Light-emitting control signal modulation method, module, and display device
By modulating the light emission control signal of the OLED screen, the time interval of the pulse cycle is differentiated or made uniform, which solves the problem of uneven brightness under PWM method, improves the flicker phenomenon, and enhances the uniformity of screen brightness.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- BOE TECHNOLOGY GROUP CO LTD
- Filing Date
- 2024-11-20
- Publication Date
- 2026-05-28
AI Technical Summary
When adjusting the brightness of an OLED screen, there are differences in brightness between different pulse cycles under PWM mode, resulting in the flicker phenomenon. In particular, insufficient charging time at low brightness levels leads to uneven brightness.
By modulating the pulse period of the light emission control signal, the effective time period of the first N pulse periods within a frame is controlled to be longer than that of other pulse periods. During the ineffective time period, the voltage is invalid, and during the effective time period, the voltage is valid. The modulation circuit controls the time period of each pulse period to be differentiated or uniform.
It improves the brightness difference between different pulse cycles, reduces or eliminates flicker phenomenon, and enhances the brightness uniformity of OLED screens.
Smart Images
Figure CN2024133137_28052026_PF_FP_ABST
Abstract
Description
Light emission control signal modulation method, module and display device Technical Field
[0001] This disclosure relates to the technical field, and more particularly to a method, module, and display device for modulating a light emission control signal. Background Technology
[0002] OLED (Organic Light Emitting Diode) screens employ a PWM (Pulse Width Modulation) method for brightness adjustment. This involves controlling the drive current flowing through the light-emitting element by adjusting the duty cycle of the light-emitting control signal. In this case, the control signal uses a multi-pulse design within a single frame, and the number of pulses is typically matched to other control signals in the pixel circuitry. During operation, within the same frame, the brightness of the first pulse is lower than that of the second pulse, and brightness differences exist between pulses across different frame durations. Summary of the Invention
[0003] In one aspect, embodiments of this disclosure provide a method for modulating a light emission control signal, wherein the light emission control signal is a PWM signal, and one frame time includes M pulse cycles; M is an integer greater than 1; the pulse cycle includes sequentially set invalid time periods and valid time periods; the method for modulating the light emission control signal includes:
[0004] The duration of the effective time period included in the first N pulse cycles of a frame is greater than the duration of the effective time period included in the other pulse cycles of the frame excluding the first N pulse cycles; N is a positive integer; N is less than M;
[0005] During the invalid time period, the potential of the light emission control signal is an invalid voltage; during the valid time period, the voltage of the light emission control signal is a valid voltage.
[0006] In at least one embodiment of this disclosure, N equals 1; the light emission control signal modulation method includes:
[0007] The duration of the invalid time period included in the first pulse cycle of a frame is controlled to be less than the duration of the invalid time period included in the pulse cycles other than the first pulse cycle of the frame.
[0008] In at least one embodiment of this disclosure, N equals 1; the light emission control signal modulation method includes:
[0009] The duration of the invalid time period included in the first pulse period of a frame is greater than the duration of the invalid time period included in the pulse periods other than the first pulse period of the frame.
[0010] The light emission control signal modulation method described in at least one embodiment of this disclosure includes: controlling the duration of the invalid time period included in the pulse period other than the first pulse period of the frame time to be equal.
[0011] In at least one embodiment of this disclosure, N equals 1, and the light emission control signal modulation method includes:
[0012] The duration of invalid time periods included in each pulse cycle of a frame is the same.
[0013] In at least one embodiment of this disclosure, N is greater than 1; the light emission control signal modulation method includes:
[0014] The duration of the effective time segment included in the nth pulse cycle is greater than the duration of the effective time segment included in the (n+1)th pulse cycle.
[0015] n+1 is less than or equal to N, where n is a positive integer.
[0016] The light emission control signal modulation method described in at least one embodiment of this disclosure includes:
[0017] The duration of each pulse cycle within a frame is equal.
[0018] The light emission control signal modulation method described in at least one embodiment of this disclosure includes:
[0019] The duration of invalid time periods included in each pulse cycle of a frame is equal.
[0020] In a second aspect, embodiments of this disclosure provide a light emission control signal generation module for generating a light emission control signal, wherein the light emission control signal is a PWM signal, and one frame time includes M pulse cycles; M is an integer greater than 1; the pulse cycle includes an invalid time period and an effective time period set sequentially; the light emission control signal generation module includes a modulation circuit and a generation circuit;
[0021] The modulation circuit is used to control the duration of the effective time period included in the first N pulse periods of a frame, which is greater than the duration of the effective time period included in the other pulse periods of the frame excluding the N pulse periods; N is a positive integer; N is less than M;
[0022] The generation circuit is used to control the potential of the light emission control signal to be an invalid voltage during the invalid time period and to control the voltage of the light emission control signal to be an effective voltage during the effective time period.
[0023] In at least one embodiment of this disclosure, N equals 1; the modulation circuit is used to control the duration of the invalid time period included in the first pulse period of a frame time to be less than the duration of the invalid time period included in the pulse periods other than the first pulse period of the frame time.
[0024] In at least one embodiment of this disclosure, N equals 1; the modulation circuit is used to control the duration of the invalid time period included in the first pulse period of a frame time to be greater than the duration of the invalid time period included in the pulse periods other than the first pulse period of the frame time.
[0025] In at least one embodiment of this disclosure, the modulation circuit is used to control the duration of the invalid time period included in the pulse period other than the first pulse period of the frame time to be equal.
[0026] In at least one embodiment of this disclosure, N equals 1.
[0027] The modulation circuit is used to control that the duration of the invalid time periods included in each pulse period of a frame is the same.
[0028] In at least one embodiment of this disclosure, N is greater than 1; the modulation circuit is used to control the duration of the effective time period included in the nth pulse period to be greater than the duration of the effective time period included in the (n+1)th pulse period.
[0029] n+1 is less than or equal to N, where n is a positive integer.
[0030] In at least one embodiment of this disclosure, the modulation circuit is used to control that the duration of each pulse period included in a frame is equal.
[0031] In at least one embodiment of this disclosure, the modulation circuit is used to control that the duration of invalid time periods included in each pulse period of a frame is equal.
[0032] In a third aspect, embodiments of this disclosure provide a display device, including a multi-row pixel circuit and a light-emitting control module, wherein the light-emitting control module includes multiple levels of the above-described light-emitting control signal generation modules;
[0033] The light emission control signal generation module is used to provide light emission control signals for the corresponding row pixel circuits. Attached Figure Description
[0034] Figure 1 is a circuit diagram of at least one embodiment of a pixel circuit;
[0035] Figure 2 is a timing diagram of at least one embodiment of the pixel circuit shown in Figure 1;
[0036] Figure 3 shows the brightness simulation results of at least one embodiment of the pixel circuit shown in Figure 1;
[0037] Figure 4 is a schematic diagram of the time allocation of each pulse period of the light emission control signal corresponding to the light emission control signal generation method according to at least one embodiment of the present disclosure;
[0038] Figure 5 shows the brightness simulation results when using at least one embodiment L1 of this disclosure;
[0039] Figure 6 is a schematic diagram of the time allocation of each pulse period of the light emission control signal corresponding to the light emission control signal generation method according to at least one embodiment of the present disclosure;
[0040] Figure 7 is a schematic diagram of the time allocation of each pulse period of the light emission control signal corresponding to the light emission control signal generation method according to at least one embodiment of the present disclosure;
[0041] Figure 8 is a schematic diagram of the time allocation of each pulse period of the light emission control signal corresponding to the light emission control signal generation method according to at least one embodiment of the present disclosure;
[0042] Figure 9 is a schematic diagram of the time allocation of each pulse period of the light emission control signal corresponding to the light emission control signal generation method according to at least one embodiment of the present disclosure;
[0043] Figure 10 is a structural diagram of a light emission control signal generation module according to at least one embodiment of the present disclosure;
[0044] Figure 11 is a structural diagram of a display device according to at least one embodiment of the present disclosure. Detailed Implementation
[0045] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this disclosure.
[0046] In all embodiments of this disclosure, the transistors used can be thin-film transistors, field-effect transistors, or other devices with similar characteristics. In the embodiments of this disclosure, to distinguish the two terminals of the transistor other than the gate, one terminal is referred to as the first terminal and the other as the second terminal.
[0047] In actual operation, when the transistor is a thin-film transistor or a field-effect transistor, the first electrode can be the drain and the second electrode can be the source; or, the first electrode can be the source and the second electrode can be the drain.
[0048] When adjusting brightness, OLED (Organic Light Emitting Diode) screens employ a PWM (Pulse Width Modulation) method. This method controls the driving current flowing through the light-emitting element by adjusting the duty cycle of the light-emitting control signal. In this case, the control signal uses a multi-pulse design within one frame, such as 3 pulses, 12 pulses, or 18 pulses. The number of pulses is usually matched with other control signals in the pixel circuitry.
[0049] Figure 1 is a circuit diagram of the relevant pixel circuit. Figure 2 is a timing diagram of at least one embodiment of the pixel circuit shown in Figure 1.
[0050] As shown in Figure 1, the pixel circuit includes an organic light-emitting diode O1, a driving transistor T0, a first transistor T1, a second transistor T2, a fourth transistor T4, a fifth transistor T5, a sixth transistor T6, a seventh transistor T7, an eighth transistor T8, and a storage capacitor Cst.
[0051] The gate of T0 is electrically connected to the first node N1, the source of T0 is electrically connected to the second node N2, and the drain of T0 is electrically connected to the third node N3.
[0052] The gate of T1 is electrically connected to the first reset control terminal RSTP, the source of T1 is electrically connected to the first initial voltage terminal I1, and the drain of T1 is electrically connected to the third node N3.
[0053] The gate of T2 is electrically connected to the compensation control terminal NSTV, the source of T2 is electrically connected to the first node N1, and the drain of T2 is electrically connected to the third node N3.
[0054] The gate of T4 is electrically connected to the scan terminal GSTV, the source of T4 is electrically connected to the data line DL, and the drain of T4 is electrically connected to the second node N2.
[0055] The gate of T5 is electrically connected to the light-emitting control terminal EM, the source of T5 is electrically connected to the power supply voltage terminal ELVDD, and the drain of T5 is electrically connected to the second node N2.
[0056] The gate of T6 is electrically connected to the light-emitting control terminal EM, the source of T6 is electrically connected to the third node N3, the drain of T6 is electrically connected to the anode of O1, and the cathode of O1 is electrically connected to the low voltage terminal ELVSS.
[0057] The gate of T7 is electrically connected to the second reset control terminal RSTH, the source of T7 is electrically connected to the second initial voltage terminal I2, and the drain of T7 is electrically connected to the anode of O1.
[0058] The gate of T8 is electrically connected to the second reset control terminal RSTH, the source of T8 is electrically connected to the third initial voltage terminal I3, and the drain of T8 is electrically connected to the second node N2.
[0059] The first terminal of Cst is electrically connected to the first node N1, and the second terminal of Cst is electrically connected to the power supply voltage terminal ELVDD; the fourth node N4 is electrically connected to the anode of O1.
[0060] In at least one embodiment shown in Figure 1, CO1 is the parasitic capacitance of O1.
[0061] In at least one embodiment of the pixel circuit shown in Figure 1, T2 is an n-type transistor, and the other transistors are p-type transistors.
[0062] Figure 2 is a timing diagram of at least one embodiment of the pixel circuit shown in Figure 1.
[0063] In at least one embodiment of the pixel circuit shown in Figure 1, during the light-emitting phase, EM provides a low-voltage signal, and current charges N4 through T0, forming a start-up voltage across O1, causing O1 to light up. In at least one embodiment of this disclosure, the structure of the pixel circuit is not limited to that shown in Figure 1, but the light-emitting principle is the same, involving a process where current is written into the first terminal of O1, forming a voltage across the low-voltage signal provided by ELVSS.
[0064] Figure 3 shows the brightness simulation results of at least one embodiment of the pixel circuit shown in Figure 1. In Figure 3, F1 represents the first frame time, F2 represents the second frame time, and LM represents the brightness.
[0065] As shown in Figure 3, within one frame, the luminous control signal provided by the EM consists of three pulses, and the duration of the low-voltage signal in each pulse is equal. The brightness results show that within the same frame, the brightness corresponding to the first pulse is lower than that of the second pulse, and the brightness corresponding to the third pulse is also lower (the brightness of each pulse is the average brightness of O1 when the luminous control signal is at a low voltage). However, there is no difference in brightness between the second and third pulses. In this case, brightness differences also exist between pulses within different frame times. For example, between the first and second frame times, there is a difference in brightness between the third pulse in the first frame and the first pulse in the second frame. This difference in brightness between pulses within the same frame or between different frames is the main cause of poor flicker.
[0066] The above problem arises because, at low brightness, the driving current through T0 is small, while N4 has a large capacitance. Therefore, a longer charging time is required to achieve the required voltage threshold for O1 to light up. During the first pulse of the first frame, when the light emission control signal is low, O1 is in the charging process for a portion of the time, not the light emission stage, resulting in low brightness during the first pulse. However, in the subsequent second and third pulses, when the light emission control signal is low, the charging process is complete, and all the time when the light emission control signal is low is used for light emission, resulting in high brightness.
[0067] The light emission control signal modulation method described in this embodiment is used to modulate a light emission control signal, wherein the light emission control signal is a PWM signal, and one frame time includes M pulse periods; M is an integer greater than 1; the pulse period includes sequentially set invalid time periods and valid time periods; the light emission control signal modulation method includes:
[0068] The duration of the effective time period included in the first N pulse cycles of a frame is greater than the duration of the effective time period included in the other pulse cycles of the frame excluding the first N pulse cycles; N is a positive integer; N is less than M;
[0069] During the invalid time period, the potential of the light emission control signal is an invalid voltage; during the valid time period, the voltage of the light emission control signal is a valid voltage.
[0070] Based on the above problems, in the light emission control signal modulation method described in the embodiments of this disclosure, the duration of the effective time period of the first N pulse cycles included in a frame time is controlled to be greater than the duration of the effective time period of other pulse cycles included in the frame time besides the first N pulse cycles, so as to improve the brightness of the light emission element corresponding to the first N pulse cycles in a frame time, thereby reducing the brightness difference between different pulse cycles and improving the flicker phenomenon.
[0071] In at least one embodiment of this disclosure, during the invalid time period, the potential of the light emission control signal is an invalid voltage, and the transistors used for light emission control (i.e., T5 and T6 in FIG1) are turned off; during the valid time period, the potential of the light emission control signal is an valid voltage, and the transistors used for light emission control are turned on.
[0072] Optionally, when the transistor controlling the light emission is a p-type transistor, the invalid voltage is high voltage and the effective voltage is low voltage;
[0073] When the transistor used for light emission control is an n-type transistor, the invalid voltage is low and the effective voltage is high.
[0074] In at least one embodiment of this disclosure, N equals 1; the light emission control signal modulation method includes:
[0075] The duration of the invalid time period included in the first pulse cycle of a frame is controlled to be less than the duration of the invalid time period included in the pulse cycles other than the first pulse cycle of the frame.
[0076] In specific implementation, N can be equal to 1. Within a frame, the duration of the invalid time period included in the first pulse period is controlled to be less than the duration of the invalid time period included in other pulse periods besides the first pulse period within the frame. Conversely, the duration of the valid time period included in the first pulse period is controlled to be greater than the duration of the valid time period included in other pulse periods besides the first pulse period within the frame.
[0077] In at least one embodiment of this disclosure, a frame time F0 comprising 2808H (1H being the charging time for one row of pixels) is used as an example for illustration; a frame time comprises three pulse periods: a first pulse period P1, a second pulse period P2, and a third pulse period P3; as shown in Figure 4.
[0078] In related technology X1, the duration of the first invalid time period W1 included in the first pulse period P1 is 836H, the duration of the first valid time period Y1 included in the first pulse period P1 is 100H, the duration of the second invalid time period W2 included in the second pulse period P2 is 836H, the duration of the second valid time period Y2 included in the second pulse period P2 is 100H, the duration of the third invalid time period W3 included in the third pulse period P3 is 836H, and the duration of the third valid time period Y3 included in the third pulse period P3 is 100H. That is, within one frame, the duration of the invalid time period is equal in the three pulse periods, and the duration of the valid time period is equal.
[0079] In at least one embodiment L1 of this disclosure, the duration of the first invalid time period W1 included in the first pulse period P1 is 814H, the duration of the first valid time period Y1 included in the first pulse period P1 is 122H, the duration of the second invalid time period W2 included in the second pulse period P2 is 836H, the duration of the second valid time period Y2 included in the second pulse period P2 is 100H, the duration of the third invalid time period W3 included in the third pulse period P3 is 836H, and the duration of the third valid time period Y3 included in the third pulse period P3 is 100H. That is, within one frame, the duration of the first valid time period Y1 is greater than the duration of the second valid time period Y2, the duration of the first valid time period Y1 is greater than the duration of the third valid time period Y3, the duration of the first invalid time period W1 is less than the duration of the second invalid time period W2, and the duration of the first invalid time period W1 is less than the duration of the third invalid time period W3; the duration of the first pulse period P1, the duration of the second pulse period P2, and the duration of the third pulse period P3 are equal.
[0080] Figure 5 shows the brightness simulation results when using at least one embodiment L1 of this disclosure. As can be seen from Figure 5, after using the light emission control signal modulation method described in at least one embodiment of this disclosure, there is no longer a brightness difference between different pulse periods, which can improve flicker.
[0081] In Figure 5, LM represents brightness, F1 represents the first frame time, and F2 represents the second frame time.
[0082] In at least one embodiment of this disclosure, a frame time comprising three pulse cycles is used as an example for illustration. In actual operation, a frame time may include multiple pulse cycles, such as six pulse cycles, eight pulse cycles, ten pulse cycles, eighteen pulse cycles, twenty-four pulse cycles, etc.
[0083] In at least one embodiment of this disclosure, N equals 1; the light emission control signal modulation method includes:
[0084] The duration of the invalid time period included in the first pulse period of a frame is greater than the duration of the invalid time period included in the pulse periods other than the first pulse period of the frame.
[0085] In specific implementation, N can be equal to 1. Within a frame, the duration of the effective time period included in the first pulse period can be controlled to be greater than the duration of the effective time period included in other pulse periods besides the first pulse period within the frame. The duration of the invalid time period included in the first pulse period within a frame can also be controlled to be greater than the duration of the invalid time period included in other pulse periods besides the first pulse period within the frame.
[0086] In at least one embodiment of this disclosure, one frame time includes three pulse periods: a first pulse period P1, a second pulse period P2, and a third pulse period P3; as shown in FIG6.
[0087] In related technology X1, the duration of the first invalid time period W1 included in the first pulse period P1 is 836H, the duration of the first valid time period Y1 included in the first pulse period P1 is 100H, the duration of the second invalid time period W2 included in the second pulse period P2 is 836H, the duration of the second valid time period Y2 included in the second pulse period P2 is 100H, the duration of the third invalid time period W3 included in the third pulse period P3 is 836H, and the duration of the third valid time period Y3 included in the third pulse period P3 is 100H. That is, within one frame, the duration of the invalid time period is equal in the three pulse periods, and the duration of the valid time period is equal.
[0088] In at least one embodiment L2 of this disclosure, the duration of the first invalid time period W1 included in the first pulse period P1 is 836H, the duration of the first valid time period Y1 included in the first pulse period P1 is 122H, the duration of the second invalid time period W2 included in the second pulse period P2 is 824H, the duration of the second valid time period Y2 included in the second pulse period P2 is 100H, the duration of the third invalid time period W3 included in the third pulse period P3 is 824H, and the duration of the third valid time period Y3 included in the third pulse period P3 is 100H. That is, the duration of the first valid time period Y1 is greater than the duration of the second valid time period Y2, the duration of the first valid time period Y1 is greater than the duration of the third valid time period Y3, the duration of the first invalid time period W1 is greater than the duration of the second invalid time period W2, and the duration of the first invalid time period W1 is greater than the duration of the third invalid time period W3.
[0089] In at least one embodiment L2 of this disclosure, within one frame, the duration of the first pulse period P1 is not equal to the duration of the second pulse period P2, and the duration of the first pulse period P1 is not equal to the duration of the third pulse period P3.
[0090] At least one embodiment L1 of this disclosure is applicable to situations where the duration of the effective time period cannot be increased by further reducing the duration of the ineffective time period when the duration of the ineffective time period is relatively short. In other words, the extended duration of the first effective time period included in the first pulse period is averaged over the ineffective time periods included in subsequent pulse periods.
[0091] The light emission control signal modulation method described in at least one embodiment of this disclosure includes: controlling the duration of the invalid time period included in the pulse period other than the first pulse period of the frame time to be equal.
[0092] In practical implementation, the duration of invalid time periods included in other pulse periods besides the first pulse period can be set to be equal to facilitate the generation of light emission control signals.
[0093] In at least one embodiment of this disclosure, N equals 1, and the light emission control signal modulation method includes:
[0094] The duration of invalid time periods included in each pulse cycle of a frame is the same.
[0095] In practice, N can be equal to 1, and the duration of the invalid time period included in the pulse period of a frame can be set to be equal, so as to generate the light emission control signal.
[0096] In at least one embodiment of this disclosure, an example is given where one frame time includes 2808H (1H is the charging time for one row of pixels); one frame time includes three pulse periods: a first pulse period P1, a second pulse period P2, and a third pulse period P3; as shown in Figure 7.
[0097] In related technology X1, the duration of the first invalid time period W1 included in the first pulse period P1 is 836H, the duration of the first valid time period Y1 included in the first pulse period P1 is 100H, the duration of the second invalid time period W2 included in the second pulse period P2 is 836H, the duration of the second valid time period Y2 included in the second pulse period P2 is 100H, the duration of the third invalid time period W3 included in the third pulse period P3 is 836H, and the duration of the third valid time period Y3 included in the third pulse period P3 is 100H. That is, within one frame, the duration of the invalid time period is equal in the three pulse periods, and the duration of the valid time period is equal.
[0098] In at least one embodiment L3 of this disclosure, the duration of the first invalid time period W1 included in the first pulse period P1 is 828H, the duration of the first valid time period Y1 included in the first pulse period P1 is 124H, the duration of the second invalid time period W2 included in the second pulse period P2 is 828H, the duration of the second valid time period Y2 included in the second pulse period P2 is 100H, the duration of the third invalid time period W3 included in the third pulse period P3 is 828H, and the duration of the third valid time period Y3 included in the third pulse period P3 is 100H. That is, in one frame, the duration of the invalid time periods in each pulse period is set to be equal.
[0099] At least one embodiment L3 of this disclosure is applicable to situations where the duration of the invalid time period included in the pulse period is short, and it is impossible to continue to increase the duration of the valid time period by reducing the duration of the invalid time period. That is, the widening time of the first valid time period in the first pulse period is averaged over the invalid time period in each pulse period.
[0100] In at least one embodiment of this disclosure, N is greater than 1; the light emission control signal modulation method includes:
[0101] The duration of the effective time segment included in the nth pulse cycle is greater than the duration of the effective time segment included in the (n+1)th pulse cycle.
[0102] n+1 is less than or equal to N, where n is a positive integer.
[0103] In practical implementation, N can be greater than 1, and the duration of the effective time period included in the nth pulse cycle can be controlled to be greater than the duration of the effective time period included in the (n+1)th pulse cycle. That is, when N equals 2, the duration of the first effective time period included in the first pulse cycle is set to be greater than the duration of the second effective time period included in the second pulse cycle; when N equals 3, the duration of the first effective time period included in the first pulse cycle is set to be greater than the duration of the second effective time period included in the second pulse cycle, and the duration of the second effective time period included in the second pulse cycle is set to be greater than the duration of the third effective time period included in the third pulse cycle; so that the display brightness is not significantly different within each pulse cycle included in a frame.
[0104] The light emission control signal modulation method described in at least one embodiment of this disclosure includes:
[0105] The duration of each pulse cycle within a frame is equal.
[0106] In practical implementation, the duration of each pulse cycle included in a frame can be set to relative to facilitate the generation of light emission control signals.
[0107] In at least one embodiment L4 of this disclosure, an example is given, which is a frame time F0 comprising eighteen pulse cycles.
[0108] In Figure 8, P1 is the first pulse cycle, P2 is the second pulse cycle, P3 is the third pulse cycle, P17 is the seventeenth pulse cycle, and P18 is the eighteenth pulse cycle.
[0109] In related technology X1, the duration of the first invalid time period W1 included in the first pulse period P1 is 140H, the duration of the first valid time period Y1 included in the first pulse period P1 is 16H, the duration of the second invalid time period W2 included in the second pulse period P2 is 140H, the duration of the second valid time period Y2 included in the second pulse period P2 is 16H, the duration of the third invalid time period W3 included in the third pulse period P3 is 140H, the duration of the third valid time period Y3 included in the third pulse period P3 is 16H, the duration of the seventeenth invalid time period W17 included in the seventeenth pulse period P17 is 140H, the duration of the seventeenth valid time period Y17 included in the seventeenth pulse period P17 is 16H, the duration of the eighteenth invalid time period W18 included in the eighteenth pulse period P18 is 140H, and the duration of the eighteenth valid time period Y18 included in the eighteenth pulse period P18 is 16H; that is, within one frame, the duration of the invalid time period is equal and the duration of the valid time period is equal in the eighteen pulse periods.
[0110] In at least one embodiment L4 of this disclosure, the first invalid time period W1 included in the first pulse period P1 lasts for 110 hours, the first valid time period Y1 included in the first pulse period P1 lasts for 46 hours, the second invalid time period W2 included in the second pulse period P2 lasts for 130 hours, the second valid time period Y2 included in the second pulse period P2 lasts for 26 hours, the third invalid time period W3 included in the third pulse period P3 lasts for 140 hours, the third valid time period Y3 included in the third pulse period P3 lasts for 16 hours, the seventeenth invalid time period W17 included in the seventeenth pulse period P17 lasts for 140 hours, the seventeenth valid time period Y17 included in the seventeenth pulse period P17 lasts for 16 hours, the eighteenth invalid time period W18 included in the eighteenth pulse period P18 lasts for 140 hours, and the eighteenth valid time period Y18 included in the eighteenth pulse period P18 lasts for 16 hours.
[0111] In at least one embodiment L4 of this disclosure, N equals 2, the duration of the first effective time period Y1 is greater than the duration of the second effective time period Y2, the duration of the first effective time period Y1 is greater than the duration of the third effective time period Y3, the duration of the second effective time period Y2 is greater than the duration of the third effective time period Y3, and the duration of the third effective time period Y3 to the duration of the eighteenth effective time period Y18 are equal.
[0112] The duration of the first invalid time period W1 is less than the duration of the second invalid time period W2. The duration of the second invalid time period W2 is less than the duration of the third invalid time period W3. The duration of the third invalid time period W3 is equal to the duration of the eighteenth invalid time period W18.
[0113] In related technologies, when a frame contains a large number of pulse cycles, there may be a situation where at least one of the first pulse cycles of a frame cannot be fully lit and its brightness is lower than that of subsequent pulse cycles. In response to this situation, at least one embodiment of this disclosure can simultaneously differentiate the duration of the effective time period of the first N pulse cycles included in a frame according to the actual circuit. In this case, the duration of each pulse cycle can be equal.
[0114] The light emission control signal modulation method described in at least one embodiment of this disclosure includes:
[0115] The duration of invalid time periods included in each pulse cycle of a frame is equal.
[0116] In practice, the duration of invalid time periods in each pulse cycle of a frame can be set to be equal to facilitate the generation of light emission control signals.
[0117] In at least one embodiment L4 of this disclosure, an example is given, which is a frame time F0 comprising eighteen pulse cycles.
[0118] In Figure 9, P1 is the first pulse cycle, P2 is the second pulse cycle, P3 is the third pulse cycle, P17 is the seventeenth pulse cycle, and P18 is the eighteenth pulse cycle.
[0119] In related technology X1, the duration of the first invalid time period W1 included in the first pulse period P1 is 140H, the duration of the first valid time period Y1 included in the first pulse period P1 is 16H, the duration of the second invalid time period W2 included in the second pulse period P2 is 140H, the duration of the second valid time period Y2 included in the second pulse period P2 is 16H, the duration of the third invalid time period W3 included in the third pulse period P3 is 140H, the duration of the third valid time period Y3 included in the third pulse period P3 is 16H, the duration of the seventeenth invalid time period W17 included in the seventeenth pulse period P17 is 140H, the duration of the seventeenth valid time period Y17 included in the seventeenth pulse period P17 is 16H, the duration of the eighteenth invalid time period W18 included in the eighteenth pulse period P18 is 140H, and the duration of the eighteenth valid time period Y18 included in the eighteenth pulse period P18 is 16H; that is, within one frame, the duration of the invalid time period is equal and the duration of the valid time period is equal in the eighteen pulse periods.
[0120] In at least one embodiment L5 of this disclosure, the duration of the first invalid time period W1 included in the first pulse period P1 is 138H, the duration of the first valid time period Y1 included in the first pulse period P1 is 42H, the duration of the second invalid time period W2 included in the second pulse period P2 is 138H, the duration of the second valid time period Y2 included in the second pulse period P2 is 26H, the duration of the third invalid time period W3 included in the third pulse period P3 is 138H, the duration of the third valid time period Y3 included in the third pulse period P3 is 16H, the duration of the seventeenth invalid time period W17 included in the seventeenth pulse period P17 is 138H, the duration of the seventeenth valid time period Y17 included in the seventeenth pulse period P17 is 16H, the duration of the eighteenth invalid time period W18 included in the eighteenth pulse period P18 is 138H, and the duration of the eighteenth valid time period Y18 included in the eighteenth pulse period P18 is 16H; that is, in each pulse period included in a frame time, the duration of the invalid time period is equal.
[0121] In at least one embodiment L5 of this disclosure, the duration of each pulse cycle is not equal. This is applicable when the duration of the invalid time period is too short to continue increasing the duration of the valid time period by reducing the duration of the invalid time period of a single pulse cycle. In other words, the extended duration of the valid time periods of the first and second pulse cycles is averaged over the invalid time period of each pulse cycle.
[0122] The light emission control signal generation module described in this embodiment is used to generate a light emission control signal, which is a PWM signal. One frame time includes M pulse cycles; M is an integer greater than 1; the pulse cycle includes an invalid time period and an effective time period set sequentially; as shown in Figure 10, the light emission control signal generation module includes a modulation circuit 11 and a generation circuit 12.
[0123] The modulation circuit 11 is used to control the duration of the effective time period included in the first N pulse periods of a frame to be greater than the duration of the effective time period included in the other pulse periods of the frame excluding the N pulse periods; N is a positive integer; N is less than M;
[0124] The generation circuit 12 is used to control the potential of the light emission control signal to be an invalid voltage during the invalid time period and to control the voltage of the light emission control signal to be an effective voltage during the effective time period.
[0125] In at least one embodiment of this disclosure, N equals 1; the modulation circuit is used to control the duration of the invalid time period included in the first pulse period of a frame time to be less than the duration of the invalid time period included in the pulse periods other than the first pulse period of the frame time.
[0126] In at least one embodiment of this disclosure, N equals 1; the modulation circuit is used to control the duration of the invalid time period included in the first pulse period of a frame time to be greater than the duration of the invalid time period included in the pulse periods other than the first pulse period of the frame time.
[0127] In the light emission control signal generation module described in at least one embodiment of this disclosure, the modulation circuit is used to control the duration of the invalid time period included in the pulse period other than the first pulse period of the frame time to be equal.
[0128] In at least one embodiment of this disclosure, N equals 1.
[0129] The modulation circuit is used to control that the duration of the invalid time periods included in each pulse period of a frame is the same.
[0130] In at least one embodiment of this disclosure, N is greater than 1; the modulation circuit is used to control the duration of the effective time period included in the nth pulse period to be greater than the duration of the effective time period included in the (n+1)th pulse period.
[0131] n+1 is less than or equal to N, where n is a positive integer.
[0132] In at least one embodiment of this disclosure, the modulation circuit is used to control that the duration of each pulse period included in a frame is equal.
[0133] In at least one embodiment of this disclosure, the modulation circuit is used to control that the duration of invalid time periods included in each pulse period of a frame is equal.
[0134] The display device described in this embodiment includes a multi-row pixel circuit and a light-emitting control module, wherein the light-emitting control module includes multiple levels of the above-described light-emitting control signal generation module;
[0135] The light emission control signal generation module is used to provide light emission control signals for the corresponding row pixel circuits.
[0136] As shown in Figure 11, the display device according to at least one embodiment of the present disclosure includes a multi-row pixel circuit and a light-emitting control module;
[0137] The first row of pixel circuits is labeled PX1, the second row of pixel circuits is labeled PX2, the (D-1)th row of pixel circuits is labeled PXD, and the Dth row of pixel circuits is labeled PXD; D is an integer greater than 3.
[0138] The module labeled EA1 is the first-level light emission control signal generation module included in the light emission control module; the module labeled EA2 is the second-level light emission control signal generation module included in the light emission control module; the module labeled EAD-1 is the (D-1)th level light emission control signal generation module included in the light emission control module; and the module labeled EAD is the Dth level light emission control signal generation module included in the light emission control module.
[0139] EA1 is used to provide the first row of light emission control signals for the first row pixel circuit PX1;
[0140] EA2 is used to provide the second row of light emission control signals for the second row pixel circuit PX2;
[0141] EAD-1 is used to provide the D-1 row light emission control signal for the D-1 row pixel circuit PXD-1;
[0142] EAD is used to provide the D-row light emission control signal for the D-row pixel circuit PXD.
[0143] The above description represents the preferred embodiments of this disclosure. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles described herein, and these improvements and modifications should also be considered within the scope of protection of this disclosure.
Claims
1. A method for modulating a light emission control signal, used to modulate a light emission control signal, wherein the light emission control signal is a PWM signal, and one frame time includes M pulse cycles; M is an integer greater than 1; the pulse period includes sequentially set invalid time periods and valid time periods; the light emission control signal modulation method includes: The duration of the effective time period included in the first N pulse cycles of a frame is greater than the duration of the effective time period included in the other pulse cycles of the frame excluding those N pulse cycles. N is a positive integer; N is less than M; During the invalid time period, the potential of the light emission control signal is an invalid voltage; during the valid time period, the voltage of the light emission control signal is a valid voltage.
2. The light emission control signal modulation method as described in claim 1, wherein, N equals 1; The light emission control signal modulation method includes: The duration of the invalid time period included in the first pulse cycle of a frame is controlled to be less than the duration of the invalid time period included in the pulse cycles other than the first pulse cycle of the frame.
3. The light emission control signal modulation method as described in claim 1, wherein, N equals 1; The light emission control signal modulation method includes: The duration of the invalid time period included in the first pulse period of a frame is greater than the duration of the invalid time period included in the pulse periods other than the first pulse period of the frame.
4. The light emission control signal modulation method as described in claim 2 or 3, wherein, include: The duration of the invalid time period included in the pulse period other than the first pulse period is equal to the duration of the frame time.
5. The light emission control signal modulation method as described in claim 1, wherein, N equals 1, and the light emission control signal modulation method includes: The duration of invalid time periods included in each pulse cycle of a frame is the same.
6. The light emission control signal modulation method as described in claim 1, wherein, N is greater than 1; The light emission control signal modulation method includes: The duration of the effective time segment included in the nth pulse cycle is greater than the duration of the effective time segment included in the (n+1)th pulse cycle. n+1 is less than or equal to N, where n is a positive integer.
7. The light emission control signal modulation method as described in claim 6, wherein, include: The duration of each pulse cycle within a frame is equal.
8. The light emission control signal modulation method as described in claim 6, wherein, include: The duration of invalid time periods included in each pulse cycle of a frame is equal.
9. A light emission control signal generation module for generating a light emission control signal, wherein the light emission control signal is a PWM signal, and one frame time includes M pulse cycles; M is an integer greater than 1; the pulse cycle includes an invalid time period and an effective time period set sequentially; the light emission control signal generation module includes a modulation circuit and a generation circuit; The modulation circuit is used to control the duration of the effective time period included in the first N pulse periods of a frame, which is greater than the duration of the effective time period included in the other pulse periods of the frame excluding the N pulse periods; N is a positive integer; N is less than M; The generation circuit is used to control the potential of the light emission control signal to be an invalid voltage during the invalid time period and to control the voltage of the light emission control signal to be an effective voltage during the effective time period.
10. The light emission control signal generation module as described in claim 9, wherein, N equals 1; the modulation circuit is used to control the duration of the invalid time period included in the first pulse period of a frame to be less than the duration of the invalid time period included in the pulse periods other than the first pulse period of the frame.
11. The light emission control signal generation module as described in claim 9, wherein, N equals 1; the modulation circuit is used to control the duration of the invalid time period included in the first pulse period of a frame to be greater than the duration of the invalid time period included in the pulse periods other than the first pulse period of the frame.
12. The light emission control signal generation module as described in claim 10 or 11, wherein, The modulation circuit is used to control the duration of invalid time periods included in the pulse periods other than the first pulse period of the frame time to be equal.
13. The light emission control signal generation module as described in claim 9, wherein, N equals 1, The modulation circuit is used to control the invalid time periods included in each pulse period of a frame. The duration is the same.
14. The light emission control signal generation module as described in claim 9, wherein, N is greater than 1; the modulation circuit is used to control the duration of the effective time period included in the nth pulse period to be greater than the duration of the effective time period included in the (n+1)th pulse period. n+1 is less than or equal to N, where n is a positive integer.
15. The light emission control signal generation module as described in claim 14, wherein, The modulation circuit is used to control that the duration of each pulse period in a frame is equal.
16. The light emission control signal modulation module as described in claim 14, wherein, The modulation circuit is used to control that the duration of the invalid time periods included in each pulse period of a frame is equal.
17. A display device, comprising a multi-row pixel circuit and a light-emitting control module, wherein the light-emitting control module comprises a multi-level light-emitting control signal generation module as described in any one of claims 9 to 16; The light emission control signal generation module is used to provide light emission control signals for the corresponding row pixel circuits.
Citation Information
Patent Citations
CN115731877A
CN115995207A
CN116704947A
CN116741083A
CN116825020A