Display driving circuit, display driving method and display panel

Abstract

The present application belongs to the field of display, and specifically relates to a display driving circuit, a display driving method and a display panel, wherein the display driving circuit includes a storage unit, a data writing unit, a compensation unit and a voltage control unit, wherein a first light-emitting control unit, a fourth node, a first transistor, a second node and a display light-emitting unit are connected in sequence, the storage unit includes a first capacitor and a second capacitor, the first capacitor is connected to the control end of the first transistor through the first node, the second capacitor is connected to the first node and the second node, the first light-emitting control unit has a first power supply and a first end of the first transistor, the data writing unit is connected to a data line and a third node of the first capacitor away from one end of the first node, the compensation unit is connected to at least the first node and the fourth node, and the voltage control unit is connected to the second node and the ground end. When the display driving circuit is working, the compensation unit compensates for the threshold voltage and the power supply voltage of the driving transistor, thereby improving the problem of uneven display of the display panel.

Description

Technical Field

[0001] The present application belongs to the field of display, and specifically relates to a display driving circuit, a display driving method and a display panel. Background Art

[0002] OLED (Organic Light-Emitting Diode) display panel has the advantages of self-luminescence, flexibility, thin thickness, high brightness, low power consumption, fast response, and wide color gamut, and has broad development prospects.

[0003] The display driving circuit of the organic light emitting diode includes a driving transistor. When the scanning signal arrives, the data signal is written into the gate of the driving transistor to control the degree of opening of the driving transistor, thereby controlling the driving current through the organic light emitting diode and the brightness of the organic light emitting diode. In addition, the brightness of the organic light emitting diode is also affected by the power supply voltage. The higher the power supply voltage, the higher the brightness of the organic light emitting diode.

[0004] In the process of manufacturing display panels, it is difficult to achieve absolute uniformity of film quality at all locations, resulting in different threshold voltages (Vth) of different driving transistors, which in turn leads to different brightness of different organic light-emitting diodes, that is, uneven display of the display panel. At the same time, since the power supply voltage will form a voltage drop when it is transmitted in the metal line (especially more obvious in large-size panels), the power supply voltage drop of different organic light-emitting diodes is different, further exacerbating the uneven display of the display panel. Summary of the invention

[0005] The purpose of the present application is to provide a display driving circuit, a display driving method and a display panel to compensate for the threshold voltage of a driving transistor and improve the display unevenness problem of a display panel.

[0006] In order to achieve the above object, the present application provides a display driving circuit, including a first transistor, a first end of the first transistor is connected to a first power supply, a second end of the first transistor is connected to a second power supply through a display light emitting unit, and the display driving circuit further includes:

[0007] A storage unit, the storage unit comprising a first capacitor and a second capacitor, the first capacitor being connected to the control end of the first transistor via a first node, and the second capacitor being connected to the first node and a second node between the first transistor and the display light-emitting unit;

[0008] a first light emitting control unit connected to a first light emitting control line, the first power source and a first end of the first transistor;

[0009] a data writing unit connected to the first scan line, the data line, and a third node of the first capacitor away from one end of the first node;

[0010] a compensation unit, connected at least to the second scan line, the first node, and a fourth node between the first light emitting control unit and the first transistor;

[0011] A voltage control unit is connected to the second node and a ground terminal.

[0012] Optionally, the compensation unit includes a second transistor, a control end of the second transistor is connected to the second scan line, a first end of the second transistor is connected to the fourth node, and a second end of the second transistor is connected to the first node.

[0013] Optionally, the compensation unit further includes a third transistor, a control end of the third transistor is connected to the third scan line, a first end of the third transistor is connected to the third node, and a second end of the third transistor is connected to the fourth node.

[0014] Optionally, the second power supply is the ground terminal.

[0015] Optionally, the voltage control unit includes a fourth transistor, a control end of the fourth transistor is connected to a ground control line, a first end of the fourth transistor is connected to the second node, and a second end of the fourth transistor is connected to the ground end.

[0016] Optionally, the voltage control unit includes a fifth transistor, the control end of the fifth transistor is connected to the third scan line, the first end of the fifth transistor is connected to the second node, the second end of the fifth transistor is connected to the ground end, and the ground control line is the first scan line.

[0017] Optionally, the display driving circuit also includes a second light-emitting control unit, the second light-emitting control unit includes a sixth transistor, the control end of the sixth transistor is connected to the second light-emitting control line, the first end of the sixth transistor is connected to the second node, and the second end of the sixth transistor is connected to the display light-emitting unit.

[0018] The present application also provides a display driving method for driving the display driving circuit, the display driving method comprising:

[0019] In the initialization stage, the first light emitting control unit and the compensation unit are controlled to be turned on, the first power supply voltage is written to the first node, and the data writing unit and the voltage control unit are controlled to be turned on, and the voltage of the second node and the third node are maintained to be 0;

[0020] In the compensation stage, the first light emitting control unit is controlled to be turned off and the compensation unit, the data writing unit and the voltage control unit are kept turned on, so as to write the threshold voltage of the first transistor into the second capacitor;

[0021] In the data writing phase, the compensation unit is controlled to be turned off and the data writing unit and the voltage control unit are kept turned on, so as to write the data voltage of the data line into the third node;

[0022] In the light emitting stage, the first light emitting control unit is controlled to be turned on and the compensation unit, the data writing unit and the voltage control unit are controlled to be turned off, so that the display light emitting unit emits light.

[0023] Optionally, the compensation unit includes a second transistor and a third transistor, the control end of the second transistor is connected to the second scan line, the first end of the second transistor is connected to the fourth node, the second end of the second transistor is connected to the first node, the control end of the third transistor is connected to the third scan line, the first end of the third transistor is connected to the third node, and the second end of the third transistor is connected to the fourth node, and in the compensation stage, the second transistor is controlled to be turned on through the second scan line;

[0024] The display driving method further includes:

[0025] In the mobility compensation phase between the light emitting phases, the third transistor is turned on by controlling the third scan line, so that the charge flows from the third node to the ground terminal through the third transistor, the first transistor and the voltage control unit for discharge.

[0026] The present application also provides a display panel, comprising:

[0027] Display light emitting unit;

[0028] The display driving circuit is connected to the display light emitting unit.

[0029] The display driving circuit, display driving method and display panel disclosed in the present application have the following beneficial effects:

[0030] In the present application, the display driving circuit includes a first transistor, a storage unit, a first light-emitting control unit, a data writing unit, a compensation unit and a voltage control unit, the first light-emitting control unit, the fourth node, the first transistor, the second node and the display light-emitting unit are connected in sequence, the storage unit includes a first capacitor and a second capacitor, the first capacitor is connected to the control end of the first transistor through the first node, the second capacitor is connected to the first node and the second node, the first light-emitting control unit is connected to the first light-emitting control line, the first power supply and the first end of the first transistor, the data writing unit is connected to the first scan line, the data line and the third node of the first capacitor away from the first node, the compensation unit is at least connected to the second scan line, the first node and the fourth node between the first light-emitting control unit and the first transistor, and the voltage control unit is connected to the second node and the ground terminal. When the display driving circuit is working, the compensation unit compensates for the threshold voltage and the power supply voltage of the driving transistor, thereby improving the display unevenness problem of the display panel.

[0031] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0032] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 It is a structural schematic diagram of the display driving circuit in the first embodiment of the present application.

[0035] Figure 2 Schematic diagram of the control timing of the display driving circuit in the first embodiment of the present application.

[0036] Figure 3 It is a schematic diagram of the display driving circuit in the initialization stage in the first embodiment of the present application.

[0037] Figure 4 It is a schematic diagram of the display driving circuit in the compensation stage in the first embodiment of the present application.

[0038] Figure 5 It is a schematic diagram of the display driving circuit in the data writing stage in the first embodiment of the present application.

[0039] Figure 6It is a schematic diagram of the display driving circuit in the mobility compensation stage in the first embodiment of the present application.

[0040] Figure 7 It is a schematic diagram of the display driving circuit in the light-emitting stage in the first embodiment of the present application.

[0041] Figure 8 It is a flow chart of the display driving method in the second embodiment of the present application.

[0042] Fig. 9 It is a schematic diagram of the structure of the display panel in the third embodiment of the present application.

[0043] Description of reference numerals:

[0044] 100, display driving circuit; 110, first transistor;

[0045] 120, storage unit; 121, first capacitor; 122, second capacitor;

[0046] 130. a first light emitting control unit; 131. a seventh transistor;

[0047] 140, data writing unit; 141, eighth transistor;

[0048] 150, compensation unit; 151, second transistor; 152, third transistor;

[0049] 160, voltage control unit; 161, fourth transistor; 162, fifth transistor;

[0050] 170. A second light emitting control unit; 171. A sixth transistor;

[0051] 200, display light emitting unit;

[0052] 301, a first power source; 302, a second power source; 303, a ground terminal;

[0053] 401, a first scanning line; 402, a second scanning line; 403, a third scanning line; 404, a data line; 405, a first light-emitting control line; 406, a second light-emitting control line. DETAILED DESCRIPTION

[0054] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0055] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0056] The present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be understood as limiting the present application.

[0057] Embodiment 1

[0058] See also Figure 1 As shown, in this embodiment, the display driving circuit 100 includes a first transistor 110, a storage unit 120, a first light emitting control unit 130, a data writing unit 140, a compensation unit 150 and a voltage control unit 160. The first transistor 110 is a driving transistor, a first end of the first transistor 110 is connected to a first power source 301, and a second end of the first transistor 110 is connected to a second power source 302 through a display light emitting unit 200. The display light emitting unit 200 includes an organic light emitting diode. The voltage of the first power source 301 is greater than the voltage of the second power source 302.

[0059] The storage unit 120 includes a first capacitor 121 and a second capacitor 122. The first capacitor 121 is connected to the control end of the first transistor 110 through a first node A. The second capacitor 122 is connected to the first node A and a second node B between the first transistor 110 and the display light-emitting unit 200. The first light-emitting control unit 130 is connected to the first light-emitting control line 405, the first power source 301 and the first end of the first transistor 110. The first light-emitting control line 405 signal (EM1) controls the conduction or disconnection between the first power source 301 and the first transistor 110, and controls the voltage writing of the first power source 301.

[0060] The data writing unit 140 is connected to the first scan line 401, the data line 404, and the third node C at one end of the first capacitor 121 away from the first node A. The first scan line 401 signal (G1) controls the data line 404 signal to be written into the third node C. The data line 404 signal includes a data voltage Vdata and a non-display voltage, the non-display voltage is 0, and the data voltage Vdata is greater than 0. The compensation unit 150 is at least connected to the second scan line 402, the first node A, and the fourth node D between the first light emitting control unit 130 and the first transistor 110. The second scan line 402 signal (G2) controls the conduction or disconnection between the first node A and the fourth node D. The voltage control unit 160 is connected to the second node B and the ground terminal 303 to control the conduction or disconnection between the second node B and the ground terminal 303.

[0061] See also Figures 2 to 7 As shown, when the display driving circuit 100 works:

[0062] In the initialization stage T1, the data writing unit 140 is turned on, the data line 404 signal is written to the third node C, the voltage of the third node C is 0, the first light emitting control unit 130 and the compensation unit 150 are turned on, the first power supply 301 charges the first node A through the compensation unit 150, the voltage of the first node A is the voltage Vdd of the first power supply 301, the voltage control unit 160 is turned on, the voltage of the second node B is pulled down to 0 by the ground terminal 303, for the first transistor 110, its gate-source voltage difference Vgs=VA-VB=Vdd, the voltage Vdd of the first power supply 301 is greater than the threshold voltage Vth of the first transistor 110, and the first transistor 110 is turned on;

[0063] In the compensation stage T2, the first light-emitting control unit 130 is turned off, and the data writing unit 140, the compensation unit 150 and the voltage control unit 160 are kept turned on, so that the charge is discharged from the first node A to the ground terminal 303 through the compensation unit 150, the first transistor 110 and the voltage control unit 160 until the gate-source voltage difference Vgs of the first transistor 110 is equal to the threshold voltage Vth of the first transistor 110, and the first transistor 110 is turned off. At this time, VA=Vth+VB=Vth, that is, the threshold voltage Vth of the first transistor 110 is written into the second capacitor 122;

[0064] In the data writing stage T3, the compensation unit 150 is turned off, the first light emitting control unit 130 is kept turned off, the data writing unit 140 and the voltage control unit 160 are kept turned on, and the data voltage Vdata of the data line 404 is written to the third node C. Due to capacitive coupling and charge conservation, the voltage VA of the first node A is Vth+(C1 / (C1+C2))×Vdata, where C1 is the capacitance of the first capacitor 121, and C2 is the capacitance of the second capacitor 122. For the first transistor 110, its gate-source voltage difference Vgs=VA-VB=Vth+(C1 / (C1+C2))×Vdata>Vth, and the first transistor 110 is turned on again;

[0065] In the light emitting stage T5, the first light emitting control unit 130 is turned on, the data writing unit 140, the compensation unit 150 and the voltage control unit 160 are turned off, and the current flows through the display light emitting unit 200 via the first light emitting control unit 130 and the first transistor 110, and the display light emitting unit 200 emits light.

[0066] Since the data writing unit 140 is turned off in the light-emitting stage T5, the third node C has no charging and discharging path, the voltage difference between the first capacitor 121 and the second capacitor 122 remains unchanged, and the threshold voltage Voled of the display light-emitting unit 200 is not considered. The voltage of the first node A is VA=Vth+(C1 / (C1+C2))×Vdata, and the current I flowing through the display light-emitting unit 200 is:

[0067] I=1 / 2×μ×k×(Vgs-Vth) 2

[0068] =1 / 2×μ×k×(VA-VB-Vth) 2

[0069] =1 / 2×μ×k×(Vth+(C1 / (C1+C2))×Vdata-Vth) 2

[0070] =1 / 2×μ×k×((C1 / (C1+C2))×Vdata) 2 ;

[0071] Wherein, μ is electron mobility, k=Cox×W / L, Cox is the insulation layer capacitance per unit area of ​​the first transistor 110 , and W / L is the channel width-to-length ratio of the first transistor 110 .

[0072] It can be seen from the calculation formula of the current I flowing through the display light-emitting unit 200 that the brightness of the display light-emitting unit 200 is not affected by the threshold voltage Vth of the first transistor 110 and the voltage Vdd of the first power supply 301. It not only compensates for the threshold voltage Vth, but also compensates for the influence of the power supply voltage drop, thereby improving the uneven display problem of the display panel.

[0073] In this embodiment, the display driving circuit 100 includes a first transistor 110, a storage unit 120, a first light emitting control unit 130, a data writing unit 140, a compensation unit 150 and a voltage control unit 160. The first end of the first transistor 110 is connected to the first power supply 301, and the second end of the first transistor 110 is connected to the second power supply 302 through the display light emitting unit 200. The storage unit 120 includes a first capacitor 121 and a second capacitor 122. The first capacitor 121 is connected to the control end of the first transistor 110 through a first node A, and the second capacitor 122 is connected to the first node A and The first transistor 110 and the second node B between the display light-emitting unit 200, the first light-emitting control unit 130 connects the first light-emitting control line 405, the first power supply 301 and the first end of the first transistor 110, the data writing unit 140 connects the first scan line 401, the data line 404 and the third node C of the first capacitor 121 away from the first node A, the compensation unit 150 at least connects the second scan line 402, the first node A and the fourth node D between the first light-emitting control unit 130 and the first transistor 110, and the voltage control unit 160 connects the second node B and the ground terminal 303. When the display driving circuit 100 is working, the compensation unit 150 compensates for the threshold voltage and the power supply voltage of the driving transistor, thereby improving the display unevenness problem of the display panel.

[0074] See also Figure 1 As shown, the compensation unit 150 includes a second transistor 151, a control end of the second transistor 151 is connected to the second scan line 402, a first end of the second transistor 151 is connected to the fourth node D, and a second end of the second transistor 151 is connected to the first node A. The second scan line 402 signal controls the second transistor 151 to turn on or off.

[0075] The signal of the second scan line 402 controls the second transistor 151 to turn on or off, and controls the first node A and the fourth node D to be turned on or off. The structure is simple, which is beneficial to reducing the manufacturing cost of the display driving circuit 100 and the display panel.

[0076] See also Figure 1 As shown, the compensation unit 150 includes a third transistor 152, a control terminal of the third transistor 152 is connected to the third scan line 403, a first terminal of the third transistor 152 is connected to the third node C, and a second terminal of the third transistor 152 is connected to the fourth node D. The third scan line 403 signal (G3) controls the second transistor 151 to turn on or off.

[0077] When the compensation unit 150 includes the third transistor 152, see Figures 2 to 7 As shown, when the display driving circuit 100 works:

[0078] In the mobility compensation stage T4 (the mobility compensation stage T4 is after the data writing stage T3 and before the light emitting stage T5), the third transistor 152 is controlled to be turned on, so that the charge is discharged from the third node C to the ground terminal 303 through the third transistor 152, the first transistor 110, the second node B, and the voltage control unit 160.

[0079] In the mobility compensation stage T4, the current I0 flowing through the first transistor 110 is:

[0080] I0=1 / 2×μ×k×(Vgs-Vth) 2

[0081] =1 / 2×μ×k×(VA-VB-Vth) 2

[0082] =1 / 2×μ×k×(Vth+(C1 / (C1+C2))×Vdata-Vth) 2

[0083] =1 / 2×μ×k×((C1 / (C1+C2))×Vdata) 2 .

[0084] Controlling the time of the mobility compensation stage T4, the potential change of the third node C △Vc=-I0×t / C1, due to charge conservation and capacitive coupling, the voltage VA of the first node A is:

[0085] VA=Vth+(C1 / (C1+C2))×Vdata+(C1 / (C1+C2))×△Vc

[0086] =Vth+(C1 / (C1+C2))×Vdata+(C1 / (C1+C2))×(﹣I0×t / C1)

[0087] =Vth+(C1 / (C1+C2))×Vdata﹣(1 / (C1+C2))×I0×t.

[0088] It can be seen that the larger the electron mobility μ is, the smaller the current I0 flowing through the first transistor 110 is, so that the voltage VA of the first node A is smaller, and the current I flowing through the display light-emitting unit 200 is smaller; conversely, the smaller the electron mobility μ is, the larger the current I flowing through the display light-emitting unit 200 is, that is, compensation of the electron mobility μ is achieved.

[0089] In some embodiments, the second power source 302 is a ground terminal 303 , that is, the voltage of the second power source 302 is 0.

[0090] In the mobility compensation stage T4, the voltage of the second node B is 0. In the light-emitting stage T5, the voltage control unit 160 is turned off, and the voltage of the second node B becomes the threshold voltage Voled of the display light-emitting unit 200. Since the data writing unit 140 is turned off in the light-emitting stage T5, the third node C has no charge and discharge path, and the voltage difference between the first capacitor 121 and the second capacitor 122 remains unchanged. The voltage VA of the first node A is

[0091] VA=Vth+(C1 / (C1+C2))×Vdata﹣(1 / (C1+C2))×I0×t+Voled.

[0092] The current I flowing through the display light emitting unit 200 is:

[0093] I=1 / 2×μ×k×(Vgs-Vth) 2

[0094] =1 / 2×μ×k×(VA-VB-Vth) 2

[0095] =1 / 2×μ×k×((C1 / (C1+C2))×Vdata﹣(1 / (C1+C2))×I0×t) 2 .

[0096] The current I flowing through the display light-emitting unit 200 is not affected by the threshold voltage of the first transistor 110, the power supply voltage and the threshold voltage of the display light-emitting unit 200, and the larger the electron mobility μ, the smaller the current I0 in the mobility compensation stage T4, so that the current I flowing through the display light-emitting unit 200 remains almost unchanged, that is, the threshold voltage of the first transistor 110, the power supply voltage, the threshold voltage of the display light-emitting unit 200 and the electron mobility are compensated simultaneously.

[0097] See also Figure 1 As shown, the voltage control unit 160 includes a fourth transistor 161 , a control terminal of the fourth transistor 161 is connected to the ground control line, a first terminal of the fourth transistor 161 is connected to the second node B, and a second terminal of the fourth transistor 161 is connected to the ground terminal 303 .

[0098] Whether the second node B is grounded is controlled by a fourth transistor 161 , which has a simple structure and is beneficial to reducing the manufacturing costs of the display driving circuit 100 and the display panel.

[0099] In some embodiments, the voltage control unit 160 also includes a fifth transistor 162, the control end of the fifth transistor 162 is connected to the third scan line 403, the first end of the fifth transistor 162 is connected to the second node B, the second end of the fifth transistor 162 is connected to the ground end 303, and the ground control line is the first scan line 401.

[0100] The voltage control unit 160 includes a fourth transistor 161 and a fifth transistor 162. By adding a transistor to control whether the second node B is grounded, one control signal can be reduced.

[0101] See also Figure 1 As shown, the display driving circuit 100 further includes a second light emitting control unit 170, the second light emitting control unit 170 includes a sixth transistor 171, the control end of the sixth transistor 171 is connected to the second light emitting control line 406, the first end of the sixth transistor 171 is connected to the second node B, and the second end of the sixth transistor 171 is connected to the display light emitting unit 200. The second light emitting control line 406 signal (EM2) controls the opening or closing of the sixth transistor 171.

[0102] Adding a transistor between the driving transistor and the display light emitting unit 200 can further prevent the display light emitting unit 200 from emitting light in the first four stages.

[0103] In some embodiments, the first light-emitting control unit 130 includes a seventh transistor 131, a control end of the seventh transistor 131 is connected to the first light-emitting control line 405, a first end of the seventh transistor 131 is connected to the first power source 301, and a second end of the seventh transistor 131 is connected to the fourth node D. The data writing unit 140 includes an eighth transistor 141, a control end of the eighth transistor 141 is connected to the first scan line 401, a first end of the eighth transistor 141 is connected to the data line 404, and a second end of the eighth transistor 141 is connected to the third node C. The first transistor 110, the second transistor 151, the third transistor 152, the fourth transistor 161, the fifth transistor 162, the sixth transistor 171, the seventh transistor 131 and the eighth transistor 141 are all N-type field effect transistors or P-type field effect transistors.

[0104] The first transistor 110 , the second transistor 151 , the third transistor 152 , the fourth transistor 161 , the fifth transistor 162 , the sixth transistor 171 , the seventh transistor 131 and the eighth transistor 141 are transistors of the same type, which helps to reduce the manufacturing cost of the display driving circuit 100 and the display panel.

[0105] In some embodiments, the voltage control unit 160 includes a fourth transistor 161, the control end of the fourth transistor 161 is connected to the ground control line, the first end of the fourth transistor 161 is connected to the second node B, the second end of the fourth transistor 161 is connected to the ground end 303, one of the fourth transistor 161 and the sixth transistor 171 is an N-type field effect transistor and the other is a P-type field effect transistor, and the ground control line is the second light-emitting control line 406.

[0106] Since the voltage control unit 160 and the second light control unit 170 are not turned on at the same time, one of the fourth transistor 161 and the sixth transistor 171 is an N-type field effect transistor and the other is a P-type field effect transistor, which can reduce one transistor and one control signal.

[0107] Embodiment 2

[0108] The present application also provides a display driving method for driving the display driving circuit 100 disclosed in the first embodiment. Figure 8 As shown, the display driving method includes:

[0109] S100: In the initialization phase T1, the first light emitting control unit 130 and the compensation unit 150 are controlled to be turned on, the voltage of the first power supply 301 is written to the first node A, and the data writing unit 140 and the voltage control unit 160 are controlled to be turned on, and the voltage of the second node B and the third node C are maintained at 0;

[0110] S200: in the compensation stage T2, the first light emitting control unit 130 is controlled to be turned off and the compensation unit 150, the data writing unit 140 and the voltage control unit 160 are kept turned on, and the threshold voltage of the first transistor 110 is written into the second capacitor 122;

[0111] S300: in the data writing phase T3, the compensation unit 150 is controlled to be turned off and the data writing unit 140 and the voltage control unit 160 are kept turned on, and the data voltage Vdata of the data line 404 is written into the third node C;

[0112] S400 : In the light emitting stage T5 , the first light emitting control unit 130 is controlled to be turned on and the compensation unit 150 , the data writing unit 140 and the voltage control unit 160 are controlled to be turned off, so that the display light emitting unit 200 emits light.

[0113] Since the data writing unit 140 is turned off in the light emitting stage T5, the third node C has no charging and discharging path, the voltage difference between the first capacitor 121 and the second capacitor 122 remains unchanged, and the threshold voltage Voled of the display light emitting unit 200 is not considered. The current I flowing through the display light emitting unit 200 is 1 / 2×μ×k×((C1 / (C1+C2))×Vdata) 2 From the calculation formula of the current I flowing through the display light-emitting unit 200, it can be known that the brightness of the display light-emitting unit 200 is not affected by the threshold voltage Vth of the first transistor 110 and the voltage Vdd of the first power supply 301, which not only compensates for the threshold voltage Vth, but also compensates for the influence of the power supply voltage drop, thereby improving the display unevenness problem of the display panel.

[0114] In some embodiments, the compensation unit 150 includes a second transistor 151 and a third transistor 152. The voltage control unit 160 includes a fourth transistor 161 and a fifth transistor 162, the second light emission control unit 170 includes a sixth transistor 171, the first light emission control unit 130 includes a seventh transistor 131, the data writing unit 140 includes an eighth transistor 141, and the first transistor 110, the second transistor 151, the third transistor 152, the fourth transistor 161, the fifth transistor 162, the sixth transistor 171, the seventh transistor 131 and the eighth transistor 141 are all N-type field effect transistors.

[0115] See also Figures 2 to 7 As shown ( Figures 3 to 7 The “×” in the figure indicates that the transistor is turned off). The display driving method includes:

[0116] In the initialization stage T1, the first scan line 401 signal, the second scan line 402 signal, and the first light-emitting control line 405 signal are controlled to be high level, the third scan line 403 signal and the second light-emitting control line 406 signal are controlled to be low level, the second transistor 151, the fourth transistor 161, the seventh transistor 131 and the eighth transistor 141 are turned on, the third transistor 152, the fifth transistor 162 and the sixth transistor 171 are turned off, the data line 404 signal is written to the third node C through the eighth transistor 141, the voltage of the third node C is 0, the first power supply 301 charges the first node A through the seventh transistor 131 and the second transistor 151, the voltage of the first node A is the voltage Vdd of the first power supply 301, the voltage of the second node B is pulled down to 0 by the ground terminal 303, for the first transistor 110, its gate-source voltage difference Vgs=VA-VB=Vdd, the voltage Vdd of the first power supply 301 is greater than the threshold voltage Vth of the first transistor 110, and the first transistor 110 is turned on;

[0117] In the compensation stage T2, the first scan line 401 signal and the second scan line 402 signal are controlled to be high level, the third scan line 403 signal, the first light-emitting control line 405 signal and the second light-emitting control line 406 signal are controlled to be low level, the second transistor 151, the fourth transistor 161 and the eighth transistor 141 are turned on, the third transistor 152, the fifth transistor 162, the sixth transistor 171 and the seventh transistor 131 are turned off, and the charge is discharged from the first node A to the ground terminal 303 through the second transistor 151, the first transistor 110 and the fourth transistor 161 until the gate-source voltage difference Vgs of the first transistor 110 is equal to the threshold voltage Vth of the first transistor 110, and the first transistor 110 is turned off. At this time, VA=Vth+VB=Vth, that is, the threshold voltage Vth of the first transistor 110 is written into the second capacitor 122;

[0118] In the data writing phase T3, the signal of the first scan line 401 is controlled to be high level, the signal of the second scan line 402, the signal of the third scan line 403, the signal of the first light-emitting control line 405 and the signal of the second light-emitting control line 406 are controlled to be low level, the fourth transistor 161 and the eighth transistor 141 are turned on, the second transistor 151, the third transistor 152, the fifth transistor 162, the sixth transistor 171 and the seventh transistor 131 are turned off, and the data voltage Vdata of the data line 404 is written into the third node C. Due to capacitive coupling and charge conservation, the voltage of the first node A is Vth+(C1 / (C1+C2))×Vdata. For the first transistor 110, its gate-source voltage difference Vgs=VA-VB=Vth+(C1 / (C1+C2))×Vdata>Vth, and the first transistor 110 is turned on again;

[0119] In the mobility compensation stage T4, the signal of the third scan line 403 is controlled to be high level, the signal of the first scan line 401, the signal of the second scan line 402, the signal of the first light-emitting control line 405 and the signal of the second light-emitting control line 406 are controlled to be low level, the third transistor 152 and the fifth transistor 162 are turned on, the second transistor 151, the fourth transistor 161, the sixth transistor 171, the seventh transistor 131 and the eighth transistor 141 are turned off, and the charge is discharged from the third node C to the ground terminal 303 through the third transistor 152, the first transistor 110 and the fifth transistor 162. The third node C has no charge and discharge path, the voltage difference between the first capacitor 121 and the second capacitor 122 remains unchanged, and the voltage VA of the first node A is Vth+(C1 / (C1+C2))×Vdata-(1 / (C1+C2))×I0×t;

[0120] In the light-emitting stage T5, the first light-emitting control line 405 signal and the second light-emitting control line 406 signal are controlled to be high level, the first scan line 401 signal, the second scan line 402 signal and the third scan line 403 signal are controlled to be high level and low level, the sixth transistor 171 and the seventh transistor 131 are turned on, the second transistor 151, the third transistor 152, the fourth transistor 161, the fifth transistor 162 and the eighth transistor 141 are turned off, and the current flows through the seventh transistor 131, the first transistor 110 and the sixth transistor 171 through the display light-emitting unit 200, and the display light-emitting unit 200 emits light.

[0121] In the mobility compensation stage T4, the voltage of the second node B is 0. In the light emitting stage T5, the voltage control unit 160 is turned off, and the voltage of the second node B becomes the threshold voltage Voled of the display light emitting unit 200. The voltage of the first node A is Vth+(C1 / (C1+C2))×Vdata-(1 / (C1+C2))×I0×t+Voled, and the current I flowing through the display light emitting unit 200 is 1 / 2×μ×k×((C1 / (C1+C2))×Vdata-(1 / (C1+C2))×I0×t) 2 The current I flowing through the display light-emitting unit 200 is not affected by the threshold voltage of the first transistor 110, the power supply voltage, and the threshold voltage of the display light-emitting unit 200, and the larger the electron mobility μ, the smaller the current I0 in the mobility compensation stage T4, so that the current I flowing through the display light-emitting unit 200 is almost unchanged, that is, the threshold voltage of the first transistor 110, the power supply voltage, the threshold voltage of the display light-emitting unit 200 and the electron mobility are compensated simultaneously.

[0122] Embodiment 3

[0123] See also Fig. 9 As shown, the display panel in this embodiment includes the display driving circuit 100 and the display light emitting unit 200 disclosed in the first embodiment, and the display driving circuit 100 is connected to the display light emitting unit 200.

[0124] In this embodiment, the display panel includes a display driving circuit 100, which includes a first transistor 110, a storage unit 120, a first light emitting control unit 130, a data writing unit 140, a compensation unit 150 and a voltage control unit 160. The first end of the first transistor 110 is connected to the first power supply 301, and the second end of the first transistor 110 is connected to the second power supply 302 through the display light emitting unit 200. The storage unit 120 includes a first capacitor 121 and a second capacitor 122. The first capacitor 121 is connected to the control end of the first transistor 110 through a first node A, and the second capacitor 122 is connected to the control end of the first transistor 110 through a first node A. The first node A and the second node B between the first transistor 110 and the display light-emitting unit 200, the first light-emitting control unit 130 is connected to the first light-emitting control line 405, the first power supply 301 and the first end of the first transistor 110, the data writing unit 140 is connected to the first scan line 401, the data line 404 and the third node C of the first capacitor 121 away from the first node A, the compensation unit 150 is at least connected to the second scan line 402, the first node A and the fourth node D between the first light-emitting control unit 130 and the first transistor 110, and the voltage control unit 160 is connected to the second node B and the ground terminal 303. When the display driving circuit 100 is working, the compensation unit 150 compensates for the threshold voltage and the power supply voltage of the driving transistor, thereby improving the display unevenness problem of the display panel.

[0125] The terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the feature. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0126] In this application, unless otherwise clearly specified and limited, the terms "assembly", "connection" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0127] In the description of this specification, the description with reference to the terms "some embodiments", "exemplarily", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0128] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application. Therefore, any changes or modifications made in accordance with the claims and description of the present application should fall within the scope of the patent of this application.

Claims

1. A display driving circuit, comprising a first transistor, wherein a first end of the first transistor is connected to a first power source, and a second end of the first transistor is connected to a second power source through a display light emitting unit, wherein: The display driving circuit further includes: A storage unit, the storage unit comprising a first capacitor and a second capacitor, the first capacitor being connected to the control end of the first transistor via a first node, and the second capacitor being connected to the first node and a second node between the first transistor and the display light-emitting unit; a first light-emitting control unit connected to a first light-emitting control line, the first power source and a first end of the first transistor, wherein the display driving circuit comprises an initialization phase, a compensation phase, a data writing phase and a light-emitting phase, and the first light-emitting control unit is used to turn on the first power source and the first transistor in the initialization phase and the light-emitting phase; a data writing unit connected to the first scan line, the data line and a third node of the first capacitor away from the first node, and used for writing a non-display voltage in the initialization stage and the compensation stage and writing a data voltage in the data writing stage; a compensation unit, connected at least to the second scan line, the first node, and a fourth node between the first light emitting control unit and the first transistor, configured to conduct the electrical connection between the first node and the fourth node during the initialization stage and the compensation stage and to disconnect the electrical connection between the first node and the fourth node at least during the data writing stage; A voltage control unit is connected to the second node and the ground terminal, and is used to conduct the second node and the ground terminal during the initialization phase, the compensation phase and the data writing phase.

2. The display driving circuit according to claim 1, characterized in that: The compensation unit includes a second transistor, a control terminal of the second transistor is connected to the second scan line, a first terminal of the second transistor is connected to the fourth node, and a second terminal of the second transistor is connected to the first node.

3. The display driving circuit according to claim 2, characterized in that: The compensation unit further includes a third transistor, a control terminal of the third transistor is connected to the third scan line, a first terminal of the third transistor is connected to the third node, and a second terminal of the third transistor is connected to the fourth node.

4. The display driving circuit according to claim 1, characterized in that: The second power source is the ground terminal.

5. The display driving circuit according to claim 1, characterized in that: The voltage control unit includes a fourth transistor, a control terminal of the fourth transistor is connected to a ground control line, a first terminal of the fourth transistor is connected to the second node, and a second terminal of the fourth transistor is connected to the ground terminal.

6. The display driving circuit according to claim 5, characterized in that: The voltage control unit includes a fifth transistor, a control end of the fifth transistor is connected to the third scan line, a first end of the fifth transistor is connected to the second node, a second end of the fifth transistor is connected to the ground end, and the ground control line is the first scan line.

7. The display driving circuit according to claim 1, characterized in that: The display driving circuit also includes a second light emitting control unit, which includes a sixth transistor, a control end of the sixth transistor is connected to the second light emitting control line, a first end of the sixth transistor is connected to the second node, and a second end of the sixth transistor is connected to the display light emitting unit.

8. A display driving method, characterized in that: Used to drive the display driving circuit according to any one of claims 1 to 7, the display driving method comprising: In the initialization stage, the first light emitting control unit and the compensation unit are controlled to be turned on, the first power supply voltage is written to the first node, and the data writing unit and the voltage control unit are controlled to be turned on, and the voltage of the second node and the third node are maintained to be 0; In the compensation stage, the first light emitting control unit is controlled to be turned off and the compensation unit, the data writing unit and the voltage control unit are kept turned on, so as to write the threshold voltage of the first transistor into the second capacitor; In the data writing phase, the compensation unit is controlled to be turned off and the data writing unit and the voltage control unit are kept turned on, so as to write the data voltage of the data line into the third node; In the light emitting stage, the first light emitting control unit is controlled to be turned on and the compensation unit, the data writing unit and the voltage control unit are controlled to be turned off, so that the display light emitting unit emits light.

9. The display driving method according to claim 8, characterized in that: The compensation unit includes a second transistor and a third transistor, the control end of the second transistor is connected to the second scan line, the first end of the second transistor is connected to the fourth node, the second end of the second transistor is connected to the first node, the control end of the third transistor is connected to the third scan line, the first end of the third transistor is connected to the third node, and the second end of the third transistor is connected to the fourth node. In the compensation stage, the second transistor is controlled to be turned on through the second scan line; The display driving method further includes: In the mobility compensation stage between the data writing stage and the light emitting stage, the third transistor is turned on by controlling the third scan line, so that the charge flows from the third node through the third transistor, the first transistor, and the voltage control unit to the ground terminal for discharge.

10. A display panel, characterized in that: include: Display light emitting unit; The display driving circuit according to any one of claims 1 to 7, connected to the display light emitting unit.

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