Screen backlight state switching circuit and display screen device

Abstract

The application relates to a screen backlight state switching circuit and a display screen device. The circuit comprises a state switching trigger module, which is used for generating a state switching trigger signal in response to a continuous trigger signal of a switch key; a level state switching module, an input end of which is connected to an output end of the state switching trigger module, and which is used for switching the state of an output level when the state switching trigger signal is received; and a backlight enable module, an input end of which is connected to a first output end of the level state switching module, and an output end of the backlight enable module is used for being connected to a backlight driving circuit; wherein when the output level is a high level, the backlight enable module outputs a backlight enable signal to enable the backlight driving circuit to drive the backlight of the display screen to be turned on; and when the output level is a low level, the backlight enable module outputs a backlight disable signal to enable the backlight driving circuit to drive the backlight of the display screen to be turned off. Thus, the backlight on-off requirement of the display screen device under a specific use scenario can be met at low cost.

Description

Technical Field

[0001] This application relates to the field of display control technology, and in particular to a screen backlight state switching circuit and display device. Background Technology

[0002] With the rapid development of the Internet and the widespread use of computer terminals, the application scenarios of displays are increasing, and their forms and appearances are becoming more diverse. Among them, displays using the EDP (Embedded DisplayPort) protocol are widely used due to their high performance.

[0003] Currently, the on / off control of such EDP displays (usually referring to screen on / off control) generally adopts a solution of designing a physical switch button on the display itself. This button is usually implemented through an external circuit board, and its core function is to directly control the power supply to the display screen, thereby achieving the purpose of turning the screen display on or off. Other on / off control methods also use embedded controller (EC) chips to control the screen on / off via software instructions.

[0004] However, in practice, the relevant technologies cannot simultaneously meet the need for low-cost control of the backlight on / off state of display screen devices in specific usage scenarios. Utility Model Content

[0005] Based on this, the purpose of this application is to at least solve one of the above-mentioned technical defects, especially the technical defect that the prior art cannot simultaneously meet the requirement of low-cost control of the backlight on / off state of the display screen device in a specific usage scenario. This application provides a screen backlight state switching circuit and a display device.

[0006] In a first aspect, this application provides a screen backlight state switching circuit, the circuit comprising:

[0007] The state switching trigger module is used to generate a state switching trigger signal when a continuous trigger signal from the switch button is received.

[0008] The level state switching module has its input terminal connected to the output terminal of the state switching trigger module, and is used to switch the output level state when a state switching trigger signal is received;

[0009] The input terminal of the backlight enable module is connected to the first output terminal of the level state switching module, and the output terminal of the backlight enable module is used to connect to the backlight drive circuit.

[0010] When the output level is high, the backlight enable module outputs a backlight enable signal to enable the backlight driver circuit to drive the display screen's backlight to turn on; when the output level is low, the backlight enable module outputs a backlight disable signal to enable the backlight driver circuit to drive the display screen's backlight to turn off.

[0011] In one embodiment, the level switching module is a screen control relay module.

[0012] The first level pin of the screen control relay module is connected to the output of the state switching trigger module, and the second level pin of the screen control relay module is connected to the input of the backlight enable module.

[0013] In one embodiment, the backlight enabling module includes:

[0014] The logic gate unit has its first input connected to the second level pin of the level state switching module, its second input connected to the third level pin of the level state switching module, and its output connected to the input of the backlight enable module.

[0015] The input terminal of the backlight enable module is also used to receive a high-level signal;

[0016] When the first input of the logic gate unit receives a low level from the level state switching module, the output of the logic gate unit is valid, and the backlight driving circuit cannot receive a high level, so that the backlight is turned off; when the first input of the logic gate unit receives a high level, the output of the logic gate unit is invalid, and the backlight driving circuit receives a high level, so that the backlight is turned on.

[0017] In one embodiment, the logic gate unit includes a NAND gate unit;

[0018] The second input of the NAND gate unit is used to receive the high level output from the third level pin of the level state switching module;

[0019] Specifically, when the first input terminal of the NAND gate receives a high level output from the level state switching module, the output of the NAND gate is invalid; when the first input terminal of the NAND gate receives a low level output from the level state switching module, the output of the NAND gate is valid.

[0020] In one embodiment, the logic gate unit includes:

[0021] The first transistor unit has a first control terminal connected to the second level pin of the level state switching module, and the second control terminal of the first transistor unit is connected to the third level pin of the level state switching module.

[0022] The second transistor unit has a third control terminal connected to the input terminal of the first transistor unit, an input terminal connected to the input terminal of the backlight enable module, and is also used to access a high level. The output terminal of the second transistor unit is used to ground.

[0023] When both the first and second control terminals receive a high level, the output of the second transistor unit is invalid.

[0024] In one embodiment, the first transistor unit includes:

[0025] The first MOSFET has its gate connected to the second level pin of the level state switching module, and its source is grounded.

[0026] The second MOSFET has its gate connected to the third level pin of the level switching module; the source chain of the second MOSFET is connected to the source and drain of the first MOSFET; the drain of the second MOSFET is connected to the third control terminal of the second transistor unit and is also used to access a high level.

[0027] In one embodiment, the second transistor unit includes:

[0028] The gate of the third MOSFET is connected to the drain of the second MOSFET and is also used to input a high level; the drain of the third MOSFET is connected to the input terminal of the backlight enable module and is also used to input a high level; the source of the third MOSFET is used to ground.

[0029] In one embodiment, the state transition triggering module includes:

[0030] The control switch module has a switch button, and the first terminal is used for grounding.

[0031] The third transistor unit has a control terminal for receiving the control voltage; its output terminal is connected to the second terminal of the control switch module; and its input terminal is connected to the input terminal of the state switching trigger module and is also used to receive a high level.

[0032] When the control switch module is turned on, the output terminal of the third transistor unit is connected to a low level to turn on the third transistor unit, and the high level connected to the input terminal of the third transistor unit is pulled down to ground to generate a state switching trigger signal.

[0033] In one embodiment, the third transistor unit includes:

[0034] The fourth MOS transistor has its gate connected to a high level; its source serves as the output of the third transistor unit, and its drain serves as the input of the third transistor unit.

[0035] Secondly, this application also provides a display device, including the screen backlight state switching circuit as described above.

[0036] As can be seen from the above technical solutions, the embodiments of this application have the following advantages:

[0037] The screen backlight state switching circuit and display device provided in this application, by setting a state switching trigger module to respond to a continuous trigger signal from a switch and generate a state switching trigger signal, can transmit the state switching trigger signal to a level state switching module. When the level state switching module receives the state switching trigger signal, it switches the output level. When the output level is high, the backlight enable module outputs to cause the backlight driver circuit to drive the display backlight to turn on; when the output level is low, the backlight enable module outputs to cause the backlight driver circuit to drive the display backlight to turn off. Compared with traditional technology, this application uses a state switching trigger module to control the level state switching module to switch the output level in response to a continuous trigger signal, combined with the backlight enable module to achieve reliable backlight state switching. This can meet the low-cost backlight control requirements of display screen devices in specific application scenarios, and has the advantages of low cost, simple structure, reliable triggering, and flexible backlight state switching. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 A schematic diagram of a screen backlight state switching circuit provided in an embodiment of this application;

[0040] Figure 2 A schematic diagram of the specific structure of a backlight enabling module provided in an embodiment of this application;

[0041] Figure 3 This is a schematic diagram of the specific structure of a state switching trigger module provided in an embodiment of this application;

[0042] Figure 4 A schematic diagram of a screen backlight state switching circuit provided in an embodiment of this application;

[0043] Figure 5 This is a schematic diagram of the specific structure of a screen backlight state switching circuit provided in an embodiment of this application.

[0044] Figure label:

[0045] 10 - Screen backlight state switching circuit; 110 - State switching trigger module; 120 - Level state switching module; 130 - Backlight enable module; 131 - Logic gate unit; 111 - Control switch module; 112 - Third transistor unit; 20 - Backlight driving circuit. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0048] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0049] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0050] It is understandable that "at least one" can refer to one or more, while "multiple" can refer to two or more. "At least a part of an element" can refer to part or all of an element.

[0051] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that terms such as “comprising / including” or “having” specify the presence of the stated features, integrals, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, integrals, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0052] With the rapid development of the Internet, the number of computer terminals is increasing, the application scenarios of displays are also increasing, and the forms and appearances of displays are also different. Among them, displays based on the EDP protocol are also widely used. The power switch buttons of traditional EDP protocol displays are designed to be designed on the display through an external circuit board, and the display screen is controlled by controlling the total power supply of the display screen. In certain usage scenarios, limited space and specific requirements mean that physical power buttons on the screen cannot meet the needs of certain users. For example, in confined spaces, users may find it difficult to reach or operate physical buttons on the monitor itself. Furthermore, in scenarios requiring multi-screen displays, such as dual-screen displays, traditional screen switching technology controls the overall power supply to the screens, thus controlling their on / off state. This can cause the display device to become undetectable by the OS or BIOS, disrupting the arrangement of content on the primary and secondary screens. Users then need to re-operate on the system content after restarting the display. Similarly, if a user needs to temporarily turn off one of the secondary screens (e.g., an EDP screen) to save power or focus on the primary screen, using a physical button to cut off the power to that secondary screen will cause it to completely "disappear" from the operating system (OS) or BIOS (i.e., become undetectable), significantly reducing the ease of use. Another approach is to use an EC chip to control the screen via software. The drawback is the high cost of EC chips, which increases overall costs.

[0053] Therefore, in order to solve the above problems, this application provides a screen backlight state switching circuit and display device, which can be applied to the OS and BIOS to control the screen off and on of EDP protocol screens, and solves the problem that the screen off and on of EDP protocol screens cannot simultaneously meet the needs of low-cost control of the backlight on and off of display screen devices in specific use scenarios.

[0054] This application uses a state switching trigger module to respond to a continuous trigger signal to control the level of the state switching module to switch the output level. Combined with the backlight enable module, it realizes reliable switching of the backlight state, thereby meeting the backlight on / off requirements of display screen devices in specific usage scenarios at low cost. It has the effects of low cost, simple structure, reliable triggering and flexible switching of backlight state.

[0055] In one exemplary embodiment, Figure 1 This is a schematic diagram of the structure of a screen backlight state switching circuit provided in an embodiment of this application, as shown below. Figure 1 As shown, the screen backlight state switching circuit 10 includes a state switching trigger module 110, a level state switching module 120, and a backlight enable module 130, wherein:

[0056] The state switching trigger module 110 is used to generate a state switching trigger signal when responding to a continuous trigger signal from the switch button.

[0057] Among them, the state switching trigger module 110 can refer to a module that specifically detects the user's continuous pressing action (long press) on the physical switch button or the screen simulated switch button. When this specific triggering method is recognized, a valid state switching trigger signal can be generated.

[0058] Specifically, the state switching trigger module 110 can be configured to detect the long press operation of the switch button and generate a trigger signal. It can be implemented by using a switching circuit built with transistors or MOSFETs. The effective trigger is determined by detecting the conduction time of the button.

[0059] The level state switching module 120 has its input terminal connected to the output terminal of the state switching trigger module 110, and is used to switch the output level state when a state switching trigger signal is received.

[0060] The level state switching module 120 can refer to a module that receives a state switching trigger signal from the state switching trigger module 110. Whenever a valid trigger signal is received, the level state switching module 120 can toggle the state of its output level. For example, if the current output is high (1), it can become low (0) after receiving the trigger signal. The output level can refer to the logic level output by the level state switching module 120 that represents the desired state of the current backlight.

[0061] Specifically, the level switching module 120 can be configured to maintain a bistable output, for example, by using a relay or dual MOSFET structure to toggle the output level state when a trigger signal is received.

[0062] The input terminal of the backlight enable module 130 is connected to the first output terminal of the level state switching module 120, and the output terminal of the backlight enable module 130 is used to connect to the backlight drive circuit 20.

[0063] The backlight enable module 130 refers to a module that generates a signal that can directly control the backlight drive circuit 20 based on the level state output by the level state switching module 120. The backlight enable module 130 can be configured as a level conversion interface, for example, it can use logic gate circuits or transistor amplifier circuits to convert the control level into an enable signal that the backlight drive circuit 20 can recognize.

[0064] The backlight enable signal can be a signal that commands the backlight driver circuit 20 to operate, illuminating the backlight source (such as an LED strip) of the display screen. The backlight disable signal can be a signal that commands the backlight driver circuit 20 to stop operating, turning off the backlight source of the display screen. The backlight driver circuit 20 can be a circuit responsible for providing sufficient voltage and current to drive the backlight source of the display screen, and its operation can be determined by the "enable" or "disable" signal from the light enable module.

[0065] Specifically, when the output level is high, the backlight enable module 130 outputs a backlight enable signal to enable the backlight driver circuit 20 to drive the backlight of the display screen to turn on; when the output level is low, the backlight enable module 130 outputs a backlight disable signal to enable the backlight driver circuit 20 to drive the backlight of the display screen to turn off.

[0066] For example, the input of the state switching trigger module 110 can be connected to a physical switch button or a screen-simulated switch button. The output of the state switching trigger module 110 can be connected to the input of the level state switching module 120. When a valid long press (continuous trigger) is detected, a state switching trigger signal can be sent through this output. The output (first output) of the level state switching module 120 is connected to the input of the backlight enable module 130. This first output provides an output level representing the desired backlight state (e.g., high = on, low = off).

[0067] The output of the backlight enable module 130 can be connected to the control input pin of the backlight driver circuit 20 to output a backlight enable signal (high or low, depending on the specific design) or a backlight disable signal (which can be the opposite level to the backlight enable signal), directly controlling the working state of the backlight driver circuit 20.

[0068] In practical applications, when a user presses and holds the power button, the state switching trigger module 110 recognizes the continuous trigger signal and outputs a pulse signal to the level state switching module 120. The level state switching module 120 can toggle the current output level from high to low, or from low to high. After receiving this level signal at its input terminal, the backlight enable module 130 outputs an enable signal to the backlight driver circuit 20 to activate the backlight if the signal is high; otherwise, it outputs a disable signal to cut off the backlight power supply. The entire process does not require cutting off the main power supply to the display screen; backlight state control can be achieved solely through logic level switching.

[0069] In this embodiment, the backlight state can be quickly switched via button operation, without relying on a specific control chip or complex external circuit board design. The state switching trigger module 110 responds to a continuous trigger signal to control the level switching module 120 to switch the output level. Combined with the backlight enable module 130, reliable backlight state switching is achieved. This meets the low-cost backlight control requirements of display screen devices in specific usage scenarios, offering advantages such as low cost, simple structure, reliable triggering, and flexible backlight state switching.

[0070] In one exemplary embodiment, the level state switching module 120 is a screen control relay module.

[0071] The first level pin of the screen control relay module is connected to the output of the state switching trigger module 110, and the second level pin of the screen control relay module is connected to the input of the backlight enable module 130.

[0072] The screen control relay module refers to a relay circuit used for level state switching. For example, it can be implemented using integrated circuits or discrete components with level switching capabilities. Its function is to convert trigger signals into different level states to drive subsequent modules; as an example, the PCH bridge chip of the screen control relay module display. The first level pin refers to a physical interface for receiving trigger signals. For example, it can be implemented using metal contacts or pad structures, used to establish an electrical connection between the state switching trigger module 110 and the screen control relay module. The second level pin refers to a physical interface for outputting level signals. For example, it can be implemented using metal contacts or pad structures, used to transmit the converted level signal to the backlight enable module 130.

[0073] For example, when the state switching trigger module 110 generates a trigger signal, this signal is input to the screen control relay module through the first level pin, triggering its internal level conversion function. The screen control relay module changes its output level according to the state of the trigger signal, for example, switching from a high level to a low level or vice versa, and transmits the converted level signal to the backlight enable module 130 through the second level pin. The backlight enable module 130 determines whether to output a backlight enable signal based on the received level signal, thereby controlling the operating state of the backlight driving circuit 20.

[0074] Optionally, two GPIO ports of the PCH bridge chip can be selected for receiving and transmitting signals, as well as sending signals externally. To control the EDP screen under OS and DOS, the selected GPIO ports need to have SMI (System Management Interrupt) and SCI (System Control Interrupt) functions. The purpose is to enable the BIOS to effectively handle the corresponding interrupt events after receiving control signals.

[0075] For example, after receiving a pulse signal lasting at least 200ms, the BIOS of the screen control relay module can enable another GPIO port to send a GP_OUT signal to the third module. Before sending it to the backlight enable module 130, the BIOS can detect whether the current GP_OUT signal is high or low (e.g., default is high). When the current level is detected to be high, a low-level signal is output. When the current level is detected to be low, GPIO_OUT will output a high-level signal. The output signal will enter the backlight enable module 130.

[0076] In this embodiment, direct level conversion and transmission of backlight control signals can be achieved, avoiding the introduction of additional power control loops or software control layers, thereby reducing hardware costs and design complexity. For example, in scenarios requiring low-cost backlight control, the backlight switching function can be achieved simply by completing level conversion through a relay module, without the need for additional dedicated control chips or complex wiring. Thus, it can meet the backlight on / off requirements of display screen devices in specific usage scenarios with low cost, simple structure, reliable triggering, and flexible backlight state switching.

[0077] In one exemplary embodiment, Figure 2 This is a schematic diagram of a specific structure of a backlight enabling module provided in an embodiment of this application, as shown below. Figure 2 As shown, it is possible to Figure 1 Based on this, a partial illustrative description of the structure of the screen backlight state switching circuit 10 is provided, wherein the backlight enable module 130 may specifically include:

[0078] The logic gate unit 131 has its first input terminal connected to the second level pin of the level state switching module 120, its second input terminal connected to the third level pin of the level state switching module 120, and its output terminal connected to the input terminal of the backlight enable module 130.

[0079] The input terminal of the backlight enable module 130 is also used to connect to a high level.

[0080] When the first input terminal of logic gate unit 131 receives a low level output from the level state switching module 120, the output terminal of logic gate unit 131 is valid, and the backlight driving circuit 20 cannot receive a high level, so that the backlight is turned off; when the first input terminal of logic gate unit 131 receives a high level, the output terminal of logic gate unit 131 is invalid, and the backlight driving circuit 20 receives a high level, so that the backlight is turned on.

[0081] The logic gate unit 131 can refer to a circuit module composed of basic logic elements, such as NAND gates, NOR gates, or other combinational logic circuits, which generate corresponding logic outputs by receiving different level signals. The second and third level pins of the level switching module 120 can refer to the physical interfaces in the module used to output different control signals, such as metal pins or pad structures, used to transmit high-level or low-level signals. High-level access can refer to connecting the positive terminal of a constant voltage source to a circuit node, such as a DC power supply or voltage regulator circuit, to provide a stable voltage reference for the backlight driving circuit 20.

[0082] For example, when the second level pin of the level state switching module 120 outputs a low level, this low-level signal is transmitted to the first input terminal of the logic gate unit 131. At this time, the second input terminal of the logic gate unit 131 receives a signal from the third level pin, such as a high-level signal. The logic gate unit 131 performs logical operations according to the combination of input signals. For example, when the first input terminal of the NAND gate is low, its output terminal will output a high-level valid signal regardless of the state of the second input terminal. This valid signal disconnects the connection between the output terminal of the backlight enable module 130 and the high-level input terminal, causing the backlight driving circuit 20 to be unable to obtain operating voltage, thereby turning off the backlight. When the second level pin outputs a high level (the first input terminal of the logic gate unit 131 is connected to a high level), the output terminal of the logic gate unit 131 becomes a low-level invalid signal. At this time, the output terminal of the backlight enable module 130 is connected to the high-level input terminal, the backlight driving circuit 20 obtains operating voltage and turns on the backlight.

[0083] In this embodiment, through the hardware linkage between the level state switching module 120 and the logic gate unit 131, backlight control can be achieved simply by changing the level signal, without the need to add complex circuits or rely on software instructions. This can meet the low-cost backlight control requirements of display screen devices in specific usage scenarios.

[0084] In one exemplary embodiment, the logic gate unit includes a NAND gate unit.

[0085] The second input of the NAND gate unit is used to receive the high level output from the third level pin of the level state switching module.

[0086] Specifically, when the first input terminal of the NAND gate receives a high level output from the level state switching module, the output of the NAND gate is invalid; when the first input terminal of the NAND gate receives a low level output from the level state switching module, the output of the NAND gate is valid.

[0087] A NAND gate is a logic circuit with two inputs and one output. It outputs a high level when any input is low, and a low level when all inputs are high. This unit can be used to generate corresponding logic outputs based on the input level states, thereby controlling the on / off state of the backlight driver circuit.

[0088] The high level output of the third level pin refers to the stable voltage signal provided by the power supply module, such as a 5V or 3.3V DC power supply. It can be used to maintain the fixed high level state of the second input terminal of the NAND gate unit to ensure the stability of the reference condition for logic judgment.

[0089] For example, if the second level pin of the level state switching module outputs a high level to the first input of the NAND gate, since the second input is fixed at a high level, both inputs of the NAND gate are high, and its output is invalid. In this case, the backlight enable module can receive the directly connected high level and drive the backlight to turn on. When the second level pin of the level state switching module outputs a low level, the first input of the NAND gate is low, and its output is valid. At this time, the backlight enable module is connected to a low level; that is, the high level connected to the input of the backlight enable module is connected to ground. Therefore, the backlight enable module cannot receive the high-level signal and cannot drive the backlight to turn on. Through the simple logic judgment of the NAND gate, hardware control of the backlight state switching is achieved without relying on complex software or an additional power control module.

[0090] In this embodiment, by directly responding to the level state switching signal through a NAND gate unit, the generation of the backlight enable signal can be completed with only a single logic device, significantly simplifying the circuit structure and reducing hardware costs. It enables reliable backlight state switching at low cost, thereby meeting the backlight on / off requirements of display screen devices in specific application scenarios at low cost. It features low cost, simple structure, reliable triggering, and flexible backlight state switching.

[0091] In one exemplary embodiment, the logic gate unit may specifically include:

[0092] The first transistor unit has a first control terminal connected to the second level pin of the level state switching module, and the second control terminal of the first transistor unit is connected to the third level pin of the level state switching module.

[0093] The second transistor unit has a third control terminal connected to the input terminal of the first transistor unit. The input terminal of the second transistor unit is connected to the input terminal of the backlight enable module and is also used to access a high level. The output terminal of the second transistor unit is used to ground.

[0094] When both the first and second control terminals receive a high level, the output of the second transistor unit is invalid.

[0095] The first transistor unit refers to a switching control structure composed of two MOSFETs connected in series. Specifically, it can be implemented using NMOS or PMOS transistors. Its gates are connected to different pins of the level switching module, used to control the conduction state based on the input level signal. The second transistor unit refers to an output control unit composed of a single MOSFET, specifically implemented using an NMOS transistor. Its gate is connected to the output terminal of the first transistor unit, used to control whether the high level is pulled down to ground based on the preceding signal. The control terminal refers to the gate of the MOSFET, which can be used to receive external level signals to control the conduction state. The input terminal of the second transistor unit is the power access point connected to the backlight enable module, used to provide a high-level signal.

[0096] For example, if both the second and third level pins of the level switching module output a high level simultaneously, both MOSFETs in the first transistor unit are turned on, causing the gate of the second transistor unit to be pulled low to ground potential. At this time, the second transistor unit is in the off state, the input of the backlight enable module remains high, and the backlight driving circuit receives a valid signal to turn on the backlight. When either level pin outputs a low level, at least one MOSFET in the first transistor unit is turned off, the gate of the second transistor unit is pulled up to a high level, causing it to turn on and pull the input of the backlight enable module low to ground potential. The backlight driving circuit cannot receive a valid signal and thus turns off the backlight. This structure achieves logic control functions through the cascaded combination of transistor units.

[0097] In this embodiment, equivalent logic functions can be directly constructed using discrete MOSFETs, reducing material costs and circuit complexity. Level control logic based on transistor physical characteristics can be implemented, simplifying the circuit structure while ensuring reliable backlight state switching, making it particularly suitable for cost-sensitive display devices. The backlight enable signal is directly controlled by the on / off state of the hardware circuit, responding to physical button operations without software intervention, further reducing system power consumption and response latency.

[0098] In one exemplary embodiment, the first transistor unit includes:

[0099] The first MOSFET's gate is connected to the second level pin of the level state switching module, and the source of the first MOSFET is grounded.

[0100] The second MOSFET has its gate connected to the third level pin of the level switching module; the source chain of the second MOSFET is connected to the source and drain of the first MOSFET; the drain of the second MOSFET is connected to the third control terminal of the second transistor unit and is also used to access a high level.

[0101] The first MOSFET refers to a metal-oxide-semiconductor field-effect transistor whose conduction state is controlled by the gate voltage. Specifically, it can be implemented using an N-channel enhancement-mode MOSFET. Its source is grounded so that it conducts when the gate receives a high level, forming a current path. The second MOSFET refers to a transistor connected in series with the first MOSFET. Specifically, it can be implemented using an N-channel enhancement-mode MOSFET. Its source is connected to the source and drain of the first MOSFET. The two-stage series structure enables the level adjustment of the control terminal of the second transistor unit.

[0102] For example, when the state switching trigger module generates a state switching trigger signal, the second and third level pins of the level state switching module output high-level signals. At this time, the gates of both the first and second MOSFETs receive a high level, and both are turned on simultaneously, causing the drain level of the second MOSFET to be pulled down to a low level, thereby controlling the third control terminal of the second transistor unit to be in a low-level state. When the second and third level pins of the level state switching module output low levels, both the first and second MOSFETs are turned off, and the drain of the second MOSFET is connected to a high level, thereby driving the second transistor unit to turn on. Through the series structure of the two-stage MOSFETs, the operating state of the second transistor unit can be precisely controlled, avoiding false triggering.

[0103] In this embodiment, by combining the first and second MOSFETs in series, reliable level control can be achieved with only a few components, simplifying the circuit structure and reducing hardware costs. It enables stable control of the backlight state switching circuit at low cost. The series design of the two MOSFETs effectively isolates interference signals, avoiding malfunctions caused by level fluctuations, while also reducing board space requirements, making it suitable for cost- and size-sensitive display devices. Therefore, it can meet the low-cost backlight control requirements of display screen devices in specific application scenarios, offering advantages such as low cost, simple structure, reliable triggering, and flexible backlight state switching.

[0104] In one exemplary embodiment, the second transistor unit includes:

[0105] The gate of the third MOSFET is connected to the drain of the second MOSFET and is also used to input a high level; the drain of the third MOSFET is connected to the input terminal of the backlight enable module and is also used to input a high level; the source of the third MOSFET is used to ground.

[0106] The third MOSFET refers to a metal-oxide-semiconductor field-effect transistor, specifically an N-channel enhancement-mode MOSFET. Its gate voltage variation controls the conduction state between the drain and source. The drain of the third MOSFET is connected to the input of the backlight enable module, used to pull the high-level signal to ground when on, blocking the high-level input of the backlight drive circuit. The source of the third MOSFET is grounded to form a current loop. The gate of the third MOSFET is connected to the drain of the second MOSFET, controlling its own on / off state by receiving signals from the preceding stage. This structure directly controls the level transmission path through physical devices, avoiding reliance on software instructions and reducing control complexity.

[0107] For example, when the drain of the second MOSFET outputs a high level, the gate of the third MOSFET receives a high-level signal. At this time, the drain and source are connected, and the high level at the input of the backlight enable module is pulled down to ground. The backlight driving circuit cannot receive a valid level signal, and the backlight is turned off. When the drain of the second MOSFET outputs a low level, the gate voltage of the third MOSFET is insufficient to form a conduction condition, and the drain and source are disconnected. The high level at the input of the backlight enable module can be transmitted normally to the backlight driving circuit, and the backlight is turned on. This process achieves level switching through hardware circuitry, without the need for additional control chips.

[0108] In this embodiment, the hardware logic circuit built using MOSFETs independently controls the backlight enable signal. While maintaining the independence of backlight control, no additional control chip is needed, reducing hardware costs. Physical isolation between the backlight control circuit and the power control circuit can be achieved, allowing direct control of the backlight enable signal's on / off state through hardware logic. Therefore, the requirement for low-cost control of the display backlight's on / off state can be met.

[0109] In one exemplary embodiment, Figure 3 This is a schematic diagram of the specific structure of a state switching trigger module provided in an embodiment of this application, as shown below. Figure 3 As shown, it is possible to Figure 1 Based on this, a partial illustrative description of the structure of the screen backlight state switching circuit 10 is provided, wherein the state switching trigger module 110 may specifically include:

[0110] The control switch module 111 has a switch button, and the first terminal is used for grounding.

[0111] The third transistor unit 112 has a control terminal for receiving a control voltage; the output terminal of the third transistor unit 112 is connected to the second terminal of the control switch module 111; the input terminal of the third transistor unit 112 is connected to the input terminal of the state switching trigger module 110 and is also used to receive a high level.

[0112] When the control switch module 111 is turned on, the output terminal of the third transistor unit 112 is connected to a low level to turn on the third transistor unit 112, and the high level connected to the input terminal of the third transistor unit 112 is pulled down to ground to generate a state switching trigger signal.

[0113] The control switch module 111 can refer to a circuit unit containing physical buttons or virtual on-screen buttons. For example, it can be implemented using mechanical contacts, membrane switches, or virtual switches, and the circuit is turned on or off through the mechanical / analog action of the buttons. The third transistor unit 112 can refer to a semiconductor device used for level conversion. For example, it can be implemented using a MOSFET or a transistor, and the conduction state of the input and output terminals is adjusted by the voltage change at the control terminal. The control voltage can refer to the reference voltage that drives the transistor unit to operate. For example, it can be a stable DC voltage provided by the system power supply, such as 3.3V or 5V.

[0114] For example, when the switch button is continuously pressed, the first and second terminals of the control switch module 111 are connected, and the output terminal of the third transistor unit 112 forms a loop with ground, causing its output level to be pulled low. At this time, the control terminal of the third transistor unit 112 is in a conducting state due to the application of a control voltage, and the high level of the input terminal is pulled down to ground through the conduction path, thereby generating a low-level state switching trigger signal. This signal is transmitted to the subsequent level state switching module 120, triggering the switching of the backlight enable state.

[0115] In this embodiment, by cooperating with the control switch module 111 and the transistor unit, the backlight state switching can be achieved with only simple hardware circuitry, without the need for complex power management or software intervention, thus reducing implementation costs and improving response speed. It can quickly respond to physical button operations with low-cost hardware circuitry, accurately generate backlight state switching signals, avoid delays or false triggering caused by software control, and reduce dependence on external power supply switching, thereby improving the reliability of backlight control.

[0116] In one exemplary embodiment, the third transistor unit includes:

[0117] The fourth MOS transistor has its gate connected to a high level; its source serves as the output of the third transistor unit, and its drain serves as the input of the third transistor unit.

[0118] For example, the state switching trigger module may include a control switch module and a transistor unit, such as using a fourth MOSFET as the control voltage conduction device. When the control switch module is turned on, the source of the fourth MOSFET is grounded, and the high level at the input terminal is pulled down to a low level, thereby generating a state switching trigger signal.

[0119] In this embodiment, the backlight state switching is achieved through hardware circuitry, eliminating the need for external circuit boards or software instructions and reducing system complexity. For example, a physical switch solution requires an additional power control circuit, while the same function can be achieved through a combination of level switching and logic gates, reducing the number of components.

[0120] In some exemplary embodiments, such as Figure 4 , Figure 5 As shown, Figure 4 This is a schematic diagram of a screen backlight state switching circuit provided in an embodiment of this application. Figure 5 This is a schematic diagram of a screen backlight state switching circuit provided in an embodiment of this application, combined with... Figures 1-3 The screen backlight state switching circuit 10 includes a state switching trigger module 110, a level state switching module 120, and a backlight enable module 130; wherein:

[0121] like Figure 4 As shown, the on / off state of the EDP screen is controlled by controlling the high and low states of the BKL_EN pin. Specifically, the screen is on when the BKL_EN signal is continuously high, and the screen is off when BKL_EN is low. The circuit structure can be divided into three parts: the first part is the control pulse signal generation circuit (i.e., the state switching trigger module 110); the second part is the circuit structure for acquiring pulse signals and generating control signals (i.e., the level state switching module 120); and the third part is the part for controlling the state of the BKL_EN pin (i.e., the backlight enable module 130).

[0122] like Figure 5 As shown, the state switching trigger module 110 may include: a switch button, one end of which is connected to the source of MOSFET Q1 and the other end is grounded. When the switch button is pressed, the 3V voltage is pulled down to ground through the resistor, MOSFET Q1 is turned on, and the source and drain of MOSFET Q1 are turned on, generating a pulse signal GP_IN that lasts for at least 200ms. The signal changes from high to low and is sent to the level state switching module 120 of the second part for processing.

[0123] Alternatively, a software control mode can be used to set a screen-off option in the BIOS interface to simulate the state of a switch being pressed, or a shortcut key can be set so that when the user presses the specified shortcut key, the state of a tactile switch being pressed is simulated, i.e., GP_IN receives a continuous 200ms low pulse signal.

[0124] The level switching module 120 includes two GPIO ports of the PCH bridge chip that can be selected for receiving and transmitting signals, as well as sending signals externally. To control the EDP screen under OS and DOS, the selected GPIO ports need to have SMI (System Management Interrupt) and SCI (System Control Interrupt) functions. The purpose is to enable the BIOS to effectively process the corresponding interrupt events after receiving control signals.

[0125] For example, after receiving a pulse signal lasting at least 200ms, the BIOS of the screen control relay module can enable another GPIO port to send a GP_OUT signal to the third module. Before sending it to the backlight enable module 130, the BIOS can detect whether the current GP_OUT signal is high or low (e.g., default is high). When the current level is detected to be high, a low-level signal is output. When the current level is detected to be low, GPIO_OUT will output a high-level signal. The output signal will enter the backlight enable module 130.

[0126] The backlight enable module 130 includes three MOSFETs, Q2, Q3, and Q4, forming a NAND gate. If the GP_OUT port of the screen control relay module is low, the voltage difference between the gate and source of MOSFET Q2 is less than 2V, causing MOSFET Q2 to turn off. After MOSFET Q2 turns off, the voltage difference between the gate and source of MOSFET Q3 is also less than 2V, causing MOSFET Q3 to turn off as well. At this time, the gate of MOSFET Q4 is pulled up to 3V through resistor R5, and the voltage difference between the gate and source of MOSFET Q4 is greater than 2V, causing MOSFET Q4 to turn back on. The BKL_EN signal of the backlight drive circuit 20 is pulled down to ground, becoming a low-level signal, driving the screen backlight to turn off.

[0127] If GP_OUT outputs a high-level signal, the AND gate loop is re-established. The voltage difference between the base and source of MOSFET Q3 is greater than 2V, so MOSFET Q3 is turned on. The voltage difference between the base and source of MOSFET Q4 is less than 2V, so MOSFET Q4 is turned off. The BKL_EN of the backlight driver circuit 20 is pulled up to 3V through resistor R6, becoming a high-level signal, and the screen turns on.

[0128] In this embodiment, the effects include: turning the screen on and off without turning off the main power supply of the display; solving the inconvenience of screen control in some special scenarios; ensuring that turning off the screen does not cause the screen hardware to drop under both OS and DOS; adapting to all EDP protocols for EDP screens, regardless of the backlight interface type; and using simple circuitry to control the screen at a lower cost.

[0129] In one exemplary embodiment, this application also provides a display device including the screen backlight state switching circuit as described above.

[0130] For example, by integrating a screen backlight state switching circuit, the display device can generate a level switching signal by a state switching trigger module when the power button is continuously triggered. Upon receiving this signal, the level state switching module switches its output level from high to low or vice versa. The backlight enable module sends an enable or disable signal to the backlight driver circuit based on the output level of the level state switching module. When the output level is high, the backlight driver circuit turns on the display backlight; when the output level is low, the backlight driver circuit turns off the display backlight.

[0131] In this embodiment, the backlight state switching is achieved through pure hardware circuitry, which improves the convenience of screen control in specific scenarios. This can meet the low-cost backlight control requirements of display screen devices in specific usage scenarios, and has the effects of low cost, simple structure, reliable triggering, and flexible backlight state switching.

[0132] It should be noted that, Figures 1 to 4 The diagram shows some ports and connections for each module / unit. However, in practical applications, other connections for the ports of each module / unit can be configured according to actual needs. Other pins or ports not shown can be configured according to actual conditions. Figures 1 to 4 The examples shown are not intended to limit this application.

[0133] It is understood that the aforementioned state switching trigger module, level state switching module, and backlight enable module can also take other forms, and are not limited to the forms already mentioned in the above embodiments, as long as they can achieve the functions of state switching trigger, level state switching, and backlight enable control.

[0134] The circuit described above can be applied to display devices or similar equipment with backlight control, such as displays based on the EDP protocol.

[0135] In the description of this specification, the references to terms such as "some embodiments," "other embodiments," "specific implementation," and "another implementation" refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0136] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes said element.

[0137] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0138] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A screen backlight state switching circuit, characterized in that, The circuit includes: The state switching trigger module is used to generate a state switching trigger signal when a continuous trigger signal from the switch button is received. The level state switching module has its input terminal connected to the output terminal of the state switching trigger module, and is used to switch the output level state when a state switching trigger signal is received; The backlight enable module has its input terminal connected to the first output terminal of the level state switching module, and the output terminal of the backlight enable module is used to connect to the backlight driving circuit. When the output level is high, the backlight enable module outputs a backlight enable signal to enable the backlight driving circuit to turn on the backlight of the display screen; when the output level is low, the backlight enable module outputs a backlight disable signal to enable the backlight driving circuit to turn off the backlight of the display screen.

2. The screen backlight state switching circuit according to claim 1, characterized in that, The level state switching module is a screen control relay module. The first level pin of the screen control relay module is connected to the output terminal of the state switching trigger module, and the second level pin of the screen control relay module is connected to the input terminal of the backlight enable module.

3. The screen backlight state switching circuit according to claim 1, characterized in that, The backlight enabling module includes: The logic gate unit has its first input terminal connected to the second level pin of the level state switching module, its second input terminal connected to the third level pin of the level state switching module, and its output terminal connected to the input terminal of the backlight enable module. The input terminal of the backlight enable module is also used to connect to a high level. Specifically, when the first input terminal of the logic gate unit receives a low level output from the level state switching module, the output terminal of the logic gate unit is valid, and the backlight driving circuit cannot receive the high level, so as to turn off the backlight; when the first input terminal of the logic gate unit receives a high level, the output terminal of the logic gate unit is invalid, and the backlight driving circuit receives the high level, so as to turn on the backlight.

4. The screen backlight state switching circuit according to claim 3, characterized in that, The logic gate unit includes a NAND gate unit; The second input terminal of the NAND gate unit is used to receive the high level output by the third level pin of the level state switching module; Specifically, when the first input terminal of the NAND gate receives a high level output from the level state switching module, the output of the NAND gate is invalid; when the first input terminal of the NAND gate receives a low level output from the level state switching module, the output of the NAND gate is valid.

5. The screen backlight state switching circuit according to claim 3 or 4, characterized in that, The logic gate unit includes: The first transistor unit has a first control terminal connected to the second level pin of the level state switching module, and the second control terminal of the first transistor unit is connected to the third level pin of the level state switching module. The second transistor unit has a third control terminal connected to the input terminal of the first transistor unit, the input terminal of the second transistor unit connected to the input terminal of the backlight enable module, and is also used to access a high level. The output terminal of the second transistor unit is used to ground. When both the first control terminal and the second control terminal receive a high level, the output of the second transistor unit is invalid.

6. The screen backlight state switching circuit according to claim 5, characterized in that, The first transistor unit includes: The first MOS transistor has its gate connected to the second level pin of the level state switching module, and its source is grounded. The second MOS transistor has its gate connected to the third level pin of the level switching module; the source of the second MOS transistor is connected to the source and drain of the first MOS transistor; the drain of the second MOS transistor is connected to the third control terminal of the second transistor unit and is also used to access a high level.

7. The screen backlight state switching circuit according to claim 6, characterized in that, The second transistor unit includes: The third MOS transistor has its gate connected to the drain of the second MOS transistor and is also used to connect to a high level; the drain of the third MOS transistor is connected to the input terminal of the backlight enable module and is also used to connect to a high level; the source of the third MOS transistor is used to ground.

8. The screen backlight state switching circuit according to claim 1, characterized in that, The state transition trigger module includes: The control switch module has a switch button, and the first terminal is used for grounding. The third transistor unit has a control terminal for receiving a control voltage; its output terminal is connected to the second terminal of the control switch module; and its input terminal is connected to the input terminal of the state switching trigger module and is also used to receive a high-level signal. When the control switch module is turned on, the output terminal of the third transistor unit is connected to a low level to turn on the third transistor unit, and the high level connected to the input terminal of the third transistor unit is pulled down to ground to generate a state switching trigger signal.

9. The screen backlight state switching circuit according to claim 8, characterized in that, The third transistor unit includes: The fourth MOS transistor has its gate connected to a high level; the source of the fourth MOS transistor serves as the output terminal of the third transistor unit, and the drain of the fourth MOS transistor serves as the input terminal of the third transistor unit.

10. A display screen device, characterized in that, Includes the screen backlight state switching circuit as described in any one of claims 1-9.

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