The present disclosure relates to the technical field of display, in particular to a pixel circuit, a display panel and a display apparatus.
An organic light emitting diode (OLED), a quantum dot light emitting diode (QLED), a micro light emitting diode (micro LED) and other electroluminescent diodes have the advantages of self-luminescence, low energy consumption, etc., and are one of the hotspots in the field of display apparatus application research nowadays. Pixel circuits are commonly used to drive electroluminescent diodes to emit light. In practical applications, when a display apparatus is to display any gray scale within the gray scale range, the data voltage may be made to exceed the output range of a driver integrated circuit (IC), resulting in the problem that the dark state is not sufficiently dark, which affects the contrast of the display apparatus.
An embodiment of the present disclosure provides a pixel circuit, including:
In some embodiments, the compensation circuit includes: a first electrode and a second electrode;
In some embodiments, the orthographic projection of the first scan line on a base substrate covers the orthographic projection of the compensation conductive part on the base substrate.
In some embodiments, the light emitting control circuit includes a storage capacitor;
In some embodiments, the pixel circuit further includes a first connection part, arranged on a side of the compensation conductive part facing away from the base substrate; and
In some embodiments, the orthographic projection of the compensation conductive part on the base substrate does not overlap with an orthographic projection of the gate of the drive transistor on the base substrate; and
In some embodiments, the pixel circuit further includes a threshold compensation transistor;
In some embodiments, the first power signal line is arranged on a side of the first connection part facing away the base substrate;
In some embodiments, an orthographic projection of the first power signal line on the base substrate covers an orthographic projection of an active layer of a metal oxide transistor in the pixel circuit on the base substrate.
In some embodiments, a shape of an orthographic projection of the first power signal line on the base substrate is approximately R shape.
An embodiment of the present disclosure provides a display panel, including:
In some embodiments, the pixel circuit further includes: a first reset transistor and a threshold compensation transistor;
In some embodiments, for a same sub-pixel, the active layer of the first reset transistor and the active layer of the threshold compensation transistor are integrated in a structure.
In some embodiments, an extension direction of a channel region of the active layer of the first reset transistor is roughly the same as an extension direction of a channel region of the active layer of the threshold compensation transistor.
In some embodiments, for a same sub-pixel, an orthographic projection of a channel region of the threshold compensation transistor on the base substrate is closer to an orthographic projection of a channel region of the drive transistor on the base substrate than an orthographic projection of a channel region of the first reset transistor on the base substrate.
In some embodiments, the orthographic projection of the first power signal line on the base substrate covers an orthographic projection of the oxide semiconductor layer on the base substrate.
In some embodiments, the display panel further includes:
In some embodiments, the auxiliary reset line and the first reset line are electrically connected on an edge of a display area of the display panel.
In some embodiments, the third conductive layer further includes a second scan line, and the second scan line is electrically connected with a gate of the threshold compensation transistor;
An embodiment of the present disclosure provides a display apparatus, including the display panel.
In order to make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions in embodiments of the present disclosure will be clearly and fully described in combination with the accompanying drawings of the embodiments of the present disclosure. It is apparent that the described embodiments are some, but not all, embodiments of the present disclosure. Also, embodiments and features in the embodiments of the disclosure may be combined with one another without conflict. Based on the described embodiments of the present disclosure, all other embodiments attainable by one of ordinary skilled in the art without involving any inventive effort are within the scope of the present disclosure.
Unless otherwise defined, the technical terms or scientific terms used in the present disclosure shall have the usual meanings understood by those with ordinary skills in the field to which the present disclosure belongs. “First”, “second” and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. “Comprise” or “include” or other similar words mean that the element or item appearing before the word covers elements or items listed after the word and their equivalents, but does not exclude other elements or items. “Connecting” or “connected” or other similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.
It should be noted that the dimensions and shapes of the various figures in the drawings are not to scale and are intended to be merely illustrative of the present disclosure. The same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout.
An embodiment of the present disclosure provides a pixel circuit, and as shown in
In the above-mentioned pixel circuit provided by the embodiment of the present disclosure, the compensation circuit is electrically connected with the gate of the drive transistor, and the compensation circuit may compensate for the voltage of the gate of the drive transistor according to the channel capacitor between the gate and the first electrode of the threshold compensation transistor M2. Thus, when a level of a signal of the second scan line G2 is switched, a voltage ΔVn1, lowered by the channel capacitor between the gate and the first electrode of the threshold compensation transistor M2, of the voltage of the gate of the drive transistor M0 may be compensated through the compensation circuit, thereby improving the stability of the voltage of the gate of the drive transistor.
In some embodiments, in the embodiment of the present disclosure, the first electrode of the light emitting device L is electrically connected with the light emitting control circuit 20, and a second electrode of the light emitting device L is electrically connected with a second power end VSS. Exemplarily, the first electrode, electrically connected with the light emitting control circuit 20, of the light emitting device L is a positive electrode of the light emitting device L; and the second electrode, electrically connected with the second power end VSS, of the light emitting device L is a negative electrode of the light emitting device L. For example, the light emitting device L may be an electroluminescent diode, such as an OLED, a QLED, a Micro LED and a Mini LED. In addition, the light emitting device L realizes light emission under the action of a current when the drive transistor M0 is in a saturated state. In addition, generally, the light emitting device L has a turn-on voltage, and emits light when the voltage difference between two ends of the light emitting device L is greater than or equal to the turn-on voltage.
In some embodiments, in the embodiment of the present disclosure, a voltage Vdd of the first power end VDD is generally positive, and a voltage Vss of the second power end VSS is generally grounded or negative. In addition, a voltage Vinit of an initialization signal line VINIT and the voltage Vss of the second power end VSS need to satisfy the formula: Vinit−Vss<VL, where VL is the turn-on voltage of the light emitting device L.
In some embodiments, in the embodiment of the present disclosure, as shown in
In some embodiments, in the embodiment of the present disclosure, as shown in
In some embodiments, in the embodiment of the present disclosure, as shown in
In some embodiments, in the embodiment of the present disclosure, as shown in
In some embodiments, in the embodiment of the present disclosure, as shown in
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, in the embodiment of the present disclosure, the P-type transistor is turned on under the action of a low-level signal, and is turned off under the action of a high-level signal; and the N-type transistor is turned on under the action of a high-level signal, and is turned off under the action of a low-level signal.
Exemplarily, in the embodiment of the present disclosure, gates of the above-mentioned transistors may be used as their gates, first electrodes of the transistors may be used as their sources, and second electrodes of the transistors may be used as their drains; or the first electrodes of the above-mentioned transistors may be used as their drains, and the second electrodes of the above-mentioned transistors may be used as their sources, which is not specifically distinguished here.
Generally, transistors that use low temperature poly-silicon (LTPS) materials as active layers have high mobility, may be made thinner and smaller, and have lower power consumption. In some embodiments, in the embodiment of the present disclosure, a material of an active layer of the drive transistor M0 may include an LTPS material, the material of the active layer of the data writing transistor M3 may include the LTPS material, a material of the second reset transistor M4 may include the LTPS material, a material of the first light emitting control transistor M5 may include the LTPS material, and a material of the second light emitting control transistor M6 may include the LTPS material. That is, the data writing transistor M3, the second reset transistor M4, the first light emitting control transistor M5, the second light emitting control transistor M6, and the drive transistor M0 are all set as LTPS type transistors, so that the data writing transistor M3, the second reset transistor M4, the first light emitting control transistor M5, the second light emitting control transistor M6, and the drive transistor M0 have higher mobility, may be made thinner and smaller, and have lower power consumption.
Generally, leakage currents of transistors that use metal oxide semiconductor materials as active layers are relatively small. Therefore, in order to reduce leakage currents, In some embodiments, in the embodiment of the present disclosure, a material of an active layer of the first reset transistor M1 may include a metal oxide semiconductor material, and the material of the active layer of the threshold compensation transistor M2 may include the metal oxide semiconductor material. That is, both the first reset transistor M1 and the threshold compensation transistor M2 are set as oxide type transistors, so that the leakage currents of the first reset transistor M1 and the threshold compensation transistor M2 may be relatively small. Exemplarily, the metal oxide semiconductor material may be indium gallium zinc oxide (IGZO). Of course, the metal oxide semiconductor material may also be other metal oxide semiconductor materials, which is not limited here. Thus, the leakage currents of the first reset transistor M1 and the threshold compensation transistor M2 when the first reset transistor M1 and the threshold compensation transistor M2 are turned off may be reduced; and when the light emitting device L emits light, the interference of the leakage currents on the voltage of the gate of the drive transistor M0 may be reduced, thereby improving the stability of a drive current for the drive transistor M0 to drive the light emitting device L to emit light.
In the pixel circuit provided by the embodiment of the present disclosure, processes for preparing the LTPS type transistors and the oxide type transistors are combined to prepare the pixel circuit with low temperature poly-silicon combined with oxides, so that a leakage current of the gate of the drive transistor M0 is relatively small, and the power consumption is relatively low. Therefore, when the pixel circuit is applied to a display apparatus with an electroluminescent display panel, the stability of the voltage of the gate of the drive transistor M0 may be improved, and especially when the display apparatus reduces the refresh rate for display, the uniformity of display may be ensured.
The operation of the pixel circuit provided by the embodiment of the present disclosure will now be described with reference to a signal timing diagram shown in
It should be noted that a signal of the first scan line G1 and a signal of the second scan line G2 are composed of a high-level signal and a low-level signal, respectively. A voltage of the high-level signal is typically a high voltage VGH and a voltage of the low-level signal is typically a low voltage VGL. Of course, specific values of the high voltage VGH and the low voltage VGL may be designed and determined according to actual application requirements, which is not limited here.
Exemplarily, the absolute values of high and low levels may be equal, for example, the high level is +5 V, and the low level is −5 V. Or, the high level is +6 V, and the low level is −6 V. Or, the high level is +7 V, and the low level is −7 V. Or, the absolute values of the high and low levels may also be unequal, for example, the high level is a value greater than 0, and the low level is 0 V. Of course, in actual applications, the relationship between the absolute values of the high and low levels may be determined according to the actual application requirements, which is not limited here.
In a reset stage T1, S1=1, G2=0, G1=1, EM=1.
Since S1=1, the first reset transistor M1 is turned on to provide a signal of the initialization signal line VINIT to the gate of the drive transistor M0 to initialize the gate of the drive transistor M0. Since G2=0, the threshold compensation transistor M2 is turned off. Since G1=1, both the data writing transistor M3 and the second reset transistor M4 are turned off. Since EM=1, both the first light emitting control transistor M5 and the second light emitting control transistor M6 are turned off. A voltage of the second electrode of the first compensation capacitor CF1 is the high voltage VGH of the high-level signal of the first scan line G1, and a voltage of the first electrode of the first compensation capacitor CF1 is the voltage Vinit of the initialization signal line VINIT.
In a data writing stage T2, S1=0, G2=1, G1=0, and EM=1.
Since G1=0, the data writing transistor M3 and the second reset transistor M4 are both turned on. Since G2=1, the threshold compensation transistor M2 is turned on. The turned-on data writing transistor M3 inputs a data voltage Vda of the data line DA to the first electrode of the drive transistor M0. The turned-on threshold compensation transistor M2 turns on the gate and the second electrode of the drive transistor M0, so that the drive transistor M0 forms a diode electrical connection structure, the gate of the drive transistor M0 is charged through the data voltage Vda, and the voltage of the gate of the drive transistor M0 is made to successfully be Vda+Vth. The turned-on second reset transistor M4 provides the signal of the initialization signal line VINIT to the first electrode of the light emitting device L, to initialize the first electrode of the light emitting device L. The voltage of the second electrode of the first compensation capacitor CF1 is the low voltage VGL of the low-level signal of the first scan line G1, and the voltage of the first electrode of the first compensation capacitor CF1 is Vda+Vth. Since S1=0, the first reset transistor M1 is turned off. Since EM=1, both the first light emitting control transistor M5 and the second light emitting control transistor M6 are turned off.
In a light emitting stage T3, S1=0, G2=0, G1=1, and EM=0.
Since the second scan line G2 is switched from the high voltage VGH of the high-level signal to the low voltage VGL of the low-level signal, the voltage of the gate of the drive transistor M0 may be changed by a voltage ΔVn11 on the basis of Vda+Vth.
where CgsT2 represents the first channel capacitance value, Cc1 represents a capacitance value of the storage capacitor C1, Cf1 represents the capacitance value of the first compensation capacitor CF1, and Co represents other related capacitance values (generally being fixed values).
Since the first scan line G1 is switched from the low voltage VGL of the low-level signal to the high voltage VGH of the high-level signal, the voltage of the gate of the drive transistor M0 may be changed by a voltage ΔVn12 on the basis of Vda+Vth; where
Thus, the amount of change in the voltage of the gate of the drive transistor M0 is: ΔVn10=ΔVn11+ΔVn12. Since the difference between the capacitance value Cf1 of the first compensation capacitor CF1 and the first channel capacitance value CgsT2 satisfies 0±Δc1, it may be considered that the capacitance value Cf1 of the first compensation capacitor CF1 and the first channel capacitance value CgsT2 are equal. Therefore, ΔVn11 and ΔVn12 may cancel each other out, and ΔVn10 may be 0. In this way, after the light emitting stage T3, the voltage of the gate of the drive transistor M0 may be stabilized at Vda+Vth.
Since EM=0, the first light emitting control transistor M5 and the second light emitting control transistor M6 are both turned on. The turned-on first light emitting control transistor M5 provides a voltage of the first power end VDD to the first electrode of the drive transistor M0. The drive transistor M0 generates an operating current Ids under the action of voltages of the gate and first electrode of the drive transistor M0. Ids=K(Vdd−Vda)2, where K is a structural parameter. The turned-on second light emitting control transistor M6 turns on the second electrode of the drive transistor M0 and the first electrode of the light emitting device L, so that the light emitting device L is driven through the operating current Ids to emit light. Therefore, an operating current generated by the pixel circuit provided by the embodiment of the present disclosure has nothing to do with the threshold voltage Vth of the drive transistor M0.
The embodiment of the present disclosure further provides some pixel circuits. The schematic structural diagram of the pixel circuits is shown in
In some embodiments, in the embodiment of the present disclosure, as shown in
In some embodiments, in the embodiment of the present disclosure, a capacitance value of a channel capacitor between the gate and the first electrode of the first compensation control transistor is a second channel capacitance value CgsMF1, and a capacitance value of a channel capacitor between the gate and the second electrode of the first compensation control transistor is a third channel capacitance value CgdMF1; and the sum of the second channel capacitance value CgsMF1 and the third channel capacitance value CgdMF1 is a total channel capacitance value Cm1MF1. A difference between the total channel capacitance value CmMF1 and the first channel capacitance value CgsT2 satisfies 0±Δc2. For example, Δc2 may be 0.1, or or 0.05, which is not limited here. It should be noted that in the actual process, due to the limitation of process conditions or other factors, the first channel capacitance value may not be exactly the same as the total channel capacitance value, and there may be some deviations. Therefore, the sameness relationship between the first channel capacitance value and the total channel capacitance value only needs to substantially satisfy the above-mentioned conditions, which all belong to the protection scope of the present disclosure. For example, when the difference between the first channel capacitance value and the total channel capacitance value satisfies 0±Δc2, it may be considered that the first channel capacitance value and the total channel capacitance value are allowed to be the same within the tolerable error range.
The operation of the pixel circuit provided by the embodiment of the present disclosure will now be described with reference to the signal timing diagram shown in
It should be noted that the signal of the first scan line G1 and the signal of the second scan line G2 are composed of the high-level signal and the low-level signal, respectively. The voltage of the high-level signal is typically the high voltage VGH and the voltage of the low-level signal is typically the low voltage VGL. Of course, the specific values of the high voltage VGH and the low voltage VGL may be designed and determined according to actual application requirements, which is not limited here.
In the reset stage T1, S1=1, G2=0, G1=1, and EM=1.
Since S1=1, the first reset transistor M1 is turned on to provide the signal of the initialization signal line VINIT to the gate of the drive transistor M0 to initialize the gate of the drive transistor M0. Since G2=0, the threshold compensation transistor M2 is turned off. Since G1=1, the data writing transistor M3, the first compensation control transistor and the second reset transistor M4 are all turned off. Since EM=1, both the first light emitting control transistor M5 and the second light emitting control transistor M6 are turned off.
In the data writing stage T2, S1=0, G2=1, G1=0, and EM=1.
Since G1=0, the data writing transistor M3, the second reset transistor M4 and the first compensation control transistor are all turned on. Since G2=1, the threshold compensation transistor M2 is turned on. The turned-on data writing transistor M3 inputs the data voltage Vda of the data line DA to the first electrode of the drive transistor M0. The turned-on threshold compensation transistor M2 turns on the gate and the second electrode of the drive transistor M0, so that the drive transistor M0 forms a diode electrical connection structure, the gate of the drive transistor M0 is charged through the data voltage Vda, and the voltage of the gate of the drive transistor M0 is made to successfully be Vda+Vth. The turned-on second reset transistor M4 provides the signal of the initialization signal line VINIT to the first electrode of the light emitting device L to initialize the first electrode of the light emitting device L. Since S1=0, the first reset transistor M1 is turned off. Since EM=1, both the first light emitting control transistor M5 and the second light emitting control transistor M6 are turned off. In this stage, the first compensation control transistor has no influence on the voltage of the gate of the drive transistor M0.
In the light emitting stage T3, S1=0, G2=0, G1=1, and EM=0.
Since the second scan line G2 is switched from the high voltage VGH of the high-level signal to the low voltage VGL of the low-level signal, the voltage of the gate of the drive transistor M0 may be changed by a voltage ΔVn21 on the basis of Vda+Vth.
where CgsT2 represents the first channel capacitance value, Cc1 represents the capacitance value of the storage capacitor C1, CgsMF1 represents the second channel capacitance value, Cgd1MF1 represents the third channel capacitance value, and Co represents other related capacitance values (generally being fixed values).
Since the first scan line G1 is switched from the low voltage VGL of the low-level signal to the high voltage VGH of the high-level signal, the voltage of the gate of the drive transistor M0 may be changed by a voltage ΔVn22 on the basis of Vda+Vth, where
Thus, the amount of change in the voltage of the gate of the drive transistor M0 is: ΔVn20=ΔVn21+ΔVn22. Since the difference between the total channel capacitance value CmMF1, namely the sum of the second channel capacitance value CgsMF1 and the third channel capacitance value CgdMF1, and the first channel capacitance value CgsT2 satisfies it may be considered that the total channel capacitance value CmMF1 and the first channel capacitance value CgsT2 are equal. Therefore, ΔVn21 and ΔVn22 may cancel each other out, and ΔVn20 may be 0. In this way, after the light emitting stage T3, the voltage of the gate of the drive transistor M0 may be stabilized at Vda+Vth.
Since EM=0, the first light emitting control transistor M5 and the second light emitting control transistor M6 are both turned on. The turned-on first light emitting control transistor M5 provides the voltage of the first power end VDD to the first electrode of the drive transistor M0. The drive transistor M0 generates the operating current Ids under the action of the voltages of the gate and first electrode of the drive transistor M0. Ids=K(Vdd−Vda)2, where K is a structural parameter. The turned-on second light emitting control transistor M6 turns on the second electrode of the drive transistor M0 and the first electrode of the light emitting device L, so that the light emitting device L is driven through the operating current Ids to emit light. Therefore, the operating current generated by the pixel circuit provided by the embodiment of the present disclosure has nothing to do with the threshold voltage Vth of the drive transistor M0.
The embodiment of the present disclosure further provides some pixel circuits. The schematic structural diagram of the pixel circuits is shown in
In some embodiments, in the embodiment of the present disclosure, as shown in
In some embodiments, in the embodiment of the present disclosure, a capacitance value of a channel capacitor between the gate and the first electrode of the second compensation control transistor is a fourth channel capacitance value CgsMF2, and a difference between the fourth channel capacitance value CgsMF2 and the first channel capacitance value CgsT2 satisfies 0±Δc3. For example, Δc3 may be 0.1, or 0.01, or 0.05, which is not limited here. It should be noted that in the actual process, due to the limitation of process conditions or other factors, the first channel capacitance value may not be exactly the same as the fourth channel capacitance value, and there may be some deviations. Therefore, the sameness relationship between the first channel capacitance value and the fourth channel capacitance value only needs to substantially satisfy the above-mentioned conditions, which all belong to the protection scope of the present disclosure. For example, when the difference between the first channel capacitance value and the fourth channel capacitance value satisfies 0±Δc3, it may be considered that the first channel capacitance value and the fourth channel capacitance value are allowed to be the same within the tolerable error range.
The operation of the pixel circuit provided by the embodiment of the present disclosure will now be described with reference to the signal timing diagram shown in
It should be noted that the signal of the first scan line G1 and the signal of the second scan line G2 are composed of the high-level signal and the low-level signal, respectively. The voltage of the high-level signal is typically the high voltage VGH and the voltage of the low-level signal is typically the low voltage VGL. Of course, the specific values of the high voltage VGH and the low voltage VGL may be designed and determined according to actual application requirements, which is not limited here.
In the reset stage T1, S1=1, G2=0, G1=1, and EM=1.
Since S1=1, the first reset transistor M1 is turned on to provide the signal of the initialization signal line VINIT to the gate of the drive transistor M0 to initialize the gate of the drive transistor M0. Since G2=0, the threshold compensation transistor M2 is turned off. Since G1=1, the data writing transistor M3, the second compensation control transistor and the second reset transistor M4 are all turned off. Since EM=1, both the first light emitting control transistor M5 and the second light emitting control transistor M6 are turned off.
In the data writing stage T2, S1=0, G2=1, G1=0, and EM=1.
Since G1=0, the data writing transistor M3, the second reset transistor M4 and the second compensation control transistor are all turned on. Since G2=1, the threshold compensation transistor M2 is turned on. The turned-on data writing transistor M3 inputs the data voltage Vda of the data line DA to the first electrode of the drive transistor M0. The turned-on threshold compensation transistor M2 turns on the gate and the second electrode of the drive transistor M0, so that the drive transistor M0 forms a diode electrical connection structure, the gate of the drive transistor M0 is charged through the data voltage Vda, and the voltage of the gate of the drive transistor M0 is made to successfully be Vda+Vth. The turned-on second reset transistor M4 provides the signal of the initialization signal line VINIT to the first electrode of the light emitting device L to initialize the first electrode of the light emitting device L. Since S1=0, the first reset transistor M1 is turned off. Since EM=1, both the first light emitting control transistor M5 and the second light emitting control transistor M6 are turned off. In this stage, the second compensation control transistor has no influence on the voltage of the gate of the drive transistor M0.
In the light emitting stage T3, S1=0, G2=0, G1=1, and EM=0.
Since the second scan line G2 is switched from the high voltage VGH of the high-level signal to the low voltage VGL of the low-level signal, the voltage of the gate of the drive transistor M0 may be changed by a voltage ΔVn31 on the basis of Vda+Vth.
where CgsT2 represents the first channel capacitance value, Cc1 represents the capacitance value of the storage capacitor C1, CgsMF2 represents the fourth channel capacitance value, and Co represents other related capacitance values (generally being fixed values).
Since the first scan line G1 is switched from the low voltage VGL of the low-level signal to the high voltage VGH of the high-level signal, the voltage of the gate of the drive transistor M0 may be changed by a voltage ΔVn32 on the basis of Vda+Vth.
Thus, the amount of change in the voltage of the gate of the drive transistor M0 is: ΔVn30=ΔVn31+ΔVn32. Since the difference between the fourth channel capacitance value CgsMF2 and the first channel capacitance value CgsT2 satisfies 0±Δc3, it may be considered that the fourth channel capacitance value CgsMF2 and the first channel capacitance value CgsT2 are equal. Therefore, ΔVn31 and ΔVn32 may cancel each other out, and ΔVn30 may be 0. In this way, after the light emitting stage T3, the voltage of the gate of the drive transistor M0 may be stabilized at Vda+Vth.
Since EM=0, the first light emitting control transistor M5 and the second light emitting control transistor M6 are both turned on. The turned-on first light emitting control transistor M5 provides the voltage of the first power end VDD to the first electrode of the drive transistor M0. The drive transistor M0 generates the operating current Ids under the action of the voltages of the gate and first electrode of the drive transistor M0. Ids=K(Vdd−Vda)2, where K is a structural parameter. The turned-on second light emitting control transistor M6 turns on the second electrode of the drive transistor M0 and the first electrode of the light emitting device L, so that the light emitting device L is driven through the operating current Ids to emit light. Therefore, the operating current generated by the pixel circuit provided by the embodiment of the present disclosure has nothing to do with the threshold voltage Vth of the drive transistor M0.
The embodiment of the present disclosure further provides some pixel circuits. The schematic structural diagram of the pixel circuits is shown in
In some embodiments, in the embodiment of the present disclosure, as shown in
The operation of the pixel circuit provided by the embodiment of the present disclosure will now be described with reference to the signal timing diagram shown in
In the reset stage T1, S1=1, G2=0, G1=1, and EM=1.
Since S1=1, the first reset transistor M1 is turned on to provide the signal of the initialization signal line VINIT to the gate of the drive transistor M0 to initialize the gate of the drive transistor M0. Since G2=0, the threshold compensation transistor M2 is turned off. Since G1=1, the data writing transistor M3 and the second reset transistor M4 are all turned off. Since EM=1, both the first light emitting control transistor M5 and the second light emitting control transistor M6 are turned off. A voltage of the first electrode of the second compensation capacitor CF2 is the voltage Vinit of the initialization signal line VINIT, and a voltage of the second electrode of the second compensation capacitor CF2 is the voltage of the first electrode of the light emitting device L.
In the data writing stage T2, S1=0, G2=1, G1=0, and EM=1.
Since G1=0, the data writing transistor M3 and the second reset transistor M4 are both turned on. Since G2=1, the threshold compensation transistor M2 is turned on. The turned-on data writing transistor M3 inputs the data voltage Vda of the data line DA to the first electrode of the drive transistor M0. The turned-on threshold compensation transistor M2 turns on the gate and the second electrode of the drive transistor M0, so that the drive transistor M0 forms a diode electrical connection structure, the gate of the drive transistor M0 is charged through the data voltage Vda, and the voltage of the gate of the drive transistor M0 is made to successfully be Vda+Vth. The turned-on second reset transistor M4 provides the signal of the initialization signal line VINIT to the first electrode of the light emitting device L to initialize the first electrode of the light emitting device L. The voltage of the first electrode of the second compensation capacitor CF2 is Vda+Vth, and the voltage of the second electrode of the second compensation capacitor CF2 is the voltage Vinit of the initialization signal line VINIT. Since S1=0, the first reset transistor M1 is turned off. Since EM=1, both the first light emitting control transistor M5 and the second light emitting control transistor M6 are turned off.
In the light emitting stage T3, S1=0, G2=0, G1=1, and EM=0.
Since the second scan line G2 is switched from the high voltage VGH of the high-level signal to the low voltage VGL of the low-level signal, the voltage of the gate of the drive transistor M0 may be changed by a voltage ΔVn41 on the basis of Vda+Vth.
where CgsT2 represents the first channel capacitance value, Cc1 represents the capacitance value of the storage capacitor C1, Cf2 represents the capacitance value of the second compensation capacitor CF2, and Co represents other related capacitance values (generally being fixed values).
Since the voltage of the first electrode of the light emitting device L is changed from Vinit to Vss+VL, the voltage of the gate of the drive transistor M0 may be changed by a voltage ΔVn42 on the basis of Vda+Vth.
Thus, the amount of change in the voltage of the gate of the drive transistor M0 is: ΔVn40=ΔVn41+ΔVn42. By enabling CgsT2*(VGL−VGH)+C12*(VL+Vss−Vinit) to be substantially 0, ΔVn41 and ΔVn42 may cancel each other out, and ΔVn40 may be 0. In this way, after the light emitting stage T3, the voltage of the gate of the drive transistor M0 may be stabilized at Vda+Vth.
Since EM=0, the first light emitting control transistor M5 and the second light emitting control transistor M6 are both turned on. The turned-on first light emitting control transistor M5 provides the voltage of the first power end VDD to the first electrode of the drive transistor M0. The drive transistor M0 generates the operating current Ids under the action of the voltages of the gate and first electrode of the drive transistor M0. Ids=K(Vdd-Vda) 2, where K is a structural parameter. The turned-on second light emitting control transistor M6 turns on the second electrode of the drive transistor M0 and the first electrode of the light emitting device L, so that the light emitting device L is driven through the operating current Ids to emit light. Therefore, the operating current generated by the pixel circuit provided by the embodiment of the present disclosure has nothing to do with the threshold voltage Vth of the drive transistor M0.
The embodiment of the present disclosure further provides some pixel circuits. The schematic structural diagram of the pixel circuits is shown in
In some embodiments, in the embodiment of the present disclosure, as shown in
Exemplarily, the first reset transistor M1 and the threshold compensation transistor M2 may be P-type transistors, and the materials of the active layers of the first reset transistor M1 and the threshold compensation transistor M2 are LTPS materials.
Exemplarily, the stable transistor M7 may be an N-type transistor, and a material of an active layer of the stable transistor M7 may be a metal oxide semiconductor material.
The operation of the pixel circuit provided by the embodiment of the present disclosure will now be described with reference to a signal timing diagram shown in
In the reset stage T1, S1=0, G2=1, G1=1, EM=1, and VS=1.
Since S1=0, the first reset transistor M1 is turned on to provide the signal of the initialization signal line VINIT to the second electrode of the stable transistor M7. Since VS=1, the stable transistor M7 is turned on to provide the signal of the initialization signal line VINIT to the gate of the drive transistor M0 so as to initialize the gate of the drive transistor M0. Since G2=1, the threshold compensation transistor M2 is turned off. Since G1=1, the data writing transistor M3 and the second reset transistor M4 are both turned off. Since EM=1, both the first light emitting control transistor M5 and the second light emitting control transistor M6 are turned off. The voltage of the second electrode of the first compensation capacitor CF1 is the high voltage VGH of the high-level signal of the first scan line G1, and the voltage of the first electrode of the first compensation capacitor CF1 is the voltage Vinit of the initialization signal line VINIT.
In the data writing stage T2, S1=1, G2=0, G1=0, EM=1, and VS=1.
Since G1=0, the data writing transistor M3 and the second reset transistor M4 are both turned on. Since G2=0, the threshold compensation transistor M2 is turned on. Since VS=1, the stable transistor M7 is turned on. The turned-on data writing transistor M3 inputs the data voltage Vda of the data line DA to the first electrode of the drive transistor M0. The turned-on threshold compensation transistor M2 and the turned-on stable transistor M7 turn on the gate and the second electrode of the drive transistor M0, so that the drive transistor M0 forms a diode electrical connection structure, the gate of the drive transistor M0 is charged through the data voltage Vda, and the voltage of the gate of the drive transistor M0 is made to successfully be Vda+Vth. The turned-on second reset transistor M4 provides the signal of the initialization signal line VINIT to the first electrode of the light emitting device L to initialize the first electrode of the light emitting device L. The voltage of the second electrode of the first compensation capacitor CF1 is the low voltage VGL of the low-level signal of the first scan line G1, and the voltage of the first electrode of the first compensation capacitor CF1 is Vda+Vth. Since S1=1, the first reset transistor M1 is turned off. Since EM=1, both the first light emitting control transistor M5 and the second light emitting control transistor M6 are turned off.
In the light emitting stage T3, S1=0, G2=0, G1=1, EM=0, and VS=0.
Since the second scan line G2 is switched from the high voltage VGH of the high-level signal to the low voltage VGL of the low-level signal, the voltage of the gate of the drive transistor M0 may be changed by a voltage ΔVn11 on the basis of Vda+Vth.
where CgsT2 represents the first channel capacitance value, Cc1 represents the capacitance value of the storage capacitor C1, Cf1 represents the capacitance value of the first compensation capacitor CF1, and Co represents other related capacitance values (generally being fixed values).
Since the first scan line G1 is switched from the low voltage VGL of the low-level signal to the high voltage VGH of the high-level signal, the voltage of the gate of the drive transistor M0 may be changed by a voltage ΔVn12 on the basis of Vda+Vth.
Thus, the amount of change in the voltage of the gate of the drive transistor M0 is: ΔVn10=ΔVn11+ΔVn12. Since the difference between the capacitance value Cf1 of the first compensation capacitor CF1 and the first channel capacitance value CgsT2 satisfies 0±Δc1, it may be considered that the capacitance value Cf1 of the first compensation capacitor CF1 and the first channel capacitance value CgsT2 are equal. Therefore, ΔVn11 and ΔVn12 may cancel each other out, and ΔVn10 may be 0. In this way, after the light emitting stage T3, the voltage of the gate of the drive transistor M0 may be stabilized at Vda+Vth.
Since EM=0, the first light emitting control transistor M5 and the second light emitting control transistor M6 are both turned on. The turned-on first light emitting control transistor M5 provides the voltage of the first power end VDD to the first electrode of the drive transistor M0. The drive transistor M0 generates the operating current Ids under the action of the voltages of the gate and first electrode of the drive transistor M0. Ids=K(Vdd−Vda)2, where K is a structural parameter. The turned-on second light emitting control transistor M6 turns on the second electrode of the drive transistor M0 and the first electrode of the light emitting device L, so that the light emitting device L is driven through the operating current Ids to emit light. Therefore, the operating current generated by the pixel circuit provided by the embodiment of the present disclosure has nothing to do with the threshold voltage Vth of the drive transistor M0.
The embodiment of the present disclosure further provides some pixel circuits. The schematic structural diagram of the pixel circuits is shown in
In some embodiments, in the embodiment of the present disclosure, as shown in
The operation of the pixel circuit provided by the embodiment of the present disclosure will now be described with reference to a signal timing diagram shown in
In the reset stage T1, S1=1, G2=0, G1=1, EM=1, and CS=0.
Since S1=1, the first reset transistor M1 is turned on to provide the signal of the initialization signal line VINIT to the gate of the drive transistor M0 to initialize the gate of the drive transistor M0. Since CS=0, the second reference transistor M9 is turned on to provide a signal of a reference signal end VREF to the storage capacitor C1. Since G2=0, the threshold compensation transistor M2 is turned off. Since G1=1, the data writing transistor M3 and the second reset transistor M4 are both turned off. Since EM=1, both the first reference transistor M8 and the second light emitting control transistor M6 are turned off. The voltage of the second electrode of the first compensation capacitor CF1 is the high voltage VGH of the high-level signal of the first scan line G1, and the voltage of the first electrode of the first compensation capacitor CF1 is the voltage Vinit of the initialization signal line VINIT.
In the data writing stage T2, S1=0, G2=1, G1=0, EM=1, and CS=1.
Since G1=0, the data writing transistor M3 and the second reset transistor M4 are both turned on. The turned-on data writing transistor M3 inputs the data voltage Vda of the data line DA to the storage capacitor C1. The turned-on second reset transistor M4 provides the signal of the initialization signal line VINIT to the first electrode of the light emitting device L to initialize the first electrode of the light emitting device L. Since G2=1, the threshold compensation transistor M2 is turned on. The turned-on threshold compensation transistor M2 turns on the gate and the second electrode of the drive transistor M0, so that the drive transistor M0 forms a diode electrical connection structure, the gate of the drive transistor M0 is charged through the first power end VDD, and the voltage of the gate of the drive transistor M0 is made to successfully be Vdd+Vth. The voltage of the second electrode of the first compensation capacitor CF1 is the low voltage VGL of the low-level signal of the first scan line G1, and the voltage of the first electrode of the first compensation capacitor CF1 is Vdd+Vth. Since S1=0, the first reset transistor M1 is turned off. Since EM=1, both the first reference transistor M8 and the second light emitting control transistor M6 are turned off. Vdd is the voltage of the first power end VDD.
In the light emitting stage T3, S1=0, G2=0, G1=1, and EM=0.
Since the second scan line G2 is switched from the high voltage VGH of the high-level signal to the low voltage VGL of the low-level signal, the voltage of the gate of the drive transistor M0 may be changed by a voltage ΔVn11 on the basis of Vda+Vth.
where CgsT2 represents the first channel capacitance value, Cc1 represents the capacitance value of the storage capacitor C1, Cf1 represents the capacitance value of the first compensation capacitor CF1, and Co represents other related capacitance values (generally being fixed values).
Since the first scan line G1 is switched from the low voltage VGL of the low-level signal to the high voltage VGH of the high-level signal, the voltage of the gate of the drive transistor M0 may be changed by a voltage ΔVn12 on the basis of Vda+Vth.
Thus, the amount of change in the voltage of the gate of the drive transistor M0 is: ΔVn10=ΔVn11+ΔVn12. Since the difference between the capacitance value Cf1 of the first compensation capacitor CF1 and the first channel capacitance value CgsT2 satisfies 0±Δc1, it may be considered that the capacitance value Cf1 of the first compensation capacitor CF1 and the first channel capacitance value CgsT2 are equal. Therefore, ΔVn11 and ΔVn12 may cancel each other out, and ΔVn10 may be 0. In this way, after the light emitting stage T3, the voltage of the gate of the drive transistor M0 may be stabilized at Vda+Vth.
Since EM=0, the first reference transistor M8 and the second light emitting control transistor M6 are both turned on. The turned-on first reference transistor M8 provides the voltage of the reference signal end VREF to the storage capacitor C1, so that the voltage of the drive transistor M0 is changed into Vdd+Vth+Vda. Therefore, the drive transistor M0 generates the operating current Ids under the action of the voltages of the gate and first electrode of the drive transistor M0. Ids=K(Vda)2, where K is a structural parameter. The turned-on second light emitting control transistor M6 turns on the second electrode of the drive transistor M0 and the first electrode of the light emitting device L, so that the light emitting device L is driven through the operating current Ids to emit light. Therefore, the operating current generated by the pixel circuit provided by the embodiment of the present disclosure has nothing to do with the threshold voltage Vth of the drive transistor M0 and the voltage of the first power end VDD.
An embodiment of the present disclosure also provides a display panel. As shown in
In some embodiments, in the embodiment of the present disclosure, each sub-pixel spx may include the above-mentioned pixel circuit. It should be noted that the structure and operation of the pixel circuit may be described with reference to the above-described embodiment, and will not be described in detail here. The structure of the pixel circuit shown in
Exemplarily, as shown in
Exemplarily, a first gate insulating layer 810 is formed on a side, facing away from the base substrate 1000, of the silicon semiconductor layer 600; and used to protect the silicon semiconductor layer 600. Exemplarily, a thickness of the first gate insulating layer 810 may be 1000-1500 Å. For example, the thickness of the first gate insulating layer 810 may be 1000 Å, or 1300 Å, or 1500 Å, which is not limited here.
As shown in
Exemplarily, a thickness of the first conductive layer 100 may be 2000-3000 Å. For example, the thickness of the first conductive layer 100 may be 2000 Å, or 2500 Å, or 3000 Å, which is not limited here.
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, a first interlayer dielectric layer 820 is formed on a side, facing away from the base substrate 1000, of the first conductive layer 100; and used to insulate the first conductive layer 100 from a second conductive layer 200. Exemplarily, a thickness of the first interlayer dielectric layer 820 may be 1000-1500 Å. For example, the thickness of the first interlayer dielectric layer 820 may be 1000 Å, or 1300 Å, or 1500 Å, which is not limited here.
As shown in
Exemplarily, a thickness of the second conductive layer 200 may be 2000-3000 Å. For example, the thickness of the second conductive layer 200 may be 2000 Å, or 2500 Å, or 3000 Å, which is not limited here.
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, a second interlayer dielectric layer 830 is formed on a side, facing away from the base substrate 1000, of the second conductive layer 200; and used to insulate an oxide semiconductor layer 700 from the second conductive layer 200. As shown in
Exemplarily, a thickness of the second interlayer dielectric layer 830 may be 900-1500 Å. For example, the thickness of the second interlayer dielectric layer 830 may be 900 Å, or 1200 Å, or 1500 Å, which is not limited here.
Exemplarily, as shown in
Exemplarily, a thickness of the buffer layer 870 may be 2000-3000 Å. For example, the thickness of the buffer layer 870 may be 2000 Å, or 2500 Å, or 3000 Å, which is not limited here.
Exemplarily, a thickness of the oxide semiconductor layer 700 may be 300-600 Å. For example, the thickness of the oxide semiconductor layer 700 may be 300 Å, or 500 Å, or 600 Å, which is not limited here.
In addition, each of the active layer of the first reset transistor M1 and the active layer of the threshold compensation transistor M2 may include a third region, a fourth region, and a second channel region located between the third region and the fourth region. For example,
In addition, as shown in
Exemplarily, a second gate insulating layer 840 is formed on a side, facing away from the base substrate 1000, of the oxide semiconductor layer 700. A third conductive layer 300 is formed on a side, facing away from the base substrate 1000, of the second gate insulating layer 840. As shown in
Exemplarily, a thickness of the second gate insulating layer 840 may be 1000-2000 Å. For example, the thickness of the second gate insulating layer 840 may be 1000 Å, or 1500 Å or 2000 Å, which is not limited here.
Exemplarily, a thickness of the third conductive layer 300 may be 2000-3000 Å. For example, the thickness of the third conductive layer 300 may be 2000 Å, or 2500 Å, or 3000 Å, which is not limited here.
As shown in
Exemplarily, as shown in
Exemplarily, as shown in
In addition, the orthographic projection of the second scan line G2 on the base substrate 1000 and the orthographic projection of the channel region of the active layer of the threshold compensation transistor M2 on the base substrate 1000 have the overlapping region, and the orthographic projection of the auxiliary scan line FG on the base substrate 1000 and the orthographic projection of the channel region of the active layer of the threshold compensation transistor M2 on the base substrate 1000 have the overlapping region. In this way, light may be shielded through the second scan line G2 and the auxiliary scan line FG, thereby preventing ambient light from being incident on the channel region of the active layer of the threshold compensation transistor M2 through upper and lower sides of the display panel.
Exemplarily, as shown in
Exemplarily, as shown in
In addition, the orthographic projection of the first reset line S1 on the base substrate 1000 and the orthographic projection of the channel region of the active layer of the first reset transistor M1 on the base substrate 1000 have the overlapping region, and the orthographic projection of the auxiliary reset line FS on the base substrate 1000 and the orthographic projection of the channel region of the active layer of the first reset transistor M1 on the base substrate 1000 have the overlapping region. In this way, light may also be shielded through the first reset line S1 and the auxiliary reset line FS, thereby preventing the ambient light from being incident on the channel region of the active layer of the first reset transistor M1 through the upper and lower sides of the display panel.
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, a third interlayer dielectric layer 850 is formed on a side, facing away from the base substrate 1000, of the third conductive layer; and a fourth conductive layer 400 is formed on a side, facing away from the base substrate 1000, of the third interlayer dielectric layer 850. As shown in
Exemplarily, a thickness of the third interlayer dielectric layer 850 may be 5000-6000 Å. For example, the thickness of the third interlayer dielectric layer 850 may be 5000 Å, or 5500 Å, or 6000 Å, which is not limited here.
Exemplarily, a thickness of the fourth conductive layer 400 may be 6000-8000 Å. For example, the thickness of the fourth conductive layer 400 may be 6000 Å, or 7000 Å, or 8000 Å, which is not limited here.
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, a thickness of the interlayer insulating layer 860 may be 15000-30000 Å. For example, the thickness of the interlayer insulating layer 860 may be 15000 Å, or 20000 Å, or 30000 Å, which is not limited here.
Exemplarily, a thickness of the fifth conductive layer 500 may be 6000-8000 Å. For example, the thickness of the fifth conductive layer 500 may be 6000 Å, or 7000 Å, or 8000 Å, which is not limited here.
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, as shown in
Exemplarily, as shown in
Further, for the first power signal line VD, the threshold compensation transistor M2 and the first reset transistor M1 corresponding to the same sub-pixel, the orthographic projection of the first power signal line VD on the base substrate 1000 covers the orthographic projections of the active layers of the threshold compensation transistor M2 and the first reset transistor M1 on the base substrate 1000.
Exemplarily, as shown in
The anode switch part YZ is electrically connected with the fifth connection part LB5 through a twelfth via GK12. The anode switch part YZ is electrically connected with an anode of a light emitting device through a fourteenth via GK14. The anode switch part YZ is electrically connected with the conductor region (for example, the second region) of the active layer of the second light emitting control transistor M6 through a thirteenth via GK13. The twelfth via GK12 penetrates the interlayer insulating layer 860. The thirteenth via GK13 penetrates the third interlayer dielectric layer 850, the second gate insulating layer 840, the second interlayer dielectric layer 830, the first interlayer dielectric layer 820 and the first gate insulating layer 810. The fourteenth via GK14 penetrates a flat layer between the fifth conductive layer 500 and a layer where the anode is located.
Exemplarily, a thickness of the flat layer may be 15000 to 30000 Å. For example, the thickness of the flat layer may be 15000 Å, or 20000 Å, or 30000 Å, which is not limited here.
Exemplarily, a parasitic capacitor may include a channel capacitor and a coupling capacitance formed by overlapping of other metal layers, or the parasitic capacitor may also include a channel capacitor. The size of the compensation capacitor in the present application may consider the size of the parasitic capacitor.
Based on the same disclosed concept, an embodiment of the present disclosure also provides a display apparatus including the above pixel circuit provided by the embodiment of the present disclosure. The principle by which the display apparatus solves the problem is similar to that of the afore-mentioned pixel circuit, and therefore the implementation of the display apparatus may be referred to the implementation of the afore-mentioned pixel circuit, which will not be repeated here.
In some embodiments, in the embodiment of the present disclosure, the display apparatus may be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, and a navigator. Other essential components of the display apparatus will be apparent to those of ordinary skill in the art and are not described in detail herein, nor should they be construed as limiting the present disclosure.
Although the preferred embodiments of the present disclosure have been described, additional variations and modifications may be made to these embodiments by those skilled in the art once the basic inventive concept is known. Therefore, it is intended that the appended claims be interpreted as including the preferred embodiments and all alterations and modifications that fall within the scope of the present disclosure.
It will be apparent to those skilled in the art that various modifications and variations can be made in the disclosed embodiments without departing from the spirit or scope of the disclosed embodiments. Thus, it is intended that the present disclosure cover the modifications and variations of the disclosure provided they come within the scope of the appended claims and their equivalents.
This application is a continuation application of U.S. Patent Application No. U.S. Ser. No. 17/433,068, filed on Aug. 23, 2021, which is a National Stage of International Application No. PCT/CN2020/123332, filed on Oct. 23, 2020, and entitled ‘PIXEL CIRCUIT, DISPLAY PANEL AND DISPLAY APPARATUS’, the entire contents of which are incorporated herein by reference.
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Notice of Allowance for corresponding U.S. Appl. No. 17/433,068 issued on May 24, 2023. |
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Number | Date | Country | |
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20230401990 A1 | Dec 2023 | US |
Number | Date | Country | |
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Parent | 17433068 | US | |
Child | 18452795 | US |