby controlling the display device accordingly. However, the light intensity detection in these devices is not precise. Summary of the Invention

[0005] The embodiments of this disclosure provide a display module and display device that improve the accuracy of light intensity detection.

[0006] To achieve the above objectives, the embodiments of this disclosure adopt the following technical solutions:

[0007] On one hand, a display module is provided, the display module including a sensing circuit and a processing circuit. The sensing circuit includes a photosensitive transistor, the drain of the photosensitive transistor being electrically connected to a first voltage terminal, the source of the photosensitive transistor being electrically connected to a second voltage terminal, and the gate of the photosensitive transistor being electrically connected to a third voltage terminal. The photosensitive transistor is configured to change the magnitude of the current between the drain and the source according to the intensity of the received light; wherein the potential of the first voltage terminal is greater than the potential of the second voltage terminal, and the potential of the second voltage terminal is constant; the processing circuit is electrically connected to the sensing circuit, and the processing circuit is configured to generate a control signal based on the current and / or potential in the sensing circuit.

[0008] In some embodiments, the sensing circuit further includes a sampling load electrically connected between the first voltage terminal and the drain of the photosensitive transistor, and the processing circuit is configured to detect the voltage or current of the sampling load.

[0009] In some embodiments, the sensing circuit further includes a first sampling node located between the sampling load and the drain of the photosensitive transistor, and the processing circuit is electrically connected to the first sampling node.

[0010] In some implementations, the processing circuit includes a voltage follower, the positive input of which is electrically connected to the first sampling node.

[0011] In some embodiments, the processing circuit includes a non-inverting amplifier whose positive input terminal is electrically connected to the first sampling node.

[0012] In some embodiments, the sensing circuit further includes a second sampling node located between the sampling load and the first voltage terminal, and the processing circuit is electrically connected to the second sampling node.

[0013] In some embodiments, the processing circuit includes a differential operational amplifier, the positive input terminal of which is electrically connected to the first sampling node, and the negative input terminal of which is electrically connected to the second sampling node.

[0014] In some embodiments, the sampling load includes a sampling resistor, one end of which is electrically connected to the first voltage terminal, and the other end of which is electrically connected to the drain of the photosensitive transistor.

[0015] In some embodiments, the resistance of the sampling resistor is greater than or equal to 1MΩ and less than or equal to 50MΩ.

[0016] In some implementations, the second voltage terminal is grounded.

[0017] In some embodiments, the display module further includes a comparison circuit, which includes a light-shielding transistor, the drain of which is electrically connected to a first voltage terminal, the source of which is electrically connected to a second voltage terminal, and the gate of which is electrically connected to a third voltage terminal; the processing circuit is electrically connected to the comparison circuit, and the processing circuit is further configured to generate a control signal based on the current and / or potential in the sensing circuit and the comparison circuit.

[0018] In some embodiments, the processing circuitry further includes an analog-to-digital converter configured to convert the current and / or potential detected by the sensing circuit and the comparison circuit into digital signals.

[0019] In some embodiments, the display module includes a display panel, a control board, and a flexible circuit board electrically connected between the display panel and the control board. The transistor is disposed on the display panel, and the control board is provided with a power management chip. The source, drain, and gate of the photosensitive transistor are electrically connected to the power management chip through the flexible circuit board.

[0020] On the other hand, a display device is provided, which includes the aforementioned display module.

[0021] In some embodiments, the display device further includes a backlight module, the backlight module including a backlight panel and a driver board electrically connected to the backlight panel, and the output terminal of the processing circuit is electrically connected to the driver board.

[0022] The display module and display device provided in this disclosure increase the photocurrent in the photosensitive transistor when the illumination received by the photosensitive transistor is enhanced. Since the source of the photosensitive transistor is electrically connected to a second voltage terminal with a constant potential, the voltage Vgs between the gate and source of the photosensitive transistor remains constant, and the fundamental current in the photosensitive transistor remains constant. The total current between the drain and source of the photosensitive transistor is equal to the sum of the fundamental current and the photocurrent. Because the fundamental current remains constant, the change in the total current is equal to the change in the photocurrent. Compared with related technologies, the increase in the total current change between the drain and source improves the accuracy of light intensity detection. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 is a front view structural diagram of a display device provided in an embodiment of this disclosure;

[0025] Figure 2 is a schematic diagram of the structure of a display module provided in an embodiment of this disclosure;

[0026] Figure 3 illustrates, for example, the current of a phototransistor as a function of illuminance;

[0027] Figure 4 is a schematic diagram of an ambient light detection circuit in the related technology;

[0028] Figure 5 shows the curve of potential change of acquisition node with illuminance in related technologies;

[0029] Figure 6 illustrates, for example, the relationship between Ids current and Vgs of a phototransistor;

[0030] Figure 7 is a partial structural schematic diagram of an ambient light detection circuit provided in an embodiment of this disclosure;

[0031] Figure 8 is a partial circuit diagram of an ambient light detection circuit provided in an embodiment of this disclosure;

[0032] Figure 9 is a partial circuit diagram of an ambient light detection circuit provided in an embodiment of this disclosure;

[0033] Figure 10 is a partial circuit diagram of an ambient light detection circuit provided in an embodiment of this disclosure;

[0034] Figure 11 is a partial circuit diagram of an ambient light detection circuit provided in an embodiment of this disclosure;

[0035] Figure 12 is a partial circuit diagram of an ambient light detection circuit provided in an embodiment of this disclosure;

[0036] Figure 13 is a partial circuit diagram of an ambient light detection circuit provided in an embodiment of this disclosure.

[0037] Reference numerals: 1000 - Display device; 100 - Display module; 110 - Display panel; 120 - Control board; 130 - Flexible circuit board; 10 - Processing circuit; 20 - Sensing circuit; 30 - Comparison circuit; 21 - Sampling load. Specific Implementation

[0038] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this disclosure.

[0039] In the embodiments of this disclosure, the terms "first," "second," "third," and "fourth" are used to distinguish identical or similar items with essentially the same function and effect, solely for the purpose of clearly describing the technical solutions of the embodiments of this disclosure, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0040] In embodiments of this disclosure, "a plurality of" means two or more, and "at least one" means one or more, unless otherwise expressly and specifically defined.

[0041] In the embodiments of this disclosure, the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this disclosure.

[0042] Figure 1 is a front view structural diagram of a display device provided in an embodiment of this disclosure. As shown in Figure 1, some embodiments of this disclosure provide a display device 1000, which can be any device with display functionality. For example, the display device 1000 can be a mobile phone, wireless device, personal data assistant (PDA), handheld or portable computer, GPS receiver / navigator, camera, MP4 video player, camcorder, game console, watch, clock, calculator, television monitor, flat panel display, computer monitor, automotive display (e.g., odometer display, etc.), navigator, cockpit controller and / or display, camera view display (e.g., display of a rearview camera in a vehicle), electronic photograph, electronic billboard or sign, projector, architectural structure, packaging and aesthetic structure (e.g., display of an image of a piece of jewelry), etc. Figure 1 illustrates the display device 1000 as a computer monitor. The display device 1000 includes a display module 100, through which images are displayed.

[0043] Figure 2 is a schematic diagram of a display module provided in an embodiment of this disclosure. As shown in Figure 2, the display module 100 may include a display panel 110, a control board 120, and a flexible circuit board 130 electrically connected between the display panel 110 and the control board 120.

[0044] Display panel 110 can be a liquid crystal display (LCD), an electroluminescent display panel, or a photoluminescent display panel. When display panel 110 is a liquid crystal display panel, it can be a horizontal electric field type liquid crystal display panel or a vertical electric field type liquid crystal display panel. When display panel 110 is a horizontal electric field type liquid crystal display panel, display panel 110 can be an in-plane switching (IPS) liquid crystal display panel or an advanced super-dimensional switching (ADS) liquid crystal display panel. When display panel 110 is an electroluminescent display panel, it can be an organic light-emitting diode (OLED) display panel or a quantum dot light-emitting diode (QLED) display panel. When display panel 110 is a photoluminescent display panel, it can be a quantum dot photoluminescent display panel. The following explanation uses display panel 110 as an example of a liquid crystal display panel.

[0045] The control board 120 is used to receive image signals and generate signals required by the gate drive circuit and the data drive chip based on the image signals. For example, the control board 120 is a printed circuit board (PCB), and a timing controller is provided on the control board 120. The timing controller receives image signals and generates signals required by the gate drive circuit and the data drive chip.

[0046] The flexible printed circuit board 130 (FPC) electrically connects the control board 120 and the display panel 110. Exemplarily, the flexible printed circuit board 130 is a chip-on-film (COP). For example, a data driver chip is disposed on the flexible printed circuit board 130. Signals generated by the control board 120 are sent to the data driver chip via the flexible printed circuit board 130. The data driver chip generates data signals based on the signals from the control board 120, and these data signals are sent to each sub-pixel within the display panel 110 via the flexible printed circuit board 130.

[0047] The display device 1000 may be equipped with an ambient light detection circuit. The display device 1000 can detect the light intensity of the environment in which it is located through this circuit, and thus control the display device 1000 according to the light intensity. For example, the display device 1000 controls the brightness of the display panel 110 according to the ambient light intensity. When the ambient light intensity is low (indoor, nighttime, or other dark environments), the brightness of the display panel 110 is reduced; when the ambient light intensity is high (outdoor, daytime, or other bright environments), the brightness of the display panel 110 is increased. Of course, the display device 1000 can also perform other operations based on the light intensity, such as controlling the refresh rate and power consumption mode of the display panel 110. This embodiment of the present disclosure does not limit these operations.

[0048] The ambient light detection circuit includes a photosensitive transistor T1, which can be a thin-film transistor (TFT). When the photosensitive transistor T1 operates in the subthreshold region, it exhibits photosensitivity. With the potentials of the source, drain, and gate of the photosensitive transistor T1 remaining constant, the current between the source and drain changes with the light intensity. For example, with the potentials of the source, drain, and gate of the photosensitive transistor T1 remaining constant, an increase in the light intensity received by the photosensitive transistor T1 leads to an increase in the current between the source and drain; conversely, a decrease in the light intensity received by the photosensitive transistor T1 leads to a decrease in the current between the source and drain.

[0049] Figure 3 exemplarily illustrates the current variation curve of a phototransistor T1 with illuminance. Figure 3 shows the case where the drain potential Vd of phototransistor T1 is 5V, the gate potential Vg is 1V, and the source of phototransistor T1 is grounded. The horizontal axis in the figure represents illuminance in LUX, and the vertical axis represents the current Ids between the drain and source in A. As shown in Figure 3, when phototransistor T1 operates in the subthreshold region, the current Ids between the drain and source of phototransistor T1 increases as the illuminance received by phototransistor T1 increases.

[0050] When the potentials of the source, drain, and gate of the phototransistor T1 remain unchanged, the current between the drain and source of the phototransistor T1 when it is not illuminated is the basic current, and the current between the drain and source of the phototransistor T1 when it is illuminated is the total current. The difference between the total current and the basic current is the photocurrent, which is the current generated by the illumination.

[0051] Referring again to Figure 2, the photosensitive transistor T1 can be disposed within the display panel 110. Exemplarily, the display panel 110 can have a display area AA and a non-display area NA connected to the display area AA, with the photosensitive transistor T1 disposed in the non-display area. The non-display area NA can be located on one, two, or three sides of the display area AA, or the non-display area NA can be disposed around the display area AA.

[0052] For example, continuing to refer to Figure 2, the non-display area NA includes sub-regions located on the left and right sides of the display panel 110 and a sub-region located on the lower side of the display panel 110. Gate driving circuits can be disposed in the sub-regions on the left and right sides of the display panel 110, and the sub-region located on the lower side of the display panel 110 can be a fan-out area. Multiple fan-out lines are provided in the fan-out area, and these lines can be electrically connected to the flexible circuit board 130. The photosensitive transistor T1 can be disposed in the fan-out area. Of course, the photosensitive transistor T1 can also be disposed in other areas, as long as it allows the photosensitive transistor T1 to receive ambient light. In this embodiment, only the case where the photosensitive transistor T1 is disposed in the fan-out area is described as an example.

[0053] Figure 4 is a schematic diagram of an ambient light detection circuit in the related art. As shown in Figure 4, the ambient light detection circuit in the related art includes a photosensitive transistor T1, a collection resistor R12, and a collection circuit. The drain of the photosensitive transistor T1 is electrically connected to the DVDD terminal, the source of the photosensitive transistor T1 is electrically connected to the collection node, and the gate of the photosensitive transistor T1 is electrically connected to the VGH terminal. One end of the collection resistor R12 is electrically connected to the collection point, and the other end of the collection resistor R12 is electrically connected to the ground terminal. The collection circuit is electrically connected to the collection node.

[0054] Phototransistor T1 operates in the subthreshold region. As the light intensity received by phototransistor T1 changes, the total current between the DVDD terminal and the ground terminal changes, i.e., the current flowing through the acquisition resistor R12 changes. According to U = I*R, when the current flowing through the acquisition resistor R12 changes, the voltage across the acquisition resistor R12 changes. Since one end of the acquisition resistor R12 is electrically connected to the ground terminal, its potential is constant at zero; therefore, the potential of the acquisition node changes. The acquisition circuit is electrically connected to the acquisition node, and the light intensity received by phototransistor T1 can be determined by detecting the potential of the acquisition node.

[0055] In practical applications, it was found that the potential change detected by the acquisition circuit at the acquisition node was small, resulting in low accuracy in judging light intensity.

[0056] Figure 5 shows the potential of the acquisition node as a function of illuminance in related technologies. The horizontal axis represents illuminance in LUX, and the vertical axis represents the total current Ids between the drain and source in A. Table 1 shows the relationship between the potential of the acquisition node and illuminance. Figure 5 and Table 1 show the case where the potential at the DVDD terminal is 3V, the potential at the VGH terminal is 0.8V, and the acquisition resistor is 10MΩ. As shown in Figure 4 and Table 1, when the illuminance received by the phototransistor T1 is 0, the potential of the acquisition node is 1.15V; as the illuminance received by the phototransistor T1 increases, the potential of the acquisition node continuously increases; when the illuminance received by the phototransistor T1 is 1000 LUX, the potential of the acquisition node is 1.35V. That is, the maximum change in the potential of the acquisition node is 0.2V (1.35V-1.15V), which is relatively small and easily affected by external signal interference.

[0057] Table 1

[0058] Through analysis, the inventors discovered that when the current flowing through the acquisition resistor R12 changes, the potential of the acquisition node changes, and the voltage Vgs between the gate and source of the phototransistor T1 changes. When the voltage Vgs between the gate and source of the phototransistor T1 changes, the total current Ids between the drain and source changes (i.e., the current flowing through the acquisition resistor R12 also changes accordingly), thus reducing the potential change of the acquisition node.

[0059] Figure 6 exemplarily illustrates the relationship between the Ids current and Vgs of a phototransistor T1. The horizontal axis represents Vgs in volts (V), and the vertical axis represents the Ids current in amperes (A). As shown in Figure 6, when the phototransistor T1 operates in the subthreshold region, Vgs and Ids are positively correlated; when Vgs increases, Ids increases, and when Vgs decreases, Ids decreases.

[0060] For example, when the light intensity received by phototransistor T1 increases, the fundamental current between the drain and source remains unchanged, while the photocurrent increases, thus increasing the total current Ids. At this time, the current flowing through the acquisition resistor R12 increases, and the potential of the acquisition node rises. With the gate potential Vg of phototransistor T1 remaining constant, the voltage Vgs between the gate and source of phototransistor T1 decreases after the potential of the acquisition node rises, leading to a decrease in the fundamental current between the drain and source. Although the total current between the drain and source increases, the increase is less than the increase in photocurrent because the decrease in fundamental current partially offsets the increase in photocurrent. Because the change in the total current between the drain and source is small, the overall potential change of the acquisition node is also small.

[0061] Therefore, in this embodiment of the present disclosure, the source potential of the photosensitive transistor T1 is configured to be constant, that is, the voltage Vgs between the gate and the source remains constant, eliminating the change in Ids caused by the change in Vgs.

[0062] Figure 7 is a partial structural schematic diagram of an ambient light detection circuit provided in an embodiment of this disclosure. As shown in Figure 7, the ambient light detection circuit includes a sensing circuit 20 and a processing circuit 10.

[0063] The sensing circuit 20 includes a phototransistor T1. The drain of the phototransistor T1 is electrically connected to a first voltage terminal V1, the source of the phototransistor T1 is electrically connected to a second voltage terminal V2, and the gate of the phototransistor T1 is electrically connected to a third voltage terminal V3. The potential of the first voltage terminal V1 is greater than the potential of the second voltage terminal V2, and the potential of the second voltage terminal V2 is constant.

[0064] This embodiment does not limit the potentials of the first voltage terminal V1, the second voltage terminal V2, and the third voltage terminal V3, as long as the photosensitive transistor T1 operates in the subthreshold region and the potential of the first voltage terminal V1 is greater than the potential of the second voltage terminal V2. For example, the potential of the first voltage terminal V1 is greater than or equal to 1V and less than or equal to 5V, the potential of the second voltage terminal V2 is 0V, and the potential of the third voltage terminal V3 is 0.8V.

[0065] For example, the display module 100 is provided with a power management IC (PMIC), and the first voltage terminal V1 and the third voltage terminal V3 are electrically connected to the power management chip, so that the power management chip provides the required potential to the first voltage terminal V1 and the third voltage terminal V3 respectively.

[0066] For example, when the potential of the second voltage terminal V2 is 0V, the second voltage terminal V2 can be a ground terminal.

[0067] Of course, the potential of the second voltage terminal V2 can also be a potential greater than 0V or a constant potential less than 0V, such as 0.1V, 0.2V, -1V, -5V, etc. In this case, the second voltage terminal V2 can also be electrically connected to the power management chip so that the power management chip provides the required potential to the second voltage terminal V2.

[0068] For example, continuing to refer to FIG2, the power management chip is disposed on the control board 120, and the phototransistor T1 is disposed in the fan-out area. The phototransistor T1 is electrically connected to the power management chip via a connecting line that passes through the flexible circuit board 130. For example, the portion of the connecting line located on the flexible circuit board 130 is a bypass line of the flexible circuit board 130.

[0069] When phototransistor T1 is exposed to light, the current Ids between its drain and source changes, which in turn causes a change in the current in sensing circuit 20. Processing circuit 10 is electrically connected to sensing circuit 20 and is configured to generate a control signal by detecting changes in current and / or potential in sensing circuit 20.

[0070] The control signal is related to the light received by the photosensitive transistor T1.

[0071] The control signal can be a signal used to control other modules. For example, the control signal can be a signal to control the backlight module. When the light received by the phototransistor T1 is strong, the backlight module increases its brightness under the control of the control signal. When the light received by the phototransistor T1 is weak, the backlight module decreases its brightness under the control of the control signal.

[0072] The control signal can also be a signal used to characterize the light intensity received by the photosensitive transistor T1. For example, there is a correspondence between the control signal and the light intensity, and the light intensity received by the photosensitive transistor T1 can be determined according to the control signal, so that the display device 1000 can perform corresponding operations according to the control signal.

[0073] For example, the display panel 110 is a liquid crystal display panel 110. The display device 1000 also includes a backlight module, a backlight panel of the backlight module, and a driver board electrically connected to the backlight panel. The driver board is used to drive the backlight panel to emit light and control the brightness of the backlight panel. The processing circuit 10 is electrically connected to the driver board to provide control signals to the driver board. The driver board can control the brightness of the backlight panel according to the control signals from the processing circuit 10.

[0074] When the illumination received by phototransistor T1 increases, the photocurrent in phototransistor T1 increases. Since the source of phototransistor T1 is electrically connected to the second voltage terminal V2 with a constant potential, the voltage Vgs between the gate and source of phototransistor T1 remains constant, and the fundamental current in phototransistor T1 remains constant. The total current between the drain and source of phototransistor T1 is equal to the sum of the fundamental current and the photocurrent. Because the fundamental current remains constant, the change in the total current equals the change in the photocurrent. Compared with related technologies, this increases the change in the total current between the drain and source, thereby improving the accuracy of light intensity detection.

[0075] Referring again to Figure 7, in some embodiments, the sensing circuit 20 further includes a sampling load 21, which is electrically connected between the first voltage terminal V1 and the drain of the photosensitive transistor T1. When exposed to light, the total current in the photosensitive transistor T1 changes, that is, the current flowing through the sampling load 21 changes, and the voltage applied to the sampling load 21 changes. Therefore, the processing circuit 10 can determine the intensity of light exposure to the photosensitive transistor T1 by detecting the current and / or voltage on the sampling load 21.

[0076] When the illumination received by phototransistor T1 increases, the photocurrent in phototransistor T1 increases. Since the source of phototransistor T1 is electrically connected to the second voltage terminal V2 with a constant potential, the voltage Vgs between the gate and source of phototransistor T1 remains constant, and the fundamental current in phototransistor T1 remains constant. The current flowing through sampling load 21 is equal to the sum of the fundamental current and the photocurrent. Because the fundamental current remains constant, the change in the total current flowing through sampling load 21 equals the change in photocurrent. Compared to related technologies, this increases the change in current flowing through sampling load 21, thereby improving the accuracy of light intensity detection.

[0077] In this embodiment, the type of sampling load 21 is not limited, as long as the voltage applied on the sampling load 21 changes when the current between the first voltage terminal V1 and the second voltage terminal V2 changes.

[0078] Figure 8 is a partial circuit diagram of an ambient light detection circuit provided in an embodiment of this disclosure. As shown in Figure 8, the sampling load 21 may include a sampling resistor R21. When the current flowing through the sampling resistor R21 changes, the voltage across the sampling resistor R21 changes.

[0079] It should be noted that the resistor R22 electrically connected between the source of photosensitive transistor T1 and the second voltage terminal V2 in Figure 8 can be a zero-ohm resistor. This ensures that the source potential of photosensitive transistor T1 remains constant when the current between the first voltage terminal V1 and the second voltage terminal V2 changes. Similarly, the resistor R23 electrically connected between the gate of photosensitive transistor T1 and the third voltage terminal V3 in Figure 8 can also be a zero-ohm resistor. Setting resistors R22 and R23 facilitates testing of the sensing circuit 20.

[0080] When the sampling load 21 includes a sampling resistor R21, the sampling load 21 may include one sampling resistor R21 or multiple sampling resistors R21. When the sampling load 21 includes multiple sampling resistors R21, the multiple sampling resistors R21 can be connected in series or in parallel. In this embodiment, only one sampling resistor R21 is used as an example for illustration.

[0081] Referring again to Figures 7 and 8, the sensing circuit 20 may include a first sampling node ND1, and the processing circuit 10 is electrically connected to the first sampling node ND1, so that the processing node can detect the current and / or potential at the first sampling node ND1, and generate a control signal related to the light intensity based on the current and / or potential at the first sampling node ND1.

[0082] For example, the processing node detects the potential at the first sampling node ND1 and generates a control signal related to the light intensity based on the potential at the first sampling node ND1.

[0083] For example, if the potential of the first voltage terminal V1 is V, the resistance of the sampling resistor R21 is R, and the current between the first voltage terminal V1 and the second voltage terminal V2 is I, then the potential of the first sampling node ND1 is VI*R.

[0084] Since the phototransistor T1 has internal resistance, the circuit between the first voltage terminal V1 and the second voltage terminal V2 can be equivalent to a circuit in series between the sampling resistor R21 and the internal resistance of the phototransistor T1. The sampling resistor R21 and the internal resistance of the phototransistor T1 jointly distribute the voltage between the first voltage terminal V1 and the second voltage terminal V2. To ensure that the potential of the first sampling node ND1 varies within a reasonable range, the resistance value of the sampling resistor R21 can be on the same order of magnitude as the internal resistance of the phototransistor T1. For example, if the internal resistance of the phototransistor T1 is tens of thousands of ohms, then the resistance value of the sampling resistor R21 will also be tens of thousands of ohms; if the internal resistance of the phototransistor T1 is hundreds of thousands of ohms, then the resistance value of the sampling resistor R21 will also be hundreds of thousands of ohms; if the internal resistance of the phototransistor T1 is several megaohms, then the resistance value of the sampling resistor R21 will also be several megaohms.

[0085] For example, the gate potential Vg of the phototransistor T1 is 0.8V, the potential of the first voltage terminal V1 is between 1V and 5V, and the current between the first voltage terminal V1 and the second voltage terminal V2 is between 100nA and 1uA. It can be calculated that the internal resistance of the phototransistor T1 is approximately 1MΩ-50MΩ.

[0086] Therefore, the resistance value of the sampling resistor R21 can be greater than or equal to 1MΩ and less than or equal to 50MΩ. For example, the resistance values ​​of the sampling resistor R21 are 1MΩ, 10MΩ, 15MΩ, 20MΩ, 30MΩ, 40MΩ, 50MΩ, etc.

[0087] Optionally, the resistance of the sampling resistor R21 is greater than the internal resistance of the photosensitive transistor T1. Given that the potential of the first sampling node ND1 is VI*R, increasing the resistance of the sampling resistor R21 can increase the potential change of the first sampling node ND1, thereby making the light intensity detection more accurate.

[0088] Referring again to Figure 8, in some embodiments, the sampling circuit may include a voltage follower. The voltage follower includes a positive input terminal and an output terminal OUT. The positive input terminal is electrically connected to the sampling node, and the output terminal OUT can be electrically connected to other circuits in the processing circuit 10. The potential of the voltage follower output terminal OUT can be considered equal to the potential of the positive input terminal, thereby isolating the first sampling node ND1 from other circuits in the processing circuit 10 and preventing other circuits in the processing circuit 10 from affecting the potential of the first sampling node ND1.

[0089] For example, the positive input terminal of the voltage follower is electrically connected to the first sampling node ND1 through a resistor R24. The resistor R24 ​​can be a zero-ohm resistor, which is convenient for testing the potential of the first sampling node ND1.

[0090] Figure 9 is a partial circuit diagram of an ambient light detection circuit provided in an embodiment of this disclosure. As shown in Figure 9, in some embodiments, the processing circuit 10 may include a non-inverting amplifier, the positive input terminal of which is electrically connected to the first sampling node ND1.

[0091] For example, the positive input terminal of the non-inverting amplifier is electrically connected to the first sampling node ND1 through a resistor R24. The resistor R24 ​​can be a zero-ohm resistor, which facilitates testing the potential of the first sampling node ND1.

[0092] The non-inverting amplifier also includes a voltage divider, which includes resistors R25 and R26 connected in series between the ground terminal and the output terminal OUT. The potential at the positive input terminal is amplified to generate a non-inverting output potential at the output terminal OUT. A portion of the output potential is fed back to the negative input terminal through the voltage divider.

[0093] Figure 10 is a partial circuit diagram of an ambient light detection circuit provided in an embodiment of this disclosure. As shown in Figure 10, in some embodiments, the sensing circuit 20 further includes a second sampling node ND2, which is located between the sampling load 21 and the drain of the photosensitive transistor T1.

[0094] The processing circuit 10 is electrically connected to the first sampling node ND1 and the second sampling node ND2, respectively, so that the processing circuit 10 can collect the current and / or potential of the first sampling node ND1 and the second sampling node ND2, and generate a control signal corresponding to the light intensity based on the current and / or potential of the first sampling node ND1 and the second sampling node ND2.

[0095] Referring again to Figure 10, in some embodiments, the processing circuit 10 may include a differential operational amplifier. The positive input terminal of the differential operational amplifier is electrically connected to the first sampling node ND1, and the negative input terminal is electrically connected to the second sampling node ND2. The differential operational amplifier can amplify the signals of the first sampling node ND1 and the second sampling node ND2, thereby preventing signal interference.

[0096] Figure 11 is a partial circuit diagram of an ambient light detection circuit provided in an embodiment of this disclosure. As shown in Figure 11, the display module 100 may further include a comparison circuit 30, which includes a light-shielding transistor T2. The drain of the light-shielding transistor T2 is electrically connected to a first voltage terminal V1, the source of the light-shielding transistor T2 is electrically connected to a second voltage terminal V2, and the gate of the light-shielding transistor T2 is electrically connected to a third voltage terminal V3. The structure and size of the light-shielding transistor T2 may be the same as those of the photosensitive transistor T1, except that the photosensitive transistor T1 can receive the ambient light of the display device 1000, while the light-shielding transistor T2 cannot receive the ambient light of the display device 1000.

[0097] For example, photosensitive transistor T1 and light-shielding transistor T2 are fabricated using the same process. The side of light-shielding transistor T2 away from the substrate is provided with a light-shielding layer, which can prevent the light from the environment where the display device 1000 is located from shining on the light-shielding transistor T2. The side of photosensitive transistor T1 away from the substrate is transparent, so that the light from the environment where the display device 1000 is located can shine on the photosensitive transistor T1.

[0098] In practical applications, the changes in potential or current of the first sampling node ND1 and the second sampling node ND2 detected by the processing circuit 10 may be caused by light exposure of the photosensitive transistor T1, the influence of temperature on the sensing circuit 20, potential fluctuations at the first voltage terminal V1, the second voltage terminal V2, and the third voltage terminal V3, or even a drift in the threshold voltage of the transistor. Therefore, in order to minimize the influence of non-light exposure factors on the potential and current of the first sampling node ND1 and the second sampling node ND2, the display module 100 also includes a comparison circuit 30. The processing circuit 10 is electrically connected to the comparison circuit 30, and the processing circuit 10 is further configured to generate control signals based on the current and / or potential in the sensing circuit 20 and the comparison circuit 30.

[0099] The connection relationship between processing circuit 10 and comparison circuit 30 can be the same as that between processing circuit 10 and sensing circuit 20. Processing circuit 10 simultaneously detects the potential and / or current of sensing circuit 20 and comparison circuit 30, thereby eliminating the influence of non-lighting factors on the control signal. For example, processing circuit 10 can calculate the difference between the current or potential detected by sensing circuit 20 and the current or potential detected by comparison circuit 30, thereby eliminating the influence of non-lighting factors.

[0100] For example, the circuit composition and connection relationship of the sensing circuit 20 and the comparison circuit 30 are exactly the same.

[0101] Referring again to FIG11, in some embodiments, the display module 100 may further include an analog-to-digital converter configured to convert the current and / or potential detected by the sensing circuit 20 and the comparison circuit 30 into digital signals.

[0102] For example, the analog-to-digital converter includes a first input terminal and a second input terminal. The first input terminal is electrically connected to the sensing circuit 20 through a voltage follower, and the second input terminal is electrically connected to the comparison circuit 30 through another voltage follower. The analog-to-digital converter simultaneously acquires the signal from the sensing circuit 20 and the signal from the comparison circuit 30, and performs differential processing on the signal from the sensing circuit 20 and the signal from the comparison circuit 30.

[0103] The above example illustrates the case where the processing circuit 10 includes both a sensing circuit 20 and a comparison circuit 30, using a voltage follower as an example. When the ambient light detection circuit includes both the sensing circuit 20 and the comparison circuit 30, the processing circuit 10 may also include other units, such as a non-inverting amplifier, a differential operational amplifier, etc.

[0104] Figure 12 is a partial circuit diagram of an ambient light detection circuit provided in an embodiment of this disclosure. Exemplarily, as shown in Figure 12, the analog-to-digital converter includes a first input terminal and a second input terminal. The first input terminal is electrically connected to the sensing circuit 20 through a non-inverting amplifier, and the second input terminal is electrically connected to the comparison circuit 30 through another non-inverting amplifier. The analog-to-digital converter simultaneously acquires the signals from the sensing circuit 20 and the comparison circuit 30, and performs differential processing on the signals from the sensing circuit 20 and the comparison circuit 30.

[0105] Figure 13 is a partial circuit diagram of an ambient light detection circuit provided in an embodiment of this disclosure. Exemplarily, as shown in Figure 13, the analog-to-digital converter includes a first input terminal and a second input terminal. The first input terminal is electrically connected to the sensing circuit 20 via a differential operational amplifier, and the second input terminal is electrically connected to the comparison circuit 30 via another differential operational amplifier. The analog-to-digital converter simultaneously acquires the signals from the sensing circuit 20 and the comparison circuit 30, and performs differential processing on the signals from the sensing circuit 20 and the comparison circuit 30.

[0106] Of course, the structure of the processing circuit 10 is not limited to the structures shown in Figures 11 to 13, as long as the processing circuit 10 can detect the current and / or potential in the sensing circuit 20 and generate a control signal corresponding to the light intensity based on the detected current and / or potential. Continuing to refer to Figure 11, in some embodiments, the processing circuit 10 may further include a processor configured to generate the control signal based on the signal from the analog-to-digital converter.

[0107] The processor can be a microcontroller unit (MCU), which can be a processor dedicated to generating control signals related to light intensity, or a computing device with other functions. For example, the processor can be a timing controller in the display module 100, or it can be a processor in the backlight module used to drive the backlight panel.

[0108] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A display module, characterized by include: A sensing circuit includes a photosensitive transistor, the drain of which is electrically connected to a first voltage terminal, the source of which is electrically connected to a second voltage terminal, and the gate of which is electrically connected to a third voltage terminal. The photosensitive transistor is configured to change the current between the drain and the source according to the intensity of the received light; wherein the potential of the first voltage terminal is greater than the potential of the second voltage terminal, and the potential of the second voltage terminal is constant. A processing circuit electrically connected to the sensing circuit, the processing circuit being configured to generate a control signal based on the current and / or potential in the sensing circuit.

2. The display module of claim 1, wherein, The sensing circuit further includes a sampling load electrically connected between the first voltage terminal and the drain of the photosensitive transistor, and the processing circuit is configured to detect the voltage or current of the sampling load.

3. The display module of claim 2, wherein, The sensing circuit further includes a first sampling node, which is located between the sampling load and the drain of the photosensitive transistor, and the processing circuit is electrically connected to the first sampling node.

4. The display module of claim 3, wherein, The processing circuit includes a voltage follower, the positive input terminal of which is electrically connected to the first sampling node.

5. The display module of claim 3, wherein, The processing circuit includes a non-inverting amplifier, the positive input terminal of which is electrically connected to the first sampling node.

6. The display module of claim 3, wherein, The sensing circuit further includes a second sampling node, which is located between the sampling load and the first voltage terminal, and the processing circuit is electrically connected to the second sampling node.

7. The display module according to claim 6, characterized in that, The processing circuit includes a differential operational amplifier, the positive input terminal of which is electrically connected to the first sampling node, and the negative input terminal of which is electrically connected to the second sampling node.

8. The display module according to claim 2, characterized in that, The sampling load includes a sampling resistor, one end of which is electrically connected to the first voltage terminal, and the other end of which is electrically connected to the drain of the photosensitive transistor.

9. The display module according to claim 8, characterized in that, The resistance of the sampling resistor is greater than or equal to 1MΩ and less than or equal to 50MΩ.

10. The display module according to claim 1, characterized in that, The second voltage terminal is grounded.

11. The display module according to any one of claims 1 to 10, characterized in that, The display module further includes a comparison circuit, which includes a light-shielding transistor. The drain of the light-shielding transistor is electrically connected to a first voltage terminal, the source of the light-shielding transistor is electrically connected to a second voltage terminal, and the gate of the light-shielding transistor is electrically connected to a third voltage terminal. The processing circuit is electrically connected to the comparison circuit, and the processing circuit is further configured to generate a control signal based on the current and / or potential in the sensing circuit and the comparison circuit.

12. The display module according to claim 11, characterized in that, The processing circuit further includes an analog-to-digital converter configured to convert the current and / or potential detected by the sensing circuit and the comparison circuit into digital signals.

13. The display module according to any one of claims 1 to 10, characterized in that, The display module includes a display panel, a control board, and a flexible circuit board electrically connected between the display panel and the control board. The transistor is disposed on the display panel, and the control board is provided with a power management chip. The source, drain, and gate of the photosensitive transistor are electrically connected to the power management chip through the flexible circuit board.

14. A display device, characterized in that, Includes the display module as described in any one of claims 1 to 13.

15. The display device according to claim 14, characterized in that, The display device further includes a backlight module, which includes a backlight panel and a driver board electrically connected to the backlight panel, and the output terminal of the processing circuit is electrically connected to the driver board.

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