Display screens, display modules and electronic devices

Abstract

A display screen, a display module, and an electronic device are disclosed. The display screen includes a display pixel circuit and a controller. The display pixel circuit includes a first display pixel circuit and a second display pixel circuit. During each frame scan time of the display screen, when any one of the multiple current scan lines is located in a non-display area, the controller controls the input voltage parameter of the first display pixel circuit corresponding to the current scan line located in the display area to a first voltage, and the reset current of the photodiode in the first display pixel circuit to a first current value. When all the multiple current scan lines are located in the display area, the controller controls the input voltage parameter of the second display pixel circuit corresponding to the multiple current scan lines to a second voltage, and the reset current of the photodiode in the second display pixel circuit to a second current value. The deviation between the second current value and the first current value is less than a preset threshold. By using this application, the problem of uneven brightness display can be avoided.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a display screen, display module and electronic device. Background Technology

[0002] Currently, users are paying more and more attention to the display effect of electronic devices, and screen contrast ratio is an important indicator for evaluating display effect.

[0003] Existing technology improves screen contrast by repeatedly resetting the anodes of photodiodes in the display pixel circuit within a single scan frame. However, due to the presence of front and rear porch areas during screen driving, during multiple resets of the photodiode anodes in the display pixel circuit, one reset may fall within the front or rear porch area and not actually drive the screen. Therefore, this reset method causes uneven screen brightness. Summary of the Invention

[0004] This application provides a display screen, a display module, and an electronic device, which can effectively avoid the problem of uneven brightness display when the display screen resets the photodiode multiple times during each frame scan time, thereby improving the display effect of the display screen, display module, and electronic device.

[0005] In a first aspect, embodiments of this application provide a display screen, which includes display pixel circuits and a controller. The display pixel circuits are arranged in an array in the display area of ​​the display screen, and each display pixel circuit includes a photodiode, a first display pixel circuit, and a second display pixel circuit. During each frame scan time of the display screen, the controller is configured to: when any one of a plurality of current scan lines is located in a non-display area, control the input voltage parameter of the first display pixel circuit to a first voltage, and the reset current of the photodiode in the first display pixel circuit to a first current value; the first display pixel circuit is the display pixel circuit corresponding to the current scan line located in the display area; when all the current scan lines are located in the display area, control the input voltage parameter of the second display pixel circuit to a second voltage, and the reset current of the photodiode in the second display pixel circuit to a second current value; the deviation between the second current value and the first current value is less than a preset threshold; the second display pixel circuit is the display pixel circuit corresponding to the plurality of current scan lines.

[0006] In this embodiment, since the number of photodiodes that need to be reset when any one of the current scan lines is located in a non-display area is different from the number of photodiodes that need to be reset when all the current scan lines are located in the display area, the deviation between the first current value and the second current value can be made less than a preset threshold by controlling the input voltage parameter value of the first display pixel circuit to be different from the input voltage parameter value of the second display pixel circuit. This effectively avoids the problem of uneven brightness display when the display screen resets the photodiodes multiple times in each frame scan time, thereby improving the display effect of the display screen.

[0007] In conjunction with the first aspect, in a first possible implementation, the display pixel circuit further includes a reset switch and an initial voltage input terminal, the initial voltage input terminal being connected to the anode of the photodiode via the reset switch; the input voltage parameter value of the display pixel circuit is the anode voltage value of the photodiode.

[0008] In this embodiment, the display screen controls the magnitude of the anode voltage of the photodiode and the magnitude of the reset current of the photodiode, thereby making the deviation between the first current value and the second current value less than a preset threshold. This effectively avoids the problem of uneven brightness display when the display screen resets the photodiode multiple times during each frame scan time, thereby improving the display effect of the display screen.

[0009] In conjunction with the first possible implementation of the first aspect, in the second possible implementation, the controller is configured to control the voltage value of the initial voltage input terminal of the first display pixel circuit to a first voltage and control the reset switch of the first display pixel circuit to be turned on when any current scan line in the current scan line is located in a non-display area; and to control the voltage value of the initial voltage input terminal of the second display pixel circuit to a second voltage and control the reset switch of the second display pixel circuit to be turned on when multiple current scan lines are located in the display area.

[0010] In conjunction with the first aspect, in a third possible implementation, the display pixel circuit further includes a reset switch and an initial voltage input terminal, the initial voltage input terminal being connected to the cathode of the photodiode via the reset switch; the input voltage parameter value of the display pixel circuit is the cathode voltage value of the photodiode.

[0011] In this embodiment, the display screen controls the magnitude of the photodiode's cathode voltage and reset current, thereby ensuring that the deviation between the first and second current values ​​is less than a preset threshold. This effectively avoids uneven brightness display when the display screen resets the photodiode multiple times during each frame scan, thus improving the display effect. Furthermore, the display screen offers various methods for controlling the photodiode's reset current, providing high flexibility.

[0012] In conjunction with the third possible implementation of the first aspect, in the fourth possible implementation, the controller is configured to, when any current scan line in the current scan line is located in a non-display area, control the voltage value of the initial voltage input terminal of the first display pixel circuit to be a first voltage and control the reset switch of the first display pixel circuit to be turned on; and when multiple current scan lines are located in the display area, control the voltage value of the initial voltage input terminal of the second display pixel circuit to be a second voltage and control the reset switch of the second display pixel circuit to be turned on.

[0013] In conjunction with the first aspect, in the fifth possible implementation, the display pixel circuit further includes a driving switch, a storage capacitor, a data transmission switch, a data input terminal, and a power supply terminal. The first end of the driving switch is connected to the power supply terminal, the second end of the driving switch is connected to the anode of the photodiode, the control terminal of the driving switch is connected to the data input terminal through the data transmission switch, and the storage capacitor is connected between the first end of the driving switch and the control terminal. The input voltage parameter value of the display pixel circuit is the voltage value of the storage capacitor.

[0014] In this embodiment, the display screen controls the voltage of the storage capacitor to control the reset current of the photodiode, thereby ensuring that the deviation between the first and second current values ​​is less than a preset threshold. This effectively avoids uneven brightness display when the display screen resets the photodiode multiple times during each frame scan, thus improving the display effect. Furthermore, the display screen offers various methods for controlling the reset current of the photodiode, providing high flexibility.

[0015] In conjunction with the fifth possible implementation of the first aspect, in the sixth possible implementation, the controller is configured to control the conduction duration of the data transmission switch in the first display pixel circuit to a first duration and the voltage value of the storage capacitor in the first display pixel circuit to a first voltage when any current scan line in the current scan line is located in a non-display area; and to control the conduction duration of the data transmission switch in the second display pixel circuit to a second duration and the voltage value of the storage capacitor in the second display pixel circuit to a second voltage when multiple current scan lines are located in the display area; and to drive the switch to be in the on state when the voltage value of the storage capacitor is the first voltage or the second voltage.

[0016] In conjunction with the first aspect, in the seventh possible implementation, the display pixel circuit further includes a data transmission switch, a drive switch, a data input terminal, and a power supply terminal, wherein the first terminal of the drive switch is connected to the power supply terminal, the second terminal of the drive switch is connected to the anode of the photodiode, and the control terminal of the drive switch is connected to the data input terminal through the data transmission switch; the input voltage parameter value of the display pixel circuit is the control terminal voltage value of the drive switch.

[0017] In this embodiment, the display screen controls the reset current of the photodiode by controlling the voltage at the control terminal of the driving switch transistor. This ensures that the deviation between the first and second current values ​​is less than a preset threshold, effectively preventing uneven brightness display when the display screen resets the photodiode multiple times during each frame scan, thereby improving the display effect. Furthermore, the display screen offers various methods for controlling the reset current of the photodiode, providing high flexibility.

[0018] In conjunction with the seventh possible implementation of the first aspect, in the eighth possible implementation, the controller is configured to, when any current scan line in the current scan line is located in a non-display area, control the voltage value of the data input terminal of the first display pixel circuit to be a first voltage and control the data transmission switch of the first display pixel circuit to be turned on; when multiple current scan lines are located in the display area, control the voltage value of the data input terminal of the second display pixel circuit to be a second voltage and control the data transmission switch of the second display pixel circuit to be turned on, wherein both the first voltage and the second voltage are greater than the turn-on voltage threshold of the driving switch.

[0019] In conjunction with the first aspect, in the ninth possible implementation, the display pixel circuit further includes a data transmission switch, a drive switch, a data input terminal, and a power supply terminal, wherein the first terminal of the drive switch is connected to the power supply terminal, the second terminal of the drive switch is connected to the anode of the photodiode, and the control terminal of the drive switch is connected to the data input terminal through the data transmission switch; the input voltage parameter value of the display pixel circuit is the control terminal voltage value of the data transmission switch.

[0020] In this embodiment, the display screen controls the reset current of the photodiode by controlling the voltage at the control terminal of the data transmission switch, thereby ensuring that the deviation between the first and second current values ​​is less than a preset threshold. This effectively avoids uneven brightness display when the display screen resets the photodiode multiple times during each frame scan, thus improving the display effect. Furthermore, the display screen offers various methods for controlling the reset current of the photodiode, providing high flexibility.

[0021] In conjunction with the ninth possible implementation of the first aspect, in the tenth possible implementation, both the first voltage and the second voltage are less than the turn-on voltage threshold of the data transmission switch.

[0022] In this embodiment, the display screen adjusts the voltage value at the control terminal of the data transmission switch when it is in the off state, thereby adjusting the current flowing out of the channel of the data transmission switch and thus adjusting the reset current value of the photodiode. Furthermore, since the deviation between the second current value and the first current value is less than a preset threshold, the problem of uneven brightness display when the display screen resets the photodiode multiple times during each frame scan time can be avoided.

[0023] In conjunction with the ninth possible implementation of the first aspect, in the eleventh possible implementation, both the first voltage and the second voltage are greater than the turn-on voltage threshold of the data transmission switch.

[0024] In this embodiment, the display screen adjusts the control terminal voltage of the data transmission switch when it is in the ON state, thereby adjusting the control terminal voltage of the drive switch and thus adjusting the reset current value of the photodiode. Furthermore, since the deviation between the second current value and the first current value is less than a preset threshold, the problem of uneven brightness display when the display screen resets the photodiode multiple times during each frame scan time can be avoided.

[0025] In conjunction with the first to eleventh possible embodiments of the first aspect, in the twelfth possible embodiment, the display pixel circuit further includes a third display pixel circuit and a fourth display pixel circuit. During each frame scan time when the display screen's frame rate is the first frame rate, the controller is configured to, when any one of the multiple current scan lines is located in a non-display area, control the input voltage parameter of the first display pixel circuit to a first voltage; and when all the multiple current scan lines are located in the display area, control the input voltage parameter of the second display pixel circuit to a second voltage. During each frame scan time after the display screen's frame rate switches from the first frame rate to the second frame rate, the controller is further configured to, when any one of the multiple current scan lines is located in a non-display area, control the input voltage parameter of the third display pixel circuit to a first voltage, the reset current of the photodiode in the third display pixel circuit to a first current value, and the third display pixel circuit is the display pixel circuit corresponding to the current scan line located in the display area; and when all the multiple current scan lines are located in the display area, control the input voltage parameter of the fourth display pixel circuit to a second voltage, the reset current of the photodiode in the fourth display pixel circuit to a second current value, and the fourth display pixel circuit is the display pixel circuit corresponding to the multiple current scan lines.

[0026] In this embodiment, the difference between the first current value and the second current value is always less than a preset threshold before and after the frame rate of the display screen is switched. Therefore, regardless of whether the frame rate of the display screen is switched, the problem of uneven brightness display when the display screen resets the photodiode multiple times during each frame scan time can be avoided.

[0027] In conjunction with the twelfth possible implementation of the first aspect, in the thirteenth possible implementation, the first frame rate and the second frame rate are any two preset frame rates from K preset frame rates, where K≥F*x-x+1, the i-th preset frame rate from K preset frame rates is F*x / (x+i-1), i is a positive integer, F is the maximum frame rate of the display screen, and x is the number of multiple current scan lines.

[0028] In this embodiment, the preset frame rate values ​​contained in one set of Gamma of the display screen are more diverse than those contained in one set of Gamma in the prior art. This allows the display screen to complete frame rate switching within the same set of Gamma, thereby avoiding screen brightness and color flickering problems that occur when the display screen switches frame rates between different sets of Gamma, and improving the display effect of the display screen.

[0029] Secondly, embodiments of this application provide a display module, which includes a protective layer, an anti-fingerprint layer, and a display screen provided in any of the first to thirteenth possible embodiments. The protective layer is located on a first surface of the display screen, and the anti-fingerprint layer is located on the surface of the protective layer away from the display screen.

[0030] In this embodiment, since the number of photodiodes that need to be reset when any one of the current scan lines is located in a non-display area is different from the number of photodiodes that need to be reset when all the current scan lines are located in the display area, the deviation between the first current value and the second current value can be made less than a preset threshold by controlling the input voltage parameter value of the first display pixel circuit to be different from the input voltage parameter value of the second display pixel circuit. This effectively avoids the problem of uneven brightness display when the display screen resets the photodiodes multiple times in each frame scan time, thereby improving the display effect of the display module.

[0031] Thirdly, embodiments of this application provide an electronic device, which includes a housing and a display module provided in the third aspect connected to the housing.

[0032] In this embodiment, since the number of photodiodes that need to be reset when any one of the multiple current scan lines is located in a non-display area is different from the number of photodiodes that need to be reset when all the multiple current scan lines are located in the display area, the deviation between the first current value and the second current value can be made less than a preset threshold by controlling the input voltage parameter value of the first display pixel circuit to be different from the input voltage parameter value of the second display pixel circuit. This can effectively avoid the problem of uneven brightness display when the display screen resets the photodiodes multiple times in each frame scan time, thereby improving the screen display effect of the electronic device. Attached Figure Description

[0033] Figure 1 This is a schematic diagram illustrating the application scenario of the electronic device provided in the embodiments of this application;

[0034] Figure 2 This is a schematic diagram of three anode resets of the photodiode within one frame of scanning time provided by existing technology;

[0035] Figure 3 This is a schematic diagram of the structure of the display screen provided in the embodiment of this application;

[0036] Figure 4a This is a schematic diagram of a display pixel circuit provided in an embodiment of this application;

[0037] Figure 4b This is another schematic diagram of the display pixel circuit provided in the embodiments of this application;

[0038] Figure 5 This is a waveform diagram of the input voltage parameters of the display pixel circuit before and after the display frame rate switching provided in the embodiments of this application. Detailed Implementation

[0039] The display screen, display module, and electronic device provided in this application are applicable to electronic devices with displays, such as smartphones, tablets, desktop computers, televisions, printers, and wearable devices, and can be used in the fields of electronic equipment, automobiles, and aerospace. The following example of an electronic device, a smartphone, illustrates the application scenarios of this electronic device.

[0040] See Figure 1 , Figure 1 This is a schematic diagram illustrating an application scenario of the electronic device provided in this application. The electronic device provided in this application is suitable for... Figure 1 The smartphone shown in (a) includes a display module 1 and a housing 2 connected to the display module 1. Figure 1As shown in (b), the display module 1 includes a display screen 11, a protective layer 12, and an anti-fingerprint layer 13. The protective layer 12 is located on the upper surface of the display screen 11 and is used to protect the display screen 11. The anti-fingerprint layer 13 is located on the surface of the protective layer 12 away from the display screen 11 and is used to improve the contact angle of the display module to prevent fingerprint residue on the surface of the display module. The display screen 11 includes n*m display pixel circuits, which are arranged in an n x m row and m column configuration within the display area of ​​the display screen 11. Each display pixel circuit includes a photodiode.

[0041] When the smartphone is working normally, the controller in the display screen 11 controls multiple scanning lines to scan the display screen 1 in a top-down order. During each frame scan time of the display screen 11, when any of the multiple current scanning lines is located in a non-display area, the controller controls the input voltage parameter value of the first display pixel circuit to a first voltage. The first display pixel circuit is the display pixel circuit corresponding to the current scanning line located in the display area among the aforementioned n*m display pixel circuits. During each frame scan time of the display screen 1, when multiple current scanning lines are all located in the display area, the controller controls the input voltage parameter value of the second display pixel circuit to a second voltage. The second display pixel circuit is the display pixel circuit corresponding to the multiple current scanning lines among the aforementioned n*m display pixel circuits, so that the deviation between the reset current value of the photodiode in the first display pixel circuit and the reset current value of the photodiode in the second display pixel circuit is less than a preset threshold. Subsequently, after resetting the photodiode in the display pixel circuit of the current scan line in the display area, the controller 21 controls the display pixel circuit of the current scan line in the display area to write data voltage, and controls the brightness of the photodiode in the display pixel current of the current scan line in the display area based on the data voltage, thereby driving the display screen 11.

[0042] Understandably, since the number of photodiodes that need to be reset when any one of the current scan lines is located in a non-display area is different from the number of photodiodes that need to be reset when all the current scan lines are located in the display area, the input voltage parameter values ​​of the first display pixel circuit and the second display pixel circuit can be controlled to be different, so that the deviation between the reset current value of the photodiode in the first display pixel circuit and the reset current value of the photodiode in the second display pixel circuit is less than a preset threshold. This can effectively avoid the problem of uneven brightness display when the display screen 11 resets the photodiodes multiple times in each frame scan time, thereby improving the display effect of the display screen 11, the display module 1, and the smartphone.

[0043] The above are merely examples of application scenarios for the electronic devices provided in this application, and are not exhaustive. This application does not limit the application scenarios.

[0044] To make it easier to understand, let's first combine... Figure 2 Taking the three anode resets of the photodiode within one frame scan time as an example, the reasons for uneven brightness display on the screen are explained, followed by... Figures 3 to 5 The structure and working principle of the display screen provided in this application are illustrated with examples.

[0045] See Figure 2 , Figure 2 This is a schematic diagram of a photodiode anode reset three times within one scan frame, provided by existing technology. For example... Figure 2 As shown, the driving area during display screen driving includes the display area and the front and rear porch areas. For example, if the display area has 2520 rows and the front and rear porch areas have 60 rows, then the display screen can be considered to be driven according to 2580 rows. Assuming the photodiodes are reset three times with equal time intervals, the time interval between the three resets is the scan time corresponding to 2580 / 3 = 860 rows. When starting to scan the display screen, if... Figure 2 As shown in (a), the first scan line of the three scan lines on the display screen starts scanning downwards simultaneously from the first line in the display area, the second scan line starts scanning downwards from a position 860 lines below the first scan line in the display area, and the third scan line starts scanning downwards from a position 860 lines below the second scan line in the display area. After 800 lines of scanning time, as shown in (a), the display screen displays the first scan line starting scanning downwards from the first line in the display area, the second scan line starting scanning downwards from a position 860 lines below the first scan line in the display area. Figure 2 As shown in (b), the third scan line enters the front and rear porch areas from the display area, and remains within these areas for the next 60 scan lines. Clearly, after the third scan line enters the front and rear porch areas, the number of display pixel circuits requiring reset changes from three to two. Since the reset voltage values ​​of the photodiodes are the same before and after the third scan line enters the front and rear porch areas, but the number of photodiodes requiring reset differs, this results in… Figure 2 The image in (b) shows an example of uneven brightness on the display screen. It should be noted that... Figure 2 This example illustrates the uneven brightness display that occurs when the number of rows in the display pixel circuit that needs to be reset changes from small to large. In reality, the uneven brightness display will still occur when the number of rows in the display pixel circuit that needs to be reset changes from large to small.

[0046] Based on this, this application provides a display screen that controls the input voltage parameter value of the display pixel circuit corresponding to the current scan line in the display area when any one of the multiple current scan lines is located in the front or back porch area to be different from the input voltage parameter value of the display pixel circuit corresponding to the current scan line when all multiple current scan lines are located in the display area. This avoids the problem of uneven brightness display when the display screen resets the photodiode multiple times during each frame scan time.

[0047] See Figure 3 , Figure 3 This is a schematic diagram of the structure of the display screen provided in an embodiment of this application. For example... Figure 3 As shown, the display screen 11 includes a controller 21 and display pixel circuits. The number of display pixel circuits is n*m, and each n*m display pixel circuit corresponds to... Figure 3 The display pixel circuits shown are 111, ..., 11m; ...; 1j1, ..., 1jm; ...; 1n1, ..., 1nm. n*m display pixel circuits are arranged in an array within the display area of ​​the display screen 11. For example, the n*m ​​display pixel circuits are arranged in an n-row, m-column configuration within the display area of ​​the display screen 11. Each display pixel circuit includes a photodiode.

[0048] In one embodiment, after the display screen 11 starts operating, the controller 21 controls multiple scan lines to begin scanning the display screen 11 in a top-to-bottom order. During each frame scan of the display screen 11, when any of the multiple current scan lines is located in a non-display area, that is, when the controller 21... Figure 3 During the T2 time period shown, the input voltage parameter Vin of the first display pixel circuit is controlled to be the first voltage V1, so that the reset current value of the photodiode of the first display pixel circuit is the first current value. The driving area of ​​the display screen 11 includes the display area and the non-display area. The non-display area can be the front and rear porch areas, which do not contain display pixel circuits and are not used for screen display. The first display pixel circuit is the display pixel circuit corresponding to the current scan line in the display area among the aforementioned n*m display pixel circuits. The controller 21 also operates when multiple current scan lines are all in the display area, i.e., the controller 21 is still... Figure 3During the T1 time period shown, the input voltage parameter Vin of the second display pixel circuit is controlled to be the second voltage V2, so that the reset current value of the photodiode of the second display pixel circuit is the second current value. The second display pixel circuit refers to the display pixel circuit corresponding to multiple current scan lines among the aforementioned n*m display pixel circuits, and the deviation between the second current value and the first current value is less than a preset threshold. Furthermore, the display screen 11 provided in this application achieves multiple resets of the photodiode within each frame scan time by controlling the number of times the photodiode is reset and the frame rate of the display screen 11 within each frame scan time using two separate circuits. The number of multiple current scan lines within each frame scan time corresponds to the number of times the anode of the photodiode in the display pixel circuit is reset within each frame scan time. For example, when the number of multiple current scan lines is 3, it means that the controller 21 resets the anode of the photodiode 3 times within each frame scan time.

[0049] It should be noted that as the display pixel circuit structure changes, the magnitude relationship between the first voltage and the second voltage will also change, such as the second voltage becoming greater than the first voltage. Therefore, this application only limits the deviation between the first current value and the second current value to be less than a preset threshold, without imposing any restrictions on the magnitude relationship between the first voltage and the second voltage.

[0050] In this embodiment, since the number of photodiodes that need to be reset when any one of the multiple current scan lines is located in a non-display area is different from the number of photodiodes that need to be reset when all the multiple current scan lines are located in the display area, the input voltage parameter value of the first display pixel circuit and the input voltage parameter value of the second display pixel circuit can be controlled to be different, so that the deviation between the reset current value of the photodiode in the first display pixel circuit and the reset current value of the photodiode in the second display pixel circuit is less than a preset threshold. This can effectively avoid the problem of uneven brightness display when the display screen 11 resets the photodiodes multiple times in each frame scan time, thereby improving the display effect of the display screen 11.

[0051] Since the circuit structures of each display pixel circuit in the display screen 11 are the same, the structure of the display pixel circuit and the working principle of the display screen will be introduced below, taking the display pixel circuit 111 as an example.

[0052] Please see also Figure 4a , Figure 4a This is a schematic diagram of a display pixel circuit provided in an embodiment of this application. Figure 4aAs shown, the display pixel circuit 111 includes a photodiode PD, a reset switch RTFT, a drive switch DTFT, a data transmission switch STFT, a storage capacitor Cst, an initial voltage input terminal int, a data input terminal data, a power supply terminal ELVDD, and a power supply terminal ELVSS. Specifically, the anode of the photodiode PD is connected to the initial voltage input terminal int via the reset switch RTFT. The source and drain of the reset switch RTFT are connected to the anode of the photodiode PD and the initial voltage input terminal int, respectively. The cathode of the photodiode PD is connected to the power supply terminal ELVSS. The source of the drive switch DTFT is connected to the power supply terminal ELVDD, and the drain of the drive switch DTFT is connected to the anode of the photodiode PD. The source of the data transmission switch STFT is connected to the data input terminal data, and the drain of the data transmission switch STFT is connected to the gate of the drive switch DTFT. The storage capacitor Cst is connected between the source and gate of the drive switch DTFT. The initial voltage input terminal int, the data input terminal data, the power supply terminal ELVDD, and the power supply terminal ELVSS are connected to voltages Vint, Vdata, VDD, and VSS, respectively.

[0053] In this application, any one of the reset switch RTFT, drive switch DTFT, and data transmission switch STFT can be a low-temperature polysilicon-thin film transistor (LTPS-TFT), an oxide TFT, or a hybrid of LTPS-TFT and oxide TFT. Because the source and drain of an oxide TFT are symmetrical, the source and drain of any of the switches in this application can be interchanged when connecting them. For example, the drain and source of the reset switch RTFT are connected to the anode of the photodiode PD and the initial voltage input terminal int, respectively.

[0054] In one embodiment, during each frame scan time of the display screen 11, when any one of the multiple current scan lines is located in a non-display area, the controller 21 controls the input voltage parameter value of the first display pixel circuit to a first voltage, wherein the first display pixel circuit is the display pixel circuit corresponding to the current scan line located in the display area among the aforementioned n*m display pixel circuits. The controller 21 also controls the input voltage parameter value of the second display pixel circuit to a second voltage when all multiple current scan lines are located in the display area, wherein the second display pixel circuit is the display pixel circuit corresponding to the multiple current scan lines among the aforementioned n*m display pixel circuits. Furthermore, the deviation between the reset current value of the photodiode in the first display pixel circuit and the reset current value of the photodiode in the second display pixel circuit is less than a preset threshold. The input voltage parameter value of the display pixel circuit includes at least one of the following: the anode voltage value of the photodiode PD, the cathode voltage value of the photodiode PD, the voltage value of the storage capacitor Cst, the gate voltage value of the driving switch transistor DTFT, and the gate voltage value of the data switch transistor STFT.

[0055] In an alternative embodiment, the input voltage parameter value of the display pixel circuit is the anode voltage value of the photodiode PD.

[0056] Specifically, during each frame scan time of the display screen 11, when any of the multiple current scan lines is located in the front and rear porch areas, the controller 21 controls the voltage of the initial voltage input terminal int in the first display pixel circuit to be a first voltage, and controls the reset switch RDTD of the first display pixel circuit to be turned on, so that the anode voltage of the photodiode PD of the first display pixel circuit is the first voltage, and the reset current of the photodiode PD is the first current value when the anode voltage of the photodiode PD is the first voltage. When the anode voltage of the photodiode PD is the first voltage, the controller 21 also controls the voltage of the initial voltage input terminal int in the second display pixel voltage to be a second voltage, and controls the reset switch RTFT of the second display pixel circuit to be turned on, so that the anode voltage of the photodiode PD of the second display pixel circuit is the second voltage, and the reset current of the photodiode PD is the second current value when the anode voltage of the photodiode PD is the second voltage, and the deviation between the second current value and the first current value is greater than a preset deviation. This avoids the problem of uneven brightness display when the display screen 11 resets the photodiode PD multiple times during each frame scan time.

[0057] In another alternative embodiment, the input voltage parameter value of the display pixel circuit is the voltage value of the storage capacitor Cst.

[0058] During each frame scan of the display screen 11, when any of the multiple current scan lines is located in the front and rear porch areas, the controller 21 controls the data transmission switch STFT of the first display pixel circuit to be on for a first duration, thereby charging the storage capacitor Cst to a first voltage value. When the voltage of the storage capacitor Cst is the first voltage value, the switch DTFT is driven to be on, and the reset current of the photodiode is a first current value. When multiple current scan lines are all located in the display area, the controller 21 controls the data transmission switch STFT of the second display pixel circuit to be on for a second duration, thereby charging the storage capacitor Cst to a second voltage value. When the voltage of the storage capacitor Cst is the second voltage value, the switch DTFT is driven to be on, and the reset current of the photodiode is a second current value. Furthermore, the deviation between the second current value and the first current value is less than a preset threshold. This avoids the problem of uneven brightness display when the display screen 11 resets the photodiode PD multiple times during each frame scan.

[0059] In another alternative embodiment, the input voltage parameter value of the display pixel circuit is the gate voltage value of the driving switch transistor DTFT.

[0060] During each frame scan time of the display screen 11, when any of the multiple current scan lines is located in the front and rear porch areas, the controller 21 controls the voltage of the data input terminal (data) of the first display pixel circuit to a first voltage, and controls the data transmission switch (STFT) of the first display pixel circuit to be turned on, so that the gate voltage of the driving switch (DTFT) in the first display pixel circuit is the first voltage. When the gate voltage of the driving switch (DTFT) is the first voltage, the reset current of the photodiode (PD) is the first current value. When multiple current scan lines are all located in the display area, the controller 21 controls the voltage of the data input terminal (data) of the second display pixel circuit to a second voltage, and controls the data transmission switch (STFT) of the second display pixel circuit to be turned on, so that the gate voltage of the driving switch (DTFT) of the second display pixel circuit is the second voltage. When the gate voltage of the driving switch (DTFT) is the second voltage, the reset current of the photodiode (PD) is the second current value, and the deviation between the second current value and the first current value is less than a preset threshold. This avoids the problem of uneven brightness display when the display screen 11 resets the photodiode (PD) multiple times during each frame scan time.

[0061] In another alternative embodiment, the input voltage parameter value of the display pixel circuit is the gate voltage value of the data transmission switch transistor STFT.

[0062] Specifically, during each frame scan time of the display screen 11, when any of the multiple current scan lines is located in the front and rear porch areas, the controller 21 controls the gate voltage of the data transmission switch STFT of the first display pixel circuit to be a first voltage, which is less than the on-state voltage threshold of the data transmission switch STFT. When the control terminal voltage of the data transmission switch STFT is the first voltage, the reset current of the photodiode is the first current value. When all the multiple current scan lines are located in the display area, the controller 21 controls the gate voltage of the data transmission switch STFT of the second display pixel circuit to be a second voltage, which is less than the on-state voltage threshold of the data transmission switch STFT. When the off-state voltage of the data transmission switch STFT is the second voltage, the reset current of the photodiode is the second current value, and the deviation between the second current value and the first current value is less than a preset threshold. It can be understood that the display screen 11 adjusts the magnitude of the current flowing out of the channel of the data transmission switch STFT by adjusting the gate voltage of the data transmission switch STFT when it is in the off state, thereby adjusting the magnitude of the reset current of the photodiode PD. Furthermore, since the deviation between the second current value and the first current value is less than the preset threshold, the problem of uneven brightness display can be avoided when the display screen 11 resets the photodiode PD multiple times during each frame scan time.

[0063] Optionally, during each frame scan time of the display screen 11, when any of the multiple current scan lines is located in the front and rear porch areas, the controller 21 controls the gate voltage of the data transmission switch STFT of the first display pixel circuit to be a first voltage, which is greater than the on-state voltage threshold of the data transmission switch STFT. When the gate voltage of the data transmission switch STFT is the first voltage, the reset current of the photodiode is a first current value. When all the multiple current scan lines are located in the display area, the controller 21 controls the gate voltage of the data transmission switch STFT of the second display pixel circuit to be a second voltage, which is greater than the on-state voltage threshold of the data transmission switch STFT. When the off-state voltage of the data transmission switch STFT is the second voltage, the reset current of the photodiode is a second current value, and the deviation between the second current value and the first current value is less than a preset threshold. It can be understood that the display screen 11 adjusts the gate voltage of the driving switch DTFT by adjusting the gate voltage of the data transmission switch STFT when it is in the on state, thereby adjusting the reset current of the photodiode PD. Furthermore, since the deviation between the second current value and the first current value is less than the preset threshold, the problem of uneven brightness display can be avoided when the display screen 11 resets the photodiode PD multiple times during each frame scan time.

[0064] In another alternative embodiment, the input voltage parameter value of the display pixel circuit is the cathode voltage value of the photodiode PD.

[0065] Optional, Figure 4a The reset switch transistor RTFT shown can also be connected to the cathode of the photodiode PD. Please refer to [link to documentation] for details. Figure 4b The display pixel circuit is shown. (As shown in the image.) Figure 4b As shown, the cathode of the photodiode PD is connected to the initial voltage input terminal int via the reset switch transistor RTFT. Specifically, the source and drain of the reset switch transistor RTFT are connected to the cathode of the photodiode PD and the initial voltage input terminal int, respectively.

[0066] During each frame scan time of the display screen 11, when any of the multiple current scan lines is located in the front and rear porch areas, the controller 21 controls the voltage of the initial voltage input terminal int in the first display pixel circuit to be a first voltage, and controls the reset switch RDTD of the first display pixel circuit to be turned on, so that the cathode voltage of the photodiode PD of the first display pixel circuit is the first voltage, and when the anode voltage of the photodiode PD is the first voltage, the reset current of the photodiode PD is the first current value. When multiple current scan lines are all located in the display area, the controller 21 controls the voltage of the initial voltage input terminal int in the second display pixel circuit to be a second voltage, and controls the reset switch RTFT of the second display pixel circuit to be turned on, so that the cathode voltage of the photodiode PD of the second display pixel circuit is the second voltage, and when the anode voltage of the photodiode PD is the second voltage, the reset current of the photodiode PD is the second current value, and the deviation between the second current value and the first current value is greater than a preset deviation. Therefore, the problem of uneven brightness display when the display screen 11 resets the photodiode PD multiple times during each frame scan time can be avoided.

[0067] Furthermore, the display screen 11 can also achieve seamless switching between high and low frame rates by resetting the photodiode multiple times during each frame scan time, avoiding screen brightness and color flickering problems when switching frame rates between different Gamma levels.

[0068] During each frame scan of the display screen 11 at the first frame rate, when any one of the multiple current scan lines is located in the non-display area, the controller 21 controls the input voltage parameter of the first display pixel circuit to be a first voltage, and when all the multiple current scan lines are located in the display area, it controls the input voltage parameter of the second display pixel circuit to be a second voltage.

[0069] Subsequently, controller 21 controls the frame rate of display screen 11 to switch from a first frame rate to a second frame rate. During each frame scan time after the frame rate switch, when any of the multiple current scan lines is located in a non-display area, controller 21 controls the input voltage parameter of the third display pixel circuit to a first voltage, so that the reset current of the photodiode in the third display pixel circuit is a first current value. The third display pixel circuit is the display pixel circuit corresponding to the current scan line located in the display area among the aforementioned n*m display pixel circuits. When multiple current scan lines are all located in the display area, controller 21 also controls the input voltage parameter of the fourth display pixel circuit to a second voltage, so that the reset current of the photodiode in the fourth display pixel circuit is a second current value. The fourth display pixel circuit is the display pixel circuit corresponding to the multiple current scan lines among the aforementioned n*m display pixel circuits. For the specific control method of the input voltage parameter value of the display pixel circuit during each frame scan time before and after the frame rate switch, please refer to the description of the above embodiment; it will not be repeated here.

[0070] Wherein, the first frame rate and the second frame rate are any two preset frame rates from K preset frame rates, K ≥ F*x - x + 1, the i-th preset frame rate among the K preset frame rates is F*x / (x + i - 1), i is a positive integer, F is the maximum frame rate of the display screen 11, and x is the number of multiple current scan lines. It can be understood that the K preset frame rates are the frame rates contained within a set of Gamma. Since i is a positive integer, the number of frame rates that can be implemented within a set of Gamma provided in this application can be infinitely large.

[0071] For example, assuming the maximum frame rate F of display screen 11 is 120Hz, and the number of times the photodiode is reset during each frame scan time is 3, that is, the number of multiple current scan lines during each frame scan time is 3, then a set of Gammas of display screen 11 contains at least 358 preset frame rates of 120*3 / (3+1-1) = 120Hz, 120*3 / (3+2-1) = 90Hz, 120*3 / (3+3-1) = 72Hz, 120*3 / (3+4-1) = 60Hz, 120*3 / (3+5-1) = 51.4Hz, ..., 120*3 / (3+358-1) = 1Hz. See details. Figure 5 , Figure 5 This is a waveform diagram illustrating the input voltage parameters of the display pixel circuit before and after the display frame rate switching provided in this application embodiment. For example... Figure 5 As shown, the frame rate of display screen 11 can be any one of 120Hz, 90Hz, 72Hz, 60Hz, ..., 1Hz. When the frame rate of display screen 11 is 120Hz, the three working cycles T of display screen 11 constitute one frame scan time when the frame rate of display screen 11 is 120Hz, that is... Figure 5 The diagram shows a 1-frame. One working cycle T of the display screen 11 is defined as T1 + T2, where T1 represents the time period when all three current scan lines of the display screen 11 are within the display area, and T2 represents the time period when any one of the three current scan lines of the display screen 11 is within the front or back porch area. When the frame rate of the display screen 11 is 90Hz, four working cycles T constitute one frame of the display screen 11's scanning time; when the frame rate of the display screen 11 is 72Hz, five working cycles T constitute one frame of the display screen 11's scanning time; and when the frame rate of the display screen 11 is 60Hz, six working cycles T constitute one frame of the display screen 11's scanning time.

[0072] Furthermore, assuming the first frame rate is 120Hz, the second frame rate is 90Hz, and the frame rate of display screen 11 is 120Hz during the time period t1 to t7, and the frame rate of display screen 11 switches from 120Hz to 90Hz after time t7, then during the time period t1 to t2, i.e., the time period corresponding to when all three current scan lines of display screen 11 are in the display area, controller 21 controls the input voltage parameter of the second display pixel circuit to be the second voltage V2. During the time period t2 to t3, i.e., the time period corresponding to when any one of the three current scan lines of display screen 11 is in the display area, controller 21 controls the input voltage parameter of the first display pixel circuit to be the first voltage V1. ... During the time period t6 to t7, i.e., the time period corresponding to when any one of the three current scan lines of display screen 11 is in the display area, controller 21 controls the input voltage parameter of the first display pixel circuit to be the first voltage V1. After time t7, the frame rate of display screen 11 switches from 120Hz to 90Hz. During the time period from t7 to t8, which corresponds to the time period when all three current scan lines of display screen 11 are in the display area, controller 21 controls the input voltage parameter value of the fourth display pixel circuit to be the second voltage V2. During the time period from t8 to t9, which corresponds to the time period when any one of the three current scan lines of display screen 11 is in the display area, controller 21 controls the input voltage parameter value of the third display pixel circuit to be the first voltage V1.

[0073] Based on this, it can be seen that the preset frame rate values ​​contained in a set of Gamma values ​​for display screen 11 are more diverse than those contained in a set of Gamma values ​​in the prior art. For example, assuming the maximum frame rate of display screen 11 is 120Hz, then a set of Gamma values ​​in the prior art includes frame rates of 120Hz, 60Hz, 40Hz, 30Hz, 24Hz, 20Hz, ..., 1Hz. Obviously, a set of Gamma values ​​in the prior art does not include frame rates such as 90Hz and 72Hz. Furthermore, based on a set of Gamma values ​​in the prior art, if the frame rate of display screen 11 needs to switch from 120Hz to 90Hz, the control timing output from the driving circuit to the display pixel circuit will change. This requires switching from a set of Gamma values ​​containing 120Hz to another set of Gamma values ​​containing 72Hz, which will cause flickering in the brightness and color of display screen 11. The display screen 11 in this application can provide a set of Gamma values ​​with more diverse preset frame rate values, so that the display screen 11 can complete frame rate switching within the same set of Gamma values, thereby avoiding the problem of screen brightness and color flicker when the display screen 11 switches frame rates between different sets of Gamma values, and improving the display effect of the display screen 11.

[0074] based on Figure 3 The display screen 11 shown, and Figure 4a or Figure 4b The present application also provides a display module, which includes a display screen 11, a protective layer, and an anti-fingerprint layer. The protective layer is located on the upper surface of the display screen 11 to protect it. The anti-fingerprint layer is located on the surface of the protective layer away from the display screen 11 to improve the contact angle of the display module and prevent fingerprint residue on the surface of the display module. For the specific structure of the display module, please refer to [link to relevant documentation]. Figure 1 The structural schematic diagram of display module 1 shown in (b) is not described in detail here. The display module can also be stacked with additional layers according to actual needs to meet different application scenarios. For example, the display module can also include an antistatic layer, which is located between the anti-fingerprint layer and the protective layer, and is used to reduce the triboelectric static electricity generated on the surface of the display module.

[0075] In this embodiment, since the number of photodiodes that need to be reset when any one of the current scan lines is located in a non-display area is different from the number of photodiodes that need to be reset when all the current scan lines are located in the display area, the input voltage parameter values ​​of the first display pixel circuit and the second display pixel circuit can be controlled to be different, so that the deviation between the reset current value of the photodiode in the first display pixel circuit and the reset current value of the photodiode in the second display pixel circuit is less than a preset threshold. This can effectively avoid the problem of uneven brightness display when the display screen 11 resets the photodiodes multiple times in each frame scan time, thereby improving the display effect of the display module.

[0076] Based on the display module in the above embodiments, this application also provides an electronic device, which includes a display module and a housing connected to the display module. The specific structure of the electronic device can be found here. Figure 1 The diagram shown in (a) is a schematic diagram of the structure of a smartphone, which will not be described in detail here.

[0077] In this embodiment, since the number of photodiodes that need to be reset when any one of the multiple current scan lines is located in a non-display area is different from the number of photodiodes that need to be reset when all the multiple current scan lines are located in the display area, the input voltage parameter value of the first display pixel circuit and the input voltage parameter value of the second display pixel circuit can be controlled to be different, so that the deviation between the reset current value of the photodiode in the first display pixel circuit and the reset current value of the photodiode in the second display pixel circuit is less than a preset threshold. This can effectively avoid the problem of uneven brightness display when the display screen 11 resets the photodiodes multiple times in each frame scan time, thereby improving the screen display effect of the electronic device.

[0078] The above are merely specific embodiments of this application, but the scope of protection of this application 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 application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A display screen, characterized in that, The display screen includes a display pixel circuit and a controller, wherein: The display pixel circuits are arranged in an array in the display area of ​​the display screen. The display pixel circuits include photodiodes and include a first display pixel circuit and a second display pixel circuit. During each frame scan time of the display screen, the controller is configured to, when any one of the multiple current scan lines is located in a non-display area, control the input voltage parameter of the first display pixel circuit to a first voltage, the reset current value of the photodiode in the first display pixel circuit to a first current value, and the first display pixel circuit is the display pixel circuit corresponding to the current scan line located in the display area; when all the multiple current scan lines are located in the display area, control the input voltage parameter of the second display pixel circuit to a second voltage, the reset current value of the photodiode in the second display pixel circuit to a second current value, the deviation between the second current value and the first current value being less than a preset threshold, and the second display pixel circuit being the display pixel circuit corresponding to the multiple current scan lines.

2. The display screen according to claim 1, characterized in that, The display pixel circuit also includes a reset switch and an initial voltage input terminal, the initial voltage input terminal being connected to the anode of the photodiode through the reset switch; the input voltage parameter value of the display pixel circuit is the anode voltage value of the photodiode.

3. The display screen according to claim 2, characterized in that, The controller is configured to, when any one of the current scan lines is located in the non-display area, control the voltage of the initial voltage input terminal of the first display pixel circuit to be the first voltage and control the reset switch of the first display pixel circuit to be turned on; and when all of the multiple current scan lines are located in the display area, control the voltage of the initial voltage input terminal of the second display pixel circuit to be the second voltage and control the reset switch of the second display pixel circuit to be turned on.

4. The display screen according to claim 1, characterized in that, The display pixel circuit also includes a reset switch and an initial voltage input terminal. The initial voltage input terminal is connected to the cathode of the photodiode through the reset switch. The input voltage parameter value of the display pixel circuit is the cathode voltage value of the photodiode.

5. The display screen according to claim 4, characterized in that, The controller is configured to, when any one of the current scan lines is located in the non-display area, control the voltage of the initial voltage input terminal of the first display pixel circuit to be the first voltage and control the reset switch of the first display pixel circuit to be turned on; and when all of the multiple current scan lines are located in the display area, control the voltage of the initial voltage input terminal of the second display pixel circuit to be the second voltage and control the reset switch of the second display pixel circuit to be turned on.

6. The display screen according to claim 1, characterized in that, The display pixel circuit further includes a driving switch transistor, a storage capacitor, a data transmission switch transistor, a data input terminal, and a power supply terminal. The first end of the driving switch transistor is connected to the power supply terminal, the second end of the driving switch transistor is connected to the anode of the photodiode, the control terminal of the driving switch transistor is connected to the data input terminal through the data transmission switch transistor, and the storage capacitor is connected between the first end of the driving switch transistor and the control terminal. The input voltage parameter value of the display pixel circuit is the voltage value of the storage capacitor.

7. The display screen according to claim 6, characterized in that, The controller is configured to, when any current scan line in the current scan line is located in the non-display area, control the conduction duration of the data transmission switch in the first display pixel circuit to be a first duration, and the voltage value of the storage capacitor in the first display pixel circuit is the first voltage; when all of the current scan lines are located in the display area, control the conduction duration of the data transmission switch in the second display pixel circuit to be a second duration, and the voltage value of the storage capacitor in the second display pixel circuit is the second voltage; when the voltage value of the storage capacitor is the first voltage or the second voltage, the driving switch is in the on state.

8. The display screen according to claim 1, characterized in that, The display pixel circuit further includes a data transmission switch, a drive switch, a data input terminal, and a power supply terminal. The first terminal of the drive switch is connected to the power supply terminal, the second terminal of the drive switch is connected to the anode of the photodiode, and the control terminal of the drive switch is connected to the data input terminal through the data transmission switch. The input voltage parameter value of the display pixel circuit is the control terminal voltage value of the drive switch.

9. The display screen according to claim 8, characterized in that, The controller is configured to, when any one of the current scan lines is located in the non-display area, control the voltage at the data input terminal of the first display pixel circuit to be the first voltage and control the data transmission switch of the first display pixel circuit to be turned on; and when all of the multiple current scan lines are located in the display area, control the voltage at the data input terminal of the second display pixel circuit to be the second voltage and control the data transmission switch of the second display pixel circuit to be turned on, wherein both the first voltage and the second voltage are greater than the on-state voltage threshold of the driving switch.

10. The display screen according to claim 1, characterized in that, The display pixel circuit further includes a data transmission switch, a drive switch, a data input terminal, and a power supply terminal. The first terminal of the drive switch is connected to the power supply terminal, the second terminal of the drive switch is connected to the anode of the photodiode, and the control terminal of the drive switch is connected to the data input terminal through the data transmission switch. The input voltage parameter value of the display pixel circuit is the control terminal voltage value of the data transmission switch.

11. The display screen according to claim 10, characterized in that, Both the first voltage and the second voltage are less than the turn-on voltage threshold of the data transmission switch.

12. The display screen according to claim 10, characterized in that, Both the first voltage and the second voltage are greater than the on-voltage threshold of the data transmission switch.

13. The display screen according to any one of claims 1-12, characterized in that, The display pixel circuit further includes a third display pixel circuit and a fourth display pixel circuit; During each frame scan time at a frame rate of the display screen, the controller is configured to, when any one of the plurality of current scan lines is located in the non-display area, control the input voltage parameter of the first display pixel circuit to be the first voltage, and when all the plurality of current scan lines are located in the display area, control the input voltage parameter of the second display pixel circuit to be the second voltage. During each frame scan time after the frame rate of the display screen switches from the first frame rate to the second frame rate, the controller is further configured to, when any one of the plurality of current scan lines is located in the non-display area, control the input voltage parameter of the third display pixel circuit to be the first voltage, the reset current of the photodiode in the third display pixel circuit to be the first current value, and the third display pixel circuit is the display pixel circuit corresponding to the current scan line located in the display area; and when all the plurality of current scan lines are located in the display area, control the input voltage parameter of the fourth display pixel circuit to be the second voltage, the reset current of the photodiode in the fourth display pixel circuit to be the second current value, and the fourth display pixel circuit is the display pixel circuit corresponding to the plurality of current scan lines.

14. The display screen according to claim 13, characterized in that, The first frame rate and the second frame rate are any two preset frame rates from K preset frame rates, where K≥F*x-x+1, the i-th preset frame rate among the K preset frame rates is F*x / (x+i-1), where i is a positive integer, F is the maximum frame rate of the display screen, and x is the number of the plurality of current scan lines.

15. A display module, the display module comprising a protective layer, an anti-fingerprint layer, and a display screen as described in any one of claims 1-14, wherein, The protective layer is located on the first surface of the display screen, and the anti-fingerprint layer is located on the surface of the protective layer away from the display screen.

16. An electronic device, characterized in that, The electronic device includes a housing and a display module as described in claim 15, which is connected to the housing.

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