Display and backlight brightness adjusting circuit thereof

Abstract

The utility model discloses a display and a backlight brightness adjusting circuit thereof, which comprises a first control module, an adjustable resistor module and a second control module, and the first control module adjusts the backlight output current of the second control module by adjusting the resistance value of an adjustable resistor. The adjustable resistor is connected to the feedback pin of the backlight chip, and the resistance value of the resistor is adjusted as required, so that the maximum output current of backlight can be adjusted as required, the brightness of a screen of a display is improved as required, the stability of the brightness of the screen of the display is ensured, and the impression experience of a user is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the display backlight brightness adjustment field especially relates to a display and the adjustment circuit of its backlight brightness. BACKGROUND

[0002] The display has the characteristics of high refresh rate and fast response speed, and the display has a default MPRT (Moving Picture Response Time) function to reduce display image blur and motion blur. Specifically, after the MPRT function is turned on, the backlight inside the display is temporarily turned off during the color conversion process of the display screen, and the backlight is turned on after the color conversion of the display screen, so as to improve the clarity of the picture.

[0003] However, in the process of frequently turning on and off the backlight, the time of turning on the backlight only accounts for a small part of the whole backlight switching cycle time, that is, in the whole backlight cycle, the time of turning off the backlight is longer than the time of turning on the backlight. Please refer to Figure 1 , Figure 1 A backlight circuit diagram in the related art includes a SOC (System on Chip) chip and a backlight chip. The backlight chip can adjust the maximum output current of the backlight based on the resistance between the feedback pin and the ground. However, in the prior art, the resistance between the feedback pin and the ground is usually a fixed value, so the maximum output current of the backlight cannot be adjusted, and thus the brightness of the display cannot be improved, resulting in low screen brightness of the display and poor display experience for users. UTILITY MODEL CONTENT

[0004] The display and the adjustment circuit of the backlight brightness provided by the utility model, in the application, an adjustable resistance is connected to the feedback pin of the backlight chip. The resistance value can be adjusted according to the need, so the maximum output current of the backlight can be adjusted according to the need, and thus the brightness of the display screen can be improved according to the need, so as to ensure the stability of the screen brightness of the display and improve the experience of users.

[0005] To solve the above technical problems, the utility model provides a kind of adjustment circuit of the backlight brightness of display, including SOC chip, adjustable resistance module and backlight chip;

[0006] The resistance control output end of SOC chip is connected with the control end of adjustable resistance module;

[0007] The first end of adjustable resistance module is connected with the feedback pin of backlight chip, and the second end is grounded, for changing the resistance value based on the control of SOC chip.

[0008] Optionally, the adjustable resistance module comprises:

[0009] a first resistor module, a first end of the first resistor module is connected to a feedback pin of the backlight chip, and a second end is grounded;

[0010] a switch module, a first end of the switch module is connected to a first end of a second resistor module, a second end is grounded, and a control end is connected to an output end of the SOC chip, for being turned on or turned off based on control of the SOC chip;

[0011] the second resistor module, a second end of the resistor module is connected to a first end of the first resistor module.

[0012] Optionally, the first resistor module comprises:

[0013] a first resistor, a first end of the first resistor is connected to a first end of a second resistor, and a common end connected thereto is connected to the feedback pin of the backlight chip, and a second end is grounded;

[0014] a second resistor, a second end of the second resistor is grounded.

[0015] Optionally, the second resistor module comprises:

[0016] a third resistor, a first end of the third resistor is connected to a first end of the switch module, and a second end is connected to a first end of the first resistor module and the feedback pin of the backlight chip respectively.

[0017] Optionally, the switch module comprises:

[0018] a power electronic switch, a first end of the power electronic switch is connected to a first end of the resistor module, a second end is grounded, and a control end is connected to a resistance control output end of the SOC chip, for being turned on or turned off based on control of the SOC chip.

[0019] Optionally, the power electronic switch is an N-MOS tube, a drain of the N-MOS tube is connected to a first end of the first resistor module, a gate is connected to a resistance control output end of the SOC chip, and a source is grounded, for being turned on or turned off based on control of the SOC chip.

[0020] Optionally, further comprising:

[0021] a fourth resistor, a first end of the fourth resistor is connected to a resistance control output end of the SOC chip and a control end of an adjustable resistor respectively.

[0022] Optionally, further comprising:

[0023] a current limiting module, a first end of the current limiting module is connected to a resistance control output end of the SOC chip, and a second end is connected to a control end of an adjustable resistor.

[0024] Optionally, the current limiting module comprises:

[0025] The fifth resistor has a first end connected to a resistance control output end of the SOC chip and a second end connected to a control end of the adjustable resistor.

[0026] To solve the above problems, the utility model further provides a kind of display, including display body, further including the adjusting circuit of display's backlight brightness of above-mentioned.

[0027] The utility model provides a kind of display and the adjusting circuit of its backlight brightness, including SOC chip, adjustable resistance module and backlight chip, SOC chip passes through the resistance of adjustable resistance to adjust the maximum output current of the backlight of backlight chip.This application has accessed adjustable resistance in the feedback pin of backlight chip, adjusts the resistance according to need Resistance, therefore can also adjust the maximum output current of backlight according to need, and then according to demand improves the brightness of the screen of display, to ensure the brightness of the screen of display, improves the perceptual experience of user. BRIEF DESCRIPTION OF DRAWINGS

[0028] To more clearly illustrate the technical scheme in the embodiment of the utility model, the drawings needed in prior art and embodiment will be simply introduced below, obviously, the drawings in the following description only some embodiments of the utility model, for ordinary skilled person in the art, without creative labor, other drawings can also be obtained according to these drawings.

[0029] Figure 1 It is a backlight circuit diagram in related art;

[0030] Figure 2 It is the adjusting circuit structure diagram of the backlight brightness of a kind of display provided by the utility model;

[0031] Figure 3 It is the specific structure circuit diagram of the adjusting circuit of the backlight brightness of a kind of display provided by the utility model. DETAILED DESCRIPTION

[0032] The core of the utility model is to provide a kind of display and the adjusting circuit of its backlight brightness, this application has accessed adjustable resistance in the feedback pin of backlight chip, adjusts the resistance according to need Resistance, therefore can also adjust the maximum output current of backlight according to need, and then according to demand improves the brightness of the screen of display, to ensure the brightness of the screen of display, improves the perceptual experience of user.

[0033] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model below. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0034] Please refer to Figure 2 , Figure 2 The utility model provides a kind of structure diagram of the adjusting circuit of the backlight brightness of display.

[0035] The adjusting circuit of the backlight brightness of the display, including SOC chip U1, adjustable resistance module 1 and backlight chip U2;

[0036] The resistance control output end of SOC chip U1 is connected with the control end of adjustable resistance module 1;

[0037] The first end of adjustable resistance module 1 is connected with the feedback pin of backlight chip U2, and the second end is grounded, for changing the resistance value based on the control of SOC chip U1.

[0038] It can be understood that after starting MPRT function, the closing time of backlight is several times longer than the opening time in a backlight switching cycle, so under the condition of outputting equivalent current value, the overall backlight power will be greatly reduced when MPRT function is started, so there is a margin to continue to increase the backlight current. The control circuit capable of improving the maximum output current of backlight module is provided based on the above idea, when starting MPRT function, the feedback pin of backlight chip U2 is adjusted to improve the backlight output current, improve the brightness of display and improve the display perception under MPRT function. Specifically, SOC chip U1 can change the maximum output current of backlight by controlling the resistance value of adjustable resistance module 1 to change the brightness of display screen.

[0039] It should be noted that the IO1 pin of SOC chip U1 is connected with the EN pin of backlight chip U2, which can control the opening of backlight chip U2 by outputting high level, and control the closing of backlight chip U2 by low level; The PWM (Pulse Width Modulation) 1 pin of SOC chip U1 is connected with the PDIM pin of backlight chip U2, and the PWM2 pin of SOC chip U1 is connected with the ADIM pin of backlight chip U2, which adjusts the backlight brightness by outputting PWM waveform with different duty cycles; When MPRT function is started, the backlight is closed in the screen color conversion, and the feedback input pin FB of backlight chip U2 is used to adjust the maximum output current of backlight.

[0040] Specifically, the resistance of the adjustable resistance module 1 is set as R, and the relationship between the adjustable resistance module 1 and the backlight chip U2 satisfies the formula , wherein V FB is a backlight chip reference voltage, I LED is a maximum output current of the backlight, the maximum output current of the backlight can be changed by changing the resistance R of the adjustable resistance module 1, and the brightness of the display screen is adjusted according to requirements.

[0041] It can be seen that in the present application, the adjustable resistance is connected to the feedback pin of the backlight chip U2, and the resistance value of the resistance is adjusted according to requirements, so that the maximum output current of the backlight can be adjusted according to requirements, and the brightness of the display screen is improved according to requirements, so that the brightness of the display screen is stable, and the user's experience is improved.

[0042] On the basis of the above embodiment:

[0043] Please refer to Figure 3 , Figure 3 is a specific structure circuit diagram of the backlight brightness adjusting circuit of the display provided by the present application.

[0044] As an optional embodiment, the adjustable resistance module 1 comprises:

[0045] The first end of the first resistance module is connected to the feedback pin of the backlight chip U2, and the second end is grounded.

[0046] The first end of the switch module Q1 is connected to the first end of the second resistance module, the second end is grounded, the control end is connected to the output end of the SOC chip U1, and is used for being turned on or turned off based on the control of the SOC chip U1.

[0047] The second end of the second resistance module is connected to the first end of the first resistance module.

[0048] It can be understood that when the MPRT function is not turned on, the SOC chip U1 controls the switch module Q1 to be disconnected, at this time, the resistance value of the feedback pin of the backlight chip U2 to the ground is the resistance value of the first resistance module, and the first resistance module and the backlight chip U2 satisfy the calculation formula , wherein V FB is a backlight chip reference voltage, I LEDR1 is the resistance value of the first resistance module, and the maximum output current of the backlight can be obtained according to the resistance value of R1; when the MPRT function is turned on, the brightness of the backlight chip U2 is suddenly reduced, in order to ensure the clarity and smoothness of the display screen, a larger current is needed to compensate for the loss of brightness, the SOC chip U1 controls the switch module Q1 to be turned on, at this time, the first resistance module and the second resistance module are connected in parallel, the resistance value of the feedback pin of the backlight chip U2 to the ground is the equivalent resistance value of the first resistance module and the second resistance module connected in parallel, and the first resistance module and the second resistance module satisfy the formula wherein R1 is the resistance value of the first resistance module, R2 is the resistance value of the second resistance module, and the maximum backlight current can be adjusted according to the resistance value of R1 and R2 connected in parallel.

[0049] It should be noted that the resistance of the second resistance module can be adjusted to change the maximum output current of the backlight according to the amount of current required to be increased.

[0050] It can be seen that the display backlight brightness adjusting circuit provided by the present application can change the maximum output current of the backlight by controlling the switch module Q1 to incorporate the second resistance module into the first resistance module, and the circuit structure is simple and the cost is low.

[0051] As an optional embodiment, the first resistance module comprises:

[0052] The first resistance R1, the first end of the first resistance R1 is connected with the first end of the second resistance R2, and the common end connected is connected with the feedback pin of the backlight chip U2, and the second end is grounded;

[0053] The second resistance R2, the second end of the second resistance R2 is grounded.

[0054] It can be understood that in order to more conveniently adjust the resistance value of the first resistance module, the first resistance module can be set as the first resistance R1 and the second resistance R2 connected in parallel, and the common end of the first end connected is connected with the feedback pin of the backlight chip U2. The first resistance R1, the second resistance R2 and the backlight chip U2 satisfy the formula wherein R11 is the resistance value of the first resistance R1, R21 is the resistance value of the second resistance R2, and V FB The reference voltage of the backlight chip is adjusted by adjusting the resistance values of the first resistance R1 and the second resistance R2 to control the output of the maximum current.

[0055] In addition, considering that when the switch module Q1 is turned off, the ground resistance of the backlight chip U2 at this time is only the first resistance module, if the first resistance module is provided with only one resistance, when this resistance is damaged, the current may not be output, and the screen of the display screen cannot be normally displayed, therefore, the first resistance R1 and the second resistance R2 are connected in parallel, if one resistance is damaged, the other resistance can work normally, thereby ensuring the output of the maximum current of the backlight of the backlight chip U2.

[0056] It should be noted that the first resistance module can also be connected in parallel by N resistances, and the common end of the first end is connected to the feedback pin of the backlight chip U2.

[0057] It can be seen that the first resistance R1 and the second resistance R2 are connected in parallel, on the one hand, the resistance values of the first resistance R1 and the second resistance R2 are adjusted to realize the adjustment of the first resistance module, and on the other hand, when one of the resistances is damaged, the display screen cannot work, thereby improving the working reliability of the display screen.

[0058] As an optional embodiment, the second resistance module comprises:

[0059] The third resistance R3 has a first end connected to the first end of the switch module Q1 and a second end connected to the first end of the first resistance module and the feedback pin of the backlight chip U2.

[0060] It can be understood that when the MPRT function is turned on, the SOC chip U1 controls the switch module Q1 to be turned on, at this time, the third resistance R3 is connected in parallel with the first resistance module, the third resistance R3, the first resistance module and the backlight chip satisfy the relationship formula , wherein R1 is the resistance value of the first resistance module, R2 is the resistance value of the third resistance R3, V FB is the reference voltage of the backlight chip, I LED is the maximum output current of the backlight, and the resistance value of the third resistance R3 can be changed according to the demand, thereby adjusting the maximum output current of the backlight.

[0061] It can be seen that the third resistance R3 is integrated into the first resistance module, and the resistance value of the third resistance R3 can be changed according to the demand, thereby adjusting the maximum output current of the backlight, improving the brightness of the display screen and improving the display perception under the MPRT function.

[0062] As an optional embodiment, the switch module Q1 comprises:

[0063] The power electronic switch has a first end connected to the first end of the resistance module, a second end connected to the ground, and a control end connected to the resistance value control output end of the SOC chip U1, and is turned on or turned off based on the control of the SOC chip U1.

[0064] It can be understood that the SOC chip U1 controls the power electronic switch to be turned on, the second resistance module is combined with the first resistance module, and the maximum output current of the backlight is adjusted according to the relationship between the first resistance module, the second resistance module and the backlight chip U2, so that the brightness of the display is improved.

[0065] In addition, the power electronic switch has high reliability and can quickly respond. After receiving the turn-on signal of the SOC chip U1, accurate control can be realized. In addition, the use of the power electronic switch can also reduce the frequency of maintenance and replacement, which not only improves the working efficiency of the display screen, but also reduces the use cost and maintenance cost.

[0066] As an optional embodiment, the power electronic switch is an N-MOS tube, the drain of the N-MOS tube is connected to the first end of the second resistance module, the gate is connected to the resistance control output end of the SOC chip U1, and the source is grounded, and is used for turning on or turning off based on the control of the SOC chip U1.

[0067] Specifically, when the SOC chip U1 controls the N-MOS tube to be turned off, the first resistance module is connected to the feedback pin of the backlight chip U2; when the SOC chip U1 controls the N-MOS tube to be turned on, the first resistance module is connected in parallel with the second resistance module, and the common end of the first end in parallel is connected to the feedback pin of the backlight chip U2, so as to change the maximum output current of the backlight according to the demand.

[0068] It can be seen that the N-MOS tube has a low on-resistance, which can reduce the energy loss of the display screen during operation. In addition, the N-MOS tube also has the characteristics of strong anti-interference ability.

[0069] As an optional embodiment, the circuit further comprises:

[0070] The fourth resistance R4 has a first end connected to the resistance control output end of the SOC chip U1 and a control end of the adjustable resistance, and a second end grounded.

[0071] Considering that when the MPRT function is not enabled, the IO2 pin of the SOC chip U1 needs to be at a low level, and there may be interference current in the circuit, which can turn on when the switch module Q1 is turned off, and cannot accurately adjust the resistance of the backlight chip U2 to the ground, so as to accurately change the maximum output current of the backlight, resulting in that the displayed picture of the display screen is not smooth or has ghosting. In order to solve this problem, the fourth resistance R4 is provided, the first end of the fourth resistance R4 is connected to the resistance control output end of the SOC chip U1, and the second end is grounded. In this way, during the process of controlling the switch module Q1 by the SOC chip U1, if interference current occurs, the fourth resistance R4 can directly guide the interference current to the ground, reducing the influence of the interference current on the switch module Q1.

[0072] It can be seen that when the switch module Q1 is controlled to be closed by the SOC chip U1, the fourth resistor R4 is connected, the influence of the interference current on the switch module Q1 is reduced, and the reliability of the display is improved.

[0073] As an optional embodiment, the display further comprises:

[0074] The first end of the current limiting module is connected with the resistance control output end of the SOC chip U1 and the first end of the fourth resistor R4 respectively, and the second end is connected with the control end of the adjustable resistor.

[0075] Considering that the switch module Q1 has a parasitic capacitor, when the switch module Q1 is turned on and turned off, the parasitic capacitor is charged and discharged, thereby generating a large instantaneous current, causing the switch module Q1 to bear a large power consumption and be damaged, thereby affecting the maximum output current of the backlight.

[0076] It can be seen that the current limiting module in the application can prevent the current from being too large and damaging other electronic elements connected in series, thereby improving the reliability and stability of the circuit.

[0077] As an optional embodiment, the current limiting module comprises:

[0078] The first end of the fifth resistor R5 is connected with the resistance control output end of the SOC chip U1 and the first end of the fourth resistor R4 respectively, and the second end is connected with the control end of the adjustable resistor.

[0079] It can be understood that in order to prevent the switch module Q1 from being damaged by the instantaneous current generated by the parasitic capacitor inside the switch module Q1, the fifth resistor R5 is arranged between the resistance control output end of the SOC chip U1 and the switch module Q1, and the fifth resistor R5 is used to discharge the residual charge on the parasitic capacitor, thereby protecting the switch module Q1, so that the resistance of the first resistor module and the second resistor module can be normally adjusted, and the stability of the circuit is improved.

[0080] The utility model further provides a kind of display, including display body, further include the adjusting circuit of the backlight brightness of the display described above.

[0081] It can be understood that the adjusting circuit of the backlight brightness of the display is provided, several resistors and a switch tube are designed in the circuit, the maximum current of the backlight can be adjusted according to the requirement, the circuit structure is simple, additional cost is almost not increased, the circuit structure is compatible designed into the backlight circuit of the display, when some software function development needs to improve the brightness in a short time, the internal board card hardware of the display does not need to be modified, the corresponding control signal is output by the SOC chip U1, the resistance value of the resistance of the backlight chip U2 to the ground is changed, the maximum output current of the backlight is changed, and the brightness is improved.

[0082] The various embodiments are described in progressive manner in the specification, and each embodiment focuses on the difference from other embodiments, and the same or similar parts of each embodiment can be referred to each other.

[0083] It should also be noted that the relative terms, such as first and second, are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A backlight brightness adjustment circuit for a display, characterized in that, This includes SOC chips, adjustable resistor modules, and backlight chips; The resistance control output terminal of the SOC chip is connected to the control terminal of the adjustable resistor module; The first end of the adjustable resistor module is connected to the feedback pin of the backlight chip, and the second end is grounded, which is used to change its resistance value based on the control of the SOC chip. The adjustable resistor module includes: The first resistor module has a first end connected to the feedback pin of the backlight chip and a second end grounded. A switching module, wherein the first end of the switching module is connected to the first end of the second resistor module, the second end is grounded, and the control end is connected to the output end of the SOC chip, for use in controlling the SOC chip to turn on or off. The second resistor module has its second end connected to the first end of the first resistor module.

2. The backlight brightness adjustment circuit of the display as described in claim 1, characterized in that, The first resistor module includes: The first resistor has its first end connected to the first end of the second resistor, and the common end of the connection is connected to the feedback pin of the backlight chip. The second end is grounded. The second resistor has its second terminal grounded.

3. The backlight brightness adjustment circuit of the display as described in claim 1, characterized in that, The second resistor module includes: The third resistor has its first end connected to the first end of the switch module, and its second end connected to the first end of the first resistor module and the feedback pin of the backlight chip.

4. The backlight brightness adjustment circuit of the display as described in claim 1, characterized in that, The switching module includes: A power electronic switch, wherein the first terminal of the power electronic switch is connected to the first terminal of the resistor module, the second terminal is grounded, and the control terminal is connected to the resistance control output terminal of the SOC chip, and the switch is turned on or off based on the control of the SOC chip.

5. The backlight brightness adjustment circuit of the display as described in claim 4, characterized in that, The power electronic switch is an N-MOS transistor. The drain of the N-MOS transistor is connected to the first terminal of the first resistor module, the gate is connected to the resistance control output terminal of the SOC chip, and the source is grounded. It is used to control the conduction or cutoff based on the SOC chip.

6. The backlight brightness adjustment circuit of the display as described in claim 1, characterized in that, Also includes: The fourth resistor has its first end connected to the resistance control output terminal of the SOC chip and the control terminal of the adjustable resistor, and its second end grounded.

7. The backlight brightness adjustment circuit of the display as described in claim 6, characterized in that, Also includes: A current limiting module, wherein the first end of the current limiting module is connected to the resistance control output terminal of the SOC chip and the first end of the fourth resistor, and the second end is connected to the control terminal of the adjustable resistor.

8. The backlight brightness adjustment circuit of the display as described in claim 7, characterized in that, The current limiting module includes: The fifth resistor has its first end connected to the resistance control output terminal of the SOC chip and its second end connected to the control terminal of the adjustable resistor.

9. A display, characterized in that, It includes the display body, and also includes the backlight brightness adjustment circuit of the display as described in any one of 1 to 8.

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