CN109523957B - Drive circuit, backlight module and display panel - Google Patents
Drive circuit, backlight module and display panel Download PDFInfo
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- CN109523957B CN109523957B CN201811579749.0A CN201811579749A CN109523957B CN 109523957 B CN109523957 B CN 109523957B CN 201811579749 A CN201811579749 A CN 201811579749A CN 109523957 B CN109523957 B CN 109523957B
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/3406—Control of illumination source
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/10—Controlling the intensity of the light
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2320/00—Control of display operating conditions
- G09G2320/06—Adjustment of display parameters
- G09G2320/0626—Adjustment of display parameters for control of overall brightness
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- Theoretical Computer Science (AREA)
- Circuit Arrangement For Electric Light Sources In General (AREA)
Abstract
The application relates to a driving circuit, a backlight module and a display panel. The driving circuit comprises a control circuit and a voltage regulating circuit. The first input end of the control circuit is connected with the high-level voltage signal, the second input end of the control circuit is connected with the reference voltage signal, the third input end of the control circuit is grounded and used for receiving the high-level voltage signal and the reference voltage signal, the resistance value of the control circuit is adjusted according to the brightness of the external environment, and the control signal is generated according to the adjusted resistance value, the high-level voltage signal and the reference voltage signal. The first input end of the voltage regulating circuit is connected with the output end of the control circuit, the second input end of the voltage regulating circuit is connected with the power supply voltage, and the third input end of the voltage regulating circuit is grounded and used for receiving the control signal and the power supply voltage and generating the working voltage according to the control signal and the power supply voltage, so that the luminous light source can regulate the self brightness according to the working voltage and the difference between the self brightness and the environment brightness is reduced.
Description
Technical Field
The application relates to the field of display, in particular to a driving circuit, a backlight module and a display panel.
Background
Thin Film Transistor Liquid Crystal Display (TFT-LCD) panels are one of the major products of flat panel displays, and have become an important Display platform in the modern information technology industry and video products. In the working process of the TFT-LCD display panel, a power supply and a signal are mainly provided for a display area through a driving chip on a printed circuit board, so that image display is realized.
In the current display panel, the brightness of the backlight used is fixed and cannot be changed along with the change of the external brightness, the brightness difference is generated between the display panel and the external environment, and the brightness difference can damage human eyes.
Disclosure of Invention
Therefore, it is necessary to provide a driving circuit, a backlight module and a display panel for solving the problem that the brightness of the display panel cannot be automatically adjusted.
The application provides a drive circuit, including:
the control circuit is connected with a high-level voltage signal at a first input end, connected with a reference voltage signal at a second input end and grounded at a third input end, and used for receiving the high-level voltage signal and the reference voltage signal, adjusting the resistance value of the control circuit according to the brightness of the external environment, and generating a control signal according to the adjusted resistance value, the high-level voltage signal and the reference voltage signal; and
and the first input end of the voltage regulating circuit is connected with the output end of the control circuit, the second input end of the voltage regulating circuit is connected with the power supply voltage, and the third input end of the voltage regulating circuit is grounded and is used for receiving the control signal and the power supply voltage and generating working voltage according to the control signal and the power supply voltage.
In some embodiments provided herein, the control circuit includes:
the first input end of the first voltage division branch is connected with the high-level voltage signal, the second input end of the first voltage division branch is grounded and used for receiving the high-level voltage signal, adjusting the resistance value of the first voltage division branch according to the external environment brightness, and generating feedback voltage according to the adjusted resistance value of the first voltage division branch and the high-level voltage signal; and
and the first input end of the comparison branch circuit is connected with the reference voltage signal, and the second input end of the comparison branch circuit is connected with the first voltage division branch circuit and is used for receiving the reference voltage signal and the feedback voltage and generating a control signal according to the reference voltage signal and the feedback voltage.
In some embodiments provided herein, the voltage regulation circuit includes:
the first input end of the switch branch circuit is connected with the output end of the comparison branch circuit, the second input end of the switch branch circuit is connected with the power supply voltage, the third input end of the switch branch circuit is grounded, and the output end of the switch branch circuit is connected with the light-emitting light source and is used for receiving the control signal, taking the power supply voltage as the working voltage according to the control signal and outputting the working voltage to the light-emitting light source; and
and the input end of the second voltage division branch is connected with the power supply voltage and the second input end of the switch branch, and the output end of the second voltage division branch is connected with the output end of the switch branch and the light-emitting source.
In some embodiments provided herein, the first voltage dividing branch comprises:
the first end of the first resistor is connected with the high-level voltage signal, the second end of the first resistor is connected with the second input end of the comparison branch circuit, and the first resistor is a photoresistor; and
and the first end of the second resistor is connected with the second end of the first resistor and the second input end of the comparison branch circuit, and the second end of the second resistor is grounded.
In some embodiments provided herein, the comparing branch comprises:
and a positive input end of the comparator is connected with the reference voltage signal, a negative input end of the comparator is connected with the second end of the first resistor and the first end of the second resistor, and an output end of the comparator is connected with the first input end of the switch circuit.
In some embodiments provided herein, the switching branch comprises:
a grid of the switching tube is connected with the output end of the comparator, a source electrode of the switching tube is connected with the power supply voltage, and a drain electrode of the switching tube is connected with the light-emitting source; and
and the first end of the third resistor is connected with the output end of the comparator and the grid electrode of the switching tube, and the second end of the third resistor is grounded.
In some embodiments provided herein, the second voltage divider circuit includes:
and the first end of the fourth resistor is connected with the power supply voltage and the source electrode of the switch tube, and the second end of the fourth resistor is connected with the drain electrode of the switch tube and the light-emitting light source.
Based on the same inventive concept, the present application further provides a backlight module, including:
the LED lamp string comprises a plurality of LED lamps and is used for providing a light source; and
the driving circuit is connected with the LED lamp string and used for supplying power to the LED lamp string;
wherein the driving circuit includes:
the control circuit is connected with a high-level voltage signal at a first input end, connected with a reference voltage signal at a second input end and grounded at a third input end, and used for receiving the high-level voltage signal and the reference voltage signal, adjusting the resistance value of the control circuit according to the brightness of the external environment, and generating a control signal according to the adjusted resistance value, the high-level voltage signal and the reference voltage signal; and
and the first input end of the voltage regulating circuit is connected with the output end of the control circuit, the second input end of the voltage regulating circuit is connected with the power supply voltage, and the third input end of the voltage regulating circuit is grounded and used for receiving the control signal and the power supply voltage, generating working voltage according to the control signal and the power supply voltage and outputting the working voltage to the LED lamp string.
In some embodiments provided by the present application, the driving circuit specifically includes:
the first end of the first resistor is connected with the high-level voltage signal, and the first resistor is a photoresistor;
the first end of the second resistor is connected with the second end of the first resistor, and the second end of the second resistor is grounded;
a positive input end of the comparator is connected with the reference voltage signal, and a negative input end of the comparator is connected with the second end of the first resistor and the first end of the second resistor;
a grid electrode of the switching tube is connected with the output end of the comparator, a source electrode of the switching tube is connected with the power supply voltage, and a drain electrode of the switching tube is connected with the LED lamp string;
the first end of the third resistor is connected with the output end of the comparator and the grid electrode of the switch tube, and the second end of the third resistor is grounded; and
and the first end of the fourth resistor is connected with the power supply voltage and the source electrode of the switch tube, and the second end of the fourth resistor is connected with the drain electrode of the switch tube and the LED lamp string.
Based on the same inventive concept, the present application also provides a display panel, including:
a display area for displaying; and
the peripheral circuit area is matched with the display area and used for supplying power to the display area and providing a driving signal;
wherein the peripheral circuit region includes a driving circuit including:
the control circuit is connected with a high-level voltage signal at a first input end, connected with a reference voltage signal at a second input end and grounded at a third input end, and used for receiving the high-level voltage signal and the reference voltage signal, adjusting the resistance value of the control circuit according to the brightness of the external environment, and generating a control signal according to the adjusted resistance value, the high-level voltage signal and the reference voltage signal; and
and the first input end of the voltage regulating circuit is connected with the output end of the control circuit, the second input end of the voltage regulating circuit is connected with the power supply voltage, and the third input end of the voltage regulating circuit is grounded and is used for receiving the control signal and the power supply voltage and generating working voltage according to the control signal and the power supply voltage.
In summary, the embodiment of the present application provides a driving circuit, a backlight module and a display panel. The driving circuit comprises a control circuit and a voltage regulating circuit. The first input end of the control circuit is connected with a high-level voltage signal, the second input end of the control circuit is connected with a reference voltage signal, the third input end of the control circuit is grounded, the control circuit is used for receiving the high-level voltage signal and the reference voltage signal, adjusting the resistance value of the control circuit according to the external environment brightness, and generating a control signal according to the adjusted resistance value, the high-level voltage signal and the reference voltage signal. The first input end of the voltage regulating circuit is connected with the output end of the control circuit, the second input end of the voltage regulating circuit is connected with power supply voltage, the third input end of the voltage regulating circuit is grounded, and the voltage regulating circuit is used for receiving the control signal and the power supply voltage and generating working voltage according to the control signal and the power supply voltage. In the drive circuit that this application provided, control circuit basis external environment luminance adjustment self resistance, according to the resistance after the adjustment and high level voltage signal with reference voltage signal generates control signal, then passes through voltage regulating circuit basis control signal and mains voltage generates operating voltage, so that luminous light source can be according to operating voltage adjusts the luminance of self, reduces the difference between self luminance and the ambient brightness.
Drawings
FIG. 1 is an electrical schematic diagram of an exemplary display panel;
fig. 2 is a schematic circuit structure diagram of a driving circuit according to an embodiment of the present disclosure;
fig. 3 is a schematic diagram of a position structure of a first resistor according to an embodiment of the present disclosure;
fig. 4 is an equivalent circuit diagram of the connection between the driving circuit and the LED light string according to the embodiment of the present disclosure.
The reference numbers illustrate:
100 control circuit
110 first voltage division branch
120 compare branch
200 voltage regulating circuit
210 switch branch
220 second voltage-dividing branch
310 window
R1 first resistor
R2 second resistor
R3 third resistor
R4 fourth resistor
Equivalent resistance of Rled LED lamp string
D1 comparator
M1 switch tube
Detailed Description
In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and those skilled in the art will be able to make similar modifications without departing from the spirit of the application and it is therefore not intended to be limited to the embodiments disclosed below.
The TFT-LCD display panel is one of the major products of the current flat panel display, and has become an important display platform in the modern information technology industry and video products. Referring to fig. 1, the main driving principle of the TFT-LCD display panel includes: the system mainboard connects data such as pixel signals, control signals and the like and a power supply with a connector on a Printed Circuit Board (PCB) through wires, the data are processed by a Timing Controller (TCON) integrated Circuit on the PCB, and then are connected with a display area through the PCB and a Source-Chip on Film (S-COF) and a Gate-Chip on Film (G-COF), so that the display area obtains the required power supply and data to realize image display.
However, in the display process, the backlight brightness of the display panel is fixed and cannot be automatically changed along with the change of the external brightness, and the brightness difference between the display panel and the external environment is generated and can damage human eyes.
However, in the production process, the display panel is prone to have the problems of liquid crystal cell line defects, slight damage to electronic components and the like, and the problems are prone to cause defects of the display panel in the using process of a user, such as line breakage, corrosion and the like, and the quality of a product is seriously affected, so that aging detection is needed to be performed after the manufacturing process of the display panel is completed to test whether the problems exist. However, conventional burn-in test designs have failed to meet customer demands for the variety of voltages used in the burn-in test process.
In view of the above problem, embodiments of the present application provide a driving circuit. Referring to fig. 2, the driving circuit includes a control circuit 100 and a voltage regulating circuit 200.
The first input end of the control circuit 100 is connected with a high-level voltage signal, the second input end of the control circuit 100 is connected with a reference voltage signal, the third input end of the control circuit 100 is grounded, the control circuit 100 is used for receiving the high-level voltage signal and the reference voltage signal, adjusting the resistance value of the control circuit according to the external environment brightness, and generating a control signal according to the adjusted resistance value, the high-level voltage signal and the reference voltage signal.
The first input end of the voltage regulating circuit 200 is connected with the output end of the control circuit 100, the second input end of the voltage regulating circuit 200 is connected with the power supply voltage, the third input end of the voltage regulating circuit 200 is grounded, and the voltage regulating circuit 200 is used for receiving the control signal and the power supply voltage and generating the working voltage according to the control signal and the power supply voltage.
In this embodiment, the control circuit 100 adjusts its own resistance value according to the external ambient brightness, generates a control signal according to the adjusted resistance value, the high-level voltage signal and the reference voltage signal, and then generates a working voltage according to the control signal and the power voltage through the voltage regulating circuit 200, so that the light emitting source can adjust its own brightness according to the working voltage, and reduce the difference between its own brightness and the ambient brightness.
In some embodiments provided herein, the control circuit 100 includes a first voltage dividing branch 110 and a comparing branch 120.
The first input end of the first voltage division branch 110 is connected to the high level voltage signal, the second input end of the first voltage division branch 110 is grounded, the first voltage division branch 110 is configured to receive the high level voltage signal, adjust a resistance value of the first voltage division branch according to the external environment brightness, and generate a feedback voltage according to the adjusted resistance value of the first voltage division branch and the high level voltage signal.
A first input terminal of the comparing branch 120 is connected to the reference voltage signal, a second input terminal of the comparing branch 120 is connected to the first voltage dividing branch 110, and the comparing branch 120 is configured to receive the reference voltage signal and the feedback voltage, and generate a control signal according to the reference voltage signal and the feedback voltage.
In this embodiment, the first voltage dividing branch 110 adjusts its own resistance value according to the external environment brightness, so as to transform the output feedback voltage, and then the comparison branch 120 compares the reference voltage signal with the feedback voltage, and generates a control signal according to the comparison result, so that the voltage regulating circuit 200 adjusts the output working voltage according to the control signal.
In some embodiments provided herein, the voltage regulating circuit 200 includes a switching branch 210 and a second voltage dividing branch 220.
The first input end of the switch branch 210 is connected to the output end of the comparison branch 120, the second input end of the switch branch 210 is connected to the power voltage, the third input end of the switch branch 210 is grounded, the output end of the switch branch 210 is connected to the light emitting source, and the switch branch 210 is configured to receive the control signal, use the power voltage as the working voltage according to the control signal, and output the working voltage to the light emitting source.
The input end of the second voltage-dividing branch 220 is connected to the power supply voltage and the second input end of the switch branch 210, and the output end of the second voltage-dividing branch 220 is connected to the output end of the switch branch 210 and the light-emitting source.
In this embodiment, the switch branch 210 is opened or closed according to the control signal. When the switching branch 210 is closed, the power voltage is the working voltage and is provided to the light-emitting source through the switching branch 210. When the switching branch 210 is turned off, a working voltage is provided through the second voltage-dividing branch 220, and at this time, the working voltage is equal to a power voltage minus a voltage across the second voltage-dividing branch 220, and a voltage across the light-emitting source is reduced, thereby causing a reduction in luminance.
In some embodiments provided herein, the first voltage-dividing branch 110 includes a first resistor R1 and a second resistor R2.
A first terminal of the first resistor R1 is connected to the high level voltage signal, a second terminal of the first resistor R1 is connected to a second input terminal of the comparing branch 120, and the first resistor R1 is a photo-resistor.
A first terminal of the second resistor R2 is connected to a second terminal of the first resistor R1 and a second input terminal of the comparison branch 120, and a second terminal of the second resistor R2 is grounded.
In this embodiment, the first resistor R1 is a photo resistor, and the resistance thereof decreases with the increase of the brightness, and when the brightness in the surrounding environment reaches the brightness threshold thereof, the resistance thereof is equal to about 0. Thus, the feedback voltage is equal to VDD when the ambient brightness is greater than its brightness threshold. When the ambient brightness is less than the brightness threshold, the brightness of the first resistor R1 gradually increases, and the feedback voltage is VDD × R2/(R1+ R2).
Referring to fig. 3, a window 310 is formed on a front frame covering edge (corresponding to a dotted line in fig. 3), and the first resistor R1 detects the brightness of the surrounding environment through the window 310. That is, the first resistor R1 is located in the non-display area, and the arrangement of the first resistor R1 at this position will not affect the normal display of the display area, nor will it be blocked by the front frame to affect the detection effect.
In some embodiments, the comparing branch 120 includes a comparator D1, a positive input terminal of the comparator D1 is connected to the reference voltage signal, a negative input terminal of the comparator D1 is connected to the second terminal of the first resistor R1 and the first terminal of the second resistor R2, and an output terminal of the comparator D1 is connected to the first input terminal of the switch circuit.
In this embodiment, the voltage of the reference voltage signal is about VDD × 80%, so when the ambient brightness is greater than the brightness threshold, the voltage of the positive input terminal of the comparator D1 is less than the voltage of the negative input terminal thereof, and the comparator D1 outputs a low-level control signal. When the ambient brightness is less than the brightness threshold, the brightness of the first resistor R1 gradually increases, and the feedback voltage VDD × R2/(R1+ R2) is less than the reference voltage signal, the comparator D1 outputs a high-level control signal.
In some embodiments provided herein, the switching leg 210 includes a switching tube M1 and a third resistor R3.
The gate of the switch tube M1 is connected to the output terminal of the comparator D1, the source of the switch tube M1 is connected to the power voltage, and the drain of the switch tube M1 is connected to the light source.
The first end of the third resistor R3 is connected to the output end of the comparator D1 and the gate of the switch M1, and the second end of the third resistor R3 is grounded.
The second voltage dividing circuit includes a fourth resistor, a first end of the fourth resistor is connected to the power voltage and the source of the switch M1, and a second end of the fourth resistor is connected to the drain of the switch M1 and the light source.
It is understood that when the control signal is a low level signal, the switch tube M1 is turned on, and the power voltage is directly supplied to the light emitting source through the switch tube M1. When the control signal is a high level signal, the switching tube M1 is turned off, and the fourth resistor R4 provides a working voltage for the light source, where the working voltage provided for the light source is equal to the power voltage minus the voltage across the fourth resistor R4.
Referring to fig. 4, in this embodiment, it is assumed that the high-level voltage signal is VDD, the power supply voltage is Vled, the first resistor R1 is a photo-resistor, the resistance value of the photo-resistor decreases with the increase of the ambient brightness, the second resistor R2, the third resistor R3 and the fourth resistor R4 are all common resistors, the reference voltage is VDD × 80%, the light-emitting source is an LED light string, and the equivalent resistor of the LED light string is Rled.
When the ambient brightness is not less than the brightness threshold of the first resistor R1, the resistance of the first resistor R1 is equal to about 0 ohm, the negative input end voltage of the comparator D1 is VDD, and the positive input end voltage thereof is the reference voltage Vref (equal to about VDD × 80%), so that the control signal output by the comparator D1 is low level, the switching tube M1 is turned on, the voltage on the LED light string is the power voltage Vled, and the LED light string normally operates.
When the ambient brightness is less than the brightness threshold of the first resistor R1 (e.g., 30 lumens), the resistance of the first resistor R1 increases, the voltage value at the negative input terminal of the comparator D1 is VDD × R2/(R1+ R2), and by setting the ratio of the first resistor R1 to the second resistor R2, the voltage value VDD × R2/(R1+ R2) at the negative input terminal of the comparator D1 is less than the reference voltage signal value Vref when the ambient brightness is less than the brightness threshold of the first resistor R1. At this time, the control signal output by the comparator D1 is a high level signal, the gate of the switching tube M1 is at a high level, and the switching tube M1 is turned off. At this time, the voltage applied to the LED string is Vled × R3/(R2+ R3), that is, the voltage applied to the LED string decreases, and the backlight brightness decreases.
In some embodiments provided by the present application, the switching transistor M1 may be a field effect transistor or a triode.
Based on the same inventive concept, the application also provides a backlight module. The backlight module includes: LED lamp cluster and drive circuit. The LED lamp string comprises a plurality of LED lamps and is used for providing light sources. The driving circuit is connected with the LED lamp string and used for supplying power to the LED lamp string.
In this embodiment, the driving circuit includes a control circuit 100 and a voltage regulating circuit 200.
The first input end of the control circuit 100 is connected with a high-level voltage signal, the second input end of the control circuit 100 is connected with a reference voltage signal, the third input end of the control circuit 100 is grounded, the control circuit 100 is used for receiving the high-level voltage signal and the reference voltage signal, adjusting the resistance value of the control circuit according to the external environment brightness, and generating a control signal according to the adjusted resistance value, the high-level voltage signal and the reference voltage signal.
The first input end of the voltage regulating circuit 200 is connected with the output end of the control circuit 100, the second input end of the voltage regulating circuit 200 is connected with a power supply voltage, the third input end of the voltage regulating circuit 200 is grounded, and the voltage regulating circuit 200 is used for receiving the control signal and the power supply voltage, generating a working voltage according to the control signal and the power supply voltage and outputting the working voltage to the LED lamp string.
In some embodiments provided herein, the control circuit 100 includes a first resistor R1, a second resistor R2, and a comparator D1.
The first end of the first resistor R1 is connected with the high level voltage signal, and the first resistor R1 is a photoresistor.
The first end of the second resistor R2 is connected with the second end of the first resistor R1, and the second end of the second resistor R2 is grounded.
The positive input terminal of the comparator D1 is connected to the reference voltage signal, and the negative input terminal of the comparator D1 is connected to the second terminal of the first resistor R1 and the first terminal of the second resistor R2.
In some embodiments provided herein, the voltage regulating circuit 200 includes a switch tube M1, a third resistor R3, and a fourth resistor R4.
The grid of the switch tube M1 is connected with the output end of the comparator D1, the source of the switch tube M1 is connected with the power voltage, and the drain of the switch tube M1 is connected with the LED lamp string.
The first end of the third resistor R3 is connected to the output end of the comparator D1 and the gate of the switch M1, and the second end of the third resistor R3 is grounded.
A first end of the fourth resistor R4 is connected to the power voltage and the source of the switch M1, and a second end of the fourth resistor R4 is connected to the drain of the switch M1 and the LED string.
In this embodiment, the first resistor R1 is a photo resistor, and the resistance thereof decreases with the increase of the brightness, and when the brightness in the surrounding environment reaches the brightness threshold thereof, the resistance thereof is equal to about 0. Thus, the feedback voltage is equal to VDD when the ambient brightness is greater than its brightness threshold. When the ambient brightness is less than the brightness threshold, the brightness of the first resistor R1 gradually increases, and the feedback voltage is VDD × R2/(R1+ R2).
Assuming that the high-level voltage signal is VDD, the power supply voltage is Vled, the first resistor R1 is a photo-resistor, the second resistor R2, the third resistor R3 and the fourth resistor R4 are all common resistors, the reference voltage is VDD × 80%, and the equivalent resistor of the LED light string is Rled.
When the ambient brightness is not less than the brightness threshold of the first resistor R1, the resistance of the first resistor R1 is equal to about 0 ohm, the negative input end voltage of the comparator D1 is VDD, and the positive input end voltage thereof is the reference voltage Vref (equal to about VDD × 80%), so that the control signal output by the comparator D1 is low level, the switching tube M1 is turned on, the voltage on the LED light string is the power voltage Vled, and the LED light string normally operates.
When the ambient brightness is less than the brightness threshold of the first resistor R1 (e.g., 30 lumens), the resistance of the first resistor R1 increases, the voltage value at the negative input terminal of the comparator D1 is VDD × R2/(R1+ R2), and by setting the ratio of the first resistor R1 to the second resistor R2, the voltage value VDD × R2/(R1+ R2) at the negative input terminal of the comparator D1 is less than the reference voltage signal value Vref when the ambient brightness is less than the brightness threshold of the first resistor R1. At this time, the control signal output by the comparator D1 is a high level signal, the gate of the switching tube M1 is at a high level, and the switching tube M1 is turned off. At this time, the voltage applied to the LED string is Vled × R3/(R2+ R3), that is, the brightness of the LED string is reduced when the voltage applied to the LED string is reduced, so the backlight brightness of the backlight module is reduced.
Based on the same inventive concept, the present application also provides a display panel including a display region and a peripheral circuit region. The display area is used for displaying. The peripheral circuit area is matched with the display area and used for supplying power to the display area and providing a driving signal.
The peripheral circuit region includes a driving circuit, and the driving circuit includes a control circuit 100 and a voltage regulating circuit 200.
The first input end of the control circuit 100 is connected with a high-level voltage signal, the second input end of the control circuit 100 is connected with a reference voltage signal, the third input end of the control circuit 100 is grounded, the control circuit 100 is used for receiving the high-level voltage signal and the reference voltage signal, adjusting the resistance value of the control circuit according to the external environment brightness, and generating a control signal according to the adjusted resistance value, the high-level voltage signal and the reference voltage signal.
The first input end of the voltage regulating circuit 200 is connected with the output end of the control circuit 100, the second input end of the voltage regulating circuit 200 is connected with the power voltage, and the voltage regulating circuit 200 is used for receiving the control signal and the power voltage and generating the working voltage according to the control signal and the power voltage.
Since the driving circuit in this embodiment is the driving circuit in any of the above embodiments, the implementation and the working principle thereof are not described herein again.
In summary, the embodiment of the present application provides a driving circuit, a backlight module and a display panel. The driving circuit includes a control circuit 100 and a voltage regulating circuit 200. The first input end of the control circuit 100 is connected with a high-level voltage signal, the second input end of the control circuit 100 is connected with a reference voltage signal, the third input end of the control circuit 100 is grounded, the control circuit 100 is used for receiving the high-level voltage signal and the reference voltage signal, adjusting the resistance value of the control circuit according to the external environment brightness, and generating a control signal according to the adjusted resistance value, the high-level voltage signal and the reference voltage signal. The first input end of the voltage regulating circuit 200 is connected with the output end of the control circuit 100, the second input end of the voltage regulating circuit 200 is connected with the power supply voltage, the third input end of the voltage regulating circuit 200 is grounded, and the voltage regulating circuit 200 is used for receiving the control signal and the power supply voltage and generating the working voltage according to the control signal and the power supply voltage. In the drive circuit that this application provided, control circuit 100 basis external environment luminance adjustment self resistance, according to the resistance after the adjustment and high level voltage signal with reference voltage signal generates control signal, then passes through voltage regulating circuit 200 basis control signal with mains voltage generates operating voltage, so that luminous light source can be according to operating voltage adjusts the luminance of self, reduces the difference between self luminance and the ambient brightness.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (9)
1. A driver circuit, comprising:
the control circuit is connected with a high-level voltage signal at a first input end, connected with a reference voltage signal at a second input end and grounded at a third input end, and used for receiving the high-level voltage signal and the reference voltage signal, adjusting the resistance value of the control circuit according to the brightness of the external environment, and generating a control signal according to the adjusted resistance value, the high-level voltage signal and the reference voltage signal; and
the first input end of the voltage regulating circuit is connected with the output end of the control circuit, the second input end of the voltage regulating circuit is connected with a power supply voltage, and the third input end of the voltage regulating circuit is grounded and is used for receiving the control signal and the power supply voltage and generating a working voltage according to the control signal and the power supply voltage, so that the luminous light source can regulate the self brightness according to the working voltage and reduce the difference between the self brightness of the luminous light source and the ambient brightness;
wherein the control circuit comprises:
the first input end of the first voltage division branch is connected with the high-level voltage signal, the second input end of the first voltage division branch is grounded and used for receiving the high-level voltage signal, adjusting the resistance value of the first voltage division branch according to the external environment brightness, and generating feedback voltage according to the adjusted resistance value of the first voltage division branch and the high-level voltage signal; and
a comparison branch, a first input end of which is connected with the reference voltage signal and a second input end of which is connected with the first voltage division branch, and is used for receiving the reference voltage signal and the feedback voltage and generating a control signal according to the reference voltage signal and the feedback voltage;
the voltage regulating circuit includes:
the first input end of the switch branch circuit is connected with the output end of the comparison branch circuit, the second input end of the switch branch circuit is connected with the power supply voltage, the third input end of the switch branch circuit is grounded, and the output end of the switch branch circuit is connected with the light-emitting light source and is used for receiving the control signal, taking the power supply voltage as the working voltage according to the control signal and outputting the working voltage to the light-emitting light source; and
the input end of the second voltage division branch is connected with the power supply voltage and the second input end of the switch branch, and the output end of the second voltage division branch is connected with the output end of the switch branch and the light-emitting source;
the switch branch circuit is switched on or switched off according to the control signal, when the switch branch circuit is switched on, the power supply voltage is the working voltage and is supplied to the light-emitting light source through the switch branch circuit, and when the switch branch circuit is switched off, the working voltage is supplied through the second voltage division branch circuit.
2. The driving circuit of claim 1, wherein the first voltage-dividing branch comprises:
a first resistor, a first end of which is connected with the high level voltage signal, a second end of which is connected with a second input end of the comparison branch, and the first resistor is a photoresistor; and
and the first end of the second resistor is connected with the second end of the first resistor and the second input end of the comparison branch circuit, and the second end of the second resistor is grounded.
3. The driver circuit of claim 2, wherein the comparison branch comprises:
and the positive input end of the comparator is connected with the reference voltage signal, the negative input end of the comparator is connected with the second end of the first resistor and the first end of the second resistor, and the output end of the comparator is connected with the first input end of the switch branch circuit.
4. The drive circuit of claim 3, wherein the switching leg comprises:
a grid of the switching tube is connected with the output end of the comparator, a source electrode of the switching tube is connected with the power supply voltage, and a drain electrode of the switching tube is connected with the light-emitting source; and
and the first end of the third resistor is connected with the output end of the comparator and the grid electrode of the switching tube, and the second end of the third resistor is grounded.
5. The drive circuit of claim 4, wherein the second voltage divider circuit comprises:
and the first end of the fourth resistor is connected with the power supply voltage and the source electrode of the switch tube, and the second end of the fourth resistor is connected with the drain electrode of the switch tube and the light-emitting light source.
6. A backlight module, comprising:
the LED lamp string comprises a plurality of LED lamps and is used for providing a light source; and
the driving circuit is connected with the LED lamp string and used for supplying power to the LED lamp string;
wherein the driving circuit includes:
the control circuit is connected with a high-level voltage signal at a first input end, connected with a reference voltage signal at a second input end and grounded at a third input end, and used for receiving the high-level voltage signal and the reference voltage signal, adjusting the resistance value of the control circuit according to the brightness of the external environment, and generating a control signal according to the adjusted resistance value, the high-level voltage signal and the reference voltage signal; and
the first input end of the voltage regulating circuit is connected with the output end of the control circuit, the second input end of the voltage regulating circuit is connected with a power supply voltage, and the third input end of the voltage regulating circuit is grounded and is used for receiving the control signal and the power supply voltage, generating a working voltage according to the control signal and the power supply voltage and outputting the working voltage to the LED lamp string;
the control circuit includes:
the first input end of the first voltage division branch is connected with the high-level voltage signal, the second input end of the first voltage division branch is grounded and used for receiving the high-level voltage signal, adjusting the resistance value of the first voltage division branch according to the external environment brightness, and generating feedback voltage according to the adjusted resistance value of the first voltage division branch and the high-level voltage signal; and
a comparison branch, a first input end of which is connected with the reference voltage signal and a second input end of which is connected with the first voltage division branch, and is used for receiving the reference voltage signal and the feedback voltage and generating a control signal according to the reference voltage signal and the feedback voltage;
the voltage regulating circuit includes:
the first input end of the switch branch circuit is connected with the output end of the comparison branch circuit, the second input end of the switch branch circuit is connected with the power supply voltage, the third input end of the switch branch circuit is grounded, and the output end of the switch branch circuit is connected with the light-emitting light source and is used for receiving the control signal, taking the power supply voltage as the working voltage according to the control signal and outputting the working voltage to the light-emitting light source; and
the input end of the second voltage division branch is connected with the power supply voltage and the second input end of the switch branch, and the output end of the second voltage division branch is connected with the output end of the switch branch and the light-emitting source;
the switch branch circuit is switched on or switched off according to the control signal, when the switch branch circuit is switched on, the power supply voltage is the working voltage and is supplied to the light-emitting light source through the switch branch circuit, and when the switch branch circuit is switched off, the working voltage is supplied through the second voltage division branch circuit.
7. The backlight module of claim 6,
the first voltage division branch includes:
the first end of the first resistor is connected with the high-level voltage signal, and the first resistor is a photoresistor; and
the first end of the second resistor is connected with the second end of the first resistor, and the second end of the second resistor is grounded;
the comparison branch comprises:
and a positive input end of the comparator is connected with the reference voltage signal, and a negative input end of the comparator is connected with the second end of the first resistor and the first end of the second resistor.
8. The backlight module as set forth in claim 7, wherein the voltage regulating circuit further comprises:
a grid electrode of the switching tube is connected with the output end of the comparator, a source electrode of the switching tube is connected with the power supply voltage, and a drain electrode of the switching tube is connected with the LED lamp string;
the first end of the third resistor is connected with the output end of the comparator and the grid electrode of the switch tube, and the second end of the third resistor is grounded; and
and the first end of the fourth resistor is connected with the power supply voltage and the source electrode of the switch tube, and the second end of the fourth resistor is connected with the drain electrode of the switch tube and the LED lamp string.
9. A display panel, comprising:
a display area for displaying; and
the peripheral circuit area is matched with the display area and used for supplying power to the display area and providing a driving signal;
wherein the peripheral circuit region includes a driving circuit including:
the control circuit is connected with a high-level voltage signal at a first input end, connected with a reference voltage signal at a second input end and grounded at a third input end, and used for receiving the high-level voltage signal and the reference voltage signal, adjusting the resistance value of the control circuit according to the brightness of the external environment, and generating a control signal according to the adjusted resistance value, the high-level voltage signal and the reference voltage signal; and
the first input end of the voltage regulating circuit is connected with the output end of the control circuit, the second input end of the voltage regulating circuit is connected with a power supply voltage, and the third input end of the voltage regulating circuit is grounded and is used for receiving the control signal and the power supply voltage and generating a working voltage according to the control signal and the power supply voltage, so that the luminous light source can regulate the self brightness according to the working voltage and the difference between the self brightness of the luminous light source and the ambient brightness is reduced;
the control circuit includes:
the first input end of the first voltage division branch is connected with the high-level voltage signal, the second input end of the first voltage division branch is grounded and used for receiving the high-level voltage signal, adjusting the resistance value of the first voltage division branch according to the external environment brightness, and generating feedback voltage according to the adjusted resistance value of the first voltage division branch and the high-level voltage signal; and
a comparison branch, a first input end of which is connected with the reference voltage signal and a second input end of which is connected with the first voltage division branch, and is used for receiving the reference voltage signal and the feedback voltage and generating a control signal according to the reference voltage signal and the feedback voltage;
the voltage regulating circuit includes:
the first input end of the switch branch circuit is connected with the output end of the comparison branch circuit, the second input end of the switch branch circuit is connected with the power supply voltage, the third input end of the switch branch circuit is grounded, and the output end of the switch branch circuit is connected with the light-emitting light source and is used for receiving the control signal, taking the power supply voltage as the working voltage according to the control signal and outputting the working voltage to the light-emitting light source; and
the input end of the second voltage division branch is connected with the power supply voltage and the second input end of the switch branch, and the output end of the second voltage division branch is connected with the output end of the switch branch and the light-emitting source;
the switch branch circuit is switched on or switched off according to the control signal, when the switch branch circuit is switched on, the power supply voltage is the working voltage and is supplied to the light-emitting light source through the switch branch circuit, and when the switch branch circuit is switched off, the working voltage is supplied through the second voltage division branch circuit.
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| CN201811579749.0A CN109523957B (en) | 2018-12-24 | 2018-12-24 | Drive circuit, backlight module and display panel |
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Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112669778B (en) * | 2019-10-31 | 2022-08-12 | 荣耀终端有限公司 | Backlight control circuit, control method thereof and display terminal |
| CN113012611B (en) * | 2021-02-26 | 2022-10-04 | 深圳市华星光电半导体显示技术有限公司 | Voltage detection circuit, display device and display driving method thereof |
| CN115113671B (en) * | 2021-03-23 | 2024-03-12 | 西安青松光电技术有限公司 | Power supply device and electronic equipment |
| CN112992040B (en) * | 2021-04-13 | 2022-11-22 | 成都天马微电子有限公司 | Adjusting circuit and display device |
| CN115460734B (en) * | 2022-05-17 | 2023-12-01 | 深圳锐盟半导体有限公司 | LED control circuit, electronic equipment and electronic device |
| CN114822401B (en) * | 2022-06-30 | 2022-09-27 | 惠科股份有限公司 | Display device, source electrode chip on film and driving method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101206836A (en) * | 2006-12-20 | 2008-06-25 | 群康科技(深圳)有限公司 | Drive circuit for backlight module group |
| CN101546539A (en) * | 2008-03-27 | 2009-09-30 | 鸿富锦精密工业（深圳）有限公司 | Circuit for adjusting brightness of liquid crystal display |
| US20140063853A1 (en) * | 2012-08-29 | 2014-03-06 | Flex Lighting Ii, Llc | Film-based lightguide including a wrapped stack of input couplers and light emitting device including the same |
| US20140070078A1 (en) * | 2012-09-10 | 2014-03-13 | Brian R. Land | Optical Proximity Sensor With Ambient Light and Temperature Compensation |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2884285Y (en) * | 2006-02-09 | 2007-03-28 | 康舒科技股份有限公司 | Mobile electronic device able to control brightness of light source |
| CN201387449Y (en) * | 2009-03-20 | 2010-01-20 | 威胜集团有限公司 | Automatic backlight circuit for electronic electric watt-hour meter |
| US20120212466A1 (en) * | 2009-10-30 | 2012-08-23 | Sharp Kabushiki Kaisha | Display device |
| CN103428952A (en) * | 2012-05-25 | 2013-12-04 | 原景科技股份有限公司 | Driving current control circuit and operating method thereof |
| TWI462648B (en) * | 2012-08-06 | 2014-11-21 | Wistron Corp | Backlight driving circuit and backlight driving method |
| CN202791666U (en) * | 2012-09-18 | 2013-03-13 | 京东方科技集团股份有限公司 | LED (Light Emitting Diode) backlight and display |
| CN104700816B (en) * | 2015-01-08 | 2017-05-24 | 小米科技有限责任公司 | Method and device for setting screen brightness |
| CN105896943B (en) * | 2016-05-27 | 2018-08-28 | 南京矽力杰半导体技术有限公司 | A kind of control circuit, control method and apply its Switching Power Supply |
| CN106548755B (en) * | 2016-12-07 | 2019-11-26 | 惠州三华工业有限公司 | Brightness adjust automatically display device |
| CN107256697A (en) * | 2017-07-31 | 2017-10-17 | 昆山龙腾光电有限公司 | Backlight drive circuit |
| CN108335676A (en) * | 2018-02-02 | 2018-07-27 | 惠科股份有限公司 | Display device |
| CN108847194A (en) * | 2018-06-22 | 2018-11-20 | 惠科股份有限公司 | Display device and driving method |
-
2018
- 2018-12-24 CN CN201811579749.0A patent/CN109523957B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101206836A (en) * | 2006-12-20 | 2008-06-25 | 群康科技(深圳)有限公司 | Drive circuit for backlight module group |
| CN101546539A (en) * | 2008-03-27 | 2009-09-30 | 鸿富锦精密工业（深圳）有限公司 | Circuit for adjusting brightness of liquid crystal display |
| US20140063853A1 (en) * | 2012-08-29 | 2014-03-06 | Flex Lighting Ii, Llc | Film-based lightguide including a wrapped stack of input couplers and light emitting device including the same |
| US20140070078A1 (en) * | 2012-09-10 | 2014-03-13 | Brian R. Land | Optical Proximity Sensor With Ambient Light and Temperature Compensation |
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| Publication number | Publication date |
|---|---|
| CN109523957A (en) | 2019-03-26 |
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