Pixel control device and display apparatus

Abstract

The application relates to a pixel control device and a display device, which comprise an amplitude modulation circuit, a pulse width modulation circuit and a selection circuit. The amplitude modulation circuit is used for connecting a pixel module through the selection circuit, and the pulse width modulation circuit is used for connecting the pixel module through the selection circuit. The amplitude modulation circuit is used for accessing a data signal, and a first driving signal is generated to the selection circuit according to the data signal, wherein the first driving signal is a signal after amplitude modulation. The pulse width modulation circuit is used for accessing the data signal, and a second driving signal is generated to the selection circuit according to the data signal, wherein the second driving signal is a signal after pulse width modulation. The selection circuit is used for controlling the on-off between the amplitude modulation circuit and the pixel module, and is also used for controlling the on-off between the pulse width modulation circuit and the pixel module. The pixel control device and the display device can realize two modulation modes of amplitude modulation and pulse width modulation, thereby effectively solving the problem of uneven brightness of each pixel module under low brightness or low gray.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a pixel control device and a display device. BACKGROUND

[0002] A display screen is generally a flat display screen composed of pixel modules. Due to the performance advantages of the display screen such as rich display color, high display resolution and low power consumption, the display screen is widely used in fields such as conference places, military command, security display and commercial display.

[0003] However, the display screen may have the problem of uneven brightness of each pixel module under low-brightness or low-gray conditions. The traditional solution is to control the brightness of each pixel module by current pulse amplitude modulation. However, this light adjustment method is relatively single, and often cannot achieve a relatively ideal light adjustment effect, so that the light emission brightness of each pixel module is still uneven. SUMMARY

[0004] Therefore, it is necessary to provide a pixel control device and a display device to solve the above problems.

[0005] In a first aspect, a pixel control device is provided, comprising an amplitude modulation circuit, a pulse width modulation circuit and a selection circuit, the amplitude modulation circuit is connected to a pixel module through the selection circuit, and the pulse width modulation circuit is connected to the pixel module through the selection circuit.

[0006] The amplitude modulation circuit is configured to input a data signal and generate a first driving signal to the selection circuit according to the data signal, wherein the first driving signal is a signal after amplitude modulation.

[0007] The pulse width modulation circuit is configured to input the data signal and generate a second driving signal to the selection circuit according to the data signal, wherein the second driving signal is a signal after pulse width modulation.

[0008] The selection circuit is configured to control the on-off between the amplitude modulation circuit and the pixel module, and to control the on-off between the pulse width modulation circuit and the pixel module.

[0009] In one embodiment, the amplitude modulation circuit comprises a first data control circuit, a first light emission control circuit and a compensation circuit, the first data control circuit and the compensation circuit are connected to the first light emission control circuit, and the first light emission control circuit is connected to the selection circuit.

[0010] The first data control circuit is configured to input the data signal, and the first light emission control circuit and the compensation circuit are configured to generate the first driving signal to the selection circuit according to the data signal.

[0011] In one of the embodiments, the first data control circuit includes a transmission switch tube, the first light emitting control circuit includes a driving switch tube and a storage capacitor, and the compensation circuit includes a compensation switch tube.

[0012] The control terminal of the transmission switch tube is used for accessing a data write signal, the first terminal of the transmission switch tube is used for accessing a data signal, and the second terminal of the transmission switch tube is used for connecting the control terminal of the driving switch tube.

[0013] The first terminal of the driving switch tube is used for accessing a positive power input signal, and the second terminal of the driving switch tube is used for connecting the second terminal of the compensation switch tube.

[0014] The control terminal and the second terminal of the driving switch tube are respectively connected to the two terminals of the storage capacitor.

[0015] The control terminal of the compensation switch tube is used for accessing a sampling control signal, and the first terminal of the compensation switch tube is used for accessing a sampling signal.

[0016] In one of the embodiments, the pulse width modulation circuit includes a second data control circuit, a second light emitting control circuit and a pulse width generation circuit. The second data control circuit is connected to the pulse width generation circuit, and the pulse width generation circuit is connected to the second light emitting control circuit.

[0017] The second data control circuit is used for accessing a data signal, and the pulse width generation circuit and the second light emitting control circuit are used for generating a second driving signal to the selection circuit according to the data signal.

[0018] In one of the embodiments, the pulse width generation circuit includes a coupling capacitor and a shaping circuit, the coupling capacitor and the second data control circuit are both connected to the shaping circuit, and the shaping circuit is connected to the second light emitting control circuit.

[0019] In one of the embodiments, the selection circuit includes a first selection module and a second selection module, the amplitude modulation circuit is used for connecting the pixel module through the first selection module, the pulse width modulation circuit is used for connecting the pixel module through the second selection module, and the first selection module and the second selection module are both used for connecting the pixel module.

[0020] In one of the embodiments, the first selection module and the second selection module have the same structure.

[0021] In one of the embodiments, the first selection module includes a write control switch tube, a selection switch tube and a selection capacitor.

[0022] The control terminal of the write control switch tube is used for accessing a data write signal, the first terminal of the write control switch tube is used for accessing an amplitude modulation signal, and the second terminal of the write control switch tube is connected to the control terminal of the selection switch tube.

[0023] The first terminal of the selection switch tube is connected to the amplitude modulation circuit, and the second terminal of the selection switch tube is connected to the pixel module.

[0024] The first end of the selection capacitor is connected to the control end of the selection switch tube, and the second end of the selection capacitor is used to input a negative power supply signal.

[0025] In a second aspect, a display device is provided, comprising a pixel module and a pixel control device according to any one of the above embodiments.

[0026] In one embodiment, the pixel module comprises a light-emitting control switch tube and a light-emitting element.

[0027] The pixel control device and the display device described above comprise an amplitude modulation circuit, a pulse width modulation circuit and a selection circuit. The amplitude modulation circuit is used to connect the pixel module through the selection circuit, and the pulse width modulation circuit is used to connect the pixel module through the selection circuit. The amplitude modulation circuit is used to input a data signal and generate a first driving signal to the selection circuit according to the data signal, and the first driving signal is a signal after amplitude modulation. The pulse width modulation circuit is used to input a data signal and generate a second driving signal to the selection circuit according to the data signal, and the second driving signal is a signal after pulse width modulation. The selection circuit is used to control the on-off between the amplitude modulation circuit and the pixel module, and also used to control the on-off between the pulse width modulation circuit and the pixel module. The pixel control device and the display device can realize the adjustment of the brightness of the pixel module by the two modulation methods of amplitude modulation and pulse width modulation, through the selection circuit to control the on-off between the amplitude modulation circuit and the pixel module, and the pulse width modulation circuit and the pixel module, thereby effectively solving the problem of uneven brightness of each pixel module under low brightness or low gray. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 FIG. 1 is a structural schematic diagram of a pixel control device in one embodiment;

[0029] Figure 2 FIG. 2 is a structural schematic diagram of a pixel control device in another embodiment;

[0030] Figure 3 FIG. 3 is a structural schematic diagram of a pixel control device in another embodiment;

[0031] Figure 4 FIG. 4 is a schematic diagram of the relationship among a data signal, an analog waveform signal and a pulse width in one embodiment;

[0032] Figure 5 FIG. 5 is a structural schematic diagram of a shaping circuit in one embodiment;

[0033] Figure 6 FIG. 6 is a structural schematic diagram of a pixel control device in another embodiment;

[0034] Figure 7Fig. 1 shows a timing diagram of the operation of the pixel control device in one embodiment;

[0035] Figure 8 Fig. 2 shows a timing diagram of the operation of the pixel control device in another embodiment. DETAILED DESCRIPTION

[0036] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application.

[0037] In one embodiment, as shown in Fig. 1, a pixel control device is provided, which includes an amplitude modulation circuit 110, a pulse width modulation circuit 120 and a selection circuit 130. The amplitude modulation circuit 110 is configured to connect a pixel module 140 through the selection circuit 130, and the pulse width modulation circuit is configured to connect the pixel module 140 through the selection circuit 130. Figure 1 The amplitude modulation circuit 110 is configured to access a data signal and generate a first driving signal to the selection circuit 130 according to the data signal. Specifically, the amplitude modulation circuit 110 can include an amplitude modulation switch tube. The control end of the amplitude modulation switch tube can be configured to access the data signal, and the first end of the amplitude modulation switch tube can be configured to access a power signal. The amplitude modulation switch tube can generate the first driving signal according to the accessed data signal and power signal. The first driving signal is a signal after amplitude modulation and can be used to drive the pixel module 140 to emit light. In particular, the first driving signal can be a first current driving signal.

[0038] The pulse width modulation circuit 120 is configured to access the data signal and generate a second driving signal to the selection circuit 130 according to the data signal. Specifically, the pulse width modulation circuit 120 can access a carrier signal and generate the second driving signal according to the data signal and the carrier signal. The second driving signal is a signal after pulse width modulation and can be used to drive the pixel module 140 to emit light. Specifically, the second driving signal can be a pulse signal, and the data signal can adjust the width of the pulse signal. In particular, the second driving signal can be a second current driving signal.

[0039]

[0040] ​The selection circuit 130 is configured to control the on-off between the amplitude modulation circuit 110 and the pixel module 140. Specifically, when the selection circuit 130 controls the on between the amplitude modulation circuit 110 and the pixel module 140, the first driving signal generated by the amplitude modulation circuit 110 can be transmitted to the pixel module 140, and the pixel module 140 can emit light according to the first driving signal. When the selection circuit 130 controls the off between the amplitude modulation circuit 110 and the pixel module 140, the first driving signal generated by the amplitude modulation circuit 110 cannot be transmitted to the pixel module 140, and thus the pixel module 140 cannot emit light according to the first driving signal.

[0041] The selection circuit 130 is also configured to control the on-off between the pulse width modulation circuit 120 and the pixel module 140. Specifically, when the selection circuit 130 controls the on between the pulse width modulation circuit 120 and the pixel module 140, the second driving signal generated by the pulse width modulation circuit 120 can be transmitted to the pixel module 140, and the pixel module 140 emits light according to the second driving signal. When the selection circuit 130 controls the off between the pulse width modulation circuit 120 and the pixel module 140, the second driving signal generated by the pulse width modulation circuit 120 cannot be transmitted to the pixel module 140, and thus the pixel module 140 cannot emit light according to the second driving signal.

[0042] In addition, when the selection circuit 130 controls the on between the amplitude modulation circuit 110 and the pixel module 140, the selection circuit 130 can control the pulse width modulation circuit 120 and the pixel module 140 to remain in the off state. Thus, when the amplitude modulation circuit 110 is working, the working of the pulse width modulation circuit 120 will not be affected. Similarly, when the selection circuit 130 controls the on between the pulse width modulation circuit 120 and the pixel module 140, the selection circuit 130 can control the amplitude modulation circuit 110 and the pixel module 140 to remain in the off state, so as to reduce the mutual influence between the circuits.

[0043] In this embodiment, the pixel control device includes an amplitude modulation circuit 110, a pulse width modulation circuit 120, and a selection circuit 130. The amplitude modulation circuit 110 is used to connect to the pixel module 140 via the selection circuit 130, and the pulse width modulation circuit 120 is used to connect to the pixel module 140 via the selection circuit 130. Specifically, the amplitude modulation circuit 110 receives a data signal and generates a first driving signal to the selection circuit 130 based on the data signal; the first driving signal is a signal after amplitude modulation. The pulse width modulation circuit 120 receives a data signal and generates a second driving signal to the selection circuit 130 based on the data signal; the second driving signal is a signal after pulse width modulation. The selection circuit 130 controls the on / off connection between the amplitude modulation circuit 110 and the pixel module 140, and also controls the on / off connection between the pulse width modulation circuit 120 and the pixel module 140. The pixel control device controls the on / off state between the amplitude modulation circuit 110 and the pixel module 140, and the pulse width modulation circuit 120 and the pixel module 140 respectively through the selection circuit 130. It can adjust the brightness of the pixel module by both amplitude modulation and pulse width modulation, thereby effectively solving the problem of uneven brightness of each pixel module under low brightness or low gray conditions.

[0044] In one embodiment, such as Figure 2 As shown, the amplitude modulation circuit 110 includes a first data control circuit 111, a first light emission control circuit 112, and a compensation circuit 113. The first data control circuit 111 and the compensation circuit 113 are both connected to the first light emission control circuit 112, and the first light emission control circuit 112 is connected to the selection circuit 130.

[0045] The first data control circuit 111 is used to receive data signals and can control whether the data signals are transmitted to the first light-emitting control circuit 112. The first light-emitting control circuit 112 is used to receive power signals. The compensation circuit 113 is used to read the threshold voltage of the first light-emitting control circuit 112.

[0046] Optionally, the data signal can be a reference potential data signal. In this case, the reference potential data signal can control the conduction of the first light-emitting control circuit 112. The reference potential data signal can be preset according to the conduction conditions of the first light-emitting control circuit 112. Specifically, when the first data control circuit 111 controls the transmission of the reference potential data signal to the first light-emitting control circuit 112, the first light-emitting control circuit 112 can adjust its conduction state according to the reference potential data signal. When the first light-emitting control circuit 112 is on, the power supply signal can charge the first light-emitting control circuit 112 until the first light-emitting control circuit 112 is off. When the first light-emitting control circuit 112 is off, the compensation circuit 113 can read the threshold voltage of the first light-emitting control circuit 112.

[0047] In addition, the data signal can also be a sum of a display data signal and a compensation voltage. The display data signal can be used to control the luminance of the pixel module 140. The compensation voltage has a value equal to the threshold voltage of the first light emitting control circuit 112, and can be used to compensate the threshold voltage of the first light emitting control circuit 112. Specifically, when the first data control circuit 111 controls the data signal to be transmitted to the first light emitting control circuit 112, the first light emitting control circuit 112 can generate a first driving signal to the selection circuit 130 according to the data signal.

[0048] In this embodiment, the amplitude modulation circuit 110 includes a first data control circuit 111, a first light emitting control circuit 112, and a compensation circuit 113. The first data control circuit 111 is configured to access a data signal. The first light emitting control circuit 112 and the compensation circuit 113 are configured to generate a first driving signal to the selection circuit 130 according to the data signal. The luminance of the pixel module 140 can be effectively adjusted, so that the light emitted by each pixel module 140 is more uniform.

[0049] In one embodiment, as shown in FIG. 1, Figure 3 the first data control circuit 111 includes a transmission switch tube, the first light emitting control circuit 112 includes a driving switch tube and a storage capacitor, and the compensation circuit 113 includes a compensation switch tube.

[0050] The control end of the transmission switch tube is configured to access a data write signal, which can control the opening or closing of the transmission switch tube. The first end of the transmission switch tube is configured to access the data signal, and the second end of the transmission switch tube is configured to connect the control end of the driving switch tube. The first end of the driving switch tube is configured to access a positive power input signal VDD, and the second end of the driving switch tube is configured to connect the compensation switch tube. The control end and the second end of the driving switch tube are respectively connected to the two ends of the storage capacitor. The control end of the compensation switch tube is configured to access a sampling control signal, which can control the opening or closing of the compensation switch tube. The first end of the compensation switch tube is configured to access a sampling signal.

[0051] Specifically, when the data signal is a reference potential data signal Vref, the data write signal controls the transmission switch tube to open, and the reference potential data signal Vref can be transmitted to the control end of the driving switch tube. The driving switch tube is controlled to open under the control of the reference potential data signal Vref, and the positive power input signal VDD can charge the storage capacitor through the driving switch tube. When the potential at the first end of the driving switch tube is Vref-Vth, the driving switch tube is cut off. Wherein, Vth represents the threshold voltage of the driving switch tube. At this time, the sampling control signal controls the compensation switch tube to open, and the potential Vref-Vth at the first end of the driving switch tube can be read through the sampling signal. Since the reference potential data signal Vref is a pre-set value, the threshold voltage Vth of the driving switch tube can be obtained.

[0052] After the threshold voltage Vth of the driving switch is read, the data signal can be updated to Vdata+Vth. Wherein, Vdata represents the display data signal. When the data write signal controls the transmission switch to open, the updated data signal Vdata+Vth can be transmitted to the control end of the driving switch. The driving switch is in an on state at this time. The driving switch can generate a first driving signal according to the updated data signal Vdata+Vth and the forward power input signal. Specifically, the first driving signal can be a first current driving signal.

[0053] In this embodiment, the first data control circuit 111 includes a transmission switch, the first light-emitting control circuit 112 includes a driving switch and a storage capacitor, and the compensation circuit 113 includes a compensation switch. By controlling the opening or closing of different switches, the transmission of the data signal can be effectively controlled.

[0054] In one embodiment, as shown in Figure 2 The pulse width modulation circuit 120 includes a second data control circuit 121, a second light-emitting control circuit 122, and a pulse width generation circuit 123. The second data control circuit 121 is connected to the pulse width generation circuit 123, and the pulse width generation circuit 123 is connected to the second light-emitting control circuit 122.

[0055] The second data control circuit 121 is used to access the data signal. The working state of the second data control circuit 121 includes on and off. When the second data control circuit 121 is on, the data signal can be transmitted to the pulse width generation circuit 123. When the second data control circuit 121 is off, the data signal cannot be transmitted to the pulse width generation circuit 123.

[0056] The pulse width generation circuit 123 and the second light-emitting control circuit 122 are used to generate a second driving signal to the selection circuit 130 according to the data signal. Specifically, the pulse width generation circuit 123 can access an analog waveform signal, and generate a pulse signal according to the received data signal and the analog waveform signal. Wherein, the analog waveform signal can be a triangular wave, a sawtooth wave, a ramp wave, a sine wave, etc. The pulse signal is then transmitted to the second light-emitting control circuit 122, and the second light-emitting control circuit 122 can generate a second driving signal to the selection circuit 130 according to the pulse signal. When the selection circuit 130 controls the second light-emitting control circuit 122 to be on between the pixel module 140, the second driving signal can be transmitted to the pixel module 140.

[0057] In particular, the structure of the second data control circuit 121 can be the same as that of the first data control circuit 111. The structure of the second light-emitting control circuit 122 can be the same as that of the first light-emitting control circuit 112, so as to reduce the deviation of the data signal in the transmission process.

[0058] In this embodiment, the pulse width modulation circuit 120 comprises a second data control circuit 121, a second light emitting control circuit 122 and a pulse width generation circuit 123. The second data control circuit 121 is connected to the pulse width generation circuit 123, and the pulse width generation circuit 123 is connected to the second light emitting control circuit 122. The second data control circuit 121 is configured to access a data signal, and the pulse width generation circuit 123 and the second light emitting control circuit 122 are configured to generate a second driving signal to the selection circuit 130 according to the data signal, so that the light emitting brightness of the pixel can be adjusted by pulse width modulation.

[0059] In one embodiment, as shown in FIG. 3, the pulse width generation circuit 123 comprises a coupling capacitor and a shaping circuit. The coupling capacitor and the second data control circuit 121 are both connected to the shaping circuit, and the shaping circuit is connected to the second light emitting control circuit 122. Figure 3 As shown in FIG. 4, the data signal Vdata and the analog waveform signal are coupled through the coupling capacitor and transmitted to the shaping circuit together. The shaping circuit can convert the coupled analog waveform signal into a pulse signal. The relationship among the data signal Vdata, the analog waveform signal and the pulse width is shown in FIG. 5. As can be understood, when the value of the data signal Vdata is different, the pulse width of the pulse signal is also different.

[0060] Figure 4

[0061] In addition, the first end of the shaping circuit can be connected to the first end of the coupling capacitor, and the second end of the shaping circuit can be connected to the second light emitting control circuit 122. Specifically, the shaping circuit can be an inverter, a Schmitt trigger, a monostable trigger, etc. The structure of the inverter and the Schmitt trigger can be referred to FIG. 6. Figure 5 For example, the Schmitt trigger can comprise three N-type transistors and three P-type transistors, and different forward power signals and reverse power signals are accessed to control the Schmitt trigger separately. When the signal input to the Schmitt trigger is higher than the forward threshold voltage, the output signal of the Schmitt trigger is high; when the signal input to the Schmitt trigger is lower than the negative threshold voltage, the output signal of the Schmitt trigger is low. The forward threshold voltage and the negative threshold voltage can be determined according to the threshold voltage of the transistors. Specifically, when the output signal of the Schmitt trigger is high, the second light emitting control circuit 122 can be turned on, and the second driving signal can be transmitted to the pixel module 140 to control the pixel module to emit light. When the output signal of the Schmitt trigger is low, the second light emitting control circuit 122 is not turned on, and the pixel module 140 cannot emit light according to the second driving signal.

[0062] ​​In the embodiment, the pulse width generating circuit 123 comprises a coupling capacitor and a shaping circuit. The coupling capacitor and the second data control circuit 121 are both connected to the shaping circuit, and the shaping circuit is connected to the second light emitting control circuit 122. The coupling capacitor can couple the data signal and the analog waveform signal, and transmit the coupled signal to the shaping circuit. The shaping circuit generates a pulse signal according to the coupled signal and transmits the pulse signal to the second light emitting control circuit 122. The process can realize the modulation of the pulse width, so as to adjust the light emitting brightness of the pixel module 140.

[0063] In one embodiment, as shown in FIG. 1, the selection circuit 130 comprises a first selection module 131 and a second selection module 132. The amplitude modulation circuit 110 is used to connect the pixel module 140 through the first selection module 131, and the pulse width modulation circuit 120 is used to connect the pixel module 140 through the second selection module 132. The first selection module 131 and the second selection module 132 are both used to connect the pixel module 140. Figure 2

[0064] The first selection module 131 is used to control the conduction or turn-off between the amplitude modulation circuit 110 and the pixel module 140. The second selection module 132 is used to control the conduction or turn-off between the pulse width modulation circuit 120 and the pixel module 140.

[0065] Specifically, the first selection module 131 and the second selection module 132 can be respectively connected to different control signals to control the working state of the first selection module 131 and the second selection module 132. For example, the first selection module 131 can be connected to an amplitude modulation signal. When the amplitude modulation mode is needed to adjust the light emitting brightness of the pixel module 140, the first selection module 131 can be turned on through the amplitude modulation signal, so that the first driving signal generated by the amplitude modulation circuit 110 can be transmitted to the pixel module 140, thereby controlling the pixel module 140 to emit light. The second selection module 132 can be connected to a pulse width modulation signal. When the pulse width modulation mode is needed to adjust the light emitting brightness of the pixel module 140, the second selection module 132 can be turned on through the pulse width modulation signal, so that the second driving signal generated by the pulse width modulation circuit 120 can be transmitted to the pixel module 140, thereby controlling the pixel module 140 to emit light.

[0066] In the embodiment, the first selection module 131 and the second selection module 132 are used to control the conduction or turn-off between the amplitude modulation circuit 110 and the pulse width modulation circuit 120 and the pixel module 140, respectively. According to the actual demand, the two modulation modes can be selected to adjust the light emitting brightness of the pixel module 140, so that the light emitting of each pixel module 140 is more uniform.

[0067] ​In one embodiment, the first selection module 131 and the second selection module 132 have the same structure.

[0068] Specifically, both the first selection module 131 and the second selection module 132 may include a selection switch transistor. For example, the first selection module 131 may include a first selection switch transistor, and the second selection module 132 may include a second selection switch transistor. Furthermore, the control signals connected to each selection switch transistor are different. The control terminal of the first selection switch transistor can be used to connect to an amplitude modulation control signal, and the control terminal of the second selection switch transistor can be used to connect to a pulse width modulation control signal. Both the amplitude modulation control signal and the pulse width modulation control signal can be high or low level signals. For example, when the amplitude modulation control signal is high, the first selection switch transistor can be in the open state, and the first drive signal output by the amplitude modulation circuit 110 can be transmitted to the pixel module 140. When the amplitude modulation control signal is low, the first selection switch transistor can be in the closed state, and the amplitude modulation circuit 110 and the pixel module 140 are disconnected, so the first drive signal cannot be transmitted to the pixel module 140. Similarly, when the pulse width modulation control signal is high, the second selection switch transistor can be in the open state, and the second drive signal generated by the pulse width control circuit can be transmitted to the pixel module 140. When the pulse width modulation control signal is low, the second selection switch can be in the off state, and the second drive signal cannot be transmitted to the pixel module 140.

[0069] In this embodiment, the first selection module 131 and the second selection module 132 have the same structure, which can reduce the errors that occur during signal transmission.

[0070] In one embodiment, such as Figure 3 As shown, the first selection module 131 includes a write control switch, a selection switch, and a selection capacitor.

[0071] The write control switch transistor has a control terminal for receiving a data write signal, which controls its on / off state. The first terminal of the write control switch transistor receives an amplitude modulation signal, and the second terminal connects to the control terminal of the selection switch transistor. The first terminal of the selection switch transistor connects to the amplitude modulation circuit 110, and the second terminal connects to the pixel module 140. The first terminal of the selection capacitor connects to the control terminal of the selection switch transistor, and the second terminal connects to the negative power input signal VSS.

[0072] Specifically, the amplitude modulation signal and the data write signal can both be high-low level signals. When the data write signal is a high level signal, the write control switch tube can be opened, and the amplitude modulation signal can be transmitted to the control end of the selection switch tube through the write control switch tube and stored in the selection capacitor. In particular, when the amplitude modulation signal is a high level signal, the selection switch tube can be controlled to open, so that the current path between the amplitude modulation circuit 110 and the pixel module 140 is formed, and the pixel module 140 is controlled to emit light. When the amplitude modulation signal is a low level signal, the selection switch tube is closed, and at this time the pixel module 140 is not controlled to emit light by the amplitude modulation circuit 110.

[0073] It can be understood that when the first selection module 131 and the second selection module 132 have the same structure, the second selection module 132 can also include the write control switch tube, the selection switch tube and the selection capacitor as described above, and the working principle is basically the same, which will not be repeated here.

[0074] In an embodiment, a display device is provided, which includes the pixel module 140 and the pixel control device in any of the above embodiments, and the pixel module 140 is connected to the pixel control device.

[0075] Each pixel module 140 can be controlled to emit light by a pixel control device. The corresponding pixel control device of each pixel module 140 can use two different dimming methods to adjust the luminance of each pixel module 140, and the pixel control devices do not affect each other. For example, when a certain pixel module 140 selects the amplitude modulation method to adjust the luminance, other pixel modules 140 can select the pulse width modulation method or the amplitude modulation method to adjust the luminance.

[0076] The display device in the embodiment includes the pixel module 140 and the pixel control device in any of the above embodiments, which can effectively adjust the luminance of each pixel module 140 in the display device, so that each pixel module emits light more uniformly under low-brightness or low-gray conditions.

[0077] In an embodiment, as shown in FIG. 1, the pixel module 140 includes a light-emitting control switch tube and a light-emitting element. Figure 3

[0078] The control end of the light-emitting control switch tube can be used to access a light-emitting control signal, and the light-emitting control signal can control the opening and closing of the light-emitting control switch tube. The first end of the light-emitting control switch tube is connected to the selection circuit 130, and the second end of the light-emitting control switch tube is connected to the anode of the light-emitting element. The cathode of the light-emitting element is used to access a negative power signal VSS.

[0079] ​Specifically, when the light-emitting control signal controls the light-emitting control switch tube to open, the first driving signal or the second driving signal can be transmitted to the light-emitting element, and the light-emitting element emits light under the driving action of the first driving signal or the second driving signal.

[0080] In this embodiment, the pixel module 140 includes a light-emitting control switch tube and a light-emitting element, and the light-emitting of the light-emitting element can be controlled by controlling the opening or closing of the light-emitting control switch tube.

[0081] For ease of understanding, a more detailed specific embodiment is provided below.

[0082] In one embodiment, as shown in Figure 6 A pixel control device is provided, including an amplitude modulation circuit 110, a pulse width modulation circuit 120, and a selection circuit 130. The amplitude modulation circuit 110 includes a first data control circuit 111, a first light-emitting control circuit 112, and a compensation circuit 113. The first data control circuit 111 includes a transmission switch tube T1, the first light-emitting control circuit 112 includes a first driving switch tube T3 and a storage capacitor C1, and the compensation circuit 113 includes a compensation switch tube T2. The control end of the transmission switch tube T1 is used to access the data write signal GA, the first end of the transmission switch tube T1 is used to access the data signal Data, and the second end of the transmission switch tube T1 is used to connect the control end of the first driving switch tube T3. The first end of the first driving switch tube T3 is used to access the positive power input signal VDD, the second end of the first driving switch tube T3 is used to connect the second end of the compensation switch tube T2, and the compensation switch tube T2 is connected to the pixel module 140 through the selection circuit 130. The control end of the compensation switch tube T2 is used to access the sampling control signal RD_G, and the first end of the compensation switch tube T2 is used to access the sampling signal Sample. The two ends of the storage capacitor C1 are connected to the control end and the second end of the first driving switch tube T3, respectively.

[0083] The pulse width modulation circuit 120 comprises a second data control circuit 121, a second light-emitting control circuit 122, and a pulse width generation circuit 123. The second data control circuit 121 comprises a data writing switch tube T6, and the second light-emitting control circuit 122 comprises a second driving switch tube T9. The pulse width generation circuit 123 comprises a coupling capacitor C4 and a shaping circuit. The shaping circuit is a Schmitt trigger, and the Schmitt trigger is connected to an additional positive power supply signal VDD' and a negative power supply signal VSS'. Specifically, a control end of the data writing switch tube T6 can be used to connect a data writing signal GA, a first end of the data writing switch tube T6 can be used to connect a data signal Data, and a second end of the data writing switch tube T6 is connected to a first end of the coupling capacitor C4. A second end of the coupling capacitor C4 can be used to connect an analog waveform signal Wave. A voltage input end of the Schmitt trigger is connected to the first end of the coupling capacitor C4, and a voltage output end of the Schmitt trigger is connected to a control end of the second driving switch tube T9. A first end of the second driving switch tube T9 is used to connect a positive power supply input signal VDD, and a second end of the second driving switch tube T9 is connected to the pixel module 140 through the selection circuit 130.

[0084] The selection circuit 130 comprises a first selection module 131 and a second selection module 132. The first selection module 131 comprises a first writing control switch tube T4, a first selection switch tube T7, and a first selection capacitor C2. A control end of the first writing control switch tube T4 is used to connect the data writing signal GA, a first end of the first writing control switch tube T4 is used to connect an amplitude modulation signal PAM_con, and a second end of the first writing control switch tube T4 is connected to a first end of the first selection capacitor C2. A second end of the first selection capacitor C2 is used to connect the negative power supply signal VSS. A first end of the first selection switch tube T7 is connected to a second end of the first driving switch tube T3, and a second end of the first selection switch tube T7 is connected to the pixel module 140.

[0085] The second selection module 132 comprises a second writing control switch tube T5, a second selection switch tube T8, and a second selection capacitor C3. A control end of the second writing control switch tube T5 is used to connect the data writing signal GA, a first end of the second writing control switch tube T5 is used to connect a pulse width modulation signal PWM_con, and a second end of the second writing control switch tube T5 is connected to a first end of the second selection capacitor C3. A second end of the second selection capacitor C3 is used to connect the negative power supply signal VSS. A first end of the second selection switch tube T8 is connected to a second end of the second driving switch tube T9, and a second end of the second selection switch tube T8 is connected to the pixel module 140.

[0086] The pixel module 140 comprises a light-emitting control switch tube T10 and a light-emitting element. The control end of the light-emitting control switch tube T10 is used for inputting a light-emitting control signal EM, the first end of the light-emitting control switch tube T10 is connected with the second end of the first selection switch tube T7 and the second end of the second selection switch tube T8, and the second end of the light-emitting control switch tube T10 is connected with the anode of the light-emitting element. The cathode of the light-emitting element is used for inputting a negative power supply signal VSS.

[0087] In particular, the above-mentioned switch tubes can all be transistors, and different working time sequences are respectively proposed for the above-mentioned pixel control device in the amplitude modulation and the pulse width modulation. Figure 7 As shown in the figure, the specific working time sequence is as follows:

[0088] The t1 stage: GA and RD_G are high, T4 is opened, PAM_con is low at this time, and T7 remains closed; T1 is opened, Data writes a high-level reference potential Vref, T3 is opened, the source level potential of T3 is lifted by VDD, and T3 is cut off when being lifted to Vref-Vth; T2 is opened, and the threshold voltage Vth of T3 is obtained through the Sample signal sampling.

[0089] The t2 stage: RD_G becomes low, and GA remains high. At this time, the data written by DA is the display data Vdata of this frame plus the Vth obtained just now, that is, Vdata+Vth, the compensation of the threshold voltage is completed, and is stored on the capacitor C1; PAM_con becomes high, T7 is opened, and the potential of PAM_con is stored on C2.

[0090] The t3 stage: the EM potential is high, T10 is opened, a current path is formed through the amplitude modulation circuit 110, and the pixel module 140 keeps emitting light in the t3 stage.

[0091] When the amplitude modulation circuit 110 works, PWM_con remains low, and T8 remains closed, so as not to affect the working condition of the pulse width modulation circuit 120.

[0092] When the pixel control device is in the pulse width modulation, as shown in the figure, the specific working time sequence is as follows: Figure 8

[0093] The t1 stage: GA is high, and GA and RD_G are both row control signals. When this pixel is in the amplitude modulation working mode, other pixels in the same row can be in the pulse width modulation working mode, so RD_G is still high, and the pulse width modulation circuit 120 is not affected. In this stage, T6 is opened, Data writes display data Vdata; T5 is opened, PWM_con is low at this time, and T8 remains closed. ​

[0094] t2 stage: PWM_con becomes high level, T8 opens, the potential is stored on C3. T6 remains open, the left side of C4 keeps the potential Vdata.

[0095] t3 stage: GA is low level, EM is high level. T10 opens; T6 closes, the left side of C4 takes Vdata as the starting value, and is coupled by C4 following the change of Wave signal. The coupled signal is shaped into pulse signal by the Schmidt trigger. The pulse width, Vdata and Wave signal are shown in the following figure. In high pulse, T9 opens in high pulse, the current forms a path through the pulse width modulation circuit 120, and the pixel module 140 can emit light; in low pulse, T9 closes, and the pixel module 140 does not emit light. Through Vdata, the width of high pulse can be controlled, and the light-emitting duration is controlled, so as to adjust the light-emitting brightness of the pixel module 140, and form pulse width modulation dimming.

[0096] When the pulse width modulation circuit 120 works, PAM_con keeps low level, and T7 keeps closed, so as not to affect the work of the amplitude modulation circuit 110.

[0097] The pixel control device in the embodiment has two dimming modes of amplitude modulation and pulse width modulation, and can select the dimming mode of each pixel module 140 according to the light-emitting brightness, effectively solving the problems of uneven brightness and wavelength shift of each pixel module 140 at low brightness.

[0098] The technical features of the above-described embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0099] The above-described embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as the limitation of the patent scope of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A pixel control device, characterized in that, It includes an amplitude modulation circuit, a pulse width modulation circuit, and a selection circuit. The amplitude modulation circuit is used to connect to a pixel module through the selection circuit, and the pulse width modulation circuit is used to connect to a pixel module through the selection circuit. The amplitude modulation circuit is used to receive data signals and generate a first driving signal to the selection circuit based on the data signals; the first driving signal is a signal after amplitude modulation. The pulse width modulation circuit is used to receive data signals and generate a second driving signal to the selection circuit based on the data signals; the second driving signal is a signal after pulse width modulation. The selection circuit is used to control the on / off connection between the amplitude modulation circuit and the pixel module, and also to control the on / off connection between the pulse width modulation circuit and the pixel module; The pulse width modulation circuit includes a second data control circuit, a second light emission control circuit, and a pulse width generation circuit. The second data control circuit is connected to the pulse width generation circuit, and the pulse width generation circuit is connected to the second light emission control circuit. The second data control circuit is used to receive data signals, and the pulse width generation circuit and the second light emission control circuit are used to generate a second driving signal to the selection circuit based on the data signals. The pulse width generation circuit includes a coupling capacitor and a shaping circuit. The coupling capacitor and the second data control circuit are both connected to the shaping circuit, and the shaping circuit is connected to the second light emission control circuit.

2. The pixel control device according to claim 1, characterized in that, The amplitude modulation circuit includes a first data control circuit, a first light emission control circuit, and a compensation circuit. The first data control circuit and the compensation circuit are both connected to the first light emission control circuit, and the first light emission control circuit is connected to the selection circuit. The first data control circuit is used to receive data signals, and the first light-emitting control circuit and the compensation circuit are used to generate a first driving signal to the selection circuit according to the data signal.

3. The pixel control device according to claim 2, characterized in that, The first data control circuit includes a transmission switch transistor, the first light emission control circuit includes a driving switch transistor and a storage capacitor, and the compensation circuit includes a compensation switch transistor. The control terminal of the transmission switch is used to receive a data write signal, the first terminal of the transmission switch is used to receive a data signal, and the second terminal of the transmission switch is used to connect to the control terminal of the drive switch. The first end of the driving switch is used to connect to the positive power input signal, and the second end of the driving switch is used to connect to the second end of the compensation switch. The two ends of the storage capacitor are respectively connected to the control terminal and the second terminal of the driving switch transistor; The control terminal of the compensation switch is used to receive the sampling control signal, and the first terminal of the compensation switch is used to receive the sampling signal.

4. The pixel control device according to claim 1, characterized in that, The selection circuit includes a first selection module and a second selection module. The amplitude modulation circuit is used to connect to the pixel module through the first selection module, and the pulse width modulation circuit is used to connect to the pixel module through the second selection module. Both the first selection module and the second selection module are used to connect to the pixel module.

5. The pixel control device according to claim 4, characterized in that, The first selection module and the second selection module have the same structure.

6. The pixel control device according to claim 5, characterized in that, The first selection module includes a write control switch, a selection switch, and a selection capacitor; The control terminal of the write control switch is used to receive the data write signal, the first terminal of the write control switch is used to receive the amplitude modulation signal, and the second terminal of the write control switch is connected to the control terminal of the selection switch. The first terminal of the selection switch is connected to the amplitude modulation circuit, and the second terminal of the selection switch is connected to the pixel module. The first end of the selection capacitor is connected to the control terminal of the selection switch transistor, and the second end of the selection capacitor is used to connect to the negative power input signal.

7. A display device, characterized in that, It includes a pixel module and a pixel control device as described in any one of claims 1-6, wherein the pixel module is connected to the pixel control device.

8. The display device according to claim 7, characterized in that, The pixel module includes a light-emitting control switch and a light-emitting element.

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