A backlight brightness adjusting control circuit for an industrial computer display screen

Abstract

The utility model discloses an industrial computer display screen backlight brightness regulation control circuit, including IC chip U1, its characterized in that, the first PIN of IC chip U1 is connected with BL_PWM_IN, and the second PIN is connected with PIN GPIO, the fourth PIN of IC chip U1 is connected with BL_PWM_OUT, and BL_PWM_OUT is connected with resistance R1 and is grounded, the fifth PIN of IC chip U1 is connected with power supply VCC. Change the state of GPIO in BIOS to change the output PWM waveform, thereby can adapt to different display screen, realize the matching of different display screen, save manpower etc. of disassembly change.

Description

Technical Field

[0001] This utility model relates to the technical field of display screen backlight brightness adjustment circuit, specifically, to an industrial control computer display screen backlight brightness adjustment control circuit. Background Technology

[0002] In existing technologies, the backlight brightness adjustment logic of displays such as EDP and LVDS used in industrial control computers is achieved by adjusting the duty cycle of the PWM waveform. However, whether the first pulse of the PWM is high or low determines whether the display will light up. Some displays light up when the first pulse is high, while others light up when the first pulse is low. This can lead to situations where the display does not light up when the motherboard is paired with different displays due to differences in the backlight brightness adjustment logic from different display manufacturers. Usually, in such cases, the hardware logic control needs to be modified for adjustment, which results in wasted time. Figure 4 As shown in Figure A, the logic of this scheme is as follows: the PWM pulse input to BL_PWM_IN is as shown in Figure A. If the resistor is at the position of R5, the PWM waveform output by the BL_PWM_OUT signal is as shown in Figure B, which is the same logic as A. This scheme can only be adapted to screens that adjust brightness using low-level logic. If the resistor is at the position of R4, the PWM waveform output by the BL_PWM_OUT signal is as shown in Figure C, which is the opposite logic to A. This scheme can only be adapted to screens that adjust brightness using high-level logic.

[0003] No effective solutions have yet been proposed to address the problems in the relevant technologies. Utility Model Content

[0004] In view of the problems in the related technologies, this utility model proposes a backlight brightness adjustment control circuit for an industrial control computer display screen to overcome the above-mentioned technical problems existing in the existing related technologies.

[0005] Therefore, the specific technical solution adopted by this utility model is as follows:

[0006] An industrial control computer display screen backlight brightness adjustment control circuit includes an IC chip U1, characterized in that the first PIN of the IC chip U1 is connected to BL_PWM_IN, and the second PIN is connected to PIN GPIO;

[0007] The fourth pin of the IC chip U1 is connected to BL_PWM_OUT, and BL_PWM_OUT is connected to resistor R1 and grounded;

[0008] The fifth pin of the IC chip U1 is connected to the power supply VCC.

[0009] Preferably, the PIN GPIO input is a low level, and the output PWM is in phase with the input PWM waveform, which is adapted to the screen that turns on the backlight brightness of the display when the low level is turned on.

[0010] Preferably, the PIN GPIO input is a high level, and the output PWM is the opposite of the input PWM waveform, which is adapted to the screen that turns on the backlight brightness of the display when the high level is turned on.

[0011] Preferably, the output of the PWM waveform can be adjusted by changing the level of the A or B input terminals through the BIOS using the PIN GPIO pin.

[0012] Preferably, the IC chip U1 is a logic control chip with an XOR gate, specifically a 74LVC1G86GW chip.

[0013] The beneficial effects of this utility model are: by changing the state of GPIO in the BIOS to change the output PWM waveform, it can be adapted to different displays, achieve matching between different displays, and save manpower for disassembly and modification. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a circuit diagram of a backlight brightness adjustment control circuit for an industrial control computer display screen according to an embodiment of the present utility model;

[0016] Figure 2 This is a schematic diagram of the PWM waveform according to an embodiment of the present invention;

[0017] Figure 3 This is a brightness control logic diagram according to an embodiment of the present utility model;

[0018] Figure 4 This is a schematic diagram based on existing brightness adjustment schemes in the background technology of this utility model. Detailed Implementation

[0019] To further illustrate the various embodiments, the present invention provides accompanying drawings, which are part of the disclosure of the present invention. These drawings are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, those skilled in the art should be able to understand other possible implementation methods and the advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are usually used to represent similar components.

[0020] According to an embodiment of the present invention, a backlight brightness adjustment control circuit for an industrial control computer display screen is provided.

[0021] Example 1:

[0022] like Figure 1-3 As shown, the backlight brightness adjustment control circuit of the industrial control computer display screen according to an embodiment of the present utility model includes an IC chip U1, characterized in that the first PIN of the IC chip U1 is connected to BL_PWM_IN, and the second PIN is connected to PINGPIO.

[0023] The fourth pin of the IC chip U1 is connected to BL_PWM_OUT, and BL_PWM_OUT is connected to resistor R1 and grounded;

[0024] The fifth pin of the IC chip U1 is connected to the power supply VCC.

[0025] Example 2:

[0026] like Figure 1-3 As shown, when the PIN GPIO input is low, the output PWM is in phase with the input PWM waveform, which is suitable for screens that turn on the backlight brightness when the input is low. When the PIN GPIO input is high, the output PWM is out of phase with the input PWM waveform, which is suitable for screens that turn on the backlight brightness when the input is high. By using the PIN of the PIN GPIO to change the level of the A or B input terminal through the BIOS, the output of the PWM waveform can be adjusted. The IC chip U1 is a logic control chip with an XOR gate of 74LVC1G86GW.

[0027] To facilitate understanding of the above-mentioned technical solutions of this utility model, the working principle or operation method of this utility model in actual process will be described in detail below.

[0028] In practical applications, by using a GPIO pin to change the level of the A or B input terminal through the BIOS, the output of the PWM waveform can be adjusted, ultimately obtaining the brightness control logic required to adapt to the display screen.

[0029] like Figure 2As shown, the logic is that the PWM waveform of the input BL_PWM_IN is low. If the second PIN GPIO input of 74LVC1G86GW is low, the output PWM is in phase with the input PWM waveform, which can be adapted to a screen that turns on the backlight brightness when the level is low. If the GPIO input is high, the output PWM is out of phase with the input PWM waveform, which can be adapted to a screen that turns on the backlight brightness when the level is high.

[0030] In summary, by utilizing the above-mentioned technical solution of this utility model, the output PWM waveform can be changed by altering the GPIO state in the BIOS, thereby adapting to different displays, achieving matching between different displays, and saving manpower for disassembly and modification.

[0031] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A backlight brightness adjustment control circuit for an industrial control computer display screen, comprising an IC chip U1, characterized in that, The first PIN of the IC chip U1 is connected to BL_PWM_IN, and the second PIN is connected to PIN GPIO; The fourth pin of the IC chip U1 is connected to BL_PWM_OUT, and BL_PWM_OUT is connected to resistor R1 and grounded; The fifth pin of the IC chip U1 is connected to the power supply VCC.

2. The backlight brightness adjustment control circuit for an industrial computer display screen according to claim 1, characterized in that, The PIN GPIO input is a low level, and the output PWM is in phase with the input PWM waveform, which is adapted to turn on the screen backlight brightness when the low level is turned on.

3. The backlight brightness adjustment control circuit for an industrial computer display screen according to claim 1, characterized in that, The PIN GPIO input is high level, and the output PWM is inversely phase to the input PWM waveform, which is adapted to turn on the screen backlight brightness when the high level is turned on.

4. The backlight brightness adjustment control circuit for an industrial computer display screen according to claim 1, characterized in that, By using the PIN GPIO pin to change the level of the A or B input terminal through the BIOS, the output of the PWM waveform can be adjusted.

5. The backlight brightness adjustment control circuit for an industrial computer display screen according to claim 1, characterized in that, The IC chip U1 is a logic control chip with an XOR gate, specifically a 74LVC1G86GW chip.

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