Organic light emitting diode driving circuit, display panel and display equipment

Abstract

The invention provides an organic light-emitting diode driving circuit, a display panel and display equipment. The organic light-emitting diode driving circuit comprises an anode switch tube and a pull-down module, the output end of the anode switch tube is connected with the anode of the organic light-emitting diode, and the output end of the pull-down module is connected with the anode of the organic light-emitting diode; wherein the pull-down module is used for pulling down the anode voltage of the organic light-emitting diode at the turn-off moment of the anode switch tube. By arranging the pull-down module and pulling down the anode voltage of the organic light-emitting diode at the turn-off moment of the anode switch tube, the phenomenon that the anode voltage of the organic light-emitting diode is raised by a parasitic capacitor can be avoided, and the problem of false light emission is avoided.

Description

Technical Field

[0001] The present invention relates to the field of display, and in particular to an organic light emitting diode driving circuit, a display panel and a display device. Background Art

[0002] Since there is a parasitic capacitance between the gate of the switch tube and the anode of the OLED (Organic Light-Emitting Diode), when the switch tube switches from on to off, the gate of the switch tube switches from a low level to a high level. At this time, due to the existence of the parasitic capacitance, the anode voltage of the OLED will be raised, thereby causing the OLED to emit light incorrectly. Summary of the invention

[0003] The main purpose of the present invention is to provide an organic light emitting diode driving circuit, a display panel and a display device, aiming to solve the problem of OLED mis-lighting in the prior art.

[0004] To achieve the above object, the present invention provides an organic light emitting diode driving circuit, the organic light emitting diode driving circuit comprising an anode switch tube and a pull-down module; the output end of the anode switch tube is connected to the anode of the organic light emitting diode, and the output end of the pull-down module is connected to the anode of the organic light emitting diode; wherein:

[0005] The pull-down module is used to pull down the anode voltage of the organic light emitting diode at the moment when the anode switch tube is turned off.

[0006] Optionally, the anode switch tube includes a light-emitting control switch tube, a gate of the light-emitting control switch tube is connected to a light-emitting drive signal line, a source of the light-emitting control switch tube is connected to a light-emitting current switch tube, and a drain of the light-emitting control switch tube is connected to the anode of the organic light-emitting diode.

[0007] Optionally, the anode switch tube includes a reset switch tube, a gate of the reset switch tube is connected to a reset control signal line, a source of the reset switch tube is connected to a reset signal line, and a drain of the reset switch tube is connected to the anode of the organic light emitting diode.

[0008] Optionally, the anode switch tube includes a light-emitting control switch tube and a reset switch tube; the pull-down module includes a first pull-down unit and a second pull-down unit; the output end of the light-emitting control switch tube is connected to the anode of the organic light-emitting diode, the output end of the reset switch tube is connected to the anode of the organic light-emitting diode, the output end of the first pull-down unit is connected to the anode of the organic light-emitting diode, and the output end of the second pull-down unit is connected to the anode of the organic light-emitting diode; wherein:

[0009] The first pull-down unit is used to pull down the anode voltage of the organic light emitting diode at the moment when the light emitting control switch tube is turned off;

[0010] The second pull-down unit is used to pull down the anode voltage of the organic light emitting diode at the moment when the reset switch tube is turned off.

[0011] Optionally, the reset switch tube serves as the first pull-down unit, and the light-emitting control switch tube serves as the second pull-down unit; wherein:

[0012] The switching states of the light-emitting control switch tube and the reset switch tube are opposite.

[0013] Optionally, the organic light emitting diode driving circuit further includes an inverter; wherein:

[0014] The gate of the light-emitting control switch tube is connected to the light-emitting drive signal line, the gate of the light-emitting control switch tube is also connected to the input end of the inverter, and the output end of the inverter is connected to the gate of the reset switch tube.

[0015] Optionally, the gate of the light-emitting control switch tube is connected to the light-emitting drive signal line, and the gate of the reset switch tube is connected to the reset control signal line; wherein:

[0016] The light-emitting driving signal line and the reset control signal line transmit opposite signals.

[0017] Optionally, the gate of the light-emitting control switch tube is connected to a light-emitting drive signal line, and the light-emitting drive signal line is used to transmit a light-emitting drive signal; wherein:

[0018] The light-emitting driving signal is a pulse width modulation signal, and the duty cycle of the light-emitting driving signal is negatively correlated with the target brightness of the organic light-emitting diode.

[0019] In addition, to achieve the above-mentioned purpose, the present invention further provides a display panel, which includes an organic light emitting diode and an organic light emitting diode driving circuit, and the organic light emitting diode driving circuit is configured as the organic light emitting diode driving circuit described above.

[0020] In addition, to achieve the above objective, the present invention further provides a display device, which includes the display panel as described above.

[0021] The present invention proposes an organic light emitting diode driving circuit, a display panel and a display device, wherein the organic light emitting diode driving circuit includes an anode switch tube and a pull-down module; the output end of the anode switch tube is connected to the anode of the organic light emitting diode, and the output end of the pull-down module is connected to the anode of the organic light emitting diode; wherein: the pull-down module is used to pull down the anode voltage of the organic light emitting diode at the moment when the anode switch tube is turned off. By setting the pull-down module and pulling down the anode voltage of the organic light emitting diode at the moment when the anode switch tube is turned off, it is possible to avoid the parasitic capacitance from raising the anode voltage of the organic light emitting diode, thereby avoiding the problem of false light emission. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0023] Figure 1 A functional module diagram of an organic light emitting diode driving circuit according to an embodiment of the present invention;

[0024] Figure 2 It is a structural schematic diagram of a 7T1C driving circuit in the prior art;

[0025] Figure 3 is a schematic structural diagram of an organic light emitting diode driving circuit of the present invention;

[0026] Figure 4 A schematic diagram of signal waveforms of an organic light emitting diode driving circuit according to the present invention;

[0027] Figure 5 FIG. 4 is a waveform diagram of an EM signal in an organic light emitting diode driving circuit of the present invention.

[0028] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings.

[0029] Description of Figure Numbers:

[0030] Label name Label name 100 Pull down module T1 Light-emitting control switch tube Ta Anode switch tube T7 Reset switch OLED Organic Light Emitting Diodes C capacitance T2~T6 The second switch tube to the sixth switch tube D Inverter DETAILED DESCRIPTION

[0031] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0034] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0035] The present invention provides an organic light emitting diode driving circuit, which is applied to a display panel. Figure 1 , Figure 1 This is a functional module diagram of an embodiment of an organic light emitting diode driving circuit of the present invention. In this embodiment, the organic light emitting diode driving circuit includes an anode switch tube Ta and a pull-down module 100; the output end of the anode switch tube Ta is connected to the anode of the organic light emitting diode OLED, and the output end of the pull-down module 100 is connected to the anode of the organic light emitting diode OLED; wherein:

[0036] The pull-down module 100 is used to pull down the anode voltage of the organic light emitting diode OLED at the moment when the anode switch tube Ta is turned off.

[0037] The anode switch tube Ta is a switch tube whose source or drain is connected to the anode of the organic light emitting diode OLED; Figure 2 , Figure 2: is a topological diagram of a 7T1C driving circuit; wherein, the light-emitting control switch tube T1 and the reset switch tube T7 are both connected to the anode of the organic light-emitting diode OLED, therefore, in the 7T1C driving circuit, the anode switch tube Ta includes the light-emitting control switch tube T1 and the reset switch tube T7; it should be noted that, in practical applications, different types of driving circuits may be selected based on actual needs, and in some driving circuits, the anode switch tube Ta may include more or fewer switches, such as for a 2T1C driving circuit, the reset switch tube T7 is not provided, so the anode switch tube Ta only includes the light-emitting control switch tube T1; the same is true for other types of driving circuits, which will not be described in detail.

[0038] The device structure of the organic light emitting diode OLED mainly includes a backplane manufactured by a backplane process and an organic light emitting diode OLED part manufactured by an OLED process; a switch tube for driving the organic light emitting diode OLED is manufactured on the backplane; the organic light emitting diode OLED part mainly manufactures the transmission of electrons and holes and the light emitting layer; specifically, the backplane may include a gate, a source, a drain, a data wiring, a gate wiring, an active layer and an insulating layer; the organic light emitting diode OLED part may include an anode, a hole injection layer, a hole transport layer, a light emitting layer, an electron injection layer, an electron transport layer, a cathode and a thin film package. After the device structure of the organic light emitting diode OLED is constructed, there will be an overlap area between the gate and the anode or the electrodes overlapped by the anode, and this overlap area will generate parasitic capacitance.

[0039] The anode switch tube Ta is turned off at a high level and turned on at a low level. Therefore, when the anode switch tube Ta switches from on to off, the gate voltage of the anode switch tube Ta is converted from a low level to a high level. Due to the existence of parasitic capacitance, when the gate voltage of the anode switch tube Ta is raised, the anode voltage of the organic light emitting diode OLED will be raised. When the difference between the anode voltage and the cathode voltage of the organic light emitting diode OLED is greater than the turn-on voltage, the organic light emitting diode OLED lights up, causing the problem of false light emission.

[0040] In order to solve this problem, in the present embodiment, a pull-down module 100 is provided, and the pull-down module 100 pulls down the anode voltage of the organic light emitting diode OLED at the moment when the anode switch tube Ta is turned off; after the anode switch tube Ta is turned off, although the existence of the parasitic capacitance will cause the anode voltage of the organic light emitting diode OLED to rise, as the pull-down module 100 pulls down the anode voltage, the difference between the anode voltage and the cathode voltage of the organic light emitting diode OLED cannot be greater than the turn-on voltage under the joint action of the parasitic capacitance and the pull-down module 100, thereby avoiding the problem of false light emission of the organic light emitting diode OLED.

[0041] The pull-down module 100 may be implemented by existing components in the driving circuit, or by newly added components.

[0042] This embodiment provides a pull-down module 100 and pulls down the anode voltage of the organic light emitting diode OLED when the anode switch tube Ta is turned off, so as to prevent the parasitic capacitance from raising the anode voltage of the organic light emitting diode OLED and avoid the problem of false light emission.

[0043] Furthermore, the anode switch tube Ta includes a light-emitting control switch tube T1, a gate of the light-emitting control switch tube T1 is connected to the light-emitting drive signal line, a source of the light-emitting control switch tube T1 is connected to the light-emitting current switch tube, and a drain of the light-emitting control switch tube T1 is connected to the anode of the organic light-emitting diode OLED.

[0044] The light-emitting control switch tube T1 is used to control whether the organic light-emitting diode OLED emits light; when the light-emitting control switch tube T1 is turned on, the circuit in which it is located is turned on to generate current, driving the organic light-emitting diode OLED to emit light, and when the light-emitting control switch tube T1 is turned off, the circuit in which it is located is not turned on, and the organic light-emitting diode OLED does not emit light.

[0045] The light-emitting drive signal line EM is used to control the conduction state of the light-emitting control switch tube T1; the light-emitting control switch tube T1 is turned on when the gate is at a high level and is turned off when the gate is at a low level; when the light-emitting control switch tube T1 is switched from being turned on to being turned off, the organic light-emitting diode OLED should switch from being luminous to being non-luminous, and due to the effect of the parasitic capacitance of the light-emitting control switch tube T1, after the light-emitting control switch tube T1 is turned off, the anode voltage of the organic light-emitting diode OLED will be raised, resulting in false light emission. Therefore, in this embodiment, the light-emitting control switch tube T1 is used as the anode switch tube Ta, so that the false light emission problem caused by the parasitic capacitance of the light-emitting control switch tube T1 can be eliminated by pulling down the module 100.

[0046] Furthermore, the anode switch tube Ta includes a reset switch tube T7, a gate of the reset switch tube T7 is connected to a reset control signal line, a source of the reset switch tube T7 is connected to a reset signal line, and a drain of the reset switch tube T7 is connected to an anode of the organic light emitting diode OLED.

[0047] The reset switch tube T7 is used to reset the anode voltage of the organic light emitting diode OLED; when the reset switch tube T7 is turned on, the reset voltage on the reset signal line resets the anode voltage of the organic light emitting diode OLED, so that the anode voltage of the organic light emitting diode OLED is reset to the reset voltage; when the reset switch tube T7 is turned off, the reset voltage on the reset signal line cannot reach the anode of the organic light emitting diode OLED.

[0048] The reset control signal line SCAN(n) is used to control the conduction state of the reset switch tube T7; the reset switch tube T7 is turned on when the gate is at a high level and is turned off when the gate is at a low level; when the reset switch tube T7 is switched from being on to being off, the anode of the organic light emitting diode OLED is reset, and the organic light emitting diode OLED needs to wait for the light emitting control switch tube T1 to be turned on before emitting light; and due to the effect of the parasitic capacitance of the reset switch tube T7, false light emission will occur after the reset switch tube T7 is turned off and the light emitting control switch tube T1 is not turned on; therefore, in this embodiment, the reset switch tube T7 is used as the anode switch tube Ta, so that the false light emission problem caused by the parasitic capacitance of the reset switch tube T7 is eliminated by pulling down the module 100.

[0049] Further, the anode switch tube Ta includes a light-emitting control switch tube T1 and a reset switch tube T7; the pull-down module 100 includes a first pull-down unit and a second pull-down unit; the output end of the light-emitting control switch tube T1 is connected to the anode of the organic light-emitting diode OLED, the output end of the reset switch tube T7 is connected to the anode of the organic light-emitting diode OLED, the output end of the first pull-down unit is connected to the anode of the organic light-emitting diode OLED, and the output end of the second pull-down unit is connected to the anode of the organic light-emitting diode OLED; wherein:

[0050] The first pull-down unit is used to pull down the anode voltage of the organic light emitting diode OLED at the moment when the light emitting control switch tube T1 is turned off;

[0051] The second pull-down unit is used to pull down the anode voltage of the organic light emitting diode OLED at the moment when the reset switch tube T7 is turned off.

[0052] The first pull-down unit is set for the light-emitting control switch tube T1 to eliminate the problem of false light emission caused by the parasitic capacitance of the light-emitting control switch tube T1; the second pull-down unit is set for the reset switch tube T7 to eliminate the problem of false light emission caused by the parasitic capacitance of the reset switch tube T7.

[0053] In one implementation, the problem of false light emission can be eliminated by additionally adding a first pull-down unit and a second pull-down unit while maintaining the existing driving circuit structure unchanged.

[0054] See also Figure 2 , Figure 2It is a basic 7T1C topology in the prior art; it includes 7 switch tubes TFT and 1 capacitor C; specifically, the light-emitting control switch tube T1 is used to control whether the organic light-emitting diode OLED emits light; the second switch tube T2 is used to control the current size on the branch where it is located to adjust the light-emitting brightness of the organic light-emitting diode OLED; the third switch tube T3 is used to reset the voltage of the capacitor C; the fourth switch tube T4 is used to compensate the threshold voltage of the second switch tube T2; the fifth switch tube T5 is used to control when to supply power to the organic light-emitting diode OLED; the sixth switch tube T6 is used to transmit the data voltage to charge the capacitor C; the reset switch tube T7 is used to reset the anode of the organic light-emitting diode OLED.

[0055] It should be noted that only the 7T1C driving circuit is used as an example for description here, and other types of driving circuits can be implemented by analogy.

[0056] In the above 7T1C topology, the light-emitting control switch tube T1 is turned on only in the light-emitting phase based on the EM signal, and the reset switch tube T7 is turned on in the charging phase based on the SCAN(n) signal; and there is no specific correlation between the two signals.

[0057] At this time, a first pull-down unit is provided for the light-emitting control switch tube T1, and a second pull-down unit is provided for the reset switch tube T7, so that the anode voltage of the organic light-emitting diode OLED is pulled down at the moment when the light-emitting control switch tube T1 or the reset switch tube T7 is turned off; in order to enable the first pull-down unit to pull down the anode voltage of the organic light-emitting diode OLED at the moment when the light-emitting control switch tube T1 is turned off, the waveform of the output signal L1 of the first pull-down unit can be set to be opposite to the waveform of the EM signal, and the waveform of the output signal L2 of the second pull-down unit can be set to be opposite to the waveform of the SCAN(n) signal.

[0058] In another implementation, the existing driving circuit structure can be adjusted to eliminate the problem of false light emission through the original device. Specifically:

[0059] Further, the reset switch tube T7 serves as the first pull-down unit, and the light-emitting control switch tube T1 serves as the second pull-down unit; wherein:

[0060] The switching states of the light-emitting control switch tube T1 and the reset switch tube T7 are opposite.

[0061] It can be known from the principle of the light-emitting control switch tube T1 and the reset switch tube T7 that the light-emitting control switch tube T1 and the reset switch tube T7 are not turned on at the same time, and when the light-emitting control switch tube T1 is turned off, whether the reset switch tube T7 is turned on or off will not affect the light-emitting state of the OLED, and when the reset switch tube T7 is turned off, whether the light-emitting control switch tube T1 is turned on or off will not affect the reset function that needs to be realized for the reset switch tube T7; therefore, when the switch states of the light-emitting control switch tube T1 and the reset switch tube T7 are always opposite, the realization of their respective functions will not be affected, that is, the normal operation of the driving circuit will not be affected; at the same time, since both the light-emitting control switch tube T1 and the reset switch tube T7 have parasitic capacitance that affects the anode voltage of the organic light-emitting diode OLED, therefore, by using the light-emitting control switch tube T1 and the reset switch tube T7 as the second pull-down unit and the first pull-down unit respectively, the problem of false light emission can be eliminated without adding additional devices.

[0062] It should be noted that, since the light-emitting control switch tube T1 is used to control the light-emitting state of the organic light-emitting diode OLED, in order to ensure that the light-emitting state of the organic light-emitting diode OLED is normal; the switching state of the light-emitting control switch tube T1 is maintained unchanged, that is, the switching state of the light-emitting control switch tube T1 is still controlled by the EM signal, and the switching state of the reset switch tube T7 is adjusted at the same time, so that the switching state of the reset switch tube T7 is opposite to that of the light-emitting control tube.

[0063] Since the switch states of the light-emitting control switch tube T1 and the reset switch tube T7 are opposite; after the light-emitting control switch tube T1 is switched from on to off, the parasitic capacitance of the light-emitting control switch tube T1 will raise the anode voltage of the organic light-emitting diode OLED; at the same time, the reset switch tube T7 will be switched from off to on. On the one hand, the parasitic capacitance of the reset switch tube T7 will lower the anode voltage of the organic light-emitting diode OLED, and on the other hand, the reset switch tube T7 will reset the anode voltage of the organic light-emitting diode OLED through a reset signal, so that the anode voltage of the organic light-emitting diode OLED is maintained at the reset voltage, thereby avoiding the problem of false light emission;

[0064] After the light-emitting control switch tube T1 is switched from off to on, that is, after the reset switch tube T7 is switched from on to off, the parasitic capacitance of the reset switch tube T7 will raise the anode voltage of the organic light-emitting diode OLED; on the one hand, the organic light-emitting diode OLED needs to emit light at this time, and the organic light-emitting diode OLED is a current-driven device, so raising the anode voltage of the organic light-emitting diode OLED will not affect the light-emitting state of the organic light-emitting diode OLED; on the other hand, the parasitic capacitance of the light-emitting control switch tube T1 will lower the anode voltage of the organic light-emitting diode OLED.

[0065] In this embodiment, the parasitic capacitance of the light-emitting control switch tube T1 and the reset switch tube T7 will not cause the problem of false light emission.

[0066] Further, see Figure 3 , the organic light emitting diode OLED driving circuit also includes an inverter D; wherein:

[0067] The gate of the light-emitting control switch tube T1 is connected to the light-emitting drive signal line, and the gate of the light-emitting control switch tube T1 is also connected to the input end of the inverter D, and the output end of the inverter D is connected to the gate of the reset switch tube T7.

[0068] In this embodiment, an inverter D is added to realize the opposite switching state of the light emitting control switch tube T1 and the reset switch tube T7; the gate of the light emitting control switch tube T1 is still controlled by the EM signal output by the light emitting drive signal line to realize the control of the light emitting state of the organic light emitting diode OLED; and due to the existence of the inverter D, the gate of the reset switch tube T7 receives the EM signal output by the light emitting drive signal line. See also Figure 4 , The waveform is opposite to that of EM.

[0069] Different from the stage setting of the existing driving circuit, the stage setting of the organic light emitting diode OLED driving circuit of this embodiment is as follows:

[0070] In the reset stage, the reset switch tube T7, the second switch tube T2, and the third switch tube T3 are turned on, and the other switch tubes are turned off; the reset switch tube T7 resets the anode of the organic light emitting diode OLED, and the third switch tube T3 resets the capacitor C;

[0071] In the charging stage, the second switch tube T2, the fourth switch tube T4, the sixth switch tube T6 and the reset switch tube T7 are turned on, and the other switch tubes are turned off; the data signal sequentially charges the capacitor C through the sixth switch tube T6, the second switch tube T2 and the fourth switch tube T4, and the anode of the organic light emitting diode OLED remains in a reset state;

[0072] In the light-emitting stage, the light-emitting control switch tube T1, the second switch tube T2, and the fifth switch tube T5 are turned on, and the other switch tubes are turned off; the light-emitting control switch tube T1, the second switch tube T2, the fifth switch tube T5, and the organic light-emitting diode OLED form a loop, the second switch tube T2 controls the loop circuit based on the capacitor C voltage, and the organic light-emitting diode OLED emits light based on the loop current.

[0073] Furthermore, the gate of the light-emitting control switch tube T1 is connected to the light-emitting drive signal line, and the gate of the reset switch tube T7 is connected to the reset control signal line; wherein:

[0074] The light-emitting driving signal line and the reset control signal line transmit opposite signals.

[0075] In this embodiment, an additional reset control signal line is provided, and the reset control signal line outputs a signal to the gate of the reset switch tube T7; wherein the signal output by the reset control signal line is opposite to the EM signal output by the light-emitting drive signal line; the signal output by the reset control signal line can also be

[0076] Furthermore, the gate of the light-emitting control switch tube T1 is connected to a light-emitting drive signal line, and the light-emitting drive signal line is used to transmit a light-emitting drive signal; wherein:

[0077] The light-emitting driving signal is a pulse width modulation signal, and the duty cycle of the light-emitting driving signal is negatively correlated with the target brightness of the organic light-emitting diode OLED.

[0078] When the organic light-emitting diode OLED is displayed in high grayscale, if it is always on, it is easy to cause screen burn-in and device aging problems. When it is displayed in low grayscale, the current is too small, which is easy to cause color deviation. Therefore, on the basis of active drive normal display, the EM signal can be set to the form of PWM signal; see Figure 5 When the EM signal is high, the screen is black and does not display. When the EM signal is low, the organic light emitting diode OLED displays based on the current size. The longer the EM signal is low, the brighter the OLED display is. In order to ensure the uniformity of low-gray display, the existing design shortens the time when the EM signal is low while maintaining a relatively large current, so that the total brightness is reduced. Therefore, the duty cycle of the high-brightness EM signal is larger than that of the low-brightness. It should be noted that Figure 5 In the example, the waveform of the EM signal indicates the conduction period of the organic light emitting diode OLED. Figure 5 The low part of the waveform of the EM signal indicates that the organic light emitting diode OLED emits light; when the PWM signal is applied, Figure 5 The waveform of the EM signal is a low part, and is set to a form of a PWM signal including high and low levels based on the brightness that the organic light emitting diode OLED needs to display.

[0079] Due to the existence of common layers such as the hole transport layer, the hole injection layer, the electron injection layer, and the electron transport layer, there will be a lateral current between adjacent organic light emitting diodes OLED, which will also cause the organic light emitting diode OLED to be falsely triggered.

[0080] It can be seen from the above description that after the switch states of the light-emitting control switch tube T1 and the reset switch tube T7 are set to be opposite, compared with the prior art, the on-time of the reset switch tube T7 is increased, that is, the anode reset time of the organic light-emitting diode OLED is increased; the increase in the anode reset time shortens the lateral leakage time, thereby suppressing the occurrence of lateral leakage; at the same time, when performing low grayscale display, the on-time of the light-emitting control switch tube T1 is shorter, that is, the on-time of the reset switch tube T7 is longer, therefore, the anode reset time is further increased, further reducing the occurrence of lateral leakage, and can further avoid the problem of false triggering of the organic light-emitting diode OLED.

[0081] The present invention also protects a display panel, which includes an organic light emitting diode and an organic light emitting diode driving circuit. The structure of the organic light emitting diode driving circuit can refer to the above embodiment and will not be described in detail here. As a matter of course, since the display panel of this embodiment adopts the technical solution of the above organic light emitting diode driving circuit, the display panel has all the beneficial effects of the above organic light emitting diode driving circuit.

[0082] The present invention also protects a display device, which includes a display panel. The display panel can refer to the above embodiment and will not be described in detail here. As a matter of course, since the display device of this embodiment adopts the technical solution of the above display panel, the display device has all the beneficial effects of the above display panel.

[0083] It should be noted that, in this article, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "includes a..." does not exclude the presence of other identical elements in the process, method, article or system including the element. The serial numbers of the above-mentioned embodiments of the present invention are for description only and do not represent the advantages and disadvantages of the embodiments.

[0084] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An organic light emitting diode driving circuit, characterized in that: The organic light emitting diode driving circuit comprises an anode switch tube and a pull-down module; the output end of the anode switch tube is connected to the anode of the organic light emitting diode, and the output end of the pull-down module is connected to the anode of the organic light emitting diode; wherein: The pull-down module is used to pull down the anode voltage of the organic light emitting diode at the moment when the anode switch tube is turned off.

2. The organic light emitting diode driving circuit according to claim 1, wherein: The anode switch tube includes a light-emitting control switch tube, a gate of the light-emitting control switch tube is connected to a light-emitting drive signal line, a source of the light-emitting control switch tube is connected to a light-emitting current switch tube, and a drain of the light-emitting control switch tube is connected to an anode of the organic light-emitting diode.

3. The organic light emitting diode driving circuit according to claim 1, wherein: The anode switch tube includes a reset switch tube, a gate of the reset switch tube is connected to a reset control signal line, a source of the reset switch tube is connected to a reset signal line, and a drain of the reset switch tube is connected to an anode of the organic light emitting diode.

4. The organic light emitting diode driving circuit according to claim 1, wherein: The anode switch tube includes a light-emitting control switch tube and a reset switch tube; the pull-down module includes a first pull-down unit and a second pull-down unit; the output end of the light-emitting control switch tube is connected to the anode of the organic light-emitting diode, the output end of the reset switch tube is connected to the anode of the organic light-emitting diode, the output end of the first pull-down unit is connected to the anode of the organic light-emitting diode, and the output end of the second pull-down unit is connected to the anode of the organic light-emitting diode; wherein: The first pull-down unit is used to pull down the anode voltage of the organic light emitting diode at the moment when the light emitting control switch tube is turned off; The second pull-down unit is used to pull down the anode voltage of the organic light emitting diode at the moment when the reset switch tube is turned off.

5. The organic light emitting diode driving circuit according to claim 4, characterized in that: The reset switch tube serves as the first pull-down unit, and the light-emitting control switch tube serves as the second pull-down unit; wherein: The switching states of the light-emitting control switch tube and the reset switch tube are opposite.

6. The organic light emitting diode driving circuit according to claim 5, characterized in that: The organic light emitting diode driving circuit further includes an inverter; wherein: The gate of the light-emitting control switch tube is connected to the light-emitting drive signal line, the gate of the light-emitting control switch tube is also connected to the input end of the inverter, and the output end of the inverter is connected to the gate of the reset switch tube.

7. The organic light emitting diode driving circuit according to claim 5, characterized in that: The gate of the light-emitting control switch tube is connected to the light-emitting drive signal line, and the gate of the reset switch tube is connected to the reset control signal line; wherein: The light-emitting driving signal line and the reset control signal line transmit opposite signals.

8. The organic light emitting diode driving circuit according to claim 5, wherein: The gate of the light-emitting control switch tube is connected to a light-emitting drive signal line, and the light-emitting drive signal line is used to transmit a light-emitting drive signal; wherein: The light-emitting driving signal is a pulse width modulation signal, and the duty cycle of the light-emitting driving signal is negatively correlated with the target brightness of the organic light-emitting diode.

9. A display panel, characterized in that: The display panel includes an organic light emitting diode and an organic light emitting diode driving circuit according to any one of claims 1 to 8.

10. A display device, characterized in that: The display device comprises the display panel according to claim 9.

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