View angle switching control circuit and display device

Abstract

The utility model discloses a visual angle switching control circuit and a display device, and the visual angle switching control circuit comprises a power supply control module which receives a wide visual angle indication signal and outputs a first control signal, and receives a narrow visual angle indication signal and outputs a second control signal; the first power supply unit comprises a step-down circuit and a first voltage conversion circuit, receives the first control signal and outputs a first power supply voltage and a second power supply voltage; the second power supply unit comprises a booster circuit and a second voltage conversion circuit, receives the second control signal and outputs a third power supply voltage and a fourth power supply voltage; the first input end of the comparator receives an input signal with adjustable frequency, the second input end of the comparator receives a direct current signal, the forward power supply end of the comparator receives the first or third power supply voltage, the reverse power supply end of the comparator receives the second or fourth power supply voltage, and the output end of the comparator outputs a visual angle control signal. According to the invention, a microcontroller is prevented from generating a visual angle control signal, so that the circuit space is saved and the circuit cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of display, and in particular to a viewing angle switching control circuit and a display device. Background Art

[0002] With the popularization of electronic devices and people's emphasis on privacy, anti-peeping display devices have emerged. At present, the anti-peeping display device adopts a wide and narrow viewing angle switching technology to achieve wide and narrow viewing angle display.

[0003] At present, two square waves of different amplitudes are usually provided when realizing wide and narrow viewing angle switching, so as to be provided to the viewing angle switching electrode of the dimming panel, thereby making the display device work in a wide viewing angle mode or a narrow viewing angle mode. The viewing angle switching control circuit currently used in the display device usually includes a microprocessor and a digital-to-analog converter. The microprocessor provides a digital signal and transmits it to the digital-to-analog converter. The digital-to-analog converter generates the required waveform based on the digital signal and applies it to the wide and narrow viewing angle switching. However, in actual applications, the cost of the above-mentioned viewing angle switching control circuit is relatively high, thereby increasing the manufacturing cost of the display device.

[0004] The present application needs to propose an improved viewing angle switching control circuit and display device. Utility Model Content

[0005] In view of the above problems, an object of the present invention is to provide a viewing angle switching control circuit and a display device which can save circuit space and reduce circuit cost.

[0006] According to one aspect of the utility model, a viewing angle switching control circuit is provided, which is connected to a viewing angle switching electrode in a dimming panel in a display device to provide a viewing angle control signal, wherein the viewing angle switching control circuit comprises:

[0007] A power supply control module is connected to the wide and narrow viewing angle pins of the dimming panel, receives a wide viewing angle indication signal and outputs a first control signal accordingly, and receives a narrow viewing angle indication signal and outputs a second control signal accordingly;

[0008] A first power supply unit, comprising a step-down circuit and a first voltage conversion circuit, wherein the step-down circuit is connected to the power supply control module to receive a first control signal and output a first supply voltage, and the first voltage conversion circuit is connected to the step-down circuit to output a second supply voltage having an amplitude opposite to that of the first supply voltage;

[0009] a second power supply unit, comprising a boost circuit and a second voltage conversion circuit, wherein the boost circuit is connected to the power supply control module to receive a second control signal and output a third power supply voltage, and the second voltage conversion circuit is connected to the boost circuit to output a fourth power supply voltage having an opposite amplitude to the third power supply voltage; and

[0010] A comparator, wherein a first input terminal of the comparator receives an input signal with adjustable frequency, a second input terminal of the comparator receives a DC signal, a positive power supply terminal of the comparator is connected to the first power supply unit and the second power supply unit to receive the first power supply voltage or the third power supply voltage, a reverse power supply terminal of the comparator is connected to the first power supply unit and the second power supply unit to receive the second power supply voltage or the fourth power supply voltage, and an output terminal of the comparator outputs the corresponding viewing angle control signal.

[0011] Optionally, the power supply control module includes:

[0012] a first power supply control unit, receiving a wide viewing angle indication signal and outputting the first control signal; and

[0013] The second power supply control unit receives the narrow viewing angle indication signal and outputs the second control signal.

[0014] Optionally, the step-down circuit includes:

[0015] A first switch tube, wherein a control end of the first switch tube is connected to the power supply control module to receive the first control signal, and a first end of the first switch tube receives a power supply voltage;

[0016] a first inductor, wherein a first end of the first inductor is connected to a second end of the first switch tube, and a second end of the first inductor outputs the first supply voltage;

[0017] a first diode, a cathode of which is connected to the second end of the first switch tube, and an anode of which is grounded; and

[0018] A first capacitor, wherein a first end of the first capacitor is connected to a second end of the first inductor, and a second end of the first capacitor is connected to an anode of the first diode.

[0019] Optionally, the boost circuit comprises:

[0020] a second inductor, wherein a first end of the second inductor receives a power supply voltage;

[0021] a second switch tube, wherein a control end of the second switch tube is connected to the power supply control module to receive the second control signal, a first end of the second switch tube is connected to the second end of the second inductor, and a second end of the second switch tube is grounded;

[0022] a second diode, an anode of which is connected to the second end of the second inductor, and a cathode of which outputs the third supply voltage; and

[0023] A second capacitor, wherein a first end of the second capacitor is connected to the cathode of the second diode, and a second end of the second capacitor is grounded.

[0024] Optionally, the amplitude of the third supply voltage is greater than the amplitude of the first supply voltage, and the amplitude of the second supply voltage is greater than the amplitude of the fourth supply voltage.

[0025] Optionally, the maximum amplitude of the input signal is greater than the amplitude of the DC signal, and the minimum amplitude of the input signal is less than the amplitude of the DC signal.

[0026] Optionally, the viewing angle control signal includes a wide viewing angle control signal and a narrow viewing angle control signal, the maximum amplitude of the narrow viewing angle control signal is greater than the maximum amplitude of the wide viewing angle control signal, and the minimum amplitude of the narrow viewing angle control signal is less than the minimum amplitude of the wide viewing angle control signal.

[0027] According to another aspect of the present invention, a viewing angle switching control circuit is provided, which is connected to the viewing angle switching electrode in the dimming panel in the display device to provide a viewing angle control signal, characterized in that the viewing angle switching control circuit includes:

[0028] The timing controller is connected to the wide and narrow viewing angle pins of the dimming panel, receives the wide viewing angle indication signal and outputs the first timing signal accordingly, receives the narrow viewing angle indication signal and outputs the second timing signal accordingly,

[0029] a power supply control module, electrically connected to the timing controller, receiving the first timing signal and outputting a first control signal, receiving the second timing signal and outputting a second control signal;

[0030] A first power supply unit, comprising a step-down circuit and a first voltage conversion circuit, wherein the step-down circuit is connected to the power supply control module to receive a first control signal and output a first supply voltage, and the first voltage conversion circuit is connected to the step-down circuit to output a second supply voltage having an amplitude opposite to that of the first supply voltage;

[0031] a second power supply unit, comprising a boost circuit and a second voltage conversion circuit, wherein the boost circuit is connected to the power supply control module to receive a second control signal and output a third power supply voltage, and the second voltage conversion circuit is connected to the boost circuit to output a fourth power supply voltage having an opposite amplitude to the third power supply voltage; and

[0032] A comparator, wherein a first input terminal of the comparator receives an input signal with adjustable frequency, a second input terminal of the comparator receives a DC signal, a positive power supply terminal of the comparator is connected to the first power supply unit and the second power supply unit to receive the first power supply voltage or the third power supply voltage, a reverse power supply terminal of the comparator is connected to the first power supply unit and the second power supply unit to receive the second power supply voltage or the fourth power supply voltage, and an output terminal of the comparator outputs the corresponding viewing angle control signal.

[0033] Optionally, the power supply control module includes:

[0034] a third power supply control unit, receiving the first timing signal and outputting the first control signal; and

[0035] The fourth power supply control unit receives the second timing signal and outputs the second control signal.

[0036] According to another aspect of the present invention, a display device is provided, comprising the viewing angle switching control circuit as described above.

[0037] The viewing angle switching control circuit provided in one embodiment of the present application adopts a power supply control module, a first power supply unit, and a second power supply unit to provide a power supply voltage of different amplitudes to the positive power supply terminal of the comparator according to the wide and narrow viewing angle indication signal, and to provide a power supply voltage of opposite amplitude to the positive power supply terminal to the reverse power supply terminal of the comparator, so that the comparator outputs a viewing angle control signal with adjustable amplitude. That is, the present application does not require a microcontroller, and can generate a corresponding viewing angle control signal only through the relevant power supply circuit and the comparator, which saves circuit space and reduces circuit cost.

[0038] Furthermore, the comparator of the viewing angle switching control circuit provided by the present application receives an input signal with adjustable frequency, thereby making the frequency of the generated viewing angle control signal adjustable, thereby improving the adaptability of the viewing angle switching control circuit of the present application in different display devices.

[0039] The viewing angle switching control circuit provided in another embodiment of the present application adopts a timing control signal, a power supply control module, a first power supply unit, and a second power supply unit to provide a power supply voltage of different amplitudes to the positive power supply terminal of the comparator according to the wide and narrow viewing angle indication signal, and to provide a power supply voltage of opposite amplitude to the positive power supply terminal to the reverse power supply terminal of the comparator, so that the comparator outputs a viewing angle control signal with adjustable amplitude. That is, the present application does not require a microcontroller, and can generate a corresponding viewing angle control signal only through the relevant power supply circuit and the comparator, which saves circuit space and reduces circuit cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and other purposes, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0041] Figure 1 A schematic diagram of a viewing angle switching control circuit provided according to a first embodiment of the utility model is shown;

[0042] Figure 2 A schematic diagram of a viewing angle switching control circuit provided according to a second embodiment of the utility model is shown;

[0043] Figure 3 A circuit diagram of a first power supply unit in a viewing angle switching control circuit provided according to the first embodiment and the second embodiment of the utility model is shown;

[0044] Figure 4 A circuit diagram of a second power supply unit in a viewing angle switching control circuit provided according to the first embodiment and the second embodiment of the utility model is shown;

[0045] Figure 5 A waveform diagram of a viewing angle switching control circuit provided according to the first embodiment and the second embodiment of the utility model is shown;

[0046] Figure 6 Another waveform diagram of the viewing angle switching control circuit provided according to the first embodiment and the second embodiment of the utility model is shown;

[0047] Figure 7 A schematic diagram of a switch control circuit in a power supply control module in a viewing angle switching control circuit provided in an embodiment of the utility model is shown. DETAILED DESCRIPTION

[0048] Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements or modules are represented by the same or similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale.

[0049] At the same time, certain words are used in this patent specification and claims to refer to specific components. It should be understood by those skilled in the art that hardware manufacturers may use different terms to refer to the same component. This patent specification and claims do not use differences in names as a way to distinguish components, but rather use differences in components' functions as the criteria for distinction.

[0050] In addition, it should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the statement "comprise one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements.

[0051] Figure 1 A schematic diagram of a viewing angle switching control circuit provided according to a first embodiment of the utility model is shown. Figure 7 A schematic diagram of a switch control circuit in a power supply control module in a viewing angle switching control circuit provided in an embodiment of the utility model is shown.

[0052] like Figure 1 As shown, the viewing angle switching control circuit 100 is connected to the viewing angle switching electrode in the dimming panel in the display device to provide a viewing angle control signal HVA, thereby realizing wide and narrow viewing angle switching display. The viewing angle control signal includes a narrow viewing angle control signal HVA1 and a wide viewing angle control signal HVA2.

[0053] The viewing angle switching circuit 100 includes a power supply control module 120 , a first power supply unit 130 , a second power supply unit 140 , and a comparator U1 .

[0054] The power supply control module 120 receives the wide viewing angle indication signal H and outputs the first control signal ctrl1 accordingly, and receives the narrow viewing angle indication signal L and outputs the second control signal ctrl2 accordingly. Exemplarily, the power supply control module 120 is connected to the wide and narrow viewing angle pins of the dimming panel. That is, the wide and narrow viewing angle pins of the dimming panel output the wide viewing angle indication signal H or the narrow viewing angle indication signal L. The power supply control module 120 includes a first power supply control unit 121 and a second power supply control unit 122. The first power supply control unit 121 receives the wide viewing angle indication signal H and outputs the first control signal ctrl1. The second power supply control unit 122 receives the narrow viewing angle indication signal L and outputs the second control signal ctrl2.

[0055] Specifically, the first power supply control unit 121 includes, for example, a duty cycle control circuit and a switch control circuit, wherein the duty cycle control circuit outputs a corresponding duty cycle signal according to the wide viewing angle indication signal H, and the switch control circuit generates a corresponding first control signal ctrl1 according to the obtained duty cycle signal. The second power supply control unit 122 includes, for example, a duty cycle control circuit and a switch control circuit, wherein the duty cycle control circuit outputs a corresponding duty cycle signal according to the narrow viewing angle indication signal L, and the switch control circuit generates a corresponding second control signal ctrl2 according to the obtained duty cycle signal.

[0056] Exemplarily, the duty cycle control circuit is implemented by, for example, a 555 timer or an oscillator to generate a signal with a corresponding duty cycle. Figure 7 As shown, for example, it includes a switch K1, a switch K2 and a timing controller, wherein the switch K1 and the switch K2 are connected in series between the power supply and the ground, and the control ends of the switch K1 and the switch K2 are connected to the timing controller, and the connection node between the switch K1 and the switch K2 outputs a control signal. Among them, the timing controller outputs a signal T1 to the control end of the switch K1, and the timing controller outputs a signal T2 to the control end of the switch K2. The signal T1 and the signal T2 control the two switches to be turned on alternately, and control the time when each switch is turned on. Among them, it can be seen from the waveform of the generated control signal that the signal T1 controls the switch K1 to be turned on for a time t1 and then disconnected, and then the signal T2 controls the switch K2 to be turned on for a time t2, and so on to generate the required control signal. Among them, the relationship between the time t1 and the time t2 and the duty cycle corresponding to the output control signal is: duty cycle = t1 / (t1+t2).

[0057] The first power supply unit 130 includes a step-down circuit 131 and a first voltage conversion circuit 132. The step-down circuit 131 is connected to the first power supply control unit 121 to receive the first control signal ctrl1 and output the first power supply voltage AVEE1, and the first voltage conversion circuit 132 is connected to the step-down circuit 131 to output the second power supply voltage AVDD1 with an opposite amplitude to the first power supply voltage AVEE1.

[0058] The second power supply unit 140 includes a boost circuit 141 and a second voltage conversion circuit 142. The boost circuit 141 is connected to the second power supply control unit 122 to receive the second control signal ctrl2 and output a third power supply voltage AVEE2, and the second voltage conversion circuit 142 is connected to the boost circuit 141 to output a fourth power supply voltage AVDD2 having an opposite amplitude to the third power supply voltage AVEE2.

[0059] A first input terminal (for example, a positive input terminal) of the comparator U1 receives a frequency-adjustable input signal VIN, a second input terminal (for example, a reverse input terminal) of the comparator U1 receives a DC signal V1, a positive power supply terminal of the comparator U1 is connected to the first power supply unit 130 and the second power supply unit 140 to receive a first power supply voltage AVEE1 or a third power supply voltage AVEE2, a reverse power supply terminal of the comparator U1 is connected to the first power supply unit 130 and the second power supply unit 140 to receive a second power supply voltage AVDD1 or a fourth power supply voltage AVDD2, and an output terminal of the comparator U1 outputs a corresponding viewing angle control signal HVA.

[0060] Figure 2 A schematic diagram of a viewing angle switching control circuit provided according to a second embodiment of the utility model is shown.

[0061] like Figure 2 As shown, the viewing angle switching control circuit 200 is connected to the viewing angle switching electrode in the dimming panel in the display device to provide a viewing angle control signal HVA, thereby realizing wide and narrow viewing angle switching display. The viewing angle control signal includes a narrow viewing angle control signal HVA1 and a wide viewing angle control signal HVA2.

[0062] The viewing angle switching circuit 200 includes a timing controller 210 , a power supply control module 220 , a first power supply unit 130 , a second power supply unit 140 , and a comparator U1 .

[0063] The timing controller 210 receives the wide viewing angle indication signal and outputs a first timing signal accordingly, receives the narrow viewing angle indication signal and outputs a second timing signal accordingly,

[0064] Receive the wide viewing angle indication signal H and output the first timing signal tcon1 accordingly, receive the narrow viewing angle indication signal L and output the second timing signal tcon2 accordingly. Exemplarily, the timing controller 210 is connected to the wide and narrow viewing angle pins, that is, the wide and narrow viewing angle pins of the dimming panel output the wide viewing angle indication signal H or the narrow viewing angle indication signal L. The timing controller 210 receives the wide viewing angle indication signal H / narrow viewing angle indication signal L, and outputs, for example, the pre-stored first timing signal tcon1 / second timing signal tcon2 accordingly. Furthermore, the first timing signal tcon1 / second timing signal tcon2, for example, includes a data signal and a clock signal.

[0065] The power supply control module 220 receives the first timing signal tcon1 and outputs the first control signal ctrl1 accordingly, and receives the second timing signal tcon2 and outputs the second control signal ctrl2 accordingly. Exemplarily, the power supply control module 220 includes a third power supply control unit 221 and a fourth power supply control unit 222. The third power supply control unit 221 includes, for example, a processor, a duty cycle control circuit, and a switch control circuit. The processor processes the first timing signal tcon1 into a signal corresponding to the duty cycle, and then the duty cycle control circuit generates a corresponding duty cycle signal, and the switch control circuit generates the corresponding first control signal ctrl1 according to the obtained duty cycle signal. The fourth power supply control unit 222 includes, for example, a processor, a duty cycle control circuit, and a switch control circuit. The processor processes the second timing signal tcon2 into a signal corresponding to the duty cycle, and then the duty cycle control circuit generates a corresponding duty cycle signal, and the switch control circuit generates the corresponding second control signal ctrl2 according to the obtained duty cycle signal. Among them, the processing method of the above-mentioned processor generating the corresponding code from the timing signal is not the invention point of this case, and will not be described in detail here.

[0066] Exemplarily, the processor is a microprocessor (MCU), and the microprocessor is used to directly output a square wave signal corresponding to the received timing signal, and the square wave signal has a corresponding duty cycle. The duty cycle control circuit is implemented by a 555 timer or an oscillator to generate a signal with a corresponding duty cycle. Figure 7 As shown, for example, it includes a switch K1, a switch K2 and a timing controller, wherein the switch K1 and the switch K2 are connected in series between the power supply and the ground, and the control ends of the switch K1 and the switch K2 are connected to the timing controller, and the connection node between the switch K1 and the switch K2 outputs a control signal. Among them, the timing controller outputs a signal T1 to the control end of the switch K1, and the timing controller outputs a signal T2 to the control end of the switch K2. The signal T1 and the signal T2 control the two switches to be turned on alternately, and control the time when each switch is turned on. Among them, it can be seen from the waveform of the generated control signal that the signal T1 controls the switch K1 to be turned on for a time t1 and then disconnected, and then the signal T2 controls the switch K2 to be turned on for a time t2, and so on to generate the required control signal. Among them, the relationship between the time t1 and the time t2 and the duty cycle corresponding to the output control signal is: duty cycle = t1 / (t1+t2).

[0067] The first power supply unit 130 includes a step-down circuit 131 and a first voltage conversion circuit 132. The step-down circuit 131 is connected to the first power supply control unit 121 to receive the first control signal ctrl1 and output the first power supply voltage AVEE1, and the first voltage conversion circuit 132 is connected to the step-down circuit 131 to output the second power supply voltage AVDD1 with an opposite amplitude to the first power supply voltage AVEE1.

[0068] The second power supply unit 140 includes a boost circuit 141 and a second voltage conversion circuit 142. The boost circuit 141 is connected to the second power supply control unit 122 to receive the second control signal ctrl2 and output a third power supply voltage AVEE2, and the second voltage conversion circuit 142 is connected to the boost circuit 141 to output a fourth power supply voltage AVDD2 having an opposite amplitude to the third power supply voltage AVEE2.

[0069] A first input terminal (for example, a positive input terminal) of the comparator U1 receives a frequency-adjustable input signal VIN, a second input terminal (for example, a reverse input terminal) of the comparator U1 receives a DC signal V1, a positive power supply terminal of the comparator U1 is connected to the first power supply unit 130 and the second power supply unit 140 to receive a first power supply voltage AVEE1 or a third power supply voltage AVEE2, a reverse power supply terminal of the comparator U1 is connected to the first power supply unit 130 and the second power supply unit 140 to receive a second power supply voltage AVDD1 or a fourth power supply voltage AVDD2, and an output terminal of the comparator U1 outputs a corresponding viewing angle control signal HVA.

[0070] It should be noted that the input signal VIN received by the comparator U1 in the viewing angle switching control circuit in the first embodiment and the second embodiment is provided by the timing controller 210, for example, and is a signal with adjustable frequency. The DC signal V1 received by the comparator U1 in the viewing angle switching control circuit in the first embodiment and the second embodiment is, for example, a DC voltage with a fixed amplitude. The maximum amplitude of the input signal VIN is greater than the amplitude of the DC signal V1, and the minimum amplitude of the input signal VIN is less than the amplitude of the DC signal V2.

[0071] Furthermore, when the input signal VIN is greater than the DC signal V1, the output end of the comparator U1 outputs the supply voltage of the positive power supply end (the first supply voltage AVEE1 / the third supply voltage AVEE2). When the input signal VIN is less than the DC signal V1, the output end of the comparator U1 outputs the supply voltage of the reverse power supply end (the second supply voltage AVDD1 / the fourth supply voltage AVDD2).

[0072] Further, when the wide viewing angle indication signal H is received, the corresponding first power supply unit 130 operates and outputs the first power supply voltage AVEE1 and the second power supply voltage AVDD1 with opposite amplitudes. Correspondingly, the viewing angle control signal HVA outputted from the output end of the comparator U1 is a wide viewing angle control signal HVA2 with a maximum amplitude of the first power supply voltage AVEE1 and a minimum amplitude of the second power supply voltage AVDD1. When the narrow viewing angle indication signal L is received, the corresponding second power supply unit 140 operates and outputs the third power supply voltage AVEE2 and the fourth power supply voltage AVDD2 with opposite amplitudes. Correspondingly, the viewing angle control signal HVA outputted from the output end of the comparator U1 is a narrow viewing angle control signal HVA1 with a maximum amplitude of the third power supply voltage AVEE2 and a minimum amplitude of the fourth power supply voltage AVDD2. Exemplarily, the amplitude of the third power supply voltage AVEE2 is greater than the amplitude of the first power supply voltage AVEE1, and the amplitude of the second power supply voltage AVDD1 is greater than the amplitude of the fourth power supply voltage AVDD2.

[0073] Exemplarily, the maximum amplitude of the narrow viewing angle control signal HVA1 is greater than the maximum amplitude of the wide viewing angle control signal HVA2, and the minimum amplitude of the narrow viewing angle control signal HVA1 is less than the minimum amplitude of the wide viewing angle control signal HVA2.

[0074] Figure 3 A circuit schematic diagram of a first power supply unit in a viewing angle switching control circuit provided according to the first embodiment and the second embodiment of the utility model is shown.

[0075] like Figure 3 As shown, the first power supply unit 130 includes a step-down circuit 131 and a first voltage conversion circuit 132 .

[0076] The step-down circuit 131 receives the first control signal ctrl1 and outputs the first power supply voltage AVEE1. The first voltage conversion circuit 132 is connected to the step-down circuit 131 and outputs the second power supply voltage AVDD1 with an amplitude opposite to that of the first power supply voltage AVEE1.

[0077] The step-down circuit 131 includes a first switch tube Q1, a first inductor L1, a first diode D1, and a first capacitor C1. The control end of the first switch tube Q1 is connected to the power supply control module to receive the first control signal ctrl1, and the first end of the first switch tube Q1 receives the power supply voltage V2. The first end of the first inductor L1 is connected to the second end of the first switch tube Q1, and the second end of the first inductor L1 outputs the first power supply voltage AVEE1. The cathode of the first diode D1 is connected to the second end of the first switch tube Q1, and the anode of the first switch tube Q1 is grounded. The first end of the first capacitor C1 is connected to the second end of the first inductor L1, and the second end of the first capacitor C1 is connected to the anode of the first diode D1.

[0078] Furthermore, when the first control signal ctrl1 is at a high level, the first switch tube Q1 is turned on, the power supply voltage V2 charges the first inductor L1, and the first inductor L1 obtains a certain voltage by self-induction. When the first control signal ctrl1 is at a low level, the first switch tube Q1 is turned off, the first inductor L1 charges the load, and the voltage at the load end is less than the power supply voltage, thereby achieving voltage reduction.

[0079] Further, the first supply voltage AVEE1 = V2 * X1 generated by the voltage-reducing circuit 131 , wherein X1 is the duty cycle of the first control signal ctrl1 .

[0080] Figure 4 A circuit schematic diagram of a second power supply unit in a viewing angle switching control circuit provided according to the first embodiment and the second embodiment of the utility model is shown.

[0081] like Figure 4 As shown, the second power supply unit 140 includes a boost circuit 141 and a second voltage conversion circuit 142 .

[0082] The boost circuit 141 receives the second control signal ctrl2 and outputs a third power supply voltage AVEE2. The second voltage conversion circuit 142 is connected to the boost circuit 141 and outputs a fourth power supply voltage AVDD2 having an opposite amplitude to the third power supply voltage AVEE2.

[0083] The boost circuit 141 includes a second switch tube Q2, a second inductor L2, a second diode D2, and a second capacitor C2. The first end of the second inductor L1 receives a power supply voltage V2. The control end of the second switch tube Q2 is connected to the power supply control module to receive a second control signal ctrl2, the first end of the second switch tube Q2 is connected to the second end of the second inductor L2, and the second end of the second switch tube Q2 is grounded. The anode of the second diode D2 is connected to the second end of the second inductor L2, and the cathode of the second diode D2 outputs a third power supply voltage AVEE2. The first end of the second capacitor C2 is connected to the cathode of the second diode D2, and the second end of the second capacitor C2 is grounded.

[0084] Furthermore, when the second control signal ctrl2 is at a high level, the second switch tube Q2 is turned on, the power supply voltage V2 charges the second inductor L2, and the second inductor L2 obtains a certain voltage by self-induction. When the second control signal ctrl2 is at a low level, the second switch tube Q2 is turned off, the second inductor L2 and the power supply voltage V2 together charge the load through the first diode D1, and the voltage at the load end is greater than the power supply voltage, thereby achieving voltage boost.

[0085] Further, the third supply voltage AVEE2 generated by the boost circuit 141 is V2 / (1-X2), wherein X2 is the duty cycle of the second control signal ctrl2.

[0086] It should be noted that the first switch tube Q1 and the second switch tube Q2 are, for example, NMOS transistors. The control end of the first switch tube Q1 and the second switch tube Q2 is a gate, the first end of the first switch tube Q1 and the second switch tube Q2 is a drain, and the second end of the first switch tube Q1 and the second switch tube Q2 is a source. In other embodiments, the first switch tube Q1 and the second switch tube Q2 may be PMOS transistors. In other embodiments, the first end of the first switch tube Q1 and the second switch tube Q2 is a source, and the second end of the first switch tube Q1 and the second switch tube Q2 is a drain.

[0087] The circuit structures of the first voltage conversion circuit and the second voltage conversion circuit are, for example, the same, and both are conversion circuits that can convert a positive voltage into a negative voltage with an opposite amplitude. In this embodiment, the first voltage conversion circuit and the second voltage conversion circuit can, for example, use the RTQ6752 chip provided by Richtek, which can convert a positive voltage into a negative voltage with an opposite amplitude.

[0088] Figure 5 A waveform diagram of a viewing angle switching control circuit provided according to the first embodiment and the second embodiment of the utility model is shown.

[0089] like Figure 5 As shown, a waveform diagram of the viewing angle switching control circuit generating a narrow viewing angle control signal HVA1 is shown. The input signal VIN is, for example, a square wave signal with a maximum amplitude of 1.8V and a minimum amplitude of 0V, and the amplitude of the DC signal is, for example, 0.9V. Correspondingly, the viewing angle switching control circuit receives the narrow viewing angle indication signal L, and then the second power supply unit 140 works and provides a second power supply voltage AVEE2 with an amplitude of 5V and a fourth power supply voltage AVDD2 with an amplitude of -5V. Then the comparator U1 outputs the narrow viewing angle control signal HVA1. Correspondingly, the duty cycle X2 of the second control signal ctrl2 is X2 = 1-V2 / AVEE2.

[0090] Figure 6 Another waveform diagram of the viewing angle switching control circuit provided according to the first embodiment and the second embodiment of the utility model is shown.

[0091] like Figure 6As shown, a waveform diagram of the wide viewing angle control signal HVA2 generated by the viewing angle switching control circuit is shown. The input signal VIN is, for example, a square wave signal with a maximum amplitude of 1.8V and a minimum amplitude of 0V, and the amplitude of the DC signal is, for example, 0.9V. Correspondingly, the viewing angle switching control circuit receives the wide viewing angle indication signal H, and then the first power supply unit 130 works and provides a first power supply voltage AVEE1 with an amplitude of 2.5V and a third power supply voltage AVDD1 with an amplitude of -2.5V. Then the comparator U1 outputs the wide viewing angle control signal HVA2. Correspondingly, the duty cycle X1 of the first control signal ctrl1 is equal to AVEE1 / V2.

[0092] It should be noted that the viewing angle switching control circuit provided by the present application adopts a power supply control module, a first power supply unit, and a second power supply unit to provide a power supply voltage of different amplitudes to the positive power supply terminal of the comparator according to the wide and narrow viewing angle indication signal, and to provide a power supply voltage of opposite amplitude to the positive power supply terminal to the reverse power supply terminal of the comparator, thereby making the comparator output a viewing angle control signal with adjustable amplitude. That is, the present application does not require a microcontroller, and can generate a corresponding viewing angle control signal only through the relevant power supply circuit and comparator, which saves circuit space and reduces circuit cost.

[0093] Furthermore, the comparator of the viewing angle switching control circuit provided by the present application receives an input signal with adjustable frequency, thereby making the frequency of the generated viewing angle control signal adjustable, thereby improving the adaptability of the viewing angle switching control circuit of the present application in different display devices.

[0094] The viewing angle switching control circuit provided by the present application adopts a timing control signal, a power supply control module, a first power supply unit, and a second power supply unit to provide a power supply voltage of different amplitudes to the positive power supply terminal of the comparator according to the wide and narrow viewing angle indication signal, and to provide a power supply voltage of opposite amplitude to the positive power supply terminal to the reverse power supply terminal of the comparator, so that the comparator outputs a viewing angle control signal with adjustable amplitude. That is, the present application does not require a microcontroller, and can generate a corresponding viewing angle control signal only through the relevant power supply circuit and the comparator, which saves circuit space and reduces circuit cost.

[0095] The present application also provides a display device, comprising the viewing angle switching control circuit as described above.

[0096] It should be noted that those skilled in the art will appreciate that the terms "during", "when" and "when..." used herein in connection with circuit operation are not strict terms indicating an action that occurs immediately when the start-up action begins, but that there may be some small but reasonable delay or delays between the action and the reaction initiated by the start-up action, such as various transmission delays, etc. The terms "approximately" or "substantially" used herein mean that an element value has a parameter that is expected to be close to a stated value or position.

[0097] According to the embodiments of the present invention, these embodiments do not describe all the details in detail, nor do they limit the present invention to specific embodiments. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and modify and use it based on the present invention.

Claims

1. A viewing angle switching control circuit, connected to a viewing angle switching electrode in a dimming panel in a display device to provide a viewing angle control signal, characterized in that: The viewing angle switching circuit comprises: A power supply control module is connected to the wide and narrow viewing angle pins of the dimming panel, receives a wide viewing angle indication signal and outputs a first control signal accordingly, and receives a narrow viewing angle indication signal and outputs a second control signal accordingly; A first power supply unit, comprising a step-down circuit and a first voltage conversion circuit, wherein the step-down circuit is connected to the power supply control module to receive a first control signal and output a first supply voltage, and the first voltage conversion circuit is connected to the step-down circuit to output a second supply voltage having an amplitude opposite to that of the first supply voltage; a second power supply unit, comprising a boost circuit and a second voltage conversion circuit, wherein the boost circuit is connected to the power supply control module to receive a second control signal and output a third power supply voltage, and the second voltage conversion circuit is connected to the boost circuit to output a fourth power supply voltage having an amplitude opposite to that of the third power supply voltage; and A comparator, wherein a first input terminal of the comparator receives an input signal with adjustable frequency, a second input terminal of the comparator receives a DC signal, a positive power supply terminal of the comparator is connected to the first power supply unit and the second power supply unit to receive the first power supply voltage or the third power supply voltage, a reverse power supply terminal of the comparator is connected to the first power supply unit and the second power supply unit to receive the second power supply voltage or the fourth power supply voltage, and an output terminal of the comparator outputs the corresponding viewing angle control signal.

2. The viewing angle switching control circuit according to claim 1, characterized in that: The power supply control module comprises: a first power supply control unit, receiving a wide viewing angle indication signal and outputting the first control signal; and The second power supply control unit receives the narrow viewing angle indication signal and outputs the second control signal.

3. The viewing angle switching control circuit according to claim 1, characterized in that: The step-down circuit comprises: A first switch tube, wherein a control end of the first switch tube is connected to the power supply control module to receive the first control signal, and a first end of the first switch tube receives a power supply voltage; a first inductor, wherein a first end of the first inductor is connected to a second end of the first switch tube, and a second end of the first inductor outputs the first supply voltage; a first diode, a cathode of which is connected to the second end of the first switch tube, and an anode of which is grounded; and A first capacitor, wherein a first end of the first capacitor is connected to a second end of the first inductor, and a second end of the first capacitor is connected to an anode of the first diode.

4. The viewing angle switching control circuit according to claim 1, characterized in that: The boost circuit comprises: a second inductor, wherein a first end of the second inductor receives a power supply voltage; a second switch tube, wherein a control end of the second switch tube is connected to the power supply control module to receive the second control signal, a first end of the second switch tube is connected to the second end of the second inductor, and a second end of the second switch tube is grounded; a second diode, an anode of which is connected to the second end of the second inductor, and a cathode of which outputs the third supply voltage; and A second capacitor, wherein a first end of the second capacitor is connected to the cathode of the second diode, and a second end of the second capacitor is grounded.

5. The viewing angle switching control circuit according to claim 1, characterized in that: The amplitude of the third power supply voltage is greater than the amplitude of the first power supply voltage, and the amplitude of the second power supply voltage is greater than the amplitude of the fourth power supply voltage.

6. The viewing angle switching control circuit according to claim 1, characterized in that: The maximum amplitude of the input signal is greater than the amplitude of the DC signal, and the minimum amplitude of the input signal is smaller than the amplitude of the DC signal.

7. The viewing angle switching control circuit according to claim 1, characterized in that: The viewing angle control signal includes a wide viewing angle control signal and a narrow viewing angle control signal, the maximum amplitude of the narrow viewing angle control signal is greater than the maximum amplitude of the wide viewing angle control signal, and the minimum amplitude of the narrow viewing angle control signal is less than the minimum amplitude of the wide viewing angle control signal.

8. A viewing angle switching control circuit, connected to a viewing angle switching electrode in a dimming panel in a display device to provide a viewing angle control signal, characterized in that: The viewing angle switching circuit comprises: The timing controller is connected to the wide and narrow viewing angle pins of the dimming panel, receives the wide viewing angle indication signal and outputs the first timing signal accordingly, receives the narrow viewing angle indication signal and outputs the second timing signal accordingly, a power supply control module, electrically connected to the timing controller, receiving the first timing signal and outputting a first control signal, receiving the second timing signal and outputting a second control signal; A first power supply unit, comprising a step-down circuit and a first voltage conversion circuit, wherein the step-down circuit is connected to the power supply control module to receive a first control signal and output a first supply voltage, and the first voltage conversion circuit is connected to the step-down circuit to output a second supply voltage having an amplitude opposite to that of the first supply voltage; a second power supply unit, comprising a boost circuit and a second voltage conversion circuit, wherein the boost circuit is connected to the power supply control module to receive a second control signal and output a third power supply voltage, and the second voltage conversion circuit is connected to the boost circuit to output a fourth power supply voltage having an amplitude opposite to that of the third power supply voltage; and A comparator, wherein a first input terminal of the comparator receives an input signal with adjustable frequency, a second input terminal of the comparator receives a DC signal, a positive power supply terminal of the comparator is connected to the first power supply unit and the second power supply unit to receive the first power supply voltage or the third power supply voltage, a reverse power supply terminal of the comparator is connected to the first power supply unit and the second power supply unit to receive the second power supply voltage or the fourth power supply voltage, and an output terminal of the comparator outputs the corresponding viewing angle control signal.

9. The viewing angle switching control circuit according to claim 8, characterized in that: The power supply control module comprises: a third power supply control unit, receiving the first timing signal and outputting the first control signal; and The fourth power supply control unit receives the second timing signal and outputs the second control signal.

10. A display device, characterized in that: include: A viewing angle switching control circuit as described in any one of claims 1-7, or a viewing angle switching control circuit as described in any one of claims 8-9.

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