Pixel circuit, display panel and electronic device

Abstract

The present disclosure provides a pixel circuit, a display panel and an electronic device. The pixel circuit comprises a pixel driving circuit and an organic light emitting element. The pixel driving circuit comprises a storage capacitor and has an input end and an output end. The input end and a first end of the storage capacitor are electrically connected with a negative electrode of a power supply, respectively. The output end is electrically connected with the organic light emitting element. A cathode electrode of the organic light emitting element is electrically connected with the output end. An anode electrode of the organic light emitting element is electrically connected with a positive electrode of the power supply. The output end of the pixel driving circuit is used to output a driving current to drive the organic light emitting element to emit light. By electrically connecting the cathode electrode of the organic light emitting element with the output end of the pixel driving circuit, electrically connecting the input end of the pixel driving circuit with the negative electrode, and electrically connecting the first end of the storage capacitor with the negative electrode of the power supply, the voltage of the first end of the storage capacitor can be stabilized by using the voltage-stable negative electrode of the power supply, and the problem of uneven display caused by unstable voltage of the storage capacitor can be avoided.

Description

Technical Field

[0001] This disclosure relates to the field of pixel circuit technology, and more particularly to a pixel circuit, a display panel, and an electronic device. Background Technology

[0002] Organic light-emitting diode (OLED) is a new type of display technology that uses organic semiconductor materials as the light-emitting layer. It emits light when a driving current is input into the driving circuit, thereby achieving the purpose of display. OLED has advantages such as high contrast, high brightness, high color saturation, and low power consumption. Therefore, OLED screens are widely used in various electronic products.

[0003] In the driving circuits of OLED display devices, pixel driving circuits are typically used to drive organic light-emitting diodes (OLEDs) to emit light. The pixel driving circuit achieves this by outputting a light-emitting current to the OLED. However, current OLED display device driving circuits often suffer from uneven display during the pixel-driven OLED process, affecting the display effect. Utility Model Content

[0004] To overcome the problems existing in related technologies, this disclosure provides a pixel circuit, a display panel, and an electronic device.

[0005] The first aspect of this disclosure provides a pixel circuit, comprising:

[0006] A pixel driving circuit includes a storage capacitor, wherein the input terminal of the pixel driving circuit and the first terminal of the storage capacitor are respectively electrically connected to the negative terminal of a power supply; and

[0007] An organic light-emitting element (OLED) is provided, wherein the cathode electrode of the OLED is electrically connected to the output terminal of the pixel driving circuit, and the anode electrode of the OLED is electrically connected to the positive terminal of the power supply.

[0008] The output terminal of the pixel driving circuit is used to output driving current to drive the organic light-emitting element to emit light.

[0009] In some embodiments of this disclosure, the pixel driving circuit further includes a first transistor, wherein...

[0010] The input terminal of the first transistor is electrically connected to the input terminal of the pixel driving circuit.

[0011] The output terminal of the first transistor is electrically connected to the output terminal of the pixel driving circuit.

[0012] The control terminal of the first transistor is electrically connected to the second terminal of the storage capacitor.

[0013] In some embodiments of this disclosure, the first transistor is an N-type transistor.

[0014] In some embodiments of this disclosure, the organic light-emitting element includes a first light-emitting layer, wherein...

[0015] The first light-emitting layer is located on one side surface of the cathode electrode of the organic light-emitting element;

[0016] The anode electrode of the organic light-emitting element is located on the surface of the first light-emitting layer away from the cathode electrode;

[0017] When the driving current is received, the cathode electrode of the organic light-emitting element is used to transfer electrons to the first light-emitting layer, and the anode electrode of the organic light-emitting element is used to transfer holes to the first light-emitting layer, so that the first light-emitting layer 20 emits light toward the anode electrode 30.

[0018] In some embodiments of this disclosure, the organic light-emitting element further includes:

[0019] A hole-generating layer is located on the surface of the first light-emitting layer away from the cathode electrode;

[0020] An electron-generating layer is located on the surface of the hole-generating layer away from the first light-emitting layer;

[0021] The second light-emitting layer is located between the electron-generating layer and the anode electrode;

[0022] When the driving current is received, the hole generating layer generates holes and transmits the generated holes to the first light-emitting layer, and the electron generating layer generates electrons and transmits the generated electrons to the second light-emitting layer, so that both the first light-emitting layer and the second light-emitting layer emit light toward the anode electrode.

[0023] In some embodiments of this disclosure, the pixel driving circuit further includes a compensation circuit, wherein...

[0024] The input terminal of the compensation circuit is connected between the input terminal of the first transistor and the input terminal of the pixel driving circuit.

[0025] The output terminal of the compensation circuit is connected between the output terminal of the first transistor and the output terminal of the pixel driving circuit, and is electrically connected to the second terminal of the storage capacitor.

[0026] The compensation circuit is used to receive frame data and write the frame data into the storage capacitor.

[0027] In some embodiments of this disclosure, the compensation circuit includes:

[0028] A second transistor, the input terminal of which is used to receive the frame data, the output terminal of which serves as the input terminal of the compensation circuit, the control terminal of which is used to receive a first scan signal, and the second transistor being used to input the frame data to the input terminal of the first transistor according to the first scan signal; and

[0029] The third transistor has its input terminal serving as the output terminal of the compensation circuit. The output terminal of the third transistor is electrically connected to the second terminal of the storage capacitor. The control terminal of the third transistor is used to receive a second scan signal. The third transistor is used to write frame data to the storage capacitor according to the second scan signal.

[0030] In some embodiments of this disclosure, the pixel driving circuit further includes a reset circuit for resetting the storage capacitor, the organic light-emitting element, and the first transistor.

[0031] The first terminal of the reset circuit is connected between the control terminal of the first transistor and the second terminal of the storage capacitor.

[0032] The second terminal of the reset circuit is connected between the output terminal of the first transistor and the output terminal of the pixel driving circuit.

[0033] The third terminal of the reset circuit is connected between the input terminal of the first transistor and the input terminal of the pixel driving circuit.

[0034] In some embodiments of this disclosure, the reset circuit includes a fourth transistor, wherein,

[0035] The input terminal of the fourth transistor is used to receive the first reset voltage.

[0036] The output terminal of the fourth transistor serves as the first terminal of the reset circuit.

[0037] The control terminal of the fourth transistor is used to receive the third scan signal.

[0038] The fourth transistor is used to output a first reset voltage to the storage capacitor according to the third scan signal, so as to reset the storage capacitor.

[0039] In some embodiments of this disclosure, the reset circuit further includes: a fifth transistor, wherein,

[0040] The input terminal of the fifth transistor is used to receive the second reset voltage.

[0041] The output terminal of the fifth transistor serves as the second terminal of the reset circuit.

[0042] The control terminal of the fifth transistor is used to receive the fourth scan signal.

[0043] The fifth transistor is used to output a second reset voltage to the organic light-emitting element according to the fourth scan signal, so as to reset the organic light-emitting element.

[0044] In some embodiments of this disclosure, the reset circuit further includes: a sixth transistor, wherein,

[0045] The input terminal of the sixth transistor is used to receive the third reset voltage.

[0046] The output terminal of the sixth transistor serves as the third terminal of the reset circuit.

[0047] The control terminal of the sixth transistor is used to receive the fourth scan signal.

[0048] The sixth transistor is used to input a third reset voltage to the input terminal of the first transistor according to the fourth scan signal, so as to reset the first transistor.

[0049] In some embodiments of this disclosure, the pixel driving circuit further includes a control circuit, wherein...

[0050] One end of the control circuit is connected between the input terminal of the first transistor and the input terminal of the pixel driving circuit.

[0051] The other end of the control circuit is connected between the output terminal of the first transistor and the output terminal of the pixel driving circuit.

[0052] The control circuit is used to receive control signals and control the first transistor to output the driving current to the organic light-emitting element according to the control signals.

[0053] In some embodiments of this disclosure, the control circuit includes:

[0054] A seventh transistor, which serves as one end of the control circuit, has its input terminal electrically connected to the input terminal of the pixel driving circuit, and its output terminal electrically connected to the input terminal of the first transistor. The control terminal of the seventh transistor is used to receive the control signal.

[0055] The eighth transistor serves as the other end of the control circuit. Its input terminal is electrically connected to the output terminal of the first transistor, and its output terminal is electrically connected to the output terminal of the pixel driving circuit. The control terminal of the eighth transistor is used to receive the control signal.

[0056] The seventh and eighth transistors are used to be synchronously turned on under the control of the control signal.

[0057] A second aspect of this disclosure provides a display panel including pixel circuitry as described in any of the first aspects.

[0058] A third aspect of this disclosure provides an electronic device including a pixel circuit as described in any of the first aspects, or a display panel as described in the second aspect.

[0059] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects:

[0060] In this embodiment, the cathode electrode of the organic light-emitting element (OLED) is electrically connected to the output terminal of the pixel driving circuit, and the anode electrode of the OLED is electrically connected to the positive terminal of the power supply. Since the cathode electrode of the OLED needs to inject electrons, the input terminal of the pixel driving circuit needs to be electrically connected to the negative electrode. The first terminal of the storage capacitor is also electrically connected to the negative terminal of the power supply. Thus, the first terminal of the storage capacitor can be connected to the negative terminal of the power supply with a stable voltage. The voltage of the first terminal of the storage capacitor can be stabilized by the stable negative terminal of the power supply, thereby maintaining the voltage stability of the storage capacitor. The stable voltage of the storage capacitor can ensure that the pixel driving circuit outputs a stable driving current to the OLED, so that the luminous intensity of the OLED is uniform, thereby solving the problem of uneven display and improving the display effect of the display device.

[0061] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0062] The accompanying drawings, which are incorporated in and form part of this disclosure, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0063] Figure 1 These are circuit diagrams illustrating a pixel circuit using some exemplary embodiments;

[0064] Figure 2 These are schematic cross-sectional views of an organic light-emitting element in a pixel circuit, illustrating some exemplary embodiments.

[0065] Figure 3This is a schematic cross-sectional view of an organic light-emitting element in a pixel circuit, as illustrated in some other exemplary embodiments;

[0066] Figure 4 These are circuit diagrams illustrating a pixel circuit in some other exemplary embodiments;

[0067] Figure 5 This is a circuit diagram of a pixel circuit shown in some exemplary embodiments;

[0068] Figure 6 This is a circuit diagram of a pixel circuit shown in some exemplary embodiments;

[0069] Figure 7 This is a structural block diagram of an electronic device illustrated in an exemplary embodiment of the present disclosure. Detailed Implementation

[0070] The technical solutions in the embodiments (or "implementations") of this disclosure will be clearly and completely described herein with reference to the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0071] If this disclosure uses terms relating to directional indications or positional relationships (e.g., up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationships and movements between components in a specific posture (as shown in the accompanying drawings); if the specific posture changes, the directional indications or positional relationships will also change accordingly. Furthermore, terms such as "first" and "second" in this disclosure are used only for descriptive convenience and should not be construed as indicating or implying relative importance.

[0072] Organic light-emitting diode (OLED) is a new type of display technology that uses organic semiconductor materials as the light-emitting layer. It emits light under the drive of current to achieve the purpose of display. It has advantages such as high contrast, high brightness, high color saturation, and low power consumption. Therefore, OLED technology has been widely used in various electronic products, and OLED screens are gradually becoming one of the mainstream display technologies for various electronic products.

[0073] OLED pixel driving circuits can use P-type and N-type transistors as driving transistors. P-type transistors have a larger subthreshold swing, resulting in a wider range of data manipulation. Therefore, the visual effect of OLEDs is easier to control at low grayscale levels. However, P-type transistors suffer from leakage problems. Compared to P-type transistors, N-type transistors avoid the leakage problems associated with P-type transistors, thus solving issues such as bright spots and difficulty in achieving low refresh rates caused by leakage. Using N-type transistors as driving transistors, and connecting the anode of an organic light-emitting diode (OLED) to the drain of the driving transistor, allows the light-emitting layer within the OLED to emit light towards the cathode surface. In this circuit, a storage capacitor needs to be connected between the gate and source of the driving transistor to maintain stability between the source and gate. However, the source node connected to the storage capacitor is often affected by the scan signal and the positive voltage drop of the power supply, leading to voltage instability in the storage capacitor. This instability in the gate voltage of the driving transistor causes uneven display, affecting the display effect of the device.

[0074] To address the aforementioned problems, this disclosure proposes a pixel circuit and a display device. The following embodiments are provided to further illustrate this disclosure:

[0075] For the first aspect of this application, please refer to... Figure 1 , Figure 1 This is a circuit diagram illustrating a pixel circuit with some exemplary embodiments. The pixel circuit includes: a pixel driving circuit and an organic light-emitting element (OLED) D. The pixel driving circuit includes a storage capacitor Cst, and the input terminal of the pixel driving circuit and the first terminal of the storage capacitor Cst are electrically connected to the negative terminal VSS of a power supply. The OLED D has its cathode electrode electrically connected to the output terminal of the pixel driving circuit, and its anode electrode electrically connected to the positive terminal VDD of a power supply. The output terminal of the pixel driving circuit is used to output a driving current to drive the OLED D to emit light.

[0076] For example, the organic light-emitting element D may include, but is not limited to, an organic light-emitting diode.

[0077] It should be noted that the cathode electrode of the organic light-emitting element (OLED) D requires electron injection, and the anode electrode requires hole injection. Therefore, when the output terminal of the pixel driving circuit is electrically connected to the cathode electrode of the OLED D, the input terminal of the pixel driving circuit should be electrically connected to the negative power supply VSS. When the input terminal of the pixel driving circuit is electrically connected to the anode electrode of the OLED D, the output terminal of the pixel driving circuit should be electrically connected to the positive power supply VDD. In this embodiment, the output terminal of the pixel driving circuit is electrically connected to the cathode electrode of the OLED D; therefore, the input terminal of the pixel driving circuit is electrically connected to the negative power supply VSS to meet the requirement of electron injection at the cathode electrode of the OLED D.

[0078] It is understandable that the storage capacitor Cst is electrically connected to the input terminal of the pixel driving circuit to maintain a stable voltage at the input terminal. Therefore, when the input terminal of the pixel driving circuit is connected to the negative power supply VSS, the storage capacitor Cst is naturally electrically connected to the negative power supply VSS. Thus, when the cathode electrode of the organic light-emitting element D is electrically connected to the output terminal of the pixel driving circuit, the storage capacitor Cst can be prevented from being connected between the organic light-emitting element D and the input terminal of the pixel driving circuit. This avoids the storage capacitor Cst being affected by the scanning signal and the voltage drop across the positive power supply VDD, thus ensuring a stable voltage at the first terminal of the storage capacitor Cst.

[0079] In this embodiment, the cathode electrode of the organic light-emitting element D is electrically connected to the output terminal of the pixel driving circuit, and the anode electrode of the organic light-emitting element D is electrically connected to the positive power supply VDD. Since the cathode electrode of the organic light-emitting element D needs to inject electrons, the input terminal of the pixel driving circuit needs to be electrically connected to the negative electrode. The first terminal of the storage capacitor Cst is also electrically connected to the negative power supply VSS. Thus, the first terminal of the storage capacitor Cst can be connected to the voltage-stable negative power supply VSS. The voltage-stable negative power supply VSS can stabilize the voltage of the first terminal of the storage capacitor Cst, thereby maintaining the voltage stability of the storage capacitor Cst. The voltage-stable storage capacitor Cst can ensure that the pixel driving circuit outputs a stable driving current to the organic light-emitting element D, making the luminous intensity of the organic light-emitting element D uniform, thereby solving the problem of uneven display and improving the display effect of the display device.

[0080] In some embodiments, please continue to see Figure 1 The pixel driving circuit may further include a first transistor T1, wherein the input terminal of the first transistor T1 is electrically connected to the input terminal of the pixel driving circuit, the output terminal of the first transistor T1 is electrically connected to the output terminal of the pixel driving circuit, and the control terminal of the first transistor T1 is electrically connected to the second terminal of the storage capacitor Cst.

[0081] In a preferred embodiment, the first transistor T1 is an N-type transistor. It should be noted that the active layer material of the N-type transistor is IGZO (Indium Gallium Zinc Oxide). IGZO material has characteristics such as wide bandgap, high mobility, low carrier concentration and low defect density. Therefore, the leakage current of the N-type transistor using IGZO material as the active layer material is small.

[0082] It is understandable that, when the first transistor T1 is an N-type transistor, the drain of the N-type transistor is electrically connected to the cathode electrode of the organic light-emitting element D to meet the requirement of electron injection from the cathode of the organic light-emitting element D.

[0083] In this design, the input terminal of the first transistor T1 can be understood as its source, the output terminal as its drain, and the control terminal as its gate. The storage capacitor Cst needs to be connected between the input and control terminals of the first transistor T1 to maintain a stable voltage between them. The conduction level of the first transistor T1 is related to the voltage difference between its input and control terminals. The larger the voltage difference, the greater the conduction current between its input and output terminals, resulting in a larger driving current for the organic light-emitting element D and a stronger luminous intensity from the organic light-emitting element D.

[0084] In this embodiment, a first transistor T1 is provided, with its input terminal electrically connected to the negative terminal VSS of the power supply, and its control terminal electrically connected to the second terminal of the storage capacitor Cst. Since the storage capacitor Cst is connected between the input terminal and the control terminal of the first transistor T1, the voltage between the control terminal and the input terminal of the first transistor T1 can be controlled. Furthermore, the output terminal of the first transistor T1 is electrically connected to the input terminal of the organic light-emitting element D. The storage capacitor Cst can adjust the conduction current between the input terminal and the output terminal of the first transistor T1 according to the voltage difference between the input terminal and the control terminal of the first transistor T1, thereby controlling the luminous intensity of the organic light-emitting element D. Furthermore, by setting the first transistor T1 as an N-type transistor, leakage problems associated with P-type transistors can be avoided. The input terminal of the first transistor T1 is electrically connected to the negative electrode, and the storage capacitor Cst is connected between the negative power supply VSS and the control terminal of the first transistor T1. The voltage of the storage capacitor Cst is stabilized by the stable negative power supply VSS, which avoids problems such as voltage instability at the control terminal of the first transistor T1 due to unstable voltage of the storage capacitor Cst. This improves the stability of the output current of the first transistor T1, thereby enabling the organic light-emitting element D to be in a stable light-emitting state.

[0085] In some embodiments, please refer to Figure 2 , Figure 2 This is a schematic cross-sectional view of an organic light-emitting element (OLED) D in a pixel circuit, illustrating some exemplary embodiments. The OLED D includes a cathode electrode 10, a first light-emitting layer 20a, and an anode electrode 30. The first light-emitting layer 20a is located on one side surface of the cathode electrode 10, and the anode electrode 30 is located on the surface of the first light-emitting layer 20a away from the cathode electrode 10. When the cathode electrode 10 of the OLED D receives a driving current, the cathode electrode 10 transfers electrons to the first light-emitting layer 20a, and the anode electrode 30 transfers holes to the first light-emitting layer 20a, causing the first light-emitting layer 20a to emit light towards the anode electrode 30.

[0086] It should be noted that the organic light-emitting element D in this embodiment may further include a first electron injection layer 40a, a first electron transport layer 50a, a first hole transport layer 60a, and a first hole injection layer 70a. The first electron injection layer 40a is located on one side surface of the cathode electrode 10, the first electron transport layer 50a is located on the surface of the first electron injection layer 40a away from the cathode electrode 10, the first hole transport layer 60a is located on the surface of the first light-emitting layer 20a away from the first electron transport layer 50a, and the first hole injection layer 60a is located on the surface of the first hole transport layer 70a away from the first light-emitting layer 20a.

[0087] In this process, electrons are injected into the cathode electrode 10, and the injected electrons pass through the first electron injection layer 40a and the first electron transport layer 50a to the first light-emitting layer 20a in sequence. Holes are injected into the anode electrode 30, and the injected holes pass through the first hole injection layer 70a and the first hole transport layer 60a to the first light-emitting layer 20a in sequence. In the first light-emitting layer 20a, the injected electrons and holes recombine and release photons, thereby realizing the light-emitting function of the organic light-emitting element D.

[0088] It is understood that the anode electrode 30 in this embodiment is a transparent electrode, and the first light-emitting layer 20a emits light in the direction of the anode electrode 30. Therefore, in this embodiment, the surface of the anode electrode 30 away from the first light-emitting layer 20a may also include a circularly polarized light-emitting layer 80. The circularly polarized light-emitting layer 80 can effectively reduce external light reflection and improve light emission efficiency and emitted light intensity.

[0089] In a preferred embodiment, please refer to Figure 3 , Figure 3 The schematic cross-sectional view of an organic light-emitting element D in a pixel circuit, shown for some other exemplary embodiments, further includes: a hole-generating layer 90, an electron-generating layer 100, and a second light-emitting layer 20b. The hole-generating layer 90 is located on the surface of the first light-emitting layer 20a away from the cathode electrode 10, the electron-generating layer 100 is located on the surface of the hole-generating layer 90 away from the first light-emitting layer 20a, and the second light-emitting layer 20b is located between the electron-generating layer 100 and the anode electrode 30. When the cathode electrode 10 of the organic light-emitting element D receives a driving current, the hole-generating layer 90 generates holes and transmits the generated holes to the first light-emitting layer 20a, and the electron-generating layer 100 generates electrons and transmits the generated electrons to the second light-emitting layer 20b, so that both the first light-emitting layer 20a and the second light-emitting layer 20b emit light towards the anode electrode 30.

[0090] It should be noted that the organic light-emitting element D may further include a second electron injection layer 40b, a second electron transport layer 50b, a second hole transport layer 60b, and a second hole injection layer 70b. The second electron injection layer 40b is located on the surface of the electron generating layer 100 away from the hole generating layer 90. The second electron transport layer 50b is located on the surface of the second electron injection layer 40b away from the electron generating layer 100. The second light-emitting layer 20b is located on the surface of the second electron transport layer 50b away from the second electron injection layer 40b. The second hole transport layer 60b is located on the surface of the second light-emitting layer 20b away from the second electron 50b. The second hole injection layer 70b is located on the surface of the second hole transport layer 60b away from the second light-emitting layer 20b.

[0091] In this process, electrons are injected into the cathode electrode 10, and these injected electrons sequentially pass through the first electron injection layer 40a and the first electron transport layer 50a to the first light-emitting layer 20. Holes are generated by the hole generation layer 90, and these generated holes sequentially pass through the first hole injection layer 70a and the first hole transport layer 60a to the first light-emitting layer 20a. In the first light-emitting layer 20a, the injected electrons and holes recombine, releasing photons. Furthermore, electrons are generated by the electron generation layer 100, and these generated electrons pass through the second electron injection layer 40b and the second electron transport layer 50b to the second light-emitting layer 20b. Holes are injected into the anode electrode 30, and these injected holes sequentially pass through the second hole injection layer 70b and the second hole transport layer 60b to the second light-emitting layer 20b. In the second light-emitting layer 20b, the injected electrons and holes recombine, releasing photons, thus realizing the light-emitting function of the organic light-emitting element D.

[0092] In this embodiment, by providing a cathode electrode 10, a first light-emitting layer 20a, and an anode electrode 30 in the organic light-emitting element D, when the cathode electrode of the organic light-emitting element D receives a driving current, the cathode electrode 10 transfers electrons to the first light-emitting layer 20a, and the anode electrode 30 transfers holes to the first light-emitting layer 20a, causing the first light-emitting layer 20a to emit light towards the anode electrode 30. By having the first light-emitting layer 20a of the organic light-emitting element D emit light towards the anode electrode 30, the cathode electrode 10 of the organic light-emitting element D is electrically connected to the output terminal of the pixel driving circuit, thereby making the input terminal of the pixel driving circuit electrically connected to the negative power supply VSS. Therefore, the storage capacitor Cst can be connected to the negative power supply VSS, ensuring a stable voltage for the storage capacitor Cst. Furthermore, by adding a hole generation layer 90, an electron generation layer 100, and a second light-emitting layer 20b to the organic light-emitting element D, multi-layer light emission of the first light-emitting layer 20a and the second light-emitting layer 20b can be achieved on top of the single-layer light emission of the first light-emitting layer 20a, thereby improving the luminous efficiency of the organic light-emitting element D.

[0093] In one embodiment, please refer to Figure 4 , Figure 4 The following is a circuit diagram of a pixel circuit shown in some other exemplary embodiments. The pixel circuit may also include a compensation circuit, wherein the input terminal of the compensation circuit is connected between the input terminal of the first transistor T1 and the input terminal of the pixel driving circuit, and the output terminal of the compensation circuit is connected between the output terminal of the first transistor T1 and the output terminal of the pixel driving circuit, and is electrically connected to the second terminal of the storage capacitor Cst. The compensation circuit is used to receive frame data Data and write the frame data Data into the storage capacitor Cst.

[0094] In a preferred embodiment, please continue reading Figure 4The compensation circuit may include a second transistor T2 and a third transistor T3. The input terminal of the second transistor T2 is used to receive frame data Data, and the output terminal of the second transistor T2 serves as the input terminal of the compensation circuit. The control terminal of the second transistor T2 is used to receive a first scan signal Pscan1, and the second transistor T2 is used to input frame data Data to the input terminal of the first transistor T1 according to the first scan signal Pscan1. The input terminal of the third transistor T3 serves as the output terminal of the compensation circuit, and the output terminal of the third transistor T3 is electrically connected to the second terminal of the storage capacitor Cst. The control terminal of the third transistor T3 is used to receive a second scan signal Nscan1, and the third transistor T3 is used to write frame data Data to the storage capacitor Cst according to the second scan signal Nscan1.

[0095] In this design, the second transistor T2 is a P-type transistor, and the third transistor T3 is an N-type transistor. Frame data (Data) can be understood as digital information used to control the light emission state of each pixel on the display panel. Frame data (Data) determines the color and brightness of each pixel's emission within a specific time period, thus forming a complete image on the screen. When the control terminal of the second transistor T2 receives the first scan signal Pscan1, the second transistor T2 is turned on to input the frame data (Data) to the first transistor T1. When the control terminal of the third transistor T3 receives the second scan signal Nscan1, the third transistor T3 is turned on to write the frame data (Data) to the storage capacitor Cst.

[0096] In this embodiment, the second transistor T2 in the compensation circuit can be turned on or off according to the first scan signal Pscan1 to adjust the gate voltage of the first transistor T1, thereby dynamically adjusting the gate voltage of the first transistor T1 to offset the change in the threshold voltage. Furthermore, when the pixel circuit is working, the second transistor T2 can receive frame data Data and write the frame data Data into the storage capacitor Cst through the third transistor T3 in the compensation circuit, ensuring that the storage capacitor Cst maintains a compensated voltage value. Therefore, by setting up the compensation circuit, display non-uniformity and brightness fluctuations caused by factors such as transistor characteristic changes, power supply voltage fluctuations, and temperature changes can be reduced, improving display quality and stability.

[0097] In one embodiment, please refer to Figure 5 , Figure 5This is a circuit diagram of a pixel circuit shown in some exemplary embodiments. The pixel driving circuit may further include a reset circuit for resetting the storage capacitor Cst, the organic light-emitting element D, and the first transistor T1. The first terminal of the reset circuit is connected between the control terminal of the first transistor T1 and the second terminal of the storage capacitor Cst. The second terminal of the reset circuit is connected between the output terminal of the first transistor T1 and the output terminal of the pixel driving circuit. The third terminal of the reset circuit is connected between the input terminal of the first transistor T1 and the input terminal of the pixel driving circuit.

[0098] In a preferred embodiment, the reset circuit includes a fourth transistor T4, wherein the input terminal of the fourth transistor T4 is used to receive a first reset voltage Vi1, the output terminal of the fourth transistor T4 serves as the first terminal of the reset circuit, the control terminal of the fourth transistor T4 is used to receive a third scan signal Nscan2, and the fourth transistor T4 is used to output the first reset voltage Vi1 to the storage capacitor Cst according to the third scan signal Nscan2, so as to reset the storage capacitor Cst.

[0099] The fourth transistor T4 is an N-type transistor. When the control terminal of the fourth transistor T4 receives the third scan signal Nscan2, it turns on to output the first reset voltage Vi1 to the storage capacitor Cst to reset the storage capacitor Cst.

[0100] In another preferred embodiment, the reset circuit may further include: a fifth transistor T5, wherein the input terminal of the fifth transistor T5 is used to receive a second reset voltage Vi2, the output terminal of the fifth transistor T5 serves as the second terminal of the reset circuit, the control terminal of the fifth transistor T5 is used to receive a fourth scan signal Pscan2, and the fifth transistor T5 is used to output a second reset voltage Vi2 to the organic light-emitting element D according to the fourth scan signal Pscan2, so as to reset the organic light-emitting element D.

[0101] Among them, the fifth transistor T5 is a P-type transistor. When the control terminal of the fifth transistor T5 receives the fourth scan signal Pscan2, the fifth transistor T5 turns on to output the second reset voltage Vi2 to the organic light-emitting element D to reset the organic light-emitting element D.

[0102] In another preferred embodiment, the reset circuit may further include: a sixth transistor T6, wherein the input terminal of the sixth transistor T6 is used to receive a third reset voltage Vi3, the output terminal of the sixth transistor T6 serves as the third terminal of the reset circuit, the control terminal of the sixth transistor T6 is used to receive a fourth scan signal Pscan2, and the sixth transistor T6 is used to input the third reset voltage Vi3 to the input terminal of the first transistor T1 according to the fourth scan signal Pscan2, so as to reset the first transistor T1.

[0103] The sixth transistor T6 is a P-type transistor. When the control terminal of the sixth transistor T6 receives the fourth scan signal Pscan2, the sixth transistor T6 turns on to apply the third reset voltage Vi3 to the input terminal of the first transistor T1 to reset the first transistor T1.

[0104] In this embodiment, a reset circuit is provided. The fourth transistor T4 in the reset circuit can reset the storage capacitor Cst. At the beginning of each display cycle, the voltage across the storage capacitor Cst can be set to a known initial value, clearing residual charge from the previous frame and ensuring that the new data voltage can be written correctly, avoiding the influence of the previous frame's data on the current frame. The fifth transistor T5 in the reset circuit can reset the organic light-emitting element D, preventing residual charge from causing after-effects on the organic light-emitting element D after driving stops. This restores the organic light-emitting element D to its initial state, ensuring that it is completely off when displaying black or dark images. The sixth transistor T6 in the reset circuit can reset the input terminal of the first transistor T1, reducing voltage deviation at the input terminal of the first transistor T1 and improving the stability of the output current of the first transistor T1, ensuring that the pixel circuit is in the same initial state in each display cycle. The reset circuit clears residual charge from the previous frame, ensuring that the pixel circuit always operates in its initial state, ensuring that each pixel starts working under the same conditions in each display cycle, thereby achieving a high-quality display effect.

[0105] In one embodiment, please refer to Figure 6 , Figure 6 This is a circuit diagram of a pixel circuit shown in some exemplary embodiments. The pixel driving circuit may further include a control circuit. The control circuit is used to receive a control signal EM and control the first transistor T1 to output a driving current to the organic light-emitting element D according to the control signal EM. One end of the control circuit is connected between the input terminal of the first transistor T1 and the input terminal of the pixel driving circuit, and the other end of the control circuit is connected between the output terminal of the first transistor T1 and the output terminal of the pixel driving circuit.

[0106] In a preferred embodiment, the control circuit may include a seventh transistor T7 and an eighth transistor T8. The seventh transistor T7 serves as one end of the control circuit, with its input terminal electrically connected to the input terminal of the pixel driving circuit and its output terminal electrically connected to the input terminal of the first transistor T1. The control terminal of the seventh transistor T7 is used to receive a control signal EM. The eighth transistor T8 serves as the other end of the control circuit, with its input terminal electrically connected to the output terminal of the first transistor T1 and its output terminal electrically connected to the output terminal of the pixel driving circuit. The control terminal of the eighth transistor T8 is used to receive the control signal EM. The seventh transistor T7 and the eighth transistor T8 are synchronously turned on under the control of the control signal EM.

[0107] In this configuration, both the seventh transistor T7 and the eighth transistor T8 are P-type transistors. When the control terminals of the seventh transistor T7 and the eighth transistor T8 receive the control signal EM, the control terminals of the seventh transistor T7 and the eighth transistor T8 are synchronously turned on, so that the input terminal of the first transistor T1 is connected to the negative terminal VSS of the power supply, and the output terminal of the first transistor T1 is electrically connected to the cathode electrode of the organic light-emitting element D.

[0108] In this embodiment, by setting a control circuit, it can be ensured that the pixel circuits are activated or deactivated at the correct time, achieving synchronized image display. Precise control of the activation and deactivation of the pixel circuits can reduce interference between different pixel circuits and improve display quality. Furthermore, the control circuit can be configured according to actual needs to selectively activate pixels in specific areas, achieving local refresh and reducing power consumption.

[0109] A second aspect of this disclosure provides a display panel including pixel circuitry as described in any of the first aspects.

[0110] A third aspect of this disclosure provides an electronic device including a pixel circuit as described in any of the first aspects, or a display panel as described in the second aspect.

[0111] Please refer to the appendix. Figure 7 The diagram illustrates, for example, a block diagram of the terminal device. For instance, device 700 could be a mobile phone, computer, digital broadcasting terminal, messaging device, game console, tablet device, medical device, fitness equipment, personal digital assistant, etc.

[0112] Reference Figure 7 The device 700 may include one or more of the following components: a processing component 702, a memory 704, a power supply component 706, a multimedia component 708, an audio component 710, an input / output (I / O) interface 77, a sensor component 714, and a communication component 716.

[0113] Processing component 702 typically controls the overall operation of device 700, such as operations associated with display, telephone calls, data communication, optical camera operation, and recording operations. Processing component 702 may include one or more processors 720 to execute instructions to complete all or part of the steps of the methods described above. Furthermore, processing component 702 may include one or more modules to facilitate interaction between processing component 702 and other components. For example, processing component 702 may include a multimedia module to facilitate interaction between multimedia component 708 and processing component 702.

[0114] Memory 704 is configured to store various types of data to support the operation of device 700. Examples of this data include instructions for any application or method operating on device 700, contact data, phonebook data, messages, pictures, videos, etc. Memory 704 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0115] The power supply component 706 provides power to the various components of the device 700. The power supply component 706 may include a power management system, one or more power sources, and other components associated with generating, managing, and distributing power to the device 700.

[0116] Multimedia component 708 includes a screen that provides an output interface between the device 700 and the occupant. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touchscreen to receive input signals from the occupant. The touch panel includes one or more touch sensors to sense touch, swipe, and gestures on the touch panel. The touch sensors may sense not only the boundaries of the touch or swipe action but also the duration and pressure associated with the touch or swipe operation. In some embodiments, multimedia component 708 includes a front-facing optical camera and / or a rear-facing optical camera. When the device 700 is in an operating mode, such as a shooting mode or a video mode, the front-facing optical camera and / or the rear-facing optical camera may receive external multimedia data. Each front-facing and rear-facing optical camera may be a fixed optical lens system or have focal length and optical zoom capabilities.

[0117] Audio component 710 is configured to output and / or input audio signals. For example, audio component 710 includes a microphone (MIC) configured to receive external audio signals when device 700 is in an operating mode, such as call mode, recording mode, and voice recognition mode. The received audio signals may be further stored in memory 704 or transmitted via communication component 716. In some embodiments, audio component 710 also includes a speaker for outputting audio signals.

[0118] I / O interface 77 provides an interface between processing component 702 and peripheral interface modules, such as keyboards, click wheels, buttons, etc. These buttons may include, but are not limited to, home buttons, volume buttons, power buttons, and lock buttons.

[0119] Sensor assembly 714 includes one or more sensors for providing status assessments of various aspects of device 700. For example, sensor assembly 714 may detect the on / off state of device 700, the relative positioning of components such as the display and keypad of device 700, changes in position of device 700 or a component of device 700, the presence or absence of occupant contact with device 700, orientation or acceleration / deceleration of device 700, and temperature changes of device 700. Sensor assembly 714 may also include a proximity sensor configured to detect the presence of nearby objects without any physical contact. Sensor assembly 714 may also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, sensor assembly 714 may also include an accelerometer, a gyroscope, a magnetometer, a pressure sensor, or a temperature sensor.

[0120] Communication component 716 is configured to facilitate wired or wireless communication between device 700 and other devices. Device 700 can access wireless networks based on communication standards, such as WiFi, 2G or 3G, 4G or 5G, or combinations thereof. In one exemplary embodiment, communication component 716 receives broadcast signals or broadcast-related information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, communication component 716 also includes a near-field communication (NFC) module to facilitate short-range communication. For example, the NFC module may be implemented based on radio frequency identification (RFID) technology, Infrared Data Association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology, and other technologies.

[0121] In an exemplary embodiment, device 700 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components.

[0122] The foregoing has described specific embodiments of this disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0123] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the utility model applied herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not claimed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0124] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

[0125] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A pixel circuit, characterized in that, include: A pixel driving circuit includes a storage capacitor (Cst), wherein the input terminal of the pixel driving circuit and the first terminal of the storage capacitor (Cst) are respectively electrically connected to the negative power supply (VSS); and An organic light-emitting element (D) is provided, wherein the cathode electrode of the organic light-emitting element (D) is electrically connected to the output terminal of the pixel driving circuit, and the anode electrode of the organic light-emitting element (D) is electrically connected to the positive terminal of the power supply (VDD). The output terminal of the pixel driving circuit is used to output driving current to drive the organic light-emitting element (D) to emit light.

2. The pixel circuit according to claim 1, characterized in that, The pixel driving circuit further includes a first transistor (T1), wherein, The input terminal of the first transistor (T1) is electrically connected to the input terminal of the pixel driving circuit. The output terminal of the first transistor (T1) is electrically connected to the output terminal of the pixel driving circuit. The control terminal of the first transistor (T1) is electrically connected to the second terminal of the storage capacitor (Cst).

3. The pixel circuit according to claim 2, characterized in that, The first transistor (T1) is an N-type transistor.

4. The pixel circuit according to claim 1, characterized in that, The organic light-emitting element (D) includes a first light-emitting layer (20a), wherein, The first light-emitting layer (20a) is located on one side surface of the cathode electrode (10) of the organic light-emitting element (D); The anode electrode (30) of the organic light-emitting element (D) is located on the surface of the first light-emitting layer (20a) away from the cathode electrode (10); When the driving current is received, the cathode electrode (10) of the organic light-emitting element (D) is used to transfer electrons to the first light-emitting layer (20a), and the anode electrode (30) of the organic light-emitting element (D) is used to transfer holes to the first light-emitting layer (20a), so that the first light-emitting layer (20a) emits light toward the anode electrode (30).

5. The pixel circuit according to claim 4, characterized in that, The organic light-emitting element (D) also includes: A hole-generating layer (90) is located on the surface of the first light-emitting layer (20a) away from the cathode electrode (10); An electron generating layer (100) is located on the surface of the hole generating layer (90) away from the first light-emitting layer (20a); The second light-emitting layer (20b) is located between the electron-generating layer (100) and the anode electrode (30); When the driving current is received, the hole generating layer (90) generates holes and transmits the generated holes to the first light-emitting layer (20a), and the electron generating layer (100) generates electrons and transmits the generated electrons to the second light-emitting layer (20b), so that both the first light-emitting layer (20a) and the second light-emitting layer (20b) emit light toward the anode electrode (30).

6. The pixel circuit according to claim 2, characterized in that, The pixel driving circuit further includes a compensation circuit, wherein... The input terminal of the compensation circuit is connected between the input terminal of the first transistor (T1) and the input terminal of the pixel driving circuit. The output terminal of the compensation circuit is connected between the output terminal of the first transistor (T1) and the output terminal of the pixel driving circuit, and is electrically connected to the second terminal of the storage capacitor (Cst). The compensation circuit is used to receive frame data (Data) and write the frame data (Data) into the storage capacitor (Cst).

7. The pixel circuit according to claim 6, characterized in that, The compensation circuit includes: A second transistor (T2) is used, the input of which receives the frame data (Data), and the output of which serves as the input of the compensation circuit. The control terminal of the second transistor (T2) receives a first scan signal (Pscan1), and the second transistor (T2) is used to input the frame data (Data) to the input of the first transistor (T1) according to the first scan signal (Pscan1). The third transistor (T3) has its input terminal serving as the output terminal of the compensation circuit. The output terminal of the third transistor (T3) is electrically connected to the second terminal of the storage capacitor (Cst). The control terminal of the third transistor (T3) is used to receive the second scan signal (Nscan1). The third transistor (T3) is used to write frame data (Data) to the storage capacitor (Cst) according to the second scan signal (Nscan1).

8. The pixel circuit according to claim 2, characterized in that, The pixel driving circuit further includes a reset circuit for resetting the storage capacitor (Cst), the organic light-emitting element (D), and the first transistor (T1), wherein, The first terminal of the reset circuit is connected between the control terminal of the first transistor (T1) and the second terminal of the storage capacitor (Cst). The second terminal of the reset circuit is connected between the output terminal of the first transistor (T1) and the output terminal of the pixel driving circuit. The third terminal of the reset circuit is connected between the input terminal of the first transistor (T1) and the input terminal of the pixel driving circuit.

9. The pixel circuit according to claim 8, characterized in that, The reset circuit includes a fourth transistor (T4), wherein, The input terminal of the fourth transistor (T4) is used to receive the first reset voltage (Vi1). The output terminal of the fourth transistor (T4) serves as the first terminal of the reset circuit. The control terminal of the fourth transistor (T4) is used to receive the third scan signal (Nscan2). The fourth transistor (T4) is used to output a first reset voltage (Vi1) to the storage capacitor (Cst) according to the third scan signal (Nscan2) to reset the storage capacitor (Cst).

10. The pixel circuit according to claim 8, characterized in that, The reset circuit further includes a fifth transistor (T5), wherein, The input terminal of the fifth transistor (T5) is used to receive the second reset voltage (Vi2). The output terminal of the fifth transistor (T5) serves as the second terminal of the reset circuit. The control terminal of the fifth transistor (T5) is used to receive the fourth scan signal (Pscan2). The fifth transistor (T5) is used to output a second reset voltage (Vi2) to the organic light-emitting element (D) according to the fourth scan signal (Pscan2) to reset the organic light-emitting element (D).

11. The pixel circuit according to claim 8, characterized in that, The reset circuit further includes: a sixth transistor (T6), wherein, The input terminal of the sixth transistor (T6) is used to receive the third reset voltage (Vi3). The output terminal of the sixth transistor (T6) serves as the third terminal of the reset circuit. The control terminal of the sixth transistor (T6) is used to receive the fourth scan signal (Pscan2). The sixth transistor (T6) is used to input a third reset voltage (Vi3) to the input terminal of the first transistor (T1) according to the fourth scan signal (Pscan2) to reset the first transistor (T1).

12. The pixel circuit according to claim 2, characterized in that, The pixel driving circuit further includes a control circuit, which receives a control signal (EM) and controls the first transistor (T1) to output the driving current to the organic light-emitting element (D) according to the control signal (EM). One end of the control circuit is connected between the input terminal of the first transistor (T1) and the input terminal of the pixel driving circuit. The other end of the control circuit is connected between the output terminal of the first transistor (T1) and the output terminal of the pixel driving circuit.

13. The pixel circuit according to claim 12, characterized in that, The control circuit includes: A seventh transistor (T7), which serves as one end of the control circuit, has its input terminal electrically connected to the input terminal of the pixel driving circuit, and its output terminal electrically connected to the input terminal of the first transistor (T1). The control terminal of the seventh transistor (T7) is used to receive the control signal (EM); and The eighth transistor (T8) serves as the other end of the control circuit. The input terminal of the eighth transistor (T8) is electrically connected to the output terminal of the first transistor (T1), and the output terminal of the eighth transistor (T8) is electrically connected to the output terminal of the pixel driving circuit. The control terminal of the eighth transistor (T8) is used to receive the control signal (EM). The seventh transistor (T7) and the eighth transistor (T8) are used to be synchronously turned on under the control of the control signal (EM).

14. A display panel, characterized in that, Includes the pixel circuit as described in any one of claims 1 to 13.

15. An electronic device, characterized in that, It includes the pixel circuitry as described in any one of claims 1 to 13, or the display panel as described in claim 14.

Images