Pixel driving circuit, display panel and display device

Abstract

This application discloses a pixel driving circuit, a display panel, and a display device. The pixel driving circuit includes a display driving circuit, a display light-emitting unit, a privacy driving circuit, and a privacy light-emitting unit in each pixel area. The display driving circuit includes a first active switch and a first node. The privacy driving circuit includes a second active switch. The control terminals of the first and second active switches are respectively connected to the first node. The first node receives data signals and controls the first active switch to drive the display light-emitting unit to emit light, and controls the second active switch to drive the privacy light-emitting unit to emit light. The privacy light-emitting unit and the display light-emitting unit are controlled to emit light under the same data signal. This design enables the privacy driving circuit and the display driving circuit to provide privacy protection under the control of the first node, achieving both privacy protection and display functions while reducing the complexity of the privacy control circuit.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a pixel driving circuit, a display panel, and a display device. Background Technology

[0002] With the gradual maturation of OLED organic light-emitting display technology and its increasingly widespread application as a self-emissive display technology, privacy features on display panels have become an essential function in modern society, making OLED privacy technology a hot topic of discussion recently. Traditional privacy displays involve attaching a privacy film to the surface of the display panel. These films typically employ ultra-fine venetian blind technology, similar in principle to vertical blinds. This method, which restricts light emission from the display panel at a fixed angle, is the simplest and most direct solution, boasting high yield rates and widespread application. However, privacy films also cause significant light loss and increased power consumption, and the privacy function cannot be turned off. Currently, privacy light sources can be placed in the pixel area to interfere with emitted light at wide viewing angles. The privacy function can be disabled by turning off the privacy light source.

[0003] However, the addition of privacy light sources requires additional driving circuits, data lines, control lines, etc., which increases the wiring complexity of the display panel. Summary of the Invention

[0004] The purpose of this application is to provide a pixel driving circuit, a display panel, and a display device. By setting an anti-spy driving circuit and a display driving circuit to be connected to a first node respectively, the anti-spy driving circuit and the display driving circuit are protected from peeping under the control of the first node, thereby achieving both anti-spy and display functions while reducing the complexity of the anti-spy control circuit.

[0005] This application discloses a pixel driving circuit, which includes a display driving circuit, a display light-emitting unit, a privacy driving circuit, and a privacy light-emitting unit in each pixel area. The display driving circuit includes a first active switch and a first node, and the privacy driving circuit includes a second active switch. The control terminals of the first active switch and the second active switch are respectively connected to the first node. The first node is used to receive data signals and to control the first active switch to drive the display light-emitting unit to emit light, and to control the second active switch to drive the privacy light-emitting unit to emit light. The privacy light-emitting unit and the display light-emitting unit are controlled to emit light under the same data signal.

[0006] Optionally, the display driving circuit further includes a third active switch and a first capacitor. The input terminal of the third active switch is externally connected to an external compensation circuit, and the output terminal of the third active switch is connected to a second node. One end of the display light-emitting unit is connected to the second node, and the output terminal of the first active switch is connected to the second node. One end of the first capacitor is connected to the first node, and the other end of the first capacitor is connected to the second node. The external compensation circuit is used to detect the voltage of the second node through the third active switch and compensate the input data signal of the first node. The privacy light-emitting unit operates under the drive of the compensated data signal of the first node.

[0007] Optionally, the privacy protection driving circuit further includes a fourth active switch, the input terminal of which is connected to the first node, and the output terminal of which is connected to the control terminal of the second active switch; the fourth active switch is used to control the connection or disconnection between the first node and the control terminal of the second active switch; the display driving circuit further includes a fifth active switch, the output terminal of which is connected to the first node, and the input terminal of which is connected to the data signal; the input terminal of the second active switch is connected to the privacy protection control signal, and the input terminal of the first active switch is connected to the power supply voltage signal.

[0008] Optionally, the input terminals of the multiple second active switches are respectively connected to the same privacy control signal.

[0009] Optionally, the pixel driving circuit further includes a first control signal, a second control signal, and a third control signal. The first control signal is connected to the control terminal of the fourth active switch, the second control signal is connected to the control terminal of the fifth active switch, and the third control signal is connected to the control terminal of the third active switch. The pixel driving circuit includes a reset period, a write period, and a display period. During the reset period, the third control signal is at a conducting level, the third active switch is turned on, and the second node is reset. During the write period, the second control signal and the first control signal are both at a conducting level, the fifth active switch and the fourth active switch are turned on, the first node receives a compensated data signal, and the control terminal of the second active switch turns on after receiving the compensated data signal from the first node. During the display period, the first active switch is turned on, and the display light-emitting unit emits light. Under the control of the privacy control signal, the privacy light-emitting unit emits light.

[0010] Optionally, the pixel driving circuit includes a first control signal and a second control signal, and the privacy driving circuit further includes a second capacitor, one end of which is connected to the control terminal of the second active switch, and the other end of which is connected to the output terminal of the second active switch; the first control signal is connected to the control terminals of the fourth active switch and the fifth active switch respectively, and the second control signal is connected to the control terminal of the third active switch; the pixel driving circuit includes a reset period, a write period, and a display period; during the reset period, the second control signal is at the on level, the third active switch is on, and the second node is reset; during the write period, the first control signal is at the on level, the fifth active switch and the fourth active switch are on, the first node inputs a compensated data signal, and the control terminal of the second active switch is on after receiving the compensated data signal from the first node; during the display period, the first active switch is on, and the display light-emitting unit emits light; under the control of the privacy control signal, the privacy light-emitting unit emits light.

[0011] Optionally, the pixel driving circuit includes a first control signal, and the privacy driving circuit further includes a second capacitor, one end of which is connected to the control terminal of the second active switch, and the other end of which is connected to the output terminal of the second active switch; the first control signal is respectively connected to the control terminals of the third active switch, the fourth active switch, and the fifth active switch; the pixel driving circuit includes a reset write period and a display period; during the reset write period, the first control signal is at the on level, the third active switch, the fourth active switch, and the fifth active switch are turned on, and after a preset delay, a compensated data signal is written from the first node; during the display period, the first active switch and the second active switch are turned on respectively, and the display light-emitting unit and the privacy light-emitting unit emit light respectively.

[0012] This application also discloses a display panel, including a substrate and the aforementioned pixel driving circuit. The pixel driving circuit layer is disposed on the substrate. The display panel further includes a light-emitting unit layer and a light-shielding layer. The light-emitting unit layer is disposed on the pixel driving circuit layer and includes a plurality of display light-emitting units and a plurality of privacy light-emitting units. The light-shielding layer is disposed on the light-emitting unit layer and includes a plurality of light-shielding portions, which are disposed corresponding to the privacy light-emitting units.

[0013] Optionally, at least one display light-emitting unit and one privacy light-emitting unit are provided in the same pixel area, wherein the privacy light-emitting unit emits a different color than the display light-emitting unit.

[0014] This application also discloses a display device, including a driving circuit board and the aforementioned display panel, wherein the driving circuit board is used to provide data signals to the pixel driving circuit to drive the display panel to display.

[0015] This application achieves privacy protection by setting a separate privacy-protecting light-emitting unit and a privacy-protecting driving circuit in each pixel area. The privacy-protecting driving circuit is controlled by a first node, ensuring that when the display light-emitting unit in the current pixel area emits light, the privacy-protecting light-emitting unit in the same pixel area also emits light. Through the control of the first node, synchronous illumination of the privacy-protecting light-emitting unit and the display light-emitting unit is achieved. While the display light-emitting unit is emitting light, the privacy-protecting light-emitting unit interferes with the display at wide viewing angles, thus achieving the privacy protection function. By adding a second active switch and connecting its control terminal to the first node, the problem of needing an additional driving circuit for the privacy-protecting light-emitting unit is solved. The privacy-protecting driving circuit can be synchronously controlled via data lines and control lines in the display driving circuit, reducing the wiring complexity of the display panel and improving the display effect and privacy protection capability. Attached Figure Description

[0016] The accompanying drawings, which form part of the specification, are used to provide a further understanding of the embodiments of this application and illustrate the implementation methods of this application, together with the textual description, to explain the principles of this application. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any creative effort. In the drawings:

[0017] Figure 1 This is a schematic diagram of the pixel driving circuit of this application;

[0018] Figure 2 This is a schematic diagram of the display panel of this application;

[0019] Figure 3 This is a schematic diagram of the pixel area of ​​this application;

[0020] Figure 4 This is a timing diagram of the pixel driving circuit according to the first embodiment of this application;

[0021] Figure 5 This is a schematic diagram of the pixel driving circuit according to the second embodiment of this application;

[0022] Figure 6 This is a timing diagram of the pixel driving circuit according to the second embodiment of this application;

[0023] Figure 7 This is a schematic diagram of the pixel driving circuit according to the third embodiment of this application;

[0024] Figure 8 This is a timing diagram of the pixel driving circuit according to the third embodiment of this application;

[0025] Figure 9 This is a schematic diagram of the pixel driving circuit of the fourth embodiment of this application;

[0026] Figure 10 This is a timing diagram of the pixel driving circuit according to the fourth embodiment of this application;

[0027] Figure 11 This is a schematic diagram of the display device of this application.

[0028] Among them, 100 is the display panel; 110 is the pixel driving circuit; 111 is the display driving circuit; 112 is the display light-emitting unit; 113 is the privacy driving circuit; 114 is the privacy light-emitting unit; 121 is the substrate; 122 is the light-emitting unit layer; 123 is the light-shielding part; 130 is the pixel area; 131 is the privacy sub-pixel; 132 is the display sub-pixel; 200 is the display device; 210 is the driving circuit board; N1 is the first node; N2 is the second node; T1 is the first active switch; T2 is the second active switch; T3 is the third active switch; T4 is the fourth active switch; T5 is the fifth active switch; C1 is the first capacitor; C2 is the second capacitor; Scan1 is the first control signal; Scan2 is the second control signal; Scan3 is the third control signal; Data is the data signal; Vsen is the reset signal. Detailed Implementation

[0029] It should be understood that the terminology, specific structural and functional details used herein are merely for describing particular embodiments and are representative. However, this application may be implemented in many alternative forms and should not be construed as being limited to the embodiments set forth herein.

[0030] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of technical features indicated. Therefore, unless otherwise stated, a feature specified as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. Furthermore, terms such as "upper," "lower," "left," "right," "vertical," and "horizontal," indicating orientation or positional relationships, are based on the orientation or relative positional relationships shown in the accompanying drawings and are only for the purpose of simplifying the description of this application, not indicating that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this application. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0031] The present application will now be described in detail with reference to the accompanying drawings and optional embodiments.

[0032] Figure 1 This is a schematic diagram of the pixel driving circuit of this application, see [link / reference]. Figure 1 As shown, this application discloses a pixel driving circuit 110, which includes a display driving circuit 111, a display light-emitting unit 112, a privacy driving circuit 113, and a privacy light-emitting unit 114 in each pixel area 130. The display driving circuit 111 includes a first active switch T1 and a first node N1, and the privacy driving circuit 113 includes a second active switch T2. The control terminals of the first active switch T1 and the second active switch T2 are respectively connected to the first node N1. The first node N1 is used to receive a data signal Data and to control the first active switch T1 to drive the display light-emitting unit 112 to emit light and to control the second active switch T2 to drive the privacy light-emitting unit 114 to emit light. The privacy light-emitting unit 114 and the display light-emitting unit 112 are controlled to emit light under the same data signal Data.

[0033] This application addresses the issue of privacy-preventing light-emitting units 114 and privacy-preventing driving circuits 113 in each pixel area 130. By controlling the privacy-preventing driving circuit 113 through a first node N1, the privacy-preventing light-emitting unit 114 in the current pixel area 130 illuminates simultaneously with the display light-emitting unit 112. Through the control of the first node N1, synchronous illumination of the privacy-preventing light-emitting unit 114 and the display light-emitting unit 112 is achieved. While the display light-emitting unit 112 is illuminating, the privacy-preventing light-emitting unit 114 interferes with the display at wide viewing angles, thus achieving privacy protection. By adding a second active switch T2 and connecting its control terminal to the first node N1, the problem of requiring an additional driving circuit for the privacy-preventing light-emitting unit 114 is solved. The privacy-preventing driving circuit 113 can be synchronously controlled via the data lines and control lines in the display driving circuit 111, reducing the wiring complexity of the display panel 100 and improving its display effect and privacy protection capabilities.

[0034] It is worth mentioning that, compared to the exemplary scheme where the privacy light-emitting unit 114 and the display light-emitting unit 112 share a single display driving circuit, and the privacy light-emitting unit is controlled based on the grayscale signal of the display light-emitting unit, such as controlling the privacy light-emitting unit 114 based on the anode of the display light-emitting unit 112 or the second node N2, the addition of the privacy light-emitting unit 114 means that if the privacy light-emitting unit is directly driven by the second node N2 or indirectly connected to the anode of the display light-emitting unit (second node N2), on the one hand, the driving capability of the display driving circuit 111 will be insufficient, resulting in insufficient brightness of the display light-emitting unit 112. Furthermore, when the grayscale of the display light-emitting unit 112 is different, the brightness of the corresponding privacy light-emitting unit 114 will also be different. Combined with the aforementioned insufficient driving capability of the display driving circuit 111, this will further lead to inconsistent brightness of the privacy light-emitting unit 114, particularly resulting in insufficient privacy protection in low grayscale display areas and excessive privacy protection in high grayscale display areas. This application mainly utilizes the first node N1 in the display driving circuit 111 to jointly drive the privacy light-emitting unit 114 for display, based on the pixel driving circuit 110. When the display light-emitting unit 112 of the current pixel area 130 is not lit, the privacy light-emitting unit 114 also does not emit light. The second node N2 is directly connected to one end of the display light-emitting unit 112 (generally the anode end), avoiding the problem of poor light emission from the display light-emitting unit 112 caused by using the second node N2 as the control terminal of the privacy light-emitting unit 114.

[0035] Figure 2 This is a schematic diagram of the display panel of this application. Figure 3 This is a schematic diagram of the pixel area of ​​this application, see [link / reference]. Figures 2 to 3 As shown, this application also discloses a display panel 100, which includes a pixel driving circuit 110 mentioned above on a substrate 121. The pixel driving circuit 110 layer is disposed on the substrate. The display panel 100 also includes a light-emitting unit layer 122 and a light-shielding layer. The light-emitting unit layer 122 is disposed on the pixel driving circuit 110 layer and includes a plurality of display light-emitting units 112 and a plurality of privacy light-emitting units 114. The light-shielding layer is disposed on the light-emitting unit layer 122 and includes a plurality of light-shielding portions 123, which are disposed corresponding to the privacy light-emitting units 114.

[0036] In this application, the pixel driving circuit 110 is generally disposed on the substrate 121 between the substrate and the light-emitting unit layer 122. The pixel driving circuit 110 drives one or more sub-pixels in each pixel area 130 to emit light, thereby forming a display. The privacy light-emitting unit 114 can be formed in the light-emitting unit layer 122, just like the display light-emitting unit 112, and can emit light and turn off by the control of thin-film transistors.

[0037] Within the same pixel area 130, at least one display light-emitting unit 112 and one privacy light-emitting unit 114 are provided, and the privacy light-emitting unit 114 emits a different color than the display light-emitting unit 112.

[0038] This application adds an additional privacy-protecting light-emitting unit 114 within the pixel area 130, that is, adds an additional privacy-protecting sub-pixel 131 to the pixel area 130. The display sub-pixels 132 within the pixel area 130 are generally provided with three different colored sub-pixels, such as red, green, and blue sub-pixels, thereby achieving arbitrary color display. Specifically, the red sub-pixel is provided with a display light-emitting unit 112 that emits red light or a red filter that causes the area to emit red light. When a red filter is provided, the display light-emitting unit 112 can also be a light-emitting unit that emits white light. Similarly, the green sub-pixel emits green light, and the blue sub-pixel emits blue light. The privacy-protecting sub-pixel 131 can be a privacy-protecting light-emitting unit 114 of a different color than the aforementioned red, green, and blue sub-pixels; for example, a white light-emitting unit can be used as the privacy-protecting light-emitting unit 114. A light-shielding portion 123 is generally provided above the privacy light-emitting unit 114 to block the light emitted or nearly emitted perpendicularly from the privacy light-emitting unit 114 to the substrate 121, preventing this light from affecting the display from the front viewing angle. Generally, the privacy angle can be adjusted by adjusting the area covered by the light-shielding portion 123 on the privacy light-emitting unit 114. The larger the area of ​​the light-shielding layer, the closer the corresponding privacy angle is to the wide viewing angle; the smaller the area of ​​the light-shielding layer, the larger the range of the privacy angle.

[0039] When a pixel area has only one privacy light-emitting unit 114, the privacy light-emitting unit 114 is connected to the first node N1 of any display driving circuit 111 in the display area. Its advantage is that it eliminates the need for complex connection lines; any display light-emitting unit 112 can be selected, and the privacy light-emitting unit 114 is activated based on the activation of that display light-emitting unit 112.

[0040] In this embodiment, the privacy-protecting light-emitting unit 114 can be arranged side-by-side with the display sub-pixels 132 within the pixel area 130, or arbitrarily positioned among the three display sub-pixels 132, thereby achieving the privacy-protecting function of the privacy-protecting light-emitting unit 114 over the pixel area 130. Of course, when the red, green, and blue sub-pixels of the pixel area 130 are arranged horizontally, the privacy-protecting sub-pixel 131 can be positioned above or below the three display sub-pixels 132.

[0041] However, there is a problem that the privacy light-emitting unit 114 cannot work when one display light-emitting unit 112 in the current pixel area 130 does not emit light, while the other two display light-emitting units 112 are partially or fully illuminated. To address this, the number of privacy light-emitting units 114 in the pixel area 130 can be increased, for example, to match the number of display sub-pixels 132. That is, in each pixel area 130, a privacy light-emitting unit 114 is connected to the first node N1 of the display driving circuit 111 of each display light-emitting unit 112.

[0042] Of course, considering that in actual display, it is not necessary for all privacy light-emitting units 114 in every pixel area 130 to work in order to achieve a privacy effect, and that increasing the number of privacy light-emitting units 114 in each pixel area 130 would reduce the area ratio of the display light-emitting units 112, in actual design, it is sufficient to set one privacy light-emitting unit 114 in each pixel area 130.

[0043] See also Figure 1 As shown, specifically, the display driving circuit 111 further includes a third active switch T3 and a first capacitor C1. The input terminal of the third active switch T3 is externally connected to an external compensation circuit, and the output terminal of the third active switch T3 is connected to a first node N1. One end of the display light-emitting unit 112 is connected to the first node N1, and the output terminal of the first active switch T1 is connected to the first node N1. One end of the first capacitor C1 is connected to the first node N1, and the other end of the first capacitor C1 is connected to the second node N2. The external compensation circuit is used to detect the voltage of the second node N2 through the third active switch T3 and compensate the input data signal Data of the first node N1. The privacy light-emitting unit 114 operates under the drive of the compensated data signal Data of the first node N1.

[0044] In this application, the third active switch T3 is connected to an external compensation circuit. This external compensation circuit is not located on the substrate 121 but is typically connected externally to the pixel driving circuit 110. The main function of the external compensation circuit is to generate a compensation table or compensation data by sensing the current or voltage difference caused by the line resistance or the threshold voltage of the first active switch T1 during the testing of the display panel 100, based on the data input via the data line. During normal display of the display panel 100, the external compensation circuit directly superimposes the compensation signal onto the data signal Data, resulting in a compensated data signal Data transmitted to the first node N1. This compensated data signal Data is the data signal Data after removing line resistance and capacitance interference. Under the control of this compensated data signal Data, the privacy light-emitting units 114 at different locations can overcome the uneven brightness caused by the line resistance and the time-dependent drift of the threshold voltage of the first active switch T1, allowing the privacy light-emitting units 114 at different locations to have a brightness closer to that of the display light-emitting unit 112.

[0045] It should be noted that although this embodiment only detects the output of the first active switch T1 (i.e., the second node N2) and does not detect the output of the second active switch T2, nor does it compensate separately, it still achieves a relatively accurate compensation effect. This is because the anti-spy drive circuit 113 in this embodiment is very close to its connected display drive circuit 111, so the second active switch T2 and the first active switch T1 are less affected by uneven process, and their initial threshold voltages are similar. Furthermore, since they share a common data voltage, their threshold voltage drift trends are also similar after prolonged use. Therefore, detecting only the second node N2 and compensating together simplifies the detection and compensation steps, shortens the detection and compensation time, and makes it applicable to high refresh rate modes.

[0046] It is worth mentioning that due to the increased number of data lines and control lines in the current display panel 100, the data signal (Data) and control signal attenuation caused by line resistance result in uneven brightness of the privacy light-emitting unit 114. In practice, while the uneven brightness of the privacy light-emitting unit 114 does not significantly affect the overall privacy protection effect, if the brightness difference between different areas of the privacy light-emitting unit 114 is too large, due to the refraction, reflection, and diffraction of light, the light-shielding layer cannot completely block the light emitted from the privacy light-emitting unit 114 at the forward viewing angle. Some light from the privacy light-emitting unit 114 will be added to the display at the forward viewing angle, affecting the display effect at that angle. Furthermore, if the brightness of the privacy light-emitting unit 114 is uneven, differences in brightness will appear at different locations. When the sub-pixels 132 are displayed at different gray levels, this will increase the display difference at the forward viewing angle, resulting in poor display quality. To avoid the aforementioned problems, this application controls the privacy light-emitting unit 114 using a compensated data signal Data. This compensated data signal Data avoids voltage drops caused by line resistance or capacitor interference, and also avoids uneven brightness of the privacy light-emitting unit caused by the time-dependent drift of the threshold voltage driving the thin-film transistor. Furthermore, since the brightness of the privacy light-emitting unit 114 overcomes the differences caused by line resistance and threshold voltage, the privacy effect is better at wide viewing angles, preventing the displayed content from being completely illegible at large viewing angles.

[0047] To better control the privacy-protecting light-emitting unit 114, in this embodiment, the privacy-protecting driving circuit 113 further includes a fourth active switch T4. The input terminal of the fourth active switch T4 is connected to the first node N1, and the output terminal of the fourth active switch T4 is connected to the control terminal of the second active switch T2. The fourth active switch T4 is used to control the connection or disconnection between the control terminals of the first node N1 and the second active switch T2. In this embodiment, by adding an additional fourth active switch T4 between the control terminals of the first node N1 and the second active switch T2, the fourth active switch T4 mainly controls whether the control terminal of the second active switch T2 is connected to the voltage of the first node N1. When privacy display is not required, privacy can also be switched on and off by controlling the conduction and cutoff of the fourth active switch T4.

[0048] Specifically, the display driving circuit 111 further includes a fifth active switch T5, the output terminal of which is connected to the first node N1, and the input terminal of which is connected to the data signal Data.

[0049] In the pixel driving circuit 110 of this application, the input terminal of the second active switch T2 is connected to a privacy control signal, and the input terminal of the first active switch T1 is connected to a power supply voltage signal. Both the first active switch T1 and the second active switch T2 are field-effect transistors (FETs), and the current output of the FET can be controlled by controlling the voltage at its gate. The third active switch T3, the fourth active switch T4, and the fifth active switch T5 are switching transistors, which only function as switches. Of course, the second active switch T2 can also be a switching transistor. Under different timing control conditions, the second active switch T2 can control the switching of the privacy light-emitting unit 114, and the brightness of the privacy light-emitting unit 114 can be changed by controlling the privacy control signal. When the second active switch T2 is a FET, it outputs different currents to the privacy light-emitting unit 114 according to different potentials of the first node N1, thereby achieving different brightness levels for the privacy light-emitting unit 114.

[0050] In one embodiment of this application, the input terminals of multiple second active switches T2 are respectively connected to the same privacy control signal.

[0051] In this embodiment, by connecting the input terminals of the second active switches T2 corresponding to the numerous privacy light-emitting units 114 to the same privacy control signal, the brightness of the privacy light-emitting units 114 is made consistent, and the wiring is simpler.

[0052] In one specific embodiment, the voltage of the privacy control signal can be controlled according to the brightness (grayscale) of the current display panel 100. For example, the average grayscale of the current display panel 100 is calculated, and the privacy control signal has different voltages when the average grayscale is in different grayscale ranges. The specific relationship can be proportional or exponential. For example, to simplify the calculation, it can be calculated whether the grayscale of more than half of the sub-pixels of the current display panel 100 is greater than a certain set value. If it is greater, it is considered a high grayscale display screen; if it is less, it is considered a low grayscale display screen. When displaying a high grayscale screen, the privacy light-emitting unit 114 is controlled to emit a brighter privacy light, and when displaying a low grayscale screen, the privacy light-emitting unit 114 is controlled to emit a dimmer privacy light.

[0053] Figure 4 This is a timing diagram of the pixel driving circuit of the first embodiment of this application, see below. Figure 4As shown, the pixel driving circuit 110 further includes a first control signal Scan1, a second control signal Scan2, and a third control signal Scan3. The first control signal Scan1 is connected to the control terminal of the fourth active switch T4, the second control signal Scan2 is connected to the control terminal of the fifth active switch T5, and the third control signal Scan3 is connected to the control terminal of the third active switch T3. The pixel driving circuit 110 includes a reset period, a write period, and a display period. During the reset period, the third control signal Scan3 is at the on level, and the third active switch T3 is on, resetting the second node N2. During the write period, the second control signal Scan2 and the first control signal Scan1 are at the on level, the fifth active switch T5 and the fourth active switch T4 are on, the first node N1 receives the compensated data signal Data, and the control terminal of the second active switch T2 receives the compensated data signal Data from the first node N1 and then turns on. During the display period, the first active switch T1 is on, and the display light-emitting unit 112 emits light. Under the control of the privacy control signal, the privacy light-emitting unit 114 emits light.

[0054] In this embodiment, the compensation circuit for the data signal Data is generally performed by detecting the display sub-pixels 132 before leaving the factory, and then calculating the compensation data corresponding to each display sub-pixel 132. When the display panel 100 is displaying, the third active switch T3 mainly resets the second node N2, so that the potential of the first node N1 is at a preset potential. When the second control signal Scan2 and the third control signal Scan3 are on, the potential of the first node N1 is raised to the potential of the compensated data signal Data, and the first capacitor C1 is charged. During the display period, the power supply voltage signal at the input terminal of the first active switch T1 controls the display light-emitting unit 112 to emit light, and the privacy control signal at the input terminal of the second active switch T2 controls the privacy light-emitting unit 114 to emit light. Of course, the power supply voltage signal can also be connected to the input terminal of the second active switch T2, thereby saving the routing of the privacy control signal, but there is a problem that the privacy control signal potential cannot be adjusted.

[0055] It can be understood that this conduction level is the level that, when applied to the control terminal of the active switch, causes the active switch to be in the conducting state. For example, when the active switch is an N-type thin-film transistor, the conduction level is a logic high level; when the active switch is a P-type thin-film transistor, the conduction level is a logic low level.

[0056] Figure 5 This is a schematic diagram of the pixel driving circuit according to the second embodiment of this application. Figure 6This is a timing diagram of the pixel driving circuit according to the second embodiment of this application. See also... Figures 5 to 6 As shown, the pixel driving circuit 110 includes a first control signal Scan1 and a second control signal Scan2. The first control signal Scan1 is connected to the control terminals of the fourth active switch T4 and the fifth active switch T5, respectively. The second control signal Scan2 is connected to the control terminal of the third active switch T3. The pixel driving circuit 110 includes a reset period, a write period, and a display period. During the reset period, the second control signal Scan2 is at the on level, the third active switch T3 is on, and the second node N2 is reset. During the write period, the first control signal Scan1 is at the on level, the fifth active switch T5 and the fourth active switch T4 are on, the first node N1 receives the compensated data signal Data, and the control terminal of the second active switch T2 is on after receiving the compensated data signal Data from the first node N1. During the display period, the first active switch T1 is on, and the display light-emitting unit 112 emits light. Under the control of the privacy control signal, the privacy light-emitting unit 114 emits light. Wherein, data is the data signal Data, and Vsen is the reset signal Vsen input from the external compensation circuit, which controls the second node N2 to be at a preset potential.

[0057] In this embodiment, by simultaneously controlling the fourth active switch T4 and the fifth active switch T5, the first capacitor C1 is charged when the input data signal Data is received, and the fifth active switch T5 is turned on. The presence or absence of the privacy control signal allows control of the privacy light-emitting unit 114. Compared to the previous embodiment, this reduces the number of control signals, thereby reducing wiring complexity.

[0058] Figure 7 This is a schematic diagram of the pixel driving circuit according to the third embodiment of this application. Figure 8 This is a timing diagram of the pixel driving circuit according to the third embodiment of this application. See also... Figures 7 to 8As shown, the pixel driving circuit 110 includes a first control signal Scan1, and the privacy driving circuit 113 also includes a second capacitor C2. One end of the second capacitor C2 is connected to the control terminal of the second active switch T2, and the other end of the second capacitor C2 is connected to the output terminal of the second active switch T2. The first control signal Scan1 is connected to the control terminals of the third active switch T3, the fourth active switch T4, and the fifth active switch T5, respectively. The pixel driving circuit 110 includes a reset write period and a display period. During the reset write period, the first control signal Scan1 is at the on level, and the third active switch T3, the fourth active switch T4, and the fifth active switch T5 are turned on. After a preset delay, the compensated data signal Data is written from the first node N1. During the display period, the first active switch T1 and the second active switch T2 are turned on, and the display light-emitting unit 112 and the privacy light-emitting unit 114 emit light, respectively.

[0059] In this embodiment, the control signal is further reduced to a single control line. The first control signal Scan1 controls the third active switch T3, the fourth active switch T4, and the fifth active switch T5. To avoid conflict between the reset of the first node N1 and the input of the data signal Data, the data signal Data can be input after a preset time delay, and then input after the second node N2 has completed its reset. The privacy control signal is at a preset potential during the display period, controlling the privacy light-emitting unit 114 to emit light. At this time, the first control signal Scan1, the reset signal Vsen, and the data signal Data are all at a low level. The first active switch T1 and the second active switch T2 are kept on by the action of the first capacitor C1 and the second capacitor C2, thereby enabling the display light-emitting unit 112 and the privacy light-emitting unit 114 to emit light simultaneously.

[0060] The second capacitor C2 has the same function as the first capacitor C1. During the data signal writing period, the first capacitor C1 and the second capacitor C2 are charged by the data signal Data, so as to maintain the conduction state of the first active switch T1 and the second active switch T2 during the display period.

[0061] Of course, in another embodiment, the fourth active switch T4 can also be removed by directly turning on the second capacitor C2 through the data signal Data during the writing period, or by turning on the second active switch T2. In other words, the second active switch T2 of the privacy drive circuit 113 is directly connected to the first node N1, without the need for the fourth active switch T4.

[0062] Figure 9This is a schematic diagram of the pixel driving circuit according to the fourth embodiment of this application. Figure 10 This is a timing diagram of the pixel driving circuit according to the fourth embodiment of this application. See also... Figures 9 to 10 As shown, the fourth active switch T4 is omitted in the second embodiment. The pixel driving circuit 110 includes a reset period, a write period, and a display period. The reset period is the same as described above. During the write period, the data signal Data is input to the first node N1, which charges not only the first capacitor C1 but also the second capacitor C2, so that the privacy light-emitting unit 114 can emit light during the display period.

[0063] Figure 11 This is a schematic diagram of the display device of this application, see [link / reference]. Figure 11 As shown, this application also discloses a display device 200, which includes a driving circuit board 210 and a display panel 100 as described in any of the above embodiments. The driving circuit board 210 is used to drive the display panel 100 to display. The driving circuit board 210 differs from the pixel driving circuit 110 in that it is disposed outside the substrate 121 and requires bonding for connection. It is typically used to provide voltage and control signals to the pixel driving circuit 110.

[0064] It should be noted that the inventive concept of this application can form many embodiments, but due to the limited space of the application documents, they cannot all be listed. Therefore, without conflict, the embodiments described above or the technical features can be arbitrarily combined to form new embodiments. After the embodiments or technical features are combined, the original technical effect will be enhanced.

[0065] The above description, in conjunction with specific optional embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of this application, and all such modifications or substitutions should be considered within the scope of protection of this application.

Claims

1. A pixel driving circuit, characterized by comprising: The display driving circuit, the display light-emitting unit, the anti-peep driving circuit and the anti-peep light-emitting unit are respectively arranged in each pixel region; The display driving circuit comprises a first active switch and a first node, and the anti-peep driving circuit comprises a second active switch. Control ends of the first active switch and the second active switch are respectively connected to the first node. The first node is used for receiving a data signal. The first node is used for controlling the first active switch to drive the display light-emitting unit to emit light and controlling the second active switch to drive the anti-peep light-emitting unit to emit light. The anti-peep light-emitting unit and the display light-emitting unit are controlled to emit light under the same data signal. The display driving circuit further comprises a third active switch and a first capacitor. An input end of the third active switch is connected to an external compensation circuit. An output end of the third active switch is connected to a second node. One end of the display light-emitting unit is connected to the second node. An output end of the first active switch is connected to the second node. One end of the first capacitor is connected to the first node. The other end of the first capacitor is connected to the second node. The external compensation circuit is used for detecting a voltage of the second node through the third active switch and compensating the input data signal of the first node. The anti-peep light-emitting unit operates under the compensated data signal of the first node. The anti-peep driving circuit further comprises a fourth active switch. An input end of the fourth active switch is connected to the first node. An output end of the fourth active switch is connected to a control end of the second active switch. The fourth active switch is used for controlling conduction or disconnection between the first node and the control end of the second active switch. The display driving circuit further comprises a fifth active switch. An output end of the fifth active switch is connected to the first node. An input end of the fifth active switch is connected to the data signal. An input end of the second active switch is connected to an anti-peep control signal. An input end of the first active switch is connected to a power voltage signal. Input ends of a plurality of second active switches are respectively connected to the same anti-peep control signal. When the gray scale of a half number of sub-pixels in all the pixel regions is greater than a set value, a first anti-peep control signal is output. When the gray scale of a half number of sub-pixels is less than the set value, a second anti-peep control signal is output. The voltage value of the first anti-peep control signal is less than the voltage value of the second anti-peep control signal. The light intensity emitted by the anti-peep light-emitting unit under the control of the first anti-peep control signal is brighter than the light intensity emitted by the anti-peep light-emitting unit under the control of the second anti-peep control signal.

2. The pixel driving circuit according to claim 1, characterized in that, The pixel driving circuit further comprises a first control signal, a second control signal and a third control signal. The first control signal is connected to a control end of the fourth active switch. The second control signal is connected to a control end of the fifth active switch. The third control signal is connected to a control end of the third active switch. The pixel driving circuit comprises a reset period, a write period and a display period, in the reset period, the third control signal is at an on level, the third active switch is turned on, and the second node is reset; in the write period, the second control signal and the first control signal are respectively at an on level, the fifth active switch and the fourth active switch are turned on, the first node inputs the compensated data signal, and the control end of the second active switch is turned on after receiving the compensated data signal of the first node; in the display period, the first active switch is turned on, and the display light emitting unit emits light; under the control of the anti-peep control signal, the anti-peep light emitting unit emits light.

3. The pixel driving circuit of claim 1, wherein, The pixel driving circuit comprises a first control signal and a second control signal, and the anti-peep driving circuit further comprises a second capacitor, one end of the second capacitor is connected to the control end of the second active switch, and the other end of the second capacitor is connected to the output end of the second active switch; the first control signal is connected to the control end of the fourth active switch and the control end of the fifth active switch, respectively, and the second control signal is connected to the control end of the third active switch; The pixel driving circuit comprises a reset period, a write period and a display period, in the reset period, the second control signal is at an on level, the third active switch is turned on, and the second node is reset; in the write period, the first control signal is at an on level, the fifth active switch and the fourth active switch are turned on, the first node inputs the compensated data signal, and the control end of the second active switch is turned on after receiving the compensated data signal of the first node; in the display period, the first active switch is turned on, and the display light emitting unit emits light; under the control of the anti-peep control signal, the anti-peep light emitting unit emits light.

4. The pixel driving circuit of claim 1, wherein, The pixel driving circuit comprises a first control signal, and the anti-peep driving circuit further comprises a second capacitor, one end of the second capacitor is connected to the control end of the second active switch, and the other end of the second capacitor is connected to the output end of the second active switch; the first control signal is connected to the control end of the third active switch, the control end of the fourth active switch and the control end of the fifth active switch, respectively; The pixel driving circuit comprises a reset write period and a display period, in the reset write period, the first control signal is at an on level, the third active switch, the fourth active switch and the fifth active switch are turned on, and after a preset time is delayed, the compensated data signal is written from the first node; in the display period, the first active switch and the second active switch are turned on respectively, and the display light emitting unit and the anti-peep light emitting unit emit light respectively.

5. A display panel, characterized by, The display panel comprises a substrate substrate and a pixel driving circuit as claimed in any one of claims 1 to 4, the pixel driving circuit layer is arranged on the substrate substrate, and the display panel further comprises: a light emitting unit layer arranged on the pixel driving circuit layer and comprising a plurality of display light emitting units and a plurality of anti-peep light emitting units; and The light shielding layer is arranged on the light emitting unit layer and comprises a plurality of light shielding portions corresponding to the anti-peep light emitting units.

6. The display panel of claim 5, wherein, At least one display light emitting unit and one anti-peep light emitting unit are arranged in the same pixel area, and the anti-peep light emitting unit is different from the display light emitting unit in light emitting color.

7. A display device, characterized by comprising: The display panel comprises a driving circuit board and the display panel according to any one of claims 5 to 6, wherein the driving circuit board is configured to provide a data signal to the pixel driving circuit to drive the display panel to display.

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