Backlight adjusting circuit and display device

Abstract

The backlight adjusting circuit and the display device are provided in the present disclosure, and relate to the technical field of display, and include a transformer, a primary switch tube, a voltage dividing sub-circuit, a backlight adjusting sub-circuit and a control sub-circuit; a first end of a primary coil of the transformer is used for being connected with a positive electrode end of a power supply, a second end of the primary coil is used for being connected with a negative electrode end of the power supply after being connected with the primary switch tube; a secondary coil of the transformer is connected with the voltage dividing sub-circuit and the backlight adjusting sub-circuit respectively; the control sub-circuit is connected with the primary switch tube, the voltage dividing sub-circuit and the backlight adjusting sub-circuit respectively; the control sub-circuit is used for controlling the on-off frequency of the primary switch tube according to a first to-be-adjusted voltage corresponding to the voltage dividing sub-circuit and a second to-be-adjusted voltage corresponding to the backlight adjusting sub-circuit, and performing backlight adjustment; the control of different sub-circuits is integrated in the same control sub-circuit, so that the circuit structure is simplified, and the backlight adjustment efficiency can be improved.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to a backlight adjustment circuit and display device. Background Technology

[0002] With the development of display technology, liquid crystal displays (LCDs) have gradually become the mainstream display devices due to their advantages such as high image quality, energy saving, thin body, and wide range of applications. LCDs typically utilize backlight sources for backlight adjustment to enhance display performance. However, the backlight adjustment circuitry in these technologies is complex. Utility Model Content

[0003] To overcome the problems existing in related technologies, this disclosure provides a backlight adjustment circuit and a display device.

[0004] According to a first aspect of the present disclosure, a backlight adjustment circuit is provided, comprising: a transformer, a primary switching transistor, a voltage divider circuit, a backlight adjustment sub-circuit, and a control sub-circuit; a first end of the primary coil of the transformer is connected to the positive terminal of a power supply, and a second end of the primary coil, after being connected to the primary switching transistor, is connected to the negative terminal of the power supply; the secondary coil of the transformer is connected to the voltage divider circuit and the backlight adjustment sub-circuit respectively; the control sub-circuit is connected to the primary switching transistor, the voltage divider circuit, and the backlight adjustment sub-circuit respectively; the control sub-circuit is used to control the switching frequency of the primary switching transistor according to a first adjustable voltage corresponding to the voltage divider circuit and a second adjustable voltage corresponding to the backlight adjustment sub-circuit, so as to perform backlight adjustment through the backlight adjustment sub-circuit. Thus, the control of different sub-circuits is integrated into a single control sub-circuit, which simplifies the circuit structure and reduces the space occupied on the circuit board. Furthermore, integration into a single control sub-circuit avoids data transmission between different controllers, thereby improving backlight adjustment efficiency.

[0005] In some possible implementations, the control sub-circuit includes: a first control module connected to the voltage divider sub-circuit, used to acquire a first adjustable voltage corresponding to the voltage divider sub-circuit; a second control module connected to the backlight adjustment sub-circuit, used to acquire a second adjustable voltage corresponding to the backlight adjustment sub-circuit; and a control unit connected to both the first and second control modules, used to control the switching frequency of the primary switching transistor according to the first and second adjustable voltages, so as to adjust the backlight through the backlight adjustment sub-circuit. All the aforementioned modules are located within the same control sub-circuit, avoiding data transmission between different controllers and improving backlight adjustment efficiency.

[0006] In some possible implementations, the first control module includes: a first sampling unit connected to the voltage divider circuit for acquiring the output voltage of the voltage divider circuit; and a first comparator connected to the first sampling unit for obtaining the first voltage to be adjusted based on the difference between the output voltage and a first reference voltage. This facilitates subsequent backlight adjustment and improves the backlight adjustment effect.

[0007] In some possible implementations, the backlight adjustment sub-circuit includes: a backlight source, a first end of which is connected to a first end of the secondary coil; the second control module includes: a second sampling unit connected to a second end of the backlight source, used to acquire the voltage at the second end of the backlight source; and a second comparator connected to the second sampling unit, used to obtain the second voltage to be adjusted based on the difference between the voltage at the second end of the backlight source and a second reference voltage. This facilitates subsequent backlight adjustment and improves the backlight adjustment effect.

[0008] In some possible implementations, the voltage divider circuit includes: a secondary switch; a first terminal of the secondary switch is connected to a second terminal of the secondary coil, and the second terminal of the secondary switch is connected to a third terminal of the secondary coil; the control circuit includes: a first drive unit and a control unit; the first drive unit is connected to the third terminal of the secondary switch and the control unit; the control unit is used to control the switching frequency of the secondary switch by controlling the first drive unit according to the first voltage to be regulated and the second voltage to be regulated.

[0009] In some possible implementations, the voltage divider circuit further includes: a first capacitor and a first diode; the second terminal of the secondary switch is connected to the third terminal of the secondary coil in sequence through the first capacitor and the first diode; the negative terminal of the first diode is connected to the third terminal of the secondary coil, the first capacitor is connected to the positive terminal of the first diode, and the positive terminal of the first diode is grounded.

[0010] In some possible implementations, the backlight adjustment sub-circuit includes: a backlight source and a variable resistor; a first end of the backlight source is connected to a first end of the secondary coil, a second end of the backlight source is connected to a first end of the variable resistor, a second end of the variable resistor is connected to the control sub-circuit, and a third end of the variable resistor is grounded; the control sub-circuit is further configured to dim the backlight source by adjusting the resistance value of the variable resistor.

[0011] In some possible implementations, the control sub-circuit includes: a second drive unit and a control unit; the second drive unit is connected to the control unit and the variable resistor respectively; the control unit is further configured to adjust the resistance value of the variable resistor by controlling the second drive unit.

[0012] In some possible implementations, the backlight adjustment sub-circuit further includes: a sampling resistor; the third terminal of the variable resistor is connected to the first terminal of the sampling resistor, and the second terminal of the sampling resistor is grounded; the control sub-circuit includes: a third sampling unit connected to the first terminal of the sampling resistor, used to acquire the current flowing through the backlight source according to the resistance value of the sampling resistor; a third comparator connected to the third sampling unit, used to obtain the current to be adjusted according to the difference between the current and a preset current; and a control unit connected to the third comparator and the backlight source, used to adjust the backlight of the backlight source by adjusting the resistance value of the variable resistor according to the current to be adjusted.

[0013] In some possible implementations, the backlight adjustment circuit further includes a second transistor and a second capacitor; the positive terminal of the second transistor is connected to the first end of the secondary coil, the negative terminal of the second transistor is connected to the first end of the backlight source, and the two ends of the second capacitor are respectively connected to the negative terminal of the second transistor and the second end of the sampling resistor.

[0014] In some possible implementations, the control sub-circuit further includes a communication isolation unit; the control unit is connected to both the first control module and the second control module via the communication isolation unit, respectively, to avoid noise interference between different modules.

[0015] According to a second aspect of the present disclosure, a display device is provided, comprising: the backlight adjustment circuit described in the first aspect.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0018] Figure 1 This is a schematic diagram of a backlight adjustment circuit according to an exemplary embodiment.

[0019] Figure 2 This is a circuit diagram illustrating a backlight adjustment circuit according to an exemplary embodiment.

[0020] Figure 3 This is a schematic diagram of the operating waveforms of a backlight adjustment circuit according to an exemplary embodiment.

[0021] Figure Labels 100 - Backlight adjustment circuit; 110 - Transformer; 120 - Primary switching transistor; 130 - Voltage divider circuit; 140 - Backlight adjustment circuit; 150 - Control circuit. Detailed Implementation

[0022] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0023] It should be noted that all actions involving the acquisition of signals, information, or data in this disclosure are carried out in compliance with the relevant data protection laws and policies of the country where the location is situated, and with authorization from the owner of the relevant device.

[0024] With the development of display technology, liquid crystal displays (LCDs) have gradually become the mainstream display devices due to their advantages such as high image quality, energy saving, thin body, and wide application range. LCDs typically utilize backlight sources for backlight adjustment to enhance display performance. However, the backlight adjustment circuit structure in related technologies is complex. For example, the backlight circuit in related technologies includes a transformer, the primary side of which is connected to and controlled by a flyback controller. The secondary side of the transformer is connected to and controlled by a buck controller. The flyback controller and buck controller are two independent controllers, resulting in a complex structure and occupying a large amount of circuit board space.

[0025] To solve the above problems, this disclosure provides a backlight adjustment circuit. Please refer to [link / reference]. Figure 1 The backlight adjustment circuit 100 includes: a transformer 110, a primary switching transistor 120, a voltage divider circuit 130, a backlight adjustment circuit 140, and a control circuit 150.

[0026] The first end of the primary coil of the transformer 110 is connected to the positive terminal of the power supply E, and the second end of the primary coil, after being connected to the primary switching transistor 120, is connected to the negative terminal of the power supply E. The secondary coil of the transformer 110 is connected to the voltage divider circuit 130 and the backlight adjustment circuit 140, respectively. The control sub-circuit 150 is connected to the primary switching transistor 120, the voltage divider circuit 130, and the backlight adjustment circuit 140, respectively.

[0027] The control sub-circuit 150 is used to control the switching frequency of the primary switching transistor 120 according to the first adjustable voltage corresponding to the voltage divider sub-circuit 130 and the second adjustable voltage corresponding to the backlight adjustment sub-circuit 140, so as to adjust the backlight through the backlight adjustment sub-circuit 140.

[0028] Both the voltage divider circuit 130 and the backlight adjustment circuit 140 are configured with desired voltages. When the voltage divider circuit 130 differs from its desired voltage, a first adjustable voltage is obtained. It is easy to understand that adjusting the voltage according to the first adjustable voltage will bring the voltage of the voltage divider circuit 130 to the desired voltage. Similarly, when the backlight adjustment circuit 140 differs from its desired voltage, backlight adjustment is required, and a second adjustable voltage is obtained. It is easy to understand that adjusting the voltage according to the second adjustable voltage will bring the voltage of the backlight adjustment circuit 140 to the desired voltage.

[0029] In transformer 110, the coil connected to power supply E is the primary coil, and the other coil is the secondary coil. Transformer 110 steps up or down the voltage to power the voltage divider circuit 130 and the backlight adjustment circuit 140 connected to the secondary coil. Control circuit 150, based on the first and second adjustable voltages, controls the switching frequency of the primary switch 120 to control the electrical energy entering the primary coil, thereby controlling the electrical energy output from the secondary coil. In other words, control circuit 150 controls the electrical energy entering the backlight adjustment circuit 140 by controlling the switching frequency of the primary switch 120, thus achieving backlight adjustment.

[0030] In this embodiment, the control of different sub-circuits is integrated into a single control sub-circuit, which simplifies the circuit structure and reduces the space occupied on the circuit board. Furthermore, integration into a single control sub-circuit avoids data transmission between different controllers, thus improving backlight adjustment efficiency.

[0031] In one possible implementation, the control sub-circuit 150 includes: The first control module is connected to the voltage divider circuit 130 and is used to obtain the first voltage to be adjusted corresponding to the voltage divider circuit 130.

[0032] The second control module is connected to the backlight adjustment sub-circuit and is used to obtain the second voltage to be adjusted corresponding to the backlight adjustment sub-circuit.

[0033] The control unit is connected to the first control module and the second control module respectively, and is used to control the switching frequency of the primary switch 120 according to the first voltage to be adjusted and the second voltage to be adjusted, so as to adjust the backlight through the backlight adjustment sub-circuit.

[0034] For example, please refer to Figure 2 The control unit adjusts the voltage V according to the first voltage to be adjusted. comp-12V Second adjustable voltage V comp-LED After weighting, control information is obtained, and the switching frequency of the primary switch 120 is controlled according to the control information. Controlling the switching frequency can be understood as controlling the on-time and off-time of the primary switch within one cycle.

[0035] In this embodiment, the first voltage to be adjusted is obtained by the first control module in the control sub-circuit, and the second voltage to be adjusted is obtained by the second control unit. The control unit adjusts the switching frequency of the primary switch 120 according to the first voltage to be adjusted and the second voltage to be adjusted, thereby performing backlight adjustment. The aforementioned functions are all concentrated in the control sub-circuit, avoiding data transmission in different controllers and improving backlight adjustment efficiency.

[0036] As one way, please refer to Figure 2 The first control module includes: The first sampling unit is connected to the voltage divider circuit 130 and is used to collect the output voltage of the voltage divider circuit 130. A first comparator A1 is connected to the first sampling unit and is used to obtain the first voltage to be adjusted based on the difference between the output voltage and the first reference voltage.

[0037] For example, the sign of this difference can be used to determine the magnitude relationship between the input voltage and the first reference voltage.

[0038] The first reference voltage is built into the first comparator. The first comparator A1 compares the acquired output voltage with the first reference voltage to obtain the first adjustable voltage. The first adjustable voltage reflects the voltage difference between the output voltage and the first reference voltage.

[0039] For example, the first reference voltage can be 12V.

[0040] Optionally, please refer to Figure 2 The backlight adjustment sub-circuit includes: A backlight source, wherein the first end of the backlight source is connected to the first end of the secondary coil.

[0041] For example, the backlight source can be Figure 2 The LED beads in the display. By adjusting the backlight, the brightness and color temperature of the display can be adjusted, thereby enhancing the visual experience.

[0042] The second control module includes: The second sampling unit is connected to the second end of the backlight source and is used to collect the voltage at the second end of the backlight source. The second comparator A2 is connected to the second sampling unit and is used to obtain the second voltage to be adjusted based on the difference between the voltage at the second end of the backlight source and the second reference voltage.

[0043] For example, the sign of this difference can be used to determine the magnitude relationship between the voltage at the second terminal and the second reference voltage.

[0044] The second reference voltage can be a voltage built into the second comparator or an input voltage. The second comparator A2 compares the voltage at the second terminal of the backlight source with the second reference voltage to obtain the second adjustment voltage. The first voltage to be adjusted reflects the difference between the voltage at the second terminal and the second reference voltage.

[0045] In one possible implementation, please refer to Figure 2 The voltage divider circuit includes: a secondary switch Q1; The first terminal of the secondary switch Q1 is connected to the second terminal of the secondary coil, and the second terminal of the secondary switch Q1 is connected to the third terminal of the secondary coil. Please continue reading. Figure 2 The control sub-circuit includes: a first drive unit and a control unit; The first drive unit is connected to the third terminal of the secondary switch Q1 and the control unit; The control unit is configured to adjust the voltage V according to the first voltage to be adjusted. comp-12V and the second voltage to be adjusted V comp-LED By controlling the first driving unit, the switching frequency of the secondary switch Q1 is controlled, so that the output voltage of the secondary coil is distributed between the backlight adjustment sub-circuit and the control sub-circuit, thereby performing backlight adjustment.

[0046] For example, the control unit calculates k·V comp-12V / V comp-LED Therefore, the on-time of the secondary switch Q1 within one cycle is calculated to be k·V. comp-12V / V comp-LED It is easy to understand that, within a cycle, the remainder, excluding the on-time, is the off-time. Here, k is a set constant.

[0047] It is understandable that when the first adjustable voltage V corresponding to the voltage divider circuit... comp-12V When V increases, it indicates that more electrical energy needs to be supplied to the voltage divider circuit. Therefore, the on-time of the secondary switch Q1 in the control unit increases, thereby increasing the electrical energy output from the secondary coil to the voltage divider circuit. Alternatively, when V...comp-LED When the value increases, it indicates that the electrical energy required to be supplied to the backlight adjustment sub-circuit increases. Therefore, the conduction time of the secondary switch Q1 of the control unit decreases, so that the electrical energy output from the secondary coil to the backlight adjustment sub-circuit increases, providing electrical energy for backlight adjustment.

[0048] For example, such as Figure 2 If the secondary switch Q1 can be a MOS (Metal-Oxide-Semiconductor Field-Effect Transistor), then the first terminal of the aforementioned secondary switch Q1 is the d terminal of the MOS transistor, the second terminal of the secondary switch Q1 is the s terminal of the MOS transistor, and the third terminal of the secondary switch Q1 is the g terminal.

[0049] In one possible implementation, the voltage divider circuit further includes: a second capacitor C2 and a first diode D2; The second terminal of the secondary switch is connected to the third terminal of the secondary coil in sequence through the second capacitor C2 and the first diode D2; The negative terminal of the first diode D2 is connected to the third terminal of the secondary coil, the second capacitor C2 is connected to the positive terminal of the first diode D2, and the positive terminal of the first diode D2 is grounded.

[0050] In one possible implementation, the backlight adjustment sub-circuit includes: a backlight source LED and a variable resistor; The first terminal LED+ of the backlight LED is connected to the first terminal of the secondary coil, the second terminal LED- of the backlight LED is connected to the first terminal of the variable resistor, the second terminal of the variable resistor is connected to the control sub-circuit, and the third terminal of the variable resistor is grounded. The control sub-circuit is also used to dim the backlight source by adjusting the resistance value of the variable resistor.

[0051] The controller adjusts the current value of the control sub-circuit by adjusting the resistance value of the variable resistor, thereby adjusting the current value flowing through the backlight LED and thus adjusting the backlight brightness.

[0052] For example, the variable resistor can be a MOSFET Q2. The first terminal of the variable resistor is the drain (d) terminal of the MOSFET Q2, the second terminal of the variable resistor is the gate (g) terminal of the MOSFET Q2, and the third terminal of the variable resistor is grounded and is the source (s) terminal of the MOSFET Q2.

[0053] Optionally, the control sub-circuit includes: a second drive unit and a control unit; The second drive unit is connected to both the control unit and the variable resistor. The control unit is further configured to adjust the resistance value of the variable resistor by controlling the second drive unit.

[0054] For example, the control sub-circuit can adjust the brightness of the backlight source by adjusting the operation of the MOSFET Q2 in the variable resistance region, thereby achieving backlight adjustment.

[0055] Optionally, the backlight adjustment sub-circuit further includes: a sampling resistor RISN; The third terminal of the variable resistor is connected to the first terminal of the sampling resistor RISN, and the second terminal of the sampling resistor RISN is grounded. The control sub-circuit includes: The third sampling unit is connected to the first terminal of the sampling resistor RISN and is used to collect the current flowing through the backlight source based on the resistance value of the sampling resistor RISN. The third comparator A3 is connected to the third sampling unit and is used to obtain the current to be adjusted based on the difference between the current and the preset current. The control unit, connected to the third comparator A3 and the backlight source, is used to adjust the backlight of the backlight source by adjusting the resistance value of the variable resistor RISN according to the current to be adjusted.

[0056] The preset current can be built into the third comparator or it can be an input.

[0057] Since the sampling resistor RISN in the backlight adjustment sub-current circuit and the backlight source are connected in series, the current flowing through them is the same. If the circuit operates according to the preset current, the backlight source will illuminate at the desired brightness. The third comparator A3 compares the difference between the current and the preset current, and obtains the current to be adjusted based on this difference. The control unit adjusts the resistance value of the variable resistor RISN according to the current to be adjusted, thereby changing the current in the backlight adjustment sub-circuit. The current flowing through the backlight source then changes accordingly, thus achieving backlight adjustment. For example, when the current is greater than the preset current, increasing the resistance value of the variable resistor RISN reduces the current flowing through the backlight adjustment sub-circuit, thus reducing the current flowing through the backlight source and lowering its brightness. Conversely, when the current is less than the preset current, decreasing the resistance value of the variable resistor RISN increases the current flowing through the backlight adjustment sub-circuit, thus increasing the current flowing through the backlight source and raising its brightness.

[0058] In this embodiment, the variable resistor is connected in series with the backlight source. By adjusting the resistance value of the variable resistor, the current flowing through the backlight source is adjusted, thereby further adjusting the backlight and improving the backlight adjustment effect.

[0059] Optionally, please refer to Figure 2 The regulating sub-circuit also includes: a first diode D1, the positive terminal of the first diode D1 being connected to the first end of the secondary coil, and the negative terminal of the first diode D1 being connected to the positive terminal of the backlight source LED+.

[0060] Optionally, please refer to Figure 2 The backlight adjustment sub-circuit also includes: a first capacitor C1, one end of which is connected to the negative terminal of the first diode D1, and the other end is grounded.

[0061] Optionally, please refer to Figure 2 The regulating circuit also includes a second diode D2 and a second capacitor C2. One end of the second capacitor C2 is connected to the MOSFET Q1, and the other end is connected to the positive terminal of the second diode D2. The negative terminal of the second diode D2 is connected to the third terminal of the secondary coil of the transformer.

[0062] Optionally, please refer to Figure 2 The regulating sub-circuit also includes: a first resistor R1, a third capacitor C3, a fourth capacitor Ci, a third diode D3, and a second resistor R. sense The first terminal of the first resistor R1 is connected to the positive terminal of the power supply and the first terminal of the third capacitor C3; the second terminal of the first resistor R1 is connected to the second terminal of the third capacitor C3 and the negative terminal of the third diode D3; the positive terminal of the third diode D3 is connected to the second terminal of the primary coil of the transformer; one terminal of the fourth capacitor Ci is connected to the positive terminal of the power supply, and the other terminal is grounded. The second resistor R... sense One end is grounded, and the other end is connected to the secondary switch Q1.

[0063] Alternatively, please continue reading Figure 2 The control sub-circuit further includes: a communication isolation unit; The control unit is connected to both the first control module and the second control module via the communication isolation unit. Isolation is provided between the different modules to avoid noise interference between them.

[0064] The aforementioned backlight adjustment circuit can be applied to the backlight display of an LCD screen.

[0065] Please see Figure 3 ADIM stands for analog dimming, while PWM stands for digital dimming. ADIM dimming offers higher dimming accuracy, while PWM dimming provides a faster response time. ADIM analog dimming is used during the t1-t2 phase. After t2, the duty cycle is adjusted to below a preset duty cycle (e.g., a preset duty cycle of 25%), and PWM digital dimming is then used. This implementation combines ADIM analog dimming and PWM digital dimming to ensure both backlight adjustment accuracy and speed, while preventing backlight current overshoot.

[0066] Please continue reading. Figure 3 LED- is the voltage at the negative terminal of the backlight source, LED_DRV is the drive current of the backlight source, LED_ISN is the current at the source of the MOSFET, and the LED current is the current flowing through the backlight source. With PWM dimming and ADIM dimming, the aforementioned currents change as follows: Figure 3 As shown. LED-ISN-REF is the set full-load reference value for the backlight source, that is, when the current is LED_ISN_REF, the brightness of the backlight source is at its maximum.

[0067] This disclosure also provides a display device, which includes the aforementioned backlight adjustment circuit.

[0068] For example, the display device can be a mobile phone, television, personal digital assistant, digital camera, laptop, desktop computer, etc.

[0069] Optionally, the display device also includes a monitor that adjusts the backlight via a backlight adjustment circuit.

[0070] Alternatively, the display device can be connected to the power grid via a connector to power the display device.

[0071] Optionally, the display device also includes a power supply, the positive terminal of which is connected to the first end of the primary coil of the transformer in the backlight adjustment circuit; the negative terminal of the power supply is connected to the second end of the primary coil of the transformer via a primary switching transistor. The power supply is used to supply power to the primary coil of the transformer.

[0072] The power source can be a battery built into the display device, such as a mobile phone, digital camera, or laptop.

[0073] Although terms such as “first,” “second,” and “third” may be used herein to describe various components, parts, regions, layers, or sections, these components, parts, regions, layers, or sections are not limited to these terms. Rather, these terms are used only to distinguish one component, part, region, layer, or section from another. Therefore, without departing from the teachings of the examples described herein, the first component, part, region, layer, or section mentioned in the examples may also be referred to as the second component, part, region, layer, or section. Furthermore, the terms “first” and “second” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as “first” or “second” may explicitly or implicitly include at least one of that feature. In the description herein, “a plurality” means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0074] It should be understood that spatial relative terms, such as “above,” “upper,” “below,” and “lower,” are used herein to describe the relationship between one element and another shown in the figures. In addition to the orientation depicted in the figures, these spatial relative terms are also intended to encompass different orientations of the device in use or operation. For example, if the device in the figures is flipped, an element described as “above” or “upper” relative to another element would be “below” or “lower” relative to that other element. Thus, depending on the spatial orientation of the device, the term “above” encompasses both above and below orientations. Devices may have other orientations (e.g., rotated 90 degrees or in other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0075] Furthermore, the term “exemplary” is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “exemplary” is not necessarily to be construed as advantageous compared to other aspects or designs. Rather, the use of the term “exemplary” is intended to present the concept in a concrete manner. As used herein, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless otherwise specified or clear from the context, “X applies A or B” is intended to mean any of the natural inclusive arrangements. That is, “X applies A or B” satisfies any of the foregoing instances if X applies A; X applies B; or both X applies A and B. Additionally, unless otherwise specified or clear from the context to refer to the singular form, the articles “a” and “an” as used in this application and the appended claims are generally understood to mean “one or more.”

[0076] Similarly, although this disclosure has been shown and described with respect to one or more implementations, equivalent variations and modifications will occur to those skilled in the art upon reading and understanding this specification and the accompanying drawings. This disclosure includes all such modifications and variations and is limited only by the scope of the claims. In particular, with respect to the various functions performed by the components described above (e.g., elements, resources, etc.), unless otherwise indicated, the terminology used to describe such components is intended to correspond to any component (functionally equivalent) that performs the specific function of the described component, even if structurally not equivalent to the disclosed structure. Furthermore, although specific features of this disclosure may have been disclosed with respect to only one of several implementations, such features may be combined with one or more other features of other implementations, as may be desired and advantageous to any given or particular application. Moreover, with regard to the terms “comprising,” “owning,” “having,” “having,” or variations thereof as used in the detailed description or claims, such terms are intended to be inclusive in a manner similar to the term “including.”

[0077] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

[0078] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A backlight adjustment circuit, characterized in that, include: Transformer, primary switching transistor, voltage divider circuit, backlight adjustment circuit, and control circuit; The first end of the primary coil of the transformer is used to connect to the positive terminal of the power supply, and the second end of the primary coil, after being connected to the primary switching transistor, is used to connect to the negative terminal of the power supply. The secondary coil of the transformer is connected to the voltage divider circuit and the backlight adjustment circuit, respectively. The control sub-circuit is connected to the primary switching transistor, the voltage divider sub-circuit, and the backlight adjustment sub-circuit, respectively. The control sub-circuit is used to control the switching frequency of the primary switching transistor according to the first adjustable voltage corresponding to the voltage divider sub-circuit and the second adjustable voltage corresponding to the backlight adjustment sub-circuit, so as to adjust the backlight through the backlight adjustment sub-circuit.

2. The backlight adjustment circuit according to claim 1, characterized in that, The control sub-circuit includes: A first control module is connected to the voltage divider circuit and is used to obtain the first adjustable voltage corresponding to the voltage divider circuit. The second control module is connected to the backlight adjustment sub-circuit and is used to obtain the second voltage to be adjusted corresponding to the backlight adjustment sub-circuit. The control unit is connected to the first control module and the second control module respectively, and is used to control the switching frequency of the primary switching transistor according to the first voltage to be adjusted and the second voltage to be adjusted, so as to adjust the backlight through the backlight adjustment sub-circuit.

3. The backlight adjustment circuit according to claim 2, characterized in that, The first control module includes: The first sampling unit is connected to the voltage divider circuit and is used to collect the output voltage of the voltage divider circuit; A first comparator, connected to the first sampling unit, is used to obtain the first voltage to be adjusted based on the difference between the output voltage and the first reference voltage.

4. The backlight adjustment circuit according to claim 2, characterized in that, The backlight adjustment sub-circuit includes: A backlight source, wherein the first end of the backlight source is connected to the first end of the secondary coil; The second control module includes: The second sampling unit is connected to the second end of the backlight source and is used to collect the voltage at the second end of the backlight source. The second comparator, connected to the second sampling unit, is used to obtain the second voltage to be adjusted based on the difference between the voltage at the second end of the backlight source and the second reference voltage.

5. The backlight adjustment circuit according to claim 1, characterized in that, The voltage divider circuit includes: a secondary switching transistor; The first terminal of the secondary switch is connected to the second terminal of the secondary coil, and the second terminal of the secondary switch is connected to the third terminal of the secondary coil. The control sub-circuit includes: a first drive unit and a control unit; The first drive unit is connected to the third terminal of the secondary switch and the control unit; The control unit is configured to control the switching frequency of the secondary switching transistor by controlling the first driving unit based on the first voltage to be adjusted and the second voltage to be adjusted.

6. The backlight adjustment circuit according to claim 5, characterized in that, The voltage divider circuit further includes: a first capacitor and a first diode; The second terminal of the secondary switch is connected to the third terminal of the secondary coil in sequence through the first capacitor and the first diode; The negative terminal of the first diode is connected to the third terminal of the secondary coil, the first capacitor is connected to the positive terminal of the first diode, and the positive terminal of the first diode is grounded.

7. The backlight adjustment circuit according to claim 1, characterized in that, The backlight adjustment sub-circuit includes: a backlight source and a variable resistor; The first end of the backlight source is connected to the first end of the secondary coil, the second end of the backlight source is connected to the first end of the variable resistor, the second end of the variable resistor is connected to the control sub-circuit, and the third end of the variable resistor is grounded. The control sub-circuit is also used to dim the backlight source by adjusting the resistance value of the variable resistor.

8. The backlight adjustment circuit according to claim 7, characterized in that, The control sub-circuit includes: a second drive unit and a control unit; The second drive unit is connected to both the control unit and the variable resistor. The control unit is further configured to adjust the resistance value of the variable resistor by controlling the second drive unit.

9. The backlight adjustment circuit according to claim 7, characterized in that, The backlight adjustment sub-circuit also includes: a sampling resistor; The third terminal of the variable resistor is connected to the first terminal of the sampling resistor, and the second terminal of the sampling resistor is grounded. The control sub-circuit includes: The third sampling unit is connected to the first end of the sampling resistor and is used to collect the current flowing through the backlight source based on the resistance value of the sampling resistor. The third comparator, connected to the third sampling unit, is used to obtain the current to be adjusted based on the difference between the current and the preset current. The control unit, connected to the third comparator and the backlight source, is used to adjust the backlight of the backlight source by adjusting the resistance value of the variable resistor according to the current to be adjusted.

10. The backlight adjustment circuit according to claim 9, characterized in that, The backlight adjustment circuit also includes: a second transistor and a second capacitor; The positive terminal of the second transistor is connected to the first end of the secondary coil, the negative terminal of the second transistor is connected to the first end of the backlight source, and the two ends of the second capacitor are connected to the negative terminal of the second transistor and the second end of the sampling resistor, respectively.

11. The backlight adjustment circuit according to claim 2, characterized in that, The control sub-circuit also includes: a communication isolation unit; The control unit is connected to the first control module and the second control module respectively through the communication isolation unit.

12. A display device, characterized in that, include: The backlight adjustment circuit according to any one of claims 1 to 11.

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