Voltage control circuit and display device

Abstract

The application discloses a voltage control circuit and a display device. The voltage control device comprises a voltage controller configured to output a first initial voltage; a comparator connected to an output end of the voltage controller and configured to output a first level signal and a second level signal according to the first initial voltage; a first output module connected to an output end of the comparator and configured to output a first working voltage according to the first level signal output by the output end of the comparator; and a second output module connected to the output end of the comparator and configured to output a second working voltage according to the second level signal output by the output end of the comparator. The above structure realizes switching of output voltage.

Description

TECHNICAL FIELD

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

[0002] When notebook computers, display devices and the like are in operation, sometimes a "tsee" noise can be heard, which phenomenon is called "whistling". The reason for the occurrence of the "whistling" phenomenon is that there are capacitors, inductors and other passive elements in the circuit. The DC-DC circuit on the PCBA (circuit board) inside the display is the main source of noise.

[0003] The DC-DC converter is turned on / off by a switching device, thereby generating a pulse-shaped current. By controlling the length of time (pulse width) of the opening, a stable direct current with constant voltage can be obtained, which is called PWM (pulse width modulation) and is widely used as the mainstream way of DC-DC converter. However, the switching frequency of the DC-DC converter is relatively high, reaching 100 kHz-1 MHz. Since the frequency vibration is beyond the audible range of human ear, no noise can be felt. However, due to some working scenarios, the DC-DC works intermittently, the DC-DC works at variable frequency, and the light load or load work causes the occurrence of periodic frequency acceptable to human ear, thereby causing whistling. SUMMARY

[0004] The technical problem solved by the present application is to provide a voltage control circuit and a display device to automatically switch the output voltage and improve the whistling noise.

[0005] To solve the above problems, the present application provides a voltage control circuit and a display device, the voltage control circuit comprising: a voltage controller for outputting a first initial voltage; a comparator connected to the output end of the voltage controller, for outputting a first level signal and a second level signal according to the first initial voltage; a first output module connected to the output end of the comparator, for outputting a first working voltage according to the first level signal output by the output end of the comparator; a second output module connected to the output end of the comparator, for outputting a second working voltage according to the second level signal output by the output end of the comparator, to realize the switching of the first working voltage and the second working voltage.

[0006] Among them, the second working voltage is greater than the first working voltage.

[0007] Among them, the first output module comprises a first transistor, the first transistor comprises an input end, an output end and a control end, the input end of the first transistor is connected to the output end of the voltage controller, and the control end is connected to the output end of the comparator, so as to control the on-off of the input end and the output end of the first transistor by the output signal of the comparator.

[0008] The first working voltage is equal to the first initial voltage.

[0009] The voltage control circuit further comprises a switching module, an input end of the switching module is connected with an output end of the comparator, and an output end of the switching module is connected with the second output module or the voltage controller, so as to realize switching between the first working mode and the second working mode; in the first working mode, the switching module is connected with the second output module, and the second working voltage is output through the second output module; in the second working mode, the switching module is connected with the voltage controller, and the second initial voltage is output through the voltage controller.

[0010] The second initial voltage is greater than the first initial voltage.

[0011] The second output module comprises a second transistor and an operational amplifier, the second transistor comprises an input end, an output end and a control end, the input end of the second transistor is connected with a constant voltage source, the output end of the second transistor is connected with the operational amplifier, and the control end of the second transistor is connected with the output end of the comparator, so as to control the on-off of the input end and the output end of the second transistor through the output signal of the comparator.

[0012] The first transistor and the second transistor are opposite type transistors.

[0013] The operational amplifier comprises a first resistor and a second resistor, and the output voltage of the second output module is linearly related to the ratio of the first resistor and the second resistor.

[0014] The application further provides a display device comprising a display panel and a driver for providing a voltage driving signal for the display panel, wherein the driver comprises the voltage control circuit in any of the above embodiments.

[0015] The application has the beneficial effect that whether the output voltage of the voltage controller is less than the reference voltage is detected through the comparator, so as to detect whether the display panel has a heavy load picture, when the first initial voltage output by the voltage controller is lower than the reference voltage, it is judged that the display panel has a heavy load picture, the first output module is switched to the second output module, so as to realize automatic switching of the first working voltage to the second working voltage, and then the current value of the output end is reduced, and the phenomenon of noise or heavy load picture is improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description only constitute some embodiments of the present application. Other drawings can be obtained by those of ordinary skill in the art without any creative effort.

[0017] Figure 1 A structural schematic diagram of a first embodiment of a voltage control circuit of the present application;

[0018] Figure 2 A specific structural schematic diagram of the first embodiment of the voltage control circuit of the present application;

[0019] Figure 3 A structural schematic diagram of a second embodiment of a voltage control circuit of the present application;

[0020] Figure 4 A specific structural schematic diagram of the second embodiment of the voltage control circuit of the present application;

[0021] Figure 5 A specific structural schematic diagram of an embodiment of a voltage controller of the present application;

[0022] Figure 6 A structural schematic diagram of an embodiment of a display device of the present application.

[0023] 11 voltage controller; 12 comparator; 13 first output module; 14 second output module; 15 switching module; 141 operational amplifier; T1 first transistor; T2 second transistor; 61 display panel; 62 driver. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without any creative effort belong to the scope of protection of the present application.

[0025] The terms used in the embodiments of the present application are only for the purpose of describing the specific embodiments, and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless otherwise clearly indicated. "Plural" generally includes at least two, but does not exclude the case of including at least one.

[0026] It should be understood that the term "and / or" as used herein merely describes an associated relationship, that is, there can be three cases: A and / or B, which means that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this application generally represents an "or" relationship between the front and rear associated objects. The terms "first", "second", and the like in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence.

[0027] It should be understood that the terms "include", "contain" or any other variation used herein are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the elements defined by the statement "include" do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0028] It should be noted that if the application examples involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture (as shown in the drawings), and if the specific posture changes, the directional indications will also change accordingly.

[0029] Reference to "embodiments" herein means that the specific features, structures or characteristics described in conjunction with the embodiments can be included in at least one embodiment of the application. The phrase appears in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment to other embodiments. The skilled person explicitly and implicitly understands that the embodiments described herein can be combined with other embodiments.

[0030] The application provides a voltage control circuit, please refer to Figure 1 , Figure 1 The first embodiment of the voltage control circuit of the application is a structural schematic diagram. As Figure 1 shown, the voltage control circuit includes: a voltage controller 11, a comparator 12, a first output module 13, and a second output module 14.

[0031] The voltage controller 11 is configured to output a first initial voltage.

[0032] The input end of the comparator 12 is connected with the output end of the voltage controller 11, for outputting a first level signal and a second level signal according to the first initial voltage. One of the first level signal and the second level signal is a high level signal, and the other is a low level signal. In a specific embodiment, the comparator 12 includes a first input end, a second input end and an output end. The first input end of the comparator 12 is connected with the output end of the voltage controller 11, and the second input end is connected with a reference voltage source Vref for outputting a reference voltage. The comparator 12 compares the first initial voltage output by the voltage controller 11 with the reference voltage. When the first initial voltage is not less than (greater than or equal to) the reference voltage, the first level signal is output; and when the first initial voltage is less than the reference voltage, the second level signal is output.

[0033] The first output module 13 is connected with the output end of the comparator 12, for outputting a first working voltage to the output end OUT of the voltage control circuit according to the first level signal output by the output end of the comparator 12.

[0034] The second output module 14 is connected with the output end of the comparator 12, for outputting a second working voltage to the output end OUT according to the second level signal output by the output end of the comparator 12.

[0035] The output end OUT of the voltage control circuit is connected with a load device, for supplying power to the load device. The load device includes but is not limited to a pixel circuit, a passive device, etc.

[0036] In the embodiment, when the comparator 12 outputs the first level signal, the first output module 13 works to output the first working voltage; and when the comparator 12 outputs the second level signal, the second output module 14 works to output the second working voltage. The switching of the first output module 13 and the second output module 14 is controlled by the comparator 12, so as to realize the switching of the first working voltage and the second working voltage of the output end. The second working voltage and the first working voltage are different. When a heavy load picture appears, the voltage load is too large. At this time, the first working voltage and the second working voltage are switched, so as to switch the lower working voltage to the higher working voltage, so as to increase the output voltage, thereby reducing the current flowing to the load, and improving the noise.

[0037] In the embodiment, the second working voltage is greater than the first working voltage, so that when the heavy load picture appears, the first working voltage of the output end is switched to the second working voltage to increase the output voltage, and the current flowing through the load is reduced when the load (power) is unchanged, so as to improve the noise phenomenon. In other embodiments, the first working voltage can also be greater than the second working voltage, that is, when the heavy load picture appears, the second working voltage of the output end is switched to the first working voltage, so as to improve the display picture. The first working voltage is the normal working voltage, which is usually between 12V and 18V.

[0038] Specifically, the first output module 13 includes an input end, an output end and a control end, wherein the input end is connected with the voltage controller 11, the control end is connected with the comparator 12, and the output end is connected with the load, so that the first output module 13 outputs the same first working voltage as the voltage controller 11, that is, the normal voltage, to make the device at the load end work normally, through the control of the comparator 12.

[0039] Specifically, please further refer to Figure 2 , Figure 2 is a specific structure diagram of the first embodiment of the voltage control circuit of the application. As Figure 2 shown, the first output module 13 includes a first transistor T1, the first transistor T1 includes an input end, an output end and a control end, the input end of the first transistor T1 is connected with the output end of the voltage controller 11, the output end is connected with the load, and the control end is connected with the output end of the comparator 12, so that the input end and the output end of the first transistor T1 are controlled to be turned on or turned off through the output signal (including the first level signal and the second level signal) of the comparator 12.

[0040] In the embodiment, the first working voltage is equal to the first initial voltage. In other embodiments, the first working voltage can also be not equal to the first initial voltage, and the input end of the first output module 13 is connected with other constant voltage source to output the first working voltage, which is not limited here.

[0041] Further, the second output module 14 includes a second transistor T2 and an operational amplifier 141, the second transistor T2 includes an input end, an output end and a control end, the input end of the second transistor T2 is connected with a constant voltage source Vin, the output end is connected with the output end OUT through the operational amplifier 141, and the control end is connected with the output end of the comparator 12, so that the input end and the output end of the second transistor T2 are controlled to be turned on or turned off through the output signal of the comparator 12. In the embodiment, the output voltage of the output end is amplified to the second working voltage through the operational amplifier 141, wherein the amplification multiple of the operational amplifier 141 is linearly related to the ratio of the first resistor and the second resistor.

[0042] Specifically, the operational amplifier 141 comprises a first resistor R1 and a second resistor R2, and a first input end, a second input end and an output end, wherein the first input end of the operational amplifier 141 is connected with the output end of the second transistor T2, the second input end is grounded through the first resistor R1, the output end is connected with the second input end through the second resistor R2 and with the output end OUT of the voltage control circuit, and the size of the output second working voltage is controlled by controlling the ratio of the second resistor R2 to the first resistor R1. Wherein, the amplification factor of the operational amplifier 141 is Vout / Vin=1+R2 / R1. Wherein, Vin is the voltage outputted by the constant voltage source at the input end of the second transistor T2, and Vout is the voltage transmitted to the output end. In the case of stable input voltage, the output voltage can be adjusted by adjusting the ratio of the first resistor R1 to the second resistor R2 in the embodiment.

[0043] Wherein, the first transistor T1 and the second transistor T2 are opposite type transistors, one is P-type transistor and the other is N-type transistor, which is not limited herein. In the specific embodiment, when the first initial voltage outputted by the voltage controller 11 is greater than the reference voltage, the comparator 12 outputs the first level signal, at this time, the first transistor T1 is turned on, and the first output module 13 normally outputs the first working voltage (that is, the first initial voltage). When the first initial voltage outputted by the voltage controller 11 is less than the reference voltage, the comparator 12 outputs the second level signal, at this time, the second transistor T2 is turned on, and the second output module 14 works, and the voltage of the constant voltage source is amplified to the second working voltage by the operational amplifier 141 in the second output module 14 for output, wherein the second working voltage is greater than the first working voltage, so that when the first initial voltage outputted by the voltage controller 11 is less than the reference voltage, the output voltage is switched to the higher second working voltage, in the case of unchanged load, the voltage is increased and the current is decreased, so that the current at the output end is decreased, thereby realizing the improvement of noise phenomenon and heavy load picture.

[0044] The application also provides another voltage control circuit, please refer to Figure 3 , Figure 3 is the structural schematic diagram of the second embodiment of the voltage control circuit of the application. As Figure 3As shown, the voltage control circuit comprises a voltage controller 11, a comparator 12, a first output module 13 and a second output module 14. The voltage control circuit further comprises a switching module 15, an input end of the switching module 15 is connected with an output end of the comparator 12, and an output end of the switching module 15 is selectively connected with the second output module 14 or the voltage controller 11, so as to realize switching between the first working mode and the second working mode. Specifically, in the first working mode, the output end of the switching module 15 is connected with the second output module 14, and the working voltage is switched to the second working voltage through the second output module 14, so as to eliminate the noise phenomenon and the heavy load picture. In the second working mode, the output end of the switching module 15 is connected with the voltage controller 11, the second initial voltage is switched through the internal circuit of the voltage controller 11, and then the second initial voltage is output to the output end OUT through the first output module 13, wherein the second initial voltage is greater than the first initial voltage, so as to improve the output voltage of the output end OUT, reduce the current, and improve the heavy load picture.

[0045] In a specific embodiment, the switching module 15 is a single-pole double-throw switch, which is switched by manual or logic gate. In other embodiments, it can also be other combination devices, such as opposite type double transistors, etc., which are not limited here. For details, please refer to 4, Figure 4 The specific structure diagram of the second embodiment of the voltage control circuit of the present application is shown in FIG. 4. As shown, Figure 4 The switching module 15 is a single-pole double-throw switch, when the switching module 15 is switched to the first working mode, the output end of the single-pole double-throw switch is connected with the second output module 14, and the specific working process is described in the first embodiment, which is not repeated here.

[0046] When the switching module 15 is switched to the second working mode, the output end of the switching module 15 is connected with the voltage controller 11, and the first initial voltage is pulled up to the second initial voltage through the internal circuit of the voltage controller 11. Specifically, please further refer to Figure 5 , Figure 5 The specific structure diagram of the voltage controller of the present application is shown in FIG. 5. As shown, Figure 5As shown, the voltage controller 11 internally comprises a controller IC, a detection circuit and a register ADC. The detection circuit comprises, but is not limited to, a comparator and a switching module 15. Specifically, when the first initial voltage value is detected to be lower than the reference voltage, a second level voltage is output by the comparator 12, and the voltage controller 11 is selected to be connected by the switching module 15. At this time, the voltage controller 11 outputs another set of initial voltage and gamma value codes through the internal register DAC. The register DAC stores a set of first initial voltage and first gamma value and another set of second initial voltage and second gamma value, which is not limited herein. When the first initial voltage is detected to be lower than the reference voltage, the register DAC is switched to output the second initial voltage and the corresponding gamma value, so that the voltage controller 11 realizes the switching of the output voltage. That is, when the first initial voltage is pulled down to be lower than the reference voltage in the presence of a heavy load picture, the register DAC switches the code to make the initial voltage output by the voltage controller 11 be pulled up to the second initial voltage, realizing the switching of the output voltage. It should be noted that the voltage range value of a conventional display panel is between 12V-18V, and the range of individual drivers is larger. In actual use, the output voltage value is switched by detecting the heavy load picture, and under the condition that the load remains unchanged, the voltage is increased and the current is reduced, so that the current at the load is reduced, thereby improving the display picture of the display panel or improving the working noise of the driver.

[0047] In the specific embodiment, the second initial voltage output by the voltage controller is greater than the first initial voltage and the reference voltage. When passing through the comparator, the comparator outputs a first level signal to drive the first output module to be conductive, so that the second initial voltage is output to the display panel or the driver through the first output module, thereby increasing the output voltage of the output end and improving the display picture of the display panel.

[0048] In a specific embodiment, the voltage control circuit further comprises a light emitting diode and a capacitor device, wherein the capacitor device is arranged near the output end to maintain the stability of the output voltage of the output end.

[0049] In the embodiment, the switching module is used to select whether to switch the output voltage in the first working mode or to switch the output voltage in the second working mode, so that free switching can be realized according to the actual debugging effect and the convenience of use requirements. For example, when considering that the output voltage and the gamma value in most voltage controllers are bound, the gamma value needs to be adjusted accordingly when the output voltage changes. At this time, the first working mode is preferentially selected for voltage switching. When the gamma value is not designed to be divided by the output voltage, the second working mode is selected for voltage switching, and the gamma value can be selected to be designed with other voltages at this time, which can save a gamma IC design, which is not limited herein.

[0050] The beneficial effect of the embodiment is that whether the voltage switching is performed by the second output module outside the voltage controller or by the register inside the voltage controller is selected by the switching module, so that the output voltage can be freely switched according to the actual debugging effect and the convenience of use, and no matter which working mode is selected, the output voltage can be freely switched.

[0051] The application further provides a display device, which is specifically described in Figure 6 , Figure 6 FIG. 1 is a structural schematic diagram of an embodiment of the display device of the application. As shown in the figure, the display device comprises a display panel 61 and a driver 62 for providing a voltage driving signal for the display panel 61, and the driver 62 comprises the voltage control circuit in any of the above embodiments. Figure 6

[0052] The beneficial effect of the application is that whether the output voltage of the voltage controller is less than the reference voltage is detected by the comparator, so that whether the display panel has an overload picture is detected, when the first initial voltage output by the voltage controller is lower than the reference voltage, it is judged that the display panel has an overload picture, the first output module is switched to the second output module, so that the switching from the first working voltage to the second working voltage is realized, and then the current value of the output end is reduced, and the phenomenon of noise or overload picture is improved.

[0053] The above is only an embodiment of the application, and does not limit the patent scope of the application, and any equivalent structure or equivalent flow transformation by using the content of the specification and the drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the application.​

Claims

1. A voltage control circuit, characterized by, The voltage control circuit comprises: a voltage controller configured to output a first initial voltage; a comparator connected to an output terminal of the voltage controller and configured to output a first level signal and a second level signal according to the first initial voltage; a first output module connected to an output terminal of the comparator and configured to output a first working voltage according to the first level signal output by the output terminal of the comparator; a second output module connected to the output terminal of the comparator and configured to output a second working voltage according to the second level signal output by the output terminal of the comparator, so as to realize switching between the first working voltage and the second working voltage; a switching module having an input terminal connected to the output terminal of the comparator and an output terminal connected to the second output module or the voltage controller, and configured to realize switching between a first working mode and a second working mode; in the first working mode, the switching module is connected to the second output module and outputs the second working voltage through the second output module; in the second working mode, the switching module is connected to the voltage controller and outputs the second initial voltage through the voltage controller.

2. The voltage control circuit of claim 1, wherein, The second working voltage is greater than the first working voltage.

3. The voltage control circuit of claim 1, wherein, The first output module comprises a first transistor having an input terminal, an output terminal and a control terminal, the input terminal of the first transistor being connected to the output terminal of the voltage controller, and the control terminal being connected to the output terminal of the comparator, so as to control the input terminal and the output terminal of the first transistor through the output signal of the comparator.

4. The voltage control circuit of claim 3, wherein, The first working voltage is equal to the first initial voltage.

5. The voltage control circuit of claim 1, wherein, The second initial voltage is greater than the first initial voltage.

6. The voltage control circuit of claim 3, wherein, The second output module comprises a second transistor and an operational amplifier, the second transistor having an input terminal, an output terminal and a control terminal, the input terminal of the second transistor being connected to a constant voltage source, the output terminal being connected to the operational amplifier, and the control terminal being connected to the output terminal of the comparator, so as to control the input terminal and the output terminal of the second transistor through the output signal of the comparator.

7. The voltage control circuit of claim 6, wherein, The first transistor and the second transistor are opposite type transistors.

8. The voltage control circuit of claim 6, wherein, The operational amplifier comprises a first resistor and a second resistor, and the output voltage of the second output module is linearly related to a ratio of the first resistor and the second resistor.

9. A display device comprising a display panel and a driver which supplies a voltage drive signal to the display panel, characterized by The driver comprises the voltage control circuit according to any one of claims 1 to 8.

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