The present application claims priority to Chinese patent application No. 201810338993.1 filed on Apr. 16, 2018, the entire disclosure of which is incorporated herein by reference as part of the present application.
Embodiments of the present disclosure relate to a signal processing circuit and a driving method thereof, a display panel and a driving method thereof and a display device.
With the development of display technologies, various display screens have been widely applied. These display screens can provide rich and colorful pictures and good visual experience for users. Display screens mainly include liquid crystal display (LCD) screens and organic light-emitting diode (OLED) display screens, and can be applied in electronic devices with display function, such as mobile phones, TV sets, laptops, digital cameras, instrumentation, virtual reality (VR) devices, augmented reality (AR) devices.
At least an embodiment of the present disclosure provides a signal processing circuit. The signal processing circuit comprises a shunting circuit and N buffer circuits; the shunting circuit comprises N output nodes; the N buffer circuits are respectively connected with the N output nodes; the shunting circuit is configured to output input signals to the N output nodes respectively at N different time points in response to control signals; each of the N buffer circuits is configured to buffer an input signal received by a corresponding output node; and N is an integer that is greater than or equal to 2.
For example, in the signal processing circuit provided by an embodiment of the present disclosure, a first terminal of the each of the N buffer circuits is configured to be connected with the corresponding output node to the each of the N buffer circuits; and a second terminal of the each of the N buffer circuits is configured to be connected with a first voltage terminal, so as to receive a first voltage.
For example, in the signal processing circuit provided by an embodiment of the present disclosure, the each of the N buffer circuits comprises a capacitor, a first electrode of the capacitor serves as the first terminal of the each of the N buffer circuits, and a second electrode of the capacitor serves as the second terminal of the each of the N buffer circuits.
For example, in the signal processing circuit provided by an embodiment of the present disclosure, the signal processing circuit further comprises N reset circuits, and the N reset circuits are respectively connected with the N output nodes and are configured to reset the N output nodes in response to a reset signal.
For example, in the signal processing circuit provided by an embodiment of the present disclosure, a control terminal of each of the N reset circuits is configured to be connected with a reset signal line so as to receive the reset signal, a first terminal of the each of the N reset circuits is configured to be connected with a corresponding output node, and a second terminal of the each of the N reset circuits is configured to be connected with a second voltage terminal so as to receive a second voltage.
For example, in the signal processing circuit provided by an embodiment of the present disclosure, the each of the N reset circuits comprises a reset transistor, a gate electrode of the reset transistor serves as the control terminal of the each of the N reset circuits, a first terminal of the reset transistor serves as the first terminal of the each of the N reset circuits, and a second terminal of the reset transistor serves as the second terminal of the each of the N reset circuits.
For example, in the signal processing circuit provided by an embodiment of the present disclosure, the shunting circuit further comprises an input terminal, N input control terminals and N switching circuits; the N switching circuits are connected with the input terminal, respectively connected with the N output nodes in one-to-one correspondence, and respectively connected with the N input control terminals in one-to-one correspondence; each of the N switching circuits is configured to output an input signal received from the input terminal to a corresponding output node in response to a control signal received from a corresponding input control terminal.
For example, in the signal processing circuit provided by an embodiment of the present disclosure, the each of the N switching circuits comprises a switching transistor, a gate electrode of the switching transistor is connected with the corresponding input control terminal, a first terminal of the switching transistor is connected with the input terminal, and a second terminal of the switching transistor is connected with the corresponding output node.
For example, in the signal processing circuit provided by an embodiment of the present disclosure, N is equal to 2, and the N input control terminals are connected with each other, so as to be connected with same one input control line.
For example, in the signal processing circuit provided by an embodiment of the present disclosure, the N switching circuits comprises a first switching circuit and a second switching circuit; the shunting circuit further comprises an invert circuit; and one of the first switching circuit and the second switching circuit is connected with the N input control terminals through the invert circuit.
At least an embodiment of the present disclosure provides a display panel, which comprises the signal processing circuit provided by any embodiment of the present disclosure and comprises a plurality of data lines. N data lines of the plurality of data lines are respectively connected with the N buffer circuits of the signal processing circuit, and the input signals are display data signals.
For example, the display panel provided by an embodiment of the present disclosure further comprises a plurality of pixel units which are arranged in an array. The N data lines which are connected to the signal processing circuit are connected with same one column of pixel units; the same one column of pixel units comprises N pixel unit groups; and each of the N pixel unit groups is connected with same one data line.
For example, in the display panel provided by an embodiment of the present disclosure, N is equal to 2; the N pixel unit groups comprise a first pixel unit group and a second pixel unit group; the first pixel unit group comprises pixel units at odd numbered rows, and the second pixel unit group comprises pixel units at even numbered rows.
For example, the display panel provided by an embodiment of the present disclosure further comprises an array substrate. The signal processing circuit is on the array substrate.
For example, in the display panel provided by an embodiment of the present disclosure, the N data lines which are connected to same one signal processing circuit are at different layers of the array substrate.
For example, the display panel provided by an embodiment of the present disclosure further comprises at least one gate driving circuit. The gate driving circuit is configured to provide a plurality of gate scanning signals, so as to scan the pixel units of the display panel; and a pulse duration of a gate scanning signal for (M+1)th row partially overlaps a pulse duration of a gate scanning signal for (M)th row, and M is an integer greater than 0.
At least an embodiment of the present disclosure provides a display device, which comprises the display panel provided by any embodiment of the present disclosure or the signal processing circuit provided by any embodiment of the present disclosure.
At least an embodiment of the present disclosure provides a driving method of the signal processing circuit provided by any embodiment of the present disclosure, which comprises: providing the control signals and the input signals; allowing the shunting circuit to sequentially output the input signals to the N output nodes respectively at N different time points in response to the control signals; and buffering and outputting one of the input signals through the each of the N buffer circuits.
At least an embodiment of the present disclosure provides a driving method of the display panel provided by any embodiment of the present disclosure, which comprises: providing the control signals and the display data signals; allowing the shunting circuit to sequentially output the display data signals to the N output nodes respectively at the N different time points in response to the control signals; and buffering and outputting the display data signals to N corresponding data lines through the N buffer circuits.
For example, the driving method provided by an embodiment of the present disclosure further comprises: providing gate scanning signals, so as to perform row scanning with respect to the display panel. Pulse durations of gate scanning signals which are adjacent to each other partially overlap.
In order to clearly illustrate the technical solution of the embodiments of the disclosure, the drawings of the embodiments will be briefly described in the following; it is obvious that the described drawings are only related to some embodiments of the disclosure and thus are not limitative of the disclosure.
In order to make objects, technical details and advantages of the embodiments of the disclosure apparent, the technical solutions of the embodiments will be described in a clearly and fully understandable way in connection with the drawings related to the embodiments of the disclosure. Apparently, the described embodiments are just a part but not all of the embodiments of the disclosure. Based on the described embodiments herein, those skilled in the art can obtain other embodiment(s), without any inventive work, which should be within the scope of the disclosure.
Unless otherwise defined, all the technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. The terms “first,” “second,” etc., which are used in the description and the claims of the present application for disclosure, are not intended to indicate any sequence, amount or importance, but distinguish various components. Also, the terms such as “a,” “an,” etc., are not intended to limit the amount, but indicate the existence of at least one. The terms “comprise,” “comprising,” “include,” “including,” etc., are intended to specify that the elements or the objects stated before these terms encompass the elements or the objects and equivalents thereof listed after these terms, but do not preclude the other elements or objects. The phrases “connect”, “connected”, etc., are not intended to define a physical connection or mechanical connection, but may include an electrical connection, directly or indirectly. “On,” “under,” “right,” “left” and the like are only used to indicate relative position relationship, and when the position of the object which is described is changed, the relative position relationship may be changed accordingly.
For example, the pixel array of a display screen normally comprises a plurality of rows of gate lines, and a plurality of columns of data lines that intersect the plurality of rows of gate lines. The gate driving circuit of the display screen provides turning-on and turning-off voltage signals to the plurality of rows of gate lines of the pixel array, so as to, for example, control the plurality of rows of gate lines to be in turned-on state sequentially, such that data signals can be provided to pixel units in corresponding columns of the pixel array via the data lines (e.g., the pixel circuits of the pixel units are compensated or charged under the action of the data signals), so as to form grey-scale voltages, for grey-scales of a displayed image, at the pixel units, such that a frame of the image can be displayed.
In recent years, display screens with high refreshing frequency have received increasing attentions and been widely applied. The refreshing frequency is the times of the repeated scanning, of the display screen in displaying images, within a specific time duration. Display screens with high refreshing frequency can be applied in fields such as film playing, augmented reality display, virtual reality display, e-sports, and display screens with high refreshing frequency can ameliorate image smearing phenomenon, which is caused by display delay, of dynamic pictures, such that the stability of the displayed image is good.
However, high refreshing frequency can cause the compensation time (the charging time) of the pixel circuits in the display screen to be insufficient, such that the quality of the displayed image is significantly decreased, and for example, display mura can present. By taking a 120 Hz AMOLED (Active-Matrix Organic Light Emitting Diode) display screen as an example, at this refreshing frequency, the charging time available for the pixel circuits is 3.3 μs, that is, only half of the charging time of a 60 Hz AMOLED display screen, such that the compensation time of the pixel circuit of the 120 Hz AMOLED display screen is insufficient. The inventor of the present disclosure has noted that insufficient compensation time of the pixel circuit can cause that data voltages to be not fully written, such that the display quality can be adversely affected.
Illustrative descriptions are given to the adverse effect of insufficient compensation time of the pixel circuits on the display quality in the following with reference to
In the reset stage Tre, the reset control terminals RESE of the pixel circuit receive a low electric level signal, so as to allow the first transistor Tt1 and the seventh transistor Tt7 to be turned on, such that the initial voltage Vinit is respectively applied to the anode of the light-emitting element and the second node N2 via the first transistor Tt1 and the seventh transistor Tt7 that are turned on, and the voltages of the anode of the light-emitting element and the second node N2 are set to be the initial voltage Vinit, and therefore, the anode of the light-emitting element and the second node N2 are rest. The initial voltage Vinit allows the third transistor Tt3 (driving transistor) to be in a turned-on state, and in this case, the voltage of the first node N1 is V1.
In the compensation stage Tc, the gating control terminals GAT of the pixel circuit receive a low electric level signal, so as to allow the second transistor Tt2 and the fourth transistor Tt4 to be turned on, and therefore, the data voltage Vdata can be applied to the source electrode of the third transistor Tt3, and the drain electrode of the third transistor Tt3 is electrically connected with the gate electrode of the third transistor Tt3. Because the third transistor Tt3 is in a turned-on state, the storage capacitor Cst can be charged via the drain electrode and the gate electrode of the third transistor Tt3, and the charging process is finished when the voltage of the gate electrode of the third transistor Tt3 is sufficiently increased. In this case, the voltage Vt1 of the source electrode (the first terminal) of the third transistor Tt3 is Vdata, the voltage Vt2 of the drain electrode (the second terminal) and the gate electrode (the control terminal) is changed into Vdata+Vth, that is, the voltage of the second node N2 is also Vdata+Vth, and is stored in the first terminal of the storage capacitor Cst (i.e., the terminal that is connected with the second node N2). Here, Vth is the threshold voltage of the third transistor Tt3, and in this case, the voltage of the first node N1 is still V1.
In the light-emitting stage Tem, the light-emitting control terminals EM receives a low electric level signal, so as to allow the fifth transistor Tt5 and the sixth transistor Tt6 to be turned on, such that the first terminal of the third transistor Tt3 is connected with to the first power source terminal ELVDD via the fifth transistor Tt5 that is turned on, and the voltage Vt1 of the first terminal of the third transistor Tt3 is changed into V1; in this case, under the action of the storage capacitor Cst, the voltage Vtg of the control terminal of the third transistor Tt3, that is, the voltage of the second node N2, is still Vdata+Vth. The current Ids outputted by the third transistor Tt3 in a saturated state can be calculated by the following equations:
Here, K=W/L×C×μ, W/L is the width-length ratio (i.e., the ratio between the width and the length) of the channel of the third transistor Tt3, p is the electron mobility, and C is the capacitance per unit area.
Based on the above-mentioned equations, the current Ids outputted by the third transistor Tt3 in the saturated state becomes irrelevant to the threshold voltage, such that the pixel circuit as illustrated in
The inventor of the present disclosure has noted that, when the refreshing frequency of the display panel is increased (e.g., increased from 60 Hz to 120 Hz), because the (pulse duration) time of the scanning signals and the reset signals outputted by the gate driving circuit is decreased, all of the time lengths of reset stage Tre, the compensation stage Tc and the light-emitting stage Tem are reduced (e.g., reduced by half). In this case, because the time length of the compensation stage Tc is relatively short, that is, the data written time is relatively short, the storage capacitor Cst is not sufficiently charged, this can cause the threshold voltage compensation capability of the pixel circuit is insufficient. Illustrative descriptions will be given in the following by taking the pixel circuit as illustrated in FIG. 15A as an example. As illustrated in
In the following, embodiments of the present disclosure are described in detail with reference to the accompany drawings. In should be noted that, same one character number in different accompany drawings may refer to same one element that is already described.
At least an embodiment of the present disclosure provide a signal processing circuit, and the signal processing circuit comprises a shunting circuit and N buffer circuits; the shunting circuit comprises N output nodes; the N buffer circuits are respectively connected with the N output nodes; the shunting circuit is configured to output input signals to the N output nodes respectively at N different time points in response to control signals; the buffer circuits are configured to buffer and output the input signals received by corresponding output nodes. Here, N is an integer great than or equal to 2.
As illustrated in
It should be understood that, no specific limitation will be given in embodiments of the present disclosure regarding the number of the output nodes, for example, the number of the output nodes may be two, three, four or any other number, as long as the number of the output nodes is guaranteed to be larger than or equal to 2. For example, no specific limitation will be given in embodiments of the present disclosure regarding the number of the control signals, according to demands, the number of the control signal(s) may be any number. Correspondingly, no specific limitation will be given in embodiments of the present disclosure regarding the number of the input control terminal(s) Mx, as long as the number of the input control terminal(s) Mx is equal to the number of the control signal(s).
The N buffer circuits 200 are respectively connected with the N output nodes and are configured to buffer and output the input signals received by corresponding output nodes. For example, the buffer circuit 200_1 is connected with a first output node Q1 and a first output terminal Out1, and is configured to buffer and output the input signal received by the first output node Q1 to the first output terminal Out1, and to maintain the output within a pre-determined time period; the buffer circuit 200_2 is connected with a second output node Q2 and a second output terminal Out2 and is configured to buffer and output the input signal received by the second output node Q2 to the second output terminal Out2, and to maintain the output within a pre-determined time period, and so on. For example, N output terminals Out1, Out2, . . . , and OutN may be respectively connected with N data lines, so as to provide the inputted data signals to the pixel units. For example, the number of the buffer circuits 200 is equal to the number of the output nodes, so as to guarantee that the buffer circuits 200 and the output nodes are respectively connected in one-to-one correspondence.
The first terminal 211 of the first buffer circuit 210 is configured to be connected with a corresponding output node (i.e., the first output node Q1), and the second terminal 212 of the first buffer circuit 210 is configured to be connected with a first voltage terminal VDC so as to receive a first voltage. The first terminal 221 of the second buffer circuit 220 is configured to be connected with a corresponding output node (i.e., the second output node Q2), and the second terminal 222 of the second buffer circuit 220 is configured to be connected with the first voltage terminal VDC so as to receive the first voltage. For example, the first voltage terminal VDC is a DC (direct-current) voltage terminal and the first voltage terminal VDC may provide a DC signal with a high voltage level (e.g., VDD) or may provide a DC signal with a low voltage level (e.g., VSS), and no specific limitation will be given in embodiments of the present disclosure in this respect. The shunting circuit 100 here is similar to the shunting circuit 100 as illustrated in
In the case where the control signal provided by the input control terminal Mx is at a valid electric level, the shunting circuit 100 output the input signals provided by the input terminal Input to the first output node Q1 and the second output node Q2 respectively at different time points. For example, at the first time point, the shunting circuit 100 outputs an input signal to the first output node Q1 in response to the control signal, and maintains the output within a pre-determined time period; later, at the second time point, the shunting circuit 100 outputs an input signal to the second output node Q2 in response to the control signal, and maintains the output within a pre-determined time period; then, at the third time point, the shunting circuit 100 outputs an input signal to the first output node Q1 again in response to the control signal, and maintains the output within a pre-determined time period, and so on. In the subsequent time points, the shunting circuit 100 adopts the above-mentioned method to output the input signals to the first output node Q1 and the second output node Q2 alternately and repeatedly. The first buffer circuit 210 buffers and outputs the input signal received by the first output node Q1 to the first output terminal Out1, and the second buffer circuit 220 buffers and outputs the input signal received by the second output node Q2 to the second output terminal Out2.
By this way, the input signals are divided into two sub-signals, and the frequency of the sub-signals is half of the frequency of the input signals, that is, the cycle of the sub-signals is two times as much as the cycle of the input signals. For example, by providing the sub-signals to the pixel units of the display panel, so as to serves as the display data signal, the pixel circuits in the pixel units can be compensated or charged in response to the gate scanning signals under the action of the display data signals, such that the compensation time of the pixel circuits is allowed to be prolonged to two times as much as the original compensation time, the data voltages can be written more fully, and the display quality can be improved. It should be understood that, in embodiments of the present disclosure, the extension value of the compensation time is related to the frequency of the input signal and the number of the output nodes and the number of the buffer circuits. In the case where the frequency of the input signal is a constant value, the number of the output nodes and the number of the buffer circuits may be set according to actual demands, so as to allow the extension value of the compensation time to satisfy demands.
It should be understood that, in embodiments of the present disclosure, the number of the reset circuits 300 is not limited, and may be set according to the number of the output nodes and the number of the buffer circuits 200. For example, the number of the reset circuits 300 is equal to the number of the output nodes and equal to the number of the buffer circuits 200, and each of the reset circuits 300 resets the buffer circuit 200 that is connected with this reset circuit 300.
For example, when the display panel is in operation, the scan sequence of each frame comprises a blanking time period and an effective time period. During the effective time period, progressive scanning is performed with respect to the pixel circuits of the pixel units so as to display an image; in the blanking time period, scanning operations does not performed with respect to the pixel circuits. For example, the reset circuits 300 reset the buffer circuits 200 during the blanking time period, so as to allow the display data signals of next frame of image to be buffered into the buffer circuits 200 more accurately and more quickly, such that the display quality can be improved. For example, the reset circuits 300 may also reset the buffer circuits 200 before scanning each frame of image or after the scanning of each frame of image is finished; and the reset circuits 300 may also reset the buffer circuits 200 at a designated time point (e.g., before writing data into each row of pixel units).
For example, the first terminal 311 of the first reset circuit 310 is configured to be connected with the first output node Q1, the second terminal 312 of the first reset circuit 310 is configured to be connected with a second voltage terminal VSS, so as to receive a second voltage, and the control terminal 313 of the first reset circuit 310 is configured to be connected with the reset signal line (the reset signal terminal RST), so as to receive the reset signal. The first terminal 321 of the second reset circuit 320 is configured to be connected with the second output node Q2, the second terminal 322 of the second reset circuit 320 is configured to be connected with the second voltage terminal VSS, so as to receive the second voltage, and the control terminal 323 of the second reset circuit 320 is configured to be connected with the reset signal line (the reset signal terminal RST), so as to receive the reset signal. For example, the second voltage terminal VSS provides a direct-current signal with a low voltage level (e.g., is grounded), the direct-current signal with a low voltage level is referred to as the second voltage and serves as the reset voltage; or, the second voltage terminal VSS may also provide a direct-current signal with a high voltage level. For example, in the case where the first voltage terminal VDC provides the direct-current signal with a high voltage level, the second voltage terminal VSS is equivalent to the first voltage terminal VDC.
In the case where the reset signal is at a valid electric level, the first reset circuit 310 allow the second voltage terminal VSS and the first output node Q1 to be electrically connected, and the second reset circuit 320 allows the second voltage terminal VSS and the second output node Q2 to be electrically connected, so as to reset the first output node Q1, the first buffer circuit 210, the second output node Q2 and the second buffer circuit 220. For example, the reset operation may be performed before scanning each frame of image or after scanning of each frame of image is finished. Obviously, embodiments of the present disclosure are not limited to this case. The reset operation may be performed at a designated time point according to specific implementation requirements, for example, the reset operation may be performed before buffering data by corresponding buffer circuits. Through reset operation, the input signals (e.g., the display data signals) are allowed to be buffered in the first buffer circuit 210 and the second buffer circuit 220 more accurately and more quickly, such that the display quality is improved.
In the case where the first control signal is at a valid electric level (i.e., the electric level that allows the first switching circuit 110 to be turned on), the first switching circuit 110 connects the first output node Q1 with the input terminal Input, so as to allow the input signal to be outputted to the first output node Q1. In the case where the second control signal is at a valid electric level (i.e., the electric level that allows the second switching circuit 120 to be turned on, the second switching circuit 120 connects the second output node Q2 with the input terminal Input, so as to allow the input signal to be outputted to the second output node Q2. For example, the first control signal and the second control signal alternately switched to be a valid electric level, so as to allow the input signal to be alternately outputted to the first output node Q1 and the second output node Q2.
It should be understood that, in embodiments of the present disclosure, the number of the switching circuits is not limited, and the number of the switching circuits may be set according to specific implementation requirements. In an example of the present embodiment, descriptions are given by taking the case where the shunting circuit 100 comprises two switching circuits (the first switching circuit 110 and the second switching circuit 120) as an example. For example, in other examples, the shunting circuit 100 comprises N switching circuits, correspondingly, the number of the input control terminals and the number of the output nodes are respectively equal to N, the N switching circuits are connected with the input terminal Input, and the N switching circuits are respectively connected with the N output nodes in one-to-one correspondence, and respectively connected with the N input control terminals in one-to-one correspondence. N is an integer great than or equal to 2.
For example, in the case where the control signals of the first input control terminal MxO and the second input control terminal MxE are at a valid electric level (i.e., the electric level that allows the first switching circuit 110 to be turned on), the first switching circuit 110 is electrically connects the first output node Q1 with the input terminal Input, and the control signal received by the second switching circuit 120 is an invalid electric level (i.e., the electric level that allows the second switching circuit 120 to be turned off) because of the function of the invert circuit 130, so as to allow the second output node Q2 and the input terminal Input to be disconnected. In the case where the control signals of the first input control terminal MxO and the second input control terminal MxE are an invalid electric level, the first switching circuit 110 allows the first output node Q1 and the input terminal Input to be disconnected, and in this case, because of the function of the invert circuit 130, the control signal received by the second switching circuit 120 is at a valid electric level, so as to allow the second output node Q2 is electrically connected with the input terminal Input.
By the above-mentioned methods, alternately controlling of the first switching circuit 110 and the second switching circuit 120 can be realized by adopting same one control signal, such that the control method for the circuit can be simplified, the number of the signals can be reduced, the cross-talk between signals can be avoided, and thus the signal isolation degree between the first output node Q1 and the second output node Q2 can be enhanced. It should be understood that, in embodiments of the present disclosure, the arrangements of the invert circuit 130 is not limited, and the invert circuit 130 may be connected with any one of the first switching circuit 110 and the second switching circuit 120, the arrangements may be set according to specific implementation requirements, and for example, the arrangements may be set according to the cooperation relationship between the control signals and the switching circuit.
For example, the shunting circuit 100 comprises a first switching circuit 110 and a second switching circuit 120. As illustrated in
The first buffer circuit 210 may be implemented as the first capacitor C1. The first electrode, that serves as the first terminal 211 of the first buffer circuit 210, of the first capacitor C1 is connected with the first output node Q1, the second electrode, that serves as the second terminal 212 of the first buffer circuit 210, of the first capacitor C1 is connected with the first voltage terminal VDC. The first capacitor C1 can buffer the input signal received by the first output node Q1, and output the input signal to the first output terminal Out1.
The second buffer circuit 220 may be implemented as the second capacitor C2. The first electrode, that serves as the first terminal 221 of the second buffer circuit 220, of the second capacitor C2 is connected with the second output node Q2, the second electrode, that serves as the second terminal 222 of the second buffer circuit 220, of the second capacitor C2 is connected with the first voltage terminal VDC. The second capacitor C2 can buffer the input signal received by the second output node Q2, and output the input signal to the second output terminal Out2.
For example, in the display panel, because of the influence of the wire arrangements, the buffer circuits 200 may be implemented as the circuit structures as illustrated in
For example, the first sub-capacitor C11 is a capacitor device that is formed on the display panel through manufacturing processes, for example, the capacitor device may be realized by forming dedicated capacitor electrodes, the capacitor electrodes may be realized through metal layers, semiconductor layers (for example, doped polycrystalline silicon), etc. For example, the second sub-capacitor C12 is a parasitic capacitor between data lines in the display panel, and the second sub-capacitor C12 may be realized by a parasitic capacitor between a data line and other device or wire. For example, the resistor R corresponds to the resistance of the data line in the display panel instead of a resistor device that actually existed.
It should be understood that, in embodiments of the present disclosure, the capacitances of the parasitic capacitors (the second sub-capacitor C12) in the buffer circuits 200 may be the same or different, and this is related to the wire arrangements of the data lines in the display panel. Therefore, in order to guarantee the reference point of the outputted signals of the buffer circuits 200 to be the same, the capacitances of the first sub-capacitors C11 in the buffer circuits 200 may be adjusted according to the capacitances of corresponding parasitic capacitors. That is, the capacitances of the first sub-capacitors C11 of the buffer circuits 200 may be the same or different. For example, in other examples, by adjusting the wire arrangements of the data lines, the parasitic capacitors of the buffer circuits 200 satisfy the requirements on the capacitances, and therefore, the first sub-capacitor C11 can be omitted, and buffering of the input signals can be realized only based on the parasitic capacitors. In this case, no dedicated capacitor device needs to be formed in the buffer circuit 200, and forming of the capacitor device through manufacturing processes is unnecessary, and therefore, the costs can be reduced and manufacturing efficiency can be promoted.
The second reset circuit 320 may be implemented as the fourth transistor T4, and the fourth transistor T4 serves as a reset transistor. The first terminal, that serves as the first terminal 321 of the second reset circuit 320, of the fourth transistor T4 is connected with the second output node Q2, the second terminal, that serves as the second terminal 322 of the second reset circuit 320, of the fourth transistor T4 is connected with the second voltage terminal VSS, and the gate electrode, that serves as the control terminal 323 of the second reset circuit 320, of the fourth transistor T4 is connected with the reset signal line (the reset signal terminal RST). The fourth transistor T4 is turned on in the case where the reset signal is at a valid electric level, so as to allow the second output node Q2 to be electrically connected with the second voltage terminal VSS, such that the second buffer circuit 220 (the second capacitor C2) can be reset.
For example, in the case where the control signals of the first input control terminal MxO and the second input control terminal MxE are at a low electric level, the first transistor T1 is turned on. In this case, the fifth transistor T5 is turned on as well, so as to allow the third voltage terminal VDD is electrically connected with the gate electrode of the second transistor T2, such that the gate electrode of the second transistor T2 receives a high electric level signal, the second transistor T2 is turned off. It should be noted that, the sixth transistor T6 is an N-type transistor, and thus, in this case, the sixth transistor T6 is turned off.
In the case where the control signals of the first input control terminal MxO and the second input control terminal MxE are at a high electric level, the first transistor T1 is turned off. In this case, the sixth transistor T6 is turned on to allow the second voltage terminal VSS is electrically connected with the gate electrode of the second transistor T2, so as to allow the gate electrode of the second transistor T2 to receive a low electric level signal, and to allow the second transistor T2 to be turned on. In this case, the fifth transistor T5 is turned off.
Through the above-mentioned method, phase reversion operation can be performed with respect to the control signals for the first input control terminal MxO and the second input control terminal MxE, and controlling of the first transistor T1 and the second transistor 12 can be realized by adopting only one control signal, such that the control method for the circuit can be simplified, the number of the signals can be reduced, the cross-talk between signals can be avoided, and thus the signal isolation degree between the first output node Q1 and the second output node Q2 can be enhanced.
It should be noted that, in the descriptions of embodiments of the present disclosure, N output nodes (Q1, Q2, . . . , and QN) are not components that are actually existed, and are intend to represent the conjunction of related electrically connections in the circuit diagram.
It should be understood that the transistors adopted in the embodiments of present disclosure may be thin film transistors or field-effect transistors or other switching devices with similar characteristics. Descriptions are given by taking the case that the transistors adopted in embodiments of present disclosure are thin film transistors as an example. A source electrode and a drain electrode of the transistor adopted here may be symmetrical in structure, and therefore, there is no difference in the structures of the source electrode and the drain electrode of the transistor. In the embodiments of present disclosure, in order to distinguish two terminals of the transistors other than a gate electrode, one terminal of the two terminals is denoted as a first terminal, and the other terminal of the two terminals is denoted as a second terminal.
In addition, descriptions are given by taking the case that transistors, except for the sixth transistor T6, adopted in embodiments of present disclosure are P-type transistors as an example, and in this case, the first terminal of the transistor is the source electrode, and the second terminal is the drain electrode. It should be understood that, the present disclosure comprises, but not limited to, this case. For example, one or more transistors in the signal processing circuit 10 provided by embodiments of the present disclosure may also adopt N-type transistor(s), and in this case, the first terminal of transistor is the drain electrode, and the second terminal is the source electrode, and the terminals of the transistors of a selected type can be connected corresponding by referring to the connections of the terminals of corresponding transistors in embodiments of the present disclosure. In the case where N-type transistors are adopted, indium gallium zinc oxide (IGZO), which serves as the active layers of the thin film transistors, can be adopted, and thus the sizes of the transistors can be effectively reduced and current leaking can be effectively avoided, as compared to the case where low temperature poly silicon (LTPS) or amorphous silicon (for example, hydrogenated amorphous silicon) serves as the active layers of the thin film transistors.
For example, when the signal processing circuit 10 is in operation, the control signals (provided by the first input control terminal MxO and the second input control terminal MxE) and the input signals (provided by the input terminal Input) are provided, so as to allow the shunting circuit 100 to sequentially output the input signals to two output nodes (the first output node Q1 and the second output node Q2) respectively at two different time points in response to the control signals, to allow the first buffer circuit 210 to buffer and output the input signal received by the first output node Q1 to the first output terminal Out1, and to allow the second buffer circuit 220 to buffer and output the input signal received by the second output node Q2 to the second output terminal Out2. In the first stage 1 and the second stage 2 as illustrated in
In the first stage 1, the first input control terminal MxO provides a low electric level signal, and the first transistor T1 is turned on, so as to allow the input signal at this time point to output to the first output node Q1. For example, the input signal at this time point is a first data data1. The first capacitor C1 buffers the first data data1 and is able to continuously output the first data data1 within a pre-determined time period. The second input control terminal MxE provides a high electric level signal, the second transistor T2 is turned off, and the second output node Q2 keeps the signal from the last stage or keeps the signal after resetting.
In the second stage 2, the second input control terminal MxE provides a low electric level signal, the second transistor T2 is turned on, so as to allow the input signal at this time point to output to the second output node Q2. For example, the input signal at this time point is a second data data2. The second capacitor C2 buffers the second data data2 and may continuously output the second data data2 within a pre-determined time period. The first input control terminal MxO provides a high electric level signal, the first transistor T1 is turned off, and the first output node Q1 keeps the signal from the last stage (i.e., the first data data1) or keeps the signal after resetting.
In the subsequent stages, under the control of the control signals of the first input control terminal MxO and the second input control terminal MxE, the first transistor T1 and the second transistor T2 output the input signals alternately to the first output node Q1 and the second output node Q2, so as to allow the input signals to be split into two sub-signals, and the frequency of the signals of the first output node Q1 and the second output node Q2 are half of the frequency of the input signals, that is, the time length of the cycle of the signals of the first output node Q1 as well as the second output node Q2 are two times as much as the time length of the cycle of the input signal.
For example, by providing the signals at the first output node Q1 and the second output node Q2 to the pixel units of the display panel so as to serve as display data signals, the pixel circuits in the pixel units are compensated or charged in response to the gate scanning signals and according to the display data signals, such that the compensation time of the pixel circuits is allowed to be prolonged to two times as much as the original compensation time, the data voltage can be written more fully, and the display quality can be improved. For example, in the case where the input signal is of 120 Hz, the signals at the first output node Q1 and the second output node Q2 respectively are of 60 Hz. In the case where the frequency of the display data signals is 120 Hz, the compensation time of the conventional pixel circuits is 3.3 μs. The frequency of the display data signals that the pixel unit provides to the signal processing circuit 10 is 60 Hz, and therefore, the compensation time of is 6.5 μs, and the compensation time is prolonged. Of course, embodiments of the present disclosure are not limited to this case, and the input signal (e.g., the display data signal) may be any frequency. For example, the input signal may be of 120 Hz, 90 Hz, 60 Hz or other suitable frequency, so as to adapt to a common screen with a high refresh frequency, AR/VR display, and so on. For example, by matching the frequency of the input signals with the number of the output nodes, the extension value of the compensation time can be adjusted according to demands. For example, in other examples, the frequency of the input signals is 120 Hz, the number of the output nodes is three, and the frequency of the signals at the output nodes is 40 Hz, so as to allow the compensation time to be further prolonged.
In the reset stage 0, the reset signal terminal RST provides a low electric level signal, both of the third transistor T3 and the fourth transistor T4 are turned on, so as to allow the first output node Q1 and the second output node Q2 respectively to be electrically connected with the second voltage terminal VSS, such that the first capacitor C1 and the second capacitor C2 are reset, and the signals of the first output node Q1 and the second output node Q2 are low electric levels. For example, both of the first input control terminal MxO and the second input control terminal MxE provide high electric level signals, so as to allow both of the first transistor T1 and the second transistor T2 to be turned off.
For example, reset operation may be performed before scanning each frame of image or after each frame of image is performed, and reset operation may also be performed at a specific time point according to specific demands. Through resetting, the input signals (e.g., display data signals) can be buffered into the first capacitor C1 and the second capacitor C2 with improved accuracy, such that the display quality can be improved.
At least an embodiment of the present disclosure further provides a display panel, which comprises the signal processing circuit according to any embodiment of the present disclosure and a plurality of data lines. N data lines of the plurality of data lines are respectively connected with the N buffer circuits of the signal processing circuit, the input signals are display data signals. The display panel can prolong the compensation time of pixel circuits, be compatible with current pixel circuits and a current drive chip, and the problem of insufficient compensation time for the pixel circuits in a screen with a high refresh frequency can be solved, which is in favor of improving display quality.
In the present embodiment, N is equal to 2, that is, two data lines 510 that are connected with same one signal processing circuit 10 comprise a first data line 511 and a second data line 512. The first data line 511 is connected with the first buffer circuit 210, and the second data line 512 is connected with the second buffer circuit 220. The first data line 511 and the second data line 512 are connected with same one column of pixel units P. The same one column of pixel units P comprises two pixel unit groups, that is, a first pixel unit group and a second pixel unit group. The first pixel unit group comprises the pixel units P located at odd-numbered rows and the second pixel unit group comprises the pixel units P located at even-numbered rows.
For example, the signal processing circuit 10 also is connected with the data driving circuit 400 and the control circuit (for example, a timing controller T-CON) 600 that are provided at the outside of the array substrate 500 through a wire D1 and so on, so as to respectively receive the input signals from the data driving circuit 400 and receive the control signals from the control circuit 600. For example, the above-mentioned input signals are display data signals. The data driving circuit 400 is configured to provide the display data signals to the columns of pixel units P. For example, the data driving circuit 400 may be a drive chip or a data driver. The data driving circuit 400 provides the display data signals that are provided to the columns of pixel units P respectively to the signal processing circuits 10 connected to the columns of pixel units P correspondingly. The control circuit 600 is configured to provide the control signals to the signal processing circuits 10, for example, two control signals are respectively provided to the first input control terminals MxO and the second input control terminals MxE. For example, the first input control terminals MxO of the plurality of signal processing circuits 10 are connected with same one signal line so as to receive same one first control signal, and the second input control terminals MxE of the plurality of signal processing circuits 10 are connected with same one signal line so as to receive same one second control signal. For example, the control circuit 600 may also be provided on the array substrate 500, or be integrated in the data driving circuit 400.
For example, the number of the output terminals of the data driving circuit 400 may be equal to the number of the signal processing circuits 10 and equal to the number of the columns of the pixel units P, that is, the number of the output terminals of the data driving circuit 400 of the display panel provided by embodiments of the present disclosure remains unchanged as compared to the number of the terminals of the data driver circuit of a conventional display panel, and therefore, the display panel provided by embodiments of the present disclosure may adopt a current data driver circuit (e.g., drive chip), such that the design costs and the manufacturing costs of the display panel can be reduced.
It should be understood that, according to specific implementation demands, the signal processing circuits 10 may also be provided at the outside of the array substrate 500, the signal processing circuits 10, for example, may be integrated into the data driving circuit 400, so as to increase the number of the output terminals of the data driving circuit 400.
For example, the N data lines 510 connected with same one signal processing circuit 10 are located at different layers of the array substrate 500. In the present embodiment, N is equal to 2, that is, the first data line 511 and the second data line 512 are located in different layers of the array substrate 500. Through this arrangement, the signal interference between the data lines can be decreased, while the difficulty of fabricating the array substrate is not increased, which is in favor of increasing pixels per inch (PPI). For example, in one example, the first data line 511 is formed in the data line layer of the conventional array substrate, then an insulation layer and a metal layer are additionally formed, and the second data line 512 is formed from the metal layer. This method can effectively reduce the signal interference between the first data line 511 and the second data line 512, while the manufacturing processes for the original data line layer is not affected.
It should be understood that, in embodiments of the present disclosure, the position relationship between the N data lines 510 are not limited, the N data lines 510 may be in different layers, or, part of the data lines 510 of the N data lines 510 may be in different layers. The relationship, in stacking order, between the N data lines 510 is not limited, and may be set according to actual wire arrangements of the display panel. Of course, the N data lines 510 may also be provided in the same layer provided that the manufacturing conditions allow, such that the manufacturing processes can be simplified and the panel thickness can be reduced.
For example, the display panel 20 further comprises a gate driving circuit 700, and the plurality of pixel units P are connected with the gate driving circuit 700. The gate driving circuit 700 is configured to provide a plurality of gate scanning signals so as to scan the pixel units P of the display panel 20. The number of the gate driving circuit 700 is not limited, and may be set according to specific implementation requirements. For example, in other examples, the display panel 20 comprises two gate driving circuits 700 that are respectively provided at two sides of the display panel 20, so as to realize double-side driving. For example, the gate driving circuit 700 that is provided at one side of the display panel 20 is configured to drive gate lines at odd-numbered rows, and the gate driving circuit 700 that is provided at the other side of the display panel 20 is configured to drive gate lines at even-numbered rows.
It should be understood that, in embodiments of the present disclosure, the arrangement of the gate driving circuit 700 is not limited, and may be set according to specific implementation requirements. For example, the gate driving circuit 700 may be a gate driver provided at the outside of the array substrate 500. For example, the gate driving circuit 700 may also be provided on the array substrate 500, so as to form a GOA (Gate-driver On Array) circuit, such that the number of wires for connecting the display panel 20 with other components can be reduced.
For example, for enabling the display data signals outputted by the first buffer circuit 210 and the second buffer circuit 220 to cooperate, the pulse durations (i.e., the pulse time period) of the gate scanning signals for adjacent rows partially overlap, that is, the pulse duration of the gate scanning signal for the (M+1)th row and the pulse duration of the gate scanning signal for the (M)th row partially overlap, and M is an integer larger than zero.
For example, the pixel unit P comprises a pixel circuit, and the pixel circuit for example may be implemented as a 7T1C type pixel circuit as illustrated in
During the first stage 1 and the second stage 2, the signal processing circuit 10 outputs the display data signals originated from the data driving circuit 400 respectively to the first output node Q1 and the second output node Q2 under the control of the control signals, the first buffer circuit 210 and the second buffer circuit 220 respectively buffer and output the display data signals received from the wire D1 to the first data line 511 (DO1) and the second data line 512 (DE1). The first data line 511 provides the signal at the first output node Q1 to the first pixel unit group (the pixel units P located at odd-numbered rows), and the second data line 512 provides the signal at the second output node Q2 to the second pixel unit group (the pixel units P located at even-numbered rows). During subsequent stages, the display data signals are alternately provided to the first pixel unit group and the second pixel unit group according to the above-mentioned methods.
The gate driving circuit 700 provides a plurality of gate scanning signals (G1, G2, G3, and so on), so as to scan the plurality of pixel units P. During the first stage 1 and the second stage 2, the first row of the gate scanning signal G1 (e.g., the gate scanning signal provided to the first row of the pixel units) is at a low electric level, so as to allow the first row of the pixel units P to be turned on, such that compensation or charging can be performed under the action of the display data signal provided by the first data line 511 (DO1). During the second stage 2 and the third stage 3, the second row of the gate scanning signal G2 (e.g., the gate scanning signal provided to the second row of the pixel units) is at a low electric level, so as to allow the second row of the pixel units P to be turned on, such that compensation or charging can be performed under the action of the display data signal provided by the second data line 512 (DE1). During subsequent stages, compensation or charging can be respectively performed with respect to the pixel units P located at odd-numbered rows and the pixel units P located at even-numbered rows according to the above-mentioned methods.
For example, in the present example, the pulse duration t1 of the gate scanning signals is equal to two times as much as the cycle t2 of the display data signals, so as to prolong the compensation time or the charging time as much as possible. For example, the pulse duration of the gate scanning signal for (M+1)th row and the pulse duration of the gate scanning signal for (M)th row partially overlap, and the overlapping time is t3. For example, the overlapping time t3 is equal to the cycle t2 of the display data signal, that is, the overlapping time t3 is equal to ½ of the pulse duration t1. By this way, the compensation time of the pixel circuits of the pixel units P is prolonged to two times as much as the original compensation time. For example, in other examples, in the case where same one column of pixel units P comprises N pixel unit groups, the overlapping time t3 is (N−1)/N times as much as the pulse duration t1, so as to allow the compensation time of the pixel circuits of the pixel units P is prolonged to N times of the original compensation time. The above-mentioned method allows the data voltages to be written more fully and allows the display quality to be improved.
For example, the pulse duration of the gate scanning signals is equal to N times of the cycle of the display data signals provided by the data driving circuit 400; because of the signal buffer function of the buffer circuits, the pixel units can continuously receive the display data signals during the pulse duration of the gate scanning signals, that is, the compensation time that can be used for each pixel unit is N times of the cycle of the display data signals, such that the compensation effect of the pixel circuits of the pixel units P can be improved, and the brightness uniformity of the display panel can be improved. At least an embodiment of the present disclosure further provides a display device, which comprises a signal processing circuit 10 provided by any embodiment of the present disclosure or a display panel 20 provided by any embodiment of the present disclosure. The display device can prolong the compensation time of the pixel circuits, be compatible with a current pixel circuit and a current drive chip, and the problem of insufficient compensation time for the pixel circuits in the screen with high refresh frequency can be solved, which is in favor of improving display quality.
For example, the display device may be any products or device that has display function, such as a liquid crystal panel, a liquid crystal television, a display, an OLED panel, an OLED television, an electronic paper display device, a cell phone, a tablet computer, a laptop, a digital photo frame and a navigator, and no specific limitation will be given in embodiments of the present disclosure in this respect. The technical effect of the display device may refer to related descriptions, as described in the above-mentioned embodiments, of the signal processing circuit 10 and the display panel 20, and no further description will be given here.
At least an embodiment of the present disclosure also provides a driving method of a signal processing circuit, which may be used in driving a signal processing circuit 10 provided by any embodiment of the present disclosure. By adopting the driving method, the compensation time of the pixel circuits can be prolonged, a current pixel circuit and a current drive chip can be adopted, the problem of insufficient compensation time for the pixel circuits in the screen with high refresh frequency can be solved, which is in favor of improving display quality.
For example, in one example, the driving method of the signal processing circuit comprises the following operations: providing control signals and input signals; allowing the shunting circuit 100 to sequentially output the input signals to the N output nodes respectively at N different time points in response to the control signals; buffering and outputting the input signals through buffer circuits 200, in which N is an integer great than or equal to 2.
At least an embodiment of the present disclosure also provides a driving method of a display panel, which may be used to drive the display panel 20 provided by any embodiment of the present disclosure. By adopting the driving method, the compensation time of the pixel circuits can be prolonged, a current pixel circuit and a current drive chip can be adopted, the problem of insufficient compensation time for the pixel circuits in the screen with high refresh frequency can be solved, and this is in favor of improving display quality.
For example, in one example, the driving method of the display panel comprises the following operations: providing control signals and display data signals; allowing the shunting circuit 100 to sequentially output the display data signals to the N output nodes respectively at N different time points in response to the control signals; and buffering and outputting the display data signals to corresponding N data lines through corresponding buffer circuits 200, in which N is an integer great than or equal to 2.
For example, the driving method of the display panel further comprises: providing gate scanning signals, so as to perform row scanning with respect to the display panel 20, and the pulse durations of gate scanning signals which are adjacent to each other partially overlap.
It should be understood that, the detailed descriptions and the technical effect regarding the driving method of the signal processing circuit and the driving method of the display panel may refer to the descriptions of the working principles of the signal processing circuit 10 and the display panel 20 provided by embodiments of the present disclosure, and no further description will be given here.
The following statements should be noted:
(1) The accompanying drawings involve only the structure(s) in connection with the embodiment(s) of the present disclosure, and other structure(s) can be referred to common design(s).
(2) In case of no conflict, features in one embodiment or in different embodiments can be combined.
What are described above is related to the illustrative embodiments of the disclosure only and not limitative to the scope of the disclosure; the scopes of the disclosure are defined by the accompanying claims.
Number | Date | Country | Kind |
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201810338993.1 | Apr 2018 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2018/115253 | 11/13/2018 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2019/200901 | 10/24/2019 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
20030071778 | Lee et al. | Apr 2003 | A1 |
20030071779 | Lee et al. | Apr 2003 | A1 |
20030132907 | Lee et al. | Jul 2003 | A1 |
20050100057 | Shin | May 2005 | A1 |
20060001618 | Shin | Jan 2006 | A1 |
20060055656 | Chung | Mar 2006 | A1 |
20070035506 | Lee | Feb 2007 | A1 |
20090225104 | Hu et al. | Sep 2009 | A1 |
20150155880 | Tu et al. | Jun 2015 | A1 |
20160372028 | Park | Dec 2016 | A1 |
20190244569 | Sun et al. | Aug 2019 | A1 |
Number | Date | Country |
---|---|---|
1412736 | Apr 2003 | CN |
1413737 | Apr 2003 | CN |
1432989 | Jul 2003 | CN |
1447302 | Oct 2003 | CN |
1766974 | May 2006 | CN |
1987990 | Jun 2007 | CN |
104008721 | Aug 2014 | CN |
105469765 | Apr 2016 | CN |
106257580 | Dec 2016 | CN |
106504698 | Mar 2017 | CN |
109427292 | Mar 2019 | CN |
0275140 | Jul 1988 | EP |
2018000797 | Jan 2018 | KR |
Entry |
---|
First Chinese Office Action dated May 7, 2020; Application No. 201810338993.1. |
International Search Report and Written Opinion dated Jan. 30, 2019; PCT/CN2018/115253. |
The extended European search report dated Dec. 10, 2021; Appln. No. 18887201.4. |
Number | Date | Country | |
---|---|---|---|
20210335272 A1 | Oct 2021 | US |