CN115588396A - Display device - Google Patents

Display device Download PDF

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Publication number
CN115588396A
CN115588396A CN202211202708.6A CN202211202708A CN115588396A CN 115588396 A CN115588396 A CN 115588396A CN 202211202708 A CN202211202708 A CN 202211202708A CN 115588396 A CN115588396 A CN 115588396A
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China
Prior art keywords
resistor
voltage
signal
unit
display device
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CN202211202708.6A
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Chinese (zh)
Inventor
赵贺
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Hisense Visual Technology Co Ltd
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Hisense Visual Technology Co Ltd
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Priority to CN202211202708.6A priority Critical patent/CN115588396A/en
Publication of CN115588396A publication Critical patent/CN115588396A/en
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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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S8/00—Lighting devices intended for fixed installation
    • 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]
    • H05B45/30—Driver circuits
    • H05B45/345—Current stabilisation; Maintaining constant current
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00—Light-generating elements of semiconductor light sources
    • F21Y2115/10—Light-emitting diodes [LED]
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
    • G09G2310/0243—Details of the generation of driving signals
    • 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
    • G09G2320/02—Improving the quality of display appearance
    • G09G2320/0233—Improving the luminance or brightness uniformity across the screen
    • 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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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Circuit Arrangement For Electric Light Sources In General (AREA)

Abstract

The display device that this application embodiment provided includes: the backlight module is connected with the backlight module, and the power supply module is used for receiving a power supply input signal, generating a current signal for controlling the brightness of the backlight module based on the power supply input signal and under the drive of a drive signal; the control module is connected with the power supply module and is used for providing a driving signal; and when receiving the dimming signal, adjusting the frequency of the driving signal according to the dimming signal. According to the embodiment of the application, the screen flash phenomenon of the display device can be avoided, and the film watching effect of a user is improved.

Description

Display device
Technical Field
The application relates to the technical field of display, in particular to a display device.
Background
A display device is a device having a function of displaying an image viewable by a user, and is widely used in various scenes. Such as a mobile phone, a computer or a television equipped with a display screen. In general, a power supply unit is disposed in the display device to supply power to the display device. In order to satisfy the requirement that a user can normally watch images on the display device under different light conditions, the display device needs to adjust the brightness correspondingly.
In the related art, the power of the display device is usually adjusted by changing the duty ratio of the driving signal for driving the power supply unit to adjust the magnitude of the current signal of the power supply circuit, so as to adjust the brightness of the display device. However, when the brightness of the display device is too low, a screen flash phenomenon often occurs, thereby reducing the viewing effect of the user.
Disclosure of Invention
The application provides a display device, aims at solving display device's regulation luminance when low excessively, holds the problem of taking place the screen flash phenomenon.
The application provides a display device including: the backlight module is used for providing backlight for the display device, and the power supply module is connected with the backlight module and used for receiving a power supply input signal and generating a current signal for controlling the brightness of the backlight module based on the power supply input signal and under the drive of a drive signal; the control module is connected with the power supply module and is used for providing the driving signal; and when receiving a dimming signal, adjusting the frequency of the driving signal according to the dimming signal.
Optionally, the control module includes: the processing unit and the external resistor unit with adjustable resistance; the external resistor unit is used for adjusting the resistance value of the external resistor unit according to the dimming signal; the RT pin of the processing unit is connected with one end of the external resistor unit, the other end of the external resistor unit is grounded, and the processing unit is used for generating a driving signal with corresponding frequency based on the current resistance value of the external resistor unit.
Optionally, the external resistance unit includes a signal conversion unit and a variable resistance unit; the input end of the signal conversion unit receives the dimming signal, the output end of the signal conversion unit is connected with the variable resistance unit, and the signal conversion unit is used for receiving the dimming signal and converting the dimming signal into a direct-current level signal; and the variable resistance unit is used for adjusting the resistance value of the variable resistance unit based on the direct current level signal.
Optionally, the signal conversion unit includes a first resistor, a second resistor, a third resistor, a first switching element, and a first capacitor, one end of the first resistor receives a first reference voltage, and the other end of the first resistor is connected to one end of the second resistor; the other end of the second resistor is grounded; one end of the third resistor is connected with the other end of the first resistor, and the other end of the third resistor is connected with the first end of the first switch element; the second end of the first switch element is connected with the other end of the second resistor, and the control end of the first switch element receives the dimming signal; one end of the first capacitor is connected with one end of the third resistor, and the other end of the first capacitor is connected with the second end of the first switch element; the other end of the first resistor is used as the output end of the signal conversion unit and is connected with the variable resistor unit.
Optionally, the signal conversion unit further includes: one end of the fourth resistor receives the dimming signal, and the other end of the fourth resistor is connected with the control end of the first switch element; one end of the fifth resistor is connected to the control end of the first switch element, and the other end of the fifth resistor is connected to the second end of the first switch element.
Optionally, the variable resistance unit includes: the first three-terminal regulator and the optical coupling element; a reference electrode of the first three-terminal regulator receives the direct-current level signal; the negative electrode of the first three-terminal regulator is connected with the primary side output end of the optocoupler, and the positive electrode of the first three-terminal regulator is grounded; and a primary side input end of the optical coupling element receives a second reference voltage, a secondary side input end of the optical coupling element is connected with the RT pin of the processing unit, and a secondary side output end of the optical coupling element is grounded.
Optionally, the variable resistance unit further includes: a sixth resistor and a seventh resistor; one end of the sixth resistor is connected with the RT pin of the processing unit, the other end of the sixth resistor is connected with the secondary input end of the optical coupling element, one end of the seventh resistor is connected with the RT pin of the processing unit, and the other end of the seventh resistor is grounded.
Optionally, the variable resistance unit further includes: a first voltage-dividing resistor and a second voltage-dividing resistor; one end of the first voltage-dividing resistor receives the direct-current level signal, and the other end of the first voltage-dividing resistor is connected with a reference electrode of the first three-terminal regulator; one end of the second voltage-dividing resistor is connected with the other end of the first voltage-dividing resistor, and the other end of the second voltage-dividing resistor is connected with the negative electrode of the first three-terminal regulator.
Optionally, the variable resistance unit further includes: and one end of the eighth resistor is connected with the primary side input end of the optical coupling element, and the other end of the eighth resistor is connected with the primary side output end of the optical coupling element.
Optionally, the variable resistance unit further includes: a second capacitor, a ninth resistor and a tenth resistor; one end of the second capacitor is connected with the other end of the first divider resistor, and the other end of the second capacitor is connected with one end of the ninth resistor; the other end of the ninth resistor is connected with the primary side output end of the optical coupling element; one end of the tenth resistor is connected with one end of the first voltage-dividing resistor, and the other end of the tenth resistor is connected with the primary side output end of the optical coupler element.
Optionally, the control module further includes a reference power supply unit, an input end of the reference power supply unit receives an input voltage signal, an output end of the reference power supply unit is connected to one end of the first resistor, and the reference power supply unit is configured to generate the first reference voltage based on the input voltage signal.
Optionally, the reference power supply unit includes a second three-terminal regulator, a third voltage dividing resistor, a fourth voltage dividing resistor, and a fifth voltage dividing resistor; one end of the third voltage-dividing resistor receives the input voltage signal, and the other end of the third voltage-dividing resistor is connected with one end of the fourth voltage-dividing resistor; the other end of the fourth voltage-dividing resistor is connected with one end of the fifth voltage-dividing resistor; the other end of the fifth voltage-dividing resistor is grounded; and the reference electrode of the second three-terminal regulator is connected with the other end of the fourth voltage-dividing resistor, the negative electrode of the second three-terminal regulator is connected with the other end of the third voltage-dividing resistor, and the positive electrode of the second three-terminal regulator is grounded.
Optionally, the reference power supply unit further includes a third capacitor and a fourth capacitor; one end of the third capacitor receives the input voltage signal, and the other end of the third capacitor is connected with the other end of the fifth voltage-dividing resistor; one end of the fourth capacitor is connected with the other end of the third voltage-dividing resistor, and the other end of the fourth capacitor is connected with the other end of the fifth voltage-dividing resistor.
In the display device provided by the embodiment of the application, the power supply module is connected with a backlight assembly providing backlight for the display device, the power supply module generates a current signal for controlling the brightness of the backlight assembly according to the driving signal, the control module is connected with the power supply module, and the control module adjusts the frequency of the driving signal according to the dimming signal when receiving the dimming signal. The magnitude of current signal is adjusted through the frequency of adjusting drive signal in this embodiment, and then adjusts and control display device's luminance, even when adjusting to lower luminance, current signal also is steady continuous variation like this, the condition that current signal is zero can not appear, therefore display device's screen flash phenomenon can be avoided to this application embodiment.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the embodiments of the application and, together with the description, serve to explain the principles of the embodiments of the application.
Specific embodiments of the present application have been shown by way of example in the drawings and will be described in more detail below. These drawings and written description are not intended to limit the scope of the inventive concepts of the present application in any way, but rather to illustrate the inventive concepts of the embodiments of the present application by those skilled in the art with reference to particular embodiments.
FIG. 1 is a schematic diagram of an exemplary power module;
fig. 2 is a diagram illustrating a structure of a display device according to an embodiment of the present disclosure;
fig. 3 is a schematic structural diagram of another display device provided in an embodiment of the present application;
fig. 4 is a schematic structural diagram of another display device provided in the embodiment of the present application;
FIG. 5 is a schematic diagram of an exemplary signal conversion unit;
fig. 6 is a schematic structural diagram of a signal conversion unit in another example;
FIG. 7 is a schematic diagram of an exemplary variable resistance cell;
FIG. 8 is a schematic diagram of a variable resistance unit according to an example;
fig. 9 is a schematic structural diagram of another display device according to an embodiment of the present disclosure;
fig. 10 is a schematic structural diagram of a reference power supply unit in an example;
fig. 11 is a schematic structural diagram of another display device according to an embodiment of the present application.
With the above figures, there are shown specific embodiments of the present application, which will be described in more detail below. These drawings and written description are not intended to limit the scope of the inventive concepts in any manner, but rather to illustrate the inventive concepts to those skilled in the art by reference to specific embodiments.
Detailed Description
Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.
A display device is a device having a function of displaying an image viewable by a user, and is widely used in various scenes. Such as a mobile phone, a computer or a television provided with a display screen. In general, a power supply unit is disposed in the display device to supply power to the display device.
Fig. 1 is a schematic structural diagram of a power supply unit in an example, as shown in fig. 1, the power supply unit includes a switching tube 210, a capacitor 220, and an inductor 230, wherein a first end of the switching tube 210 receives an input voltage Vin, a second end of the switching tube 210 is connected to one end of the inductor 230, and a control end of the switching tube 210 receives a driving signal; the other end of the inductor 230 is connected to one end of the capacitor 220; the other end of the capacitor 220 is grounded, the voltage across the capacitor 220 is used as an output voltage, and the driving signal is usually a square wave signal, such as a Pulse Width Modulation (PWM) signal. The switch tube is controlled by a driving signal to realize switching, and the capacitor and the inductor are used for realizing charging and discharging of the capacitor in the switching process of the switch tube so as to output stable voltage and further realize power supply to the display device.
In order to satisfy the requirement that a user can normally watch images on the display device under different light conditions, the display device needs to adjust the brightness correspondingly. In the related art, the power of the display device is usually adjusted by changing the duty ratio of the driving signal for driving the power supply unit to adjust the magnitude of the current signal of the power supply circuit, so as to adjust the brightness of the display device. In practical applications, the duty ratio is a ratio of durations of a high level and a low level of the driving signal in one period, and the duty ratio is positively correlated with the current signal. Thus, the current can be increased by increasing the duty ratio to improve the brightness of the display device, and the current can be decreased by decreasing the duty ratio to lower the brightness of the display device.
However, with reference to fig. 1, when the brightness to be adjusted is too low, the duty ratio is very small, so that the off time of the switching tube in the power supply circuit is relatively long, the current flowing through the inductor (i.e. the current signal of the power supply circuit) is easily reduced to zero, and thus the current signal cannot be continuously changed, thereby causing a screen flash phenomenon and further reducing the viewing effect of the user.
The technical means of the present application and the technical means of the present application will be described in detail below with specific examples. These several specific embodiments may be combined with each other below, and details of the same or similar concepts or processes may not be repeated in some embodiments. In the description of the present application, unless otherwise explicitly specified and defined, each term should be understood broadly in the art. Embodiments of the present application will be described below with reference to the accompanying drawings.
Fig. 2 is a schematic diagram of a structure example of a display device according to an embodiment of the present application, and as shown in fig. 2, the display device according to the embodiment includes: a backlight assembly 10, a power supply module 20 and a control module 30. Wherein the backlight assembly 10 is used to provide backlight to a display device. In practical applications, the backlight assembly 10 may include light emitting diodes, and the greater the current signal flowing through the backlight assembly 10, the greater the power of the backlight assembly 10, the higher the brightness. Conversely, the smaller the current signal flowing through the backlight assembly 10, the smaller the power of the backlight assembly 10, and the darker the brightness.
The power supply module 20 is connected to the backlight assembly 10, and the power supply module 20 is configured to receive a power supply input signal, and generate a current signal for controlling the brightness of the backlight assembly 10 based on the power supply input signal and driven by a driving signal. For example, the power supply module 20 may be connected to a commercial power, the power supply input signal may be an ac voltage signal, and the power supply module 20 generates a current signal based on the ac voltage signal and driven by the driving signal. The power supply module 20 may include a power supply unit as shown in the example of fig. 1, that is, a switching tube 210, an inductor 230 and a capacitor 220.
As in the example of fig. 2, the control module 30 is connected to the power supply module 20, and the control module 30 is configured to provide a driving signal; and when receiving the dimming signal, adjusting the frequency of the driving signal according to the dimming signal. In practical applications, the dimming signal is usually a signal generated according to the dimming requirement of the user or automatically adapting to the current light. For example, the display device may further include a main board connected to the control module 30, and the main board generates a corresponding dimming signal based on a dimming requirement of a user.
The dimming principle of the present embodiment will be described in detail below. Referring to fig. 1, the current (i.e., the current signal) flowing through the inductor 230 is calculated as follows:
Figure BDA0003873068180000061
in practice, with continued reference to the example in FIG. 1, the input voltage V in An output voltage V out And the inductance L is quantitative. Where D is the duty cycle of the drive signal, i.e. the duty cycle is the ratio of the duration of the high and low levels of the drive signal within a period, and f is the frequency of the drive signal. It is understood that in the related art, I is adjusted by changing the duty ratio D 0 When D is too small, the switch tube 210 is turned off for too long, I 0 May be 0 and thus a screen flash phenomenon may occur. In the present embodiment, the current I is controlled by adjusting the frequency f of the driving signal 0 Of (c) is used. From the above formula, when the required brightness is low, the frequency f of the driving signal is increased, and the duty ratio is not affected when the frequency is adjusted, and the duty ratio D is relatively kept unchanged. So that the frequency f is high and the current signal I is adjusted to a low brightness 0 Is also stable and continuously changed, and does not generate a current signal I 0 Zero, so that no screen flash occurs.
The adjustment process of the frequency f of the driving signal will be exemplarily described below: fig. 3 is a schematic structural diagram of another display device according to an embodiment of the present application, and as shown in fig. 3, the control module 30 includes: a processing unit 310 and an external resistor unit 320 with adjustable resistance;
the external resistor unit 320 is configured to adjust a resistance value of the external resistor unit 320 according to the dimming signal;
the RT pin of the processing unit 310 is connected to one end of the external resistor unit 320, the other end of the external resistor unit 320 is grounded, and the processing unit 310 is configured to generate a driving signal with a corresponding frequency based on the current resistance of the external resistor unit 320.
In practical applications, the processing unit 310 may be a processing chip such as a CPU or a GPU. The RT pin is an external oscillation frequency timing resistor pin of the processing unit 310. The frequency of the driving signal is usually set by an external resistor connected to the RT pin, and the calculation formula of the frequency f of the driving signal may be: f =1/RT × CT, where RT is a resistance value of an external resistor of the RT pin of the processing unit 310, and CT is a capacitance of an internal capacitor of the processing unit 310. Based on the above formula, the external resistor unit 320 is connected to the RT pin in this example, and since the resistance of the external resistor unit 320 is variable, the frequency of the driving signal also changes along with the change of the resistance of the external resistor unit 320 during the operation.
Control module in this example includes the changeable external resistance unit of processing unit and resistance to be connected processing unit's RT pin and external resistance unit, through the resistance of controlling external resistance unit, can realize the regulation and control to drive signal's frequency, and then realize the regulation to the electric current signal, so that display device can avoid appearing the screen flash phenomenon when luminance is crossed lowly.
Based on the above examples, in some examples, fig. 4 is a schematic structural diagram of another display device provided in the embodiment of the present application, and as shown in fig. 4, the external resistance unit 320 includes a signal conversion unit 330 and a variable resistance unit 340;
the input end of the signal conversion unit 330 receives the dimming signal, the output end of the signal conversion unit 330 is connected with the variable resistance unit 340, and the signal conversion unit 330 is used for receiving the dimming signal and converting the dimming signal into a direct current level signal;
the variable resistance unit 340 is configured to adjust a resistance value thereof based on the dc level signal.
In practical application, the dimming signal is usually a square wave signal generated by the motherboard, and the square wave signal is not easy to directly control the resistance of the variable resistance unit 340, so that in this example, the square wave signal is converted into a dc level signal by the signal conversion unit 330, and the variable resistance unit 340 receives the dc level signal and regulates the magnitude of the resistance of the variable resistance unit 340 according to the magnitude of the dc level signal, so that in this example, the magnitude of the resistance of the variable resistance unit 340 can be regulated according to the regulation signal, and further, the regulation of the frequency of the driving signal can be realized.
Further, in some examples, fig. 5 is a schematic structural diagram of a signal conversion unit in an example, as shown in fig. 5, the signal conversion unit 330 includes a first resistor 331, a second resistor 332, a third resistor 333, a first switch element 334, and a first capacitor 335,
one end of the first resistor 331 receives a first reference voltage, and the other end of the first resistor 331 is connected to one end of the second resistor 332; the other end of the second resistor 332 is grounded;
one end of the third resistor 333 is connected to the other end of the first resistor 331, and the other end of the third resistor 333 is connected to the first end of the first switching element 334; a second terminal of the first switching element 334 is connected to the other terminal of the second resistor 332, and a control terminal of the first switching element 334 receives the dimming signal;
one end of the first capacitor 335 is connected to one end of the third resistor 333, and the other end of the first capacitor 335 is connected to the second end of the first switching element 334; the other end of the first resistor 331 is connected to the variable resistor unit 340 as an output end of the signal conversion unit 330.
In this example, the first reference voltage is used as a power supply voltage, and the magnitude of the first reference voltage can be set according to the power of the display device, for example, the first reference power supply voltage is relatively larger when the power of the display device is larger. The first resistor 331 is connected in series with the second resistor 332, and the first resistor 331 and the second resistor 332 are used for sharing the first reference supply voltage. The first capacitor 335 may be a filter capacitor for stabilizing the voltage at the output terminal of the signal conversion unit 330. The first switching element 334 may be a triode or a field effect transistor, and the first switching element 334 is turned off according to the adjustment signal, so as to output different direct current level signals. It is worth to be noted that the dimming signal is a square wave signal, and the higher the brightness of the display device is, the larger the duty ratio of the square wave signal is, the lower the output direct current level signal is; conversely, the lower the brightness of the display device, the smaller the duty ratio of the square wave signal, and the higher the output direct current level signal.
The working process of the present example will be described as follows: the control end of the first switch element 334 receives the square wave signal for dimming, when the level is high, the first switch element 334 is turned on, the third resistor 333 is connected to the circuit and connected in parallel with the second resistor 332, the total resistance value becomes small, the voltage of the second end of the first resistor 331 of the signal conversion unit 330 increases, and the electric quantity charged by the first capacitor 335 becomes small; when the square wave signal is at a low level, the first switch element 334 is turned off, the third resistor 333 is not connected to the circuit, the total resistance is increased, the voltage at the second end of the first resistor 331 of the signal conversion unit 330 is decreased, the voltage at the two ends of the capacitor of the first capacitor 335 is increased, when the display device wants to increase the brightness, the duty ratio of the dimming signal is increased, the on time of the first switch element 334 is relatively long, the output direct current level signal is decreased, the resistance value of the variable resistor unit 340 is increased according to the direct current level signal, and the frequency of the driving signal is further decreased, so that the brightness of the display device is increased. When the display device wants to reduce the brightness, the duty ratio of the dimming signal is reduced, the on time of the first switch element 334 is relatively short, the output dc level signal becomes high, the resistance value of the variable resistance unit 340 is reduced according to the dc level signal, and the frequency of the driving signal is increased, so as to reduce the brightness of the display device.
In this example, the first resistor, the second resistor, the third resistor, the first switching element and the first capacitor are used to convert the adjustment signal into a dc level signal, so that the variable resistance unit can adjust its own resistance based on the dc level signal.
On the basis of the above, in an embodiment, fig. 6 is a schematic structural diagram of a signal conversion unit in another example, and as shown in fig. 6, the signal conversion unit 330 further includes: a fourth capacitor 366 and a fifth resistor 337;
one end of the fourth capacitor 366 receives the dimming signal, the other end of the fourth capacitor 366 is connected to the control end of the first switch element 334, and the fourth resistor 336 is used for voltage division to prevent the control end of the first switch element 334 from being subjected to an excessively high voltage.
One end of the fifth resistor 337 is connected to the control terminal of the first switching element 334, and the other end of the fifth resistor 337 is connected to the second terminal of the first switching element 334. The fifth resistor 337 is used to pull down the voltage of the second terminal of the first switching element 334 to prevent the second terminal of the first switching element 334 from being in a floating state when the first switching element 334 is turned off.
In this example, the potential risk existing during the operation of the signal conversion unit can be avoided through the fourth capacitor and the fifth resistor, and thus the stable operation of the signal conversion unit can be ensured.
The variable resistance unit 340 will be described as an example.
In an example, fig. 7 is a schematic structural diagram of the variable resistance unit in an example, and as shown in fig. 7, the variable resistance unit 340 includes: a first three terminal regulator 341, an optocoupler 342;
the reference electrode of the first three-terminal regulator 341 receives the dc level signal; the negative electrode of the first three-terminal regulator 341 is connected to the primary side output end of the optocoupler 342, and the negative electrode of the first three-terminal regulator 341 is grounded;
a primary input end of the optical coupler element 342 receives the second reference voltage, a secondary input end of the optical coupler element 342 is connected with the RT pin of the processing unit 310, and a secondary output end of the optical coupler element 342 is grounded.
In this example, the first three-terminal regulator 341 is used to stabilize the voltage of the circuit. The primary side of the optocoupler element 342 may include a light emitting diode and the secondary side may include a transistor, and the optocoupler element 342 is configured to decrease the impedance of the secondary side when the primary side light emitting diode is lit and to increase the impedance of the secondary side when the light emitting diode is dimmed.
In the working process, when the accessed direct current level signal is increased, the input voltage of the reference electrode of the first three-terminal regulator 341 is increased, the current flowing from the negative electrode to the negative electrode of the first three-terminal regulator is increased, the current flowing through the primary side of the optical coupling element 342 is increased, the light emitting diode in the optical coupling element 342 is lightened, the impedance of the secondary side of the optical coupling element 342 is reduced, and then the resistance value of the variable resistance unit 340 is reduced. On the contrary, when the accessed dc level signal decreases, the input voltage of the cathode of the first three-terminal regulator 341 decreases, the current flowing from the cathode to the cathode of the first three-terminal regulator decreases, the current flowing through the primary side of the optical coupler element 342 decreases, the light emitting diode in the optical coupler element 342 becomes dark, the impedance of the secondary side of the optical coupler element 342 increases, and thus the resistance value of the variable resistance unit 340 increases.
The variable resistance unit in this example includes a first three-terminal regulator and an optical coupling element, and the resistance value of the variable resistance unit is reduced along with the increase of the accessed direct current level signal and increased along with the decrease of the accessed direct current level signal, so that the brightness of the display device can be controlled by controlling the frequency of the driving signal.
On the basis of the above, as an embodiment, fig. 8 is a schematic structural diagram of a variable resistance unit in another example. As shown in fig. 8, the variable resistance unit 340 further includes: sixth resistance 343, seventh resistance 344;
one end of the sixth resistor 343 is connected to the RT pin of the processing unit 310, the other end of the sixth resistor 343 is connected to the secondary input end of the optical coupler 342,
one end of the seventh resistor 344 is connected to the RT pin of the processing unit 310, and the other end of the seventh resistor 344 is grounded.
In this embodiment, the sixth resistor and the seventh resistor are fixed resistors, and are configured as a variable resistor unit configuration resistor to limit the lowest resistance value of the access processing unit, and further limit the limit frequency of the driving signal, so as to avoid damage to the power supply circuit due to too low or too high frequency of the driving signal.
Further, in addition to the above-described embodiments, in one example, with continued reference to the example in fig. 8, the variable resistance unit 340 further includes: a first voltage dividing resistor 345 and a second voltage dividing resistor 346;
one end of the first voltage dividing resistor 345 receives the dc level signal, and the other end of the first voltage dividing resistor 345 is connected to the reference electrode of the first three-terminal regulator 341;
one end of the second voltage-dividing resistor 346 is connected to the other end of the first voltage-dividing resistor 345, and the other end of the second voltage-dividing resistor 346 is connected to the negative electrode of the first three-terminal regulator 341.
In this example, the first voltage dividing resistor and the second voltage dividing resistor perform voltage dividing, so as to avoid damage to the first three-terminal regulator due to the rise of the connected dc level signal. This scheme further ensures the reliability of the operation of the variable-resistance unit.
In another example, with continued reference to fig. 8, the variable resistance unit 340 further includes: and an eighth resistor 347, wherein one end of the eighth resistor 347 is connected to the primary input terminal of the optocoupler 342, and the other end of the eighth resistor 347 is connected to the primary output terminal of the optocoupler 342. The eighth resistor 347 in this example is used to ground the connected second reference voltage when the optocoupler 342 is switched off to avoid a danger caused by the floating second reference voltage.
In yet another example, with continued reference to fig. 8, the variable resistance unit 340 further includes: a second capacitor 348, a ninth resistor 349 and a tenth resistor 351;
one end of the second capacitor 348 is connected to the other end of the first voltage dividing resistor 345, and the other end of the second capacitor 348 is connected to one end of the ninth resistor 349; the other end of the ninth resistor 349 is connected to the primary side output end of the optocoupler 342;
one end of the tenth resistor 351 is connected to one end of the first voltage dividing resistor 345, and the other end of the tenth resistor 351 is connected to the primary side output terminal of the optical coupler element 342.
In this embodiment, the second capacitor 348 is a filter capacitor, and is used for filtering out a high-frequency signal when the second reference voltage fluctuates, so as to ensure the stability of the second reference voltage, and further avoid affecting the optical coupling element 342. And the ninth resistor 349 is used to share the voltage across the second capacitor 348, so as to prevent the voltage from being too large and breaking down the second capacitor 348.
The tenth resistor 351 is also a voltage dividing resistor for protecting the circuit.
It should be noted that, in the foregoing embodiment, when the dimming signal is converted into the dc level signal, the influence of the stability of the first reference point voltage on the output dc level signal is relatively large, for this reason, fig. 9 is a schematic structural diagram of another display device provided in the embodiment of the present application, and as shown in fig. 9, the adjusting module further includes a reference power supply unit 360; the input end of the reference power supply unit 360 receives an input voltage signal, the output end of the reference power supply unit 360 is connected with one end of the first resistor 331, and the reference power supply unit 360 is configured to generate a first reference voltage based on the input voltage signal. In this example, the reference power supply unit can provide a stable and reliable reference voltage for the external resistor unit.
In an example, fig. 10 is a schematic structural diagram of a reference power supply unit in an example, and as shown in fig. 10, the reference power supply unit 360 includes: a second three-terminal regulator 361, a third voltage dividing resistor 362, a fourth voltage dividing resistor 363 and a fifth voltage dividing resistor 364;
one end of the third voltage dividing resistor 362 receives an input voltage signal, and the other end of the third voltage dividing resistor 362 is connected with one end of the fourth voltage dividing resistor 363; the other end of the fourth voltage-dividing resistor 363 is connected with one end of the fifth voltage-dividing resistor 364; the other end of the fifth voltage-dividing resistor 364 is grounded;
the reference electrode of the second three-terminal regulator 361 is connected with the other end of the fourth voltage-dividing resistor 363, the negative electrode of the second three-terminal regulator 361 is connected with the other end of the third voltage-dividing resistor 362, and the negative electrode of the second three-terminal regulator 361 is grounded;
the other end of the third voltage dividing resistor 362 serves as an output terminal of the illustrated reference power supply unit 360.
In this example, the input voltage signal is typically set to 12V. The third voltage dividing resistor 362, the fourth voltage dividing resistor 363 and the fifth voltage dividing resistor 364 are connected in series to form a voltage dividing circuit. The voltage of the cathode of the second three-terminal regulator 361 is a fixed value, and is generally set to 2.5V, so that the voltage across the fifth voltage-dividing resistor 364 is limited to 2.5V, and thus the current flowing through the reference power supply unit can be controlled according to the resistance of the fifth voltage-dividing resistor, and the voltage at the output terminal of the reference power supply unit can be accurately controlled. In addition, the present example can also implement adjustment of the first reference voltage by changing the fourth voltage-dividing resistor and the fifth voltage-dividing resistor to adapt to display devices with different powers, so that the present example improves the versatility of the reference power supply unit.
In another example, with continued reference to fig. 10, the reference supply unit 360 further includes a third capacitor 365, a fourth capacitor 366;
one end of the third capacitor 365 receives an input voltage signal, and the other end of the third capacitor 365 is connected to the other end of the fifth voltage-dividing resistor 364;
one end of the fourth capacitor 366 is connected to the other end of the third voltage dividing resistor 362, and the other end of the fourth capacitor 366 is connected to the other end of the fifth voltage dividing resistor 364.
In this example, the third capacitor and the fourth capacitor are filter capacitors, and are configured to filter out a high-frequency signal when an input voltage signal fluctuates, so as to ensure that the reference power supply unit outputs an accurate and stable first reference voltage.
The following describes an exemplary working process of this embodiment with reference to a specific application scenario: fig. 11 is a schematic structural diagram of another display device according to an embodiment of the present application. As shown in fig. 11, the reference power supply unit 360 receives the input voltage signal and outputs a stable first reference voltage, when the brightness of the display device is to be improved, the duty ratio of the dimming signal is increased, the on-time of the first switching element 334 is longer, the current flowing through the first resistor 331 is increased, the voltage of the first capacitor 335 is decreased, the dc level signal is decreased, the reference electrode of the first three-terminal regulator 341 receives the decreased dc level signal, the current flowing from the negative electrode of the first three-terminal regulator 341 to the positive electrode of the first three-terminal regulator 341 is decreased, the current flowing through the primary side of the optical coupler 342 is decreased, the impedance of the secondary side of the optical coupler 342 is increased, and the resistance of the variable resistor unit is increased, the frequency f of the driving signal output by the processing unit 310 is decreased, the current signal output by the power supply module 20 is increased, and the backlight assembly 10 of the display device is lightened. On the contrary, when the brightness of the display device is to be reduced, the duty ratio of the dimming signal is decreased, the on-time of the first switching element 334 is shortened, the current flowing through the first resistor 331 is decreased, the voltage of the first capacitor 335 is increased, the dc level signal is increased, the reference electrode of the first three-terminal regulator 341 receives the increased dc level signal, the current flowing from the negative electrode of the first three-terminal regulator 341 to the positive electrode of the first three-terminal regulator 341 is increased, the current flowing through the primary side of the optical coupling element 342 is decreased, the impedance of the secondary side of the optical coupling element 342 is decreased, and the resistance of the variable resistance unit is decreased, the frequency f of the driving signal output by the processing unit 310 is increased, the current signal output by the power supply module 20 is decreased, and the backlight module 10 of the display device is darkened.
In the display device provided by the embodiment of the application, the power supply module is connected with a backlight assembly providing backlight for the display device, the power supply module generates a current signal for controlling the brightness of the backlight assembly according to the driving signal, the control module is connected with the power supply module, and the control module adjusts the frequency of the driving signal according to the dimming signal when receiving the dimming signal. In this embodiment, the magnitude of the current signal is adjusted by adjusting the frequency of the driving signal, and then the brightness of the display device is adjusted, so that even when the brightness is adjusted to be lower, the current signal is stably and continuously changed, and the condition that the current signal is zero does not occur, so that the application embodiment can avoid the screen flash phenomenon of the display device.
Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.
It will be understood that the present application is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims (13)

1. A display device, comprising:
a backlight assembly for providing backlight to the display device,
the power supply module is connected with the backlight assembly and is used for receiving a power supply input signal and generating a current signal for controlling the brightness of the backlight assembly based on the power supply input signal and under the drive of a drive signal;
the control module is connected with the power supply module and is used for providing the driving signal; and when receiving a dimming signal, adjusting the frequency of the driving signal according to the dimming signal.
2. The display device according to claim 1, wherein the control module comprises: the processing unit and the external resistor unit with adjustable resistance;
the external resistor unit is used for adjusting the resistance value of the external resistor unit according to the dimming signal;
the RT pin of the processing unit is connected with one end of the external resistor unit, the other end of the external resistor unit is grounded, and the processing unit is used for generating a driving signal with corresponding frequency based on the current resistance value of the external resistor unit.
3. The display device according to claim 2, wherein the external resistance unit includes a signal conversion unit and a variable resistance unit;
the input end of the signal conversion unit receives the dimming signal, the output end of the signal conversion unit is connected with the variable resistance unit, and the signal conversion unit is used for receiving the dimming signal and converting the dimming signal into a direct-current level signal;
and the variable resistance unit is used for adjusting the resistance value of the variable resistance unit based on the direct current level signal.
4. The display device according to claim 3, wherein the signal conversion unit comprises a first resistor, a second resistor, a third resistor, a first switching element, and a first capacitor,
one end of the first resistor receives a first reference voltage, and the other end of the first resistor is connected with one end of the second resistor; the other end of the second resistor is grounded;
one end of the third resistor is connected with the other end of the first resistor, and the other end of the third resistor is connected with the first end of the first switch element; the second end of the first switch element is connected with the other end of the second resistor, and the control end of the first switch element receives the dimming signal;
one end of the first capacitor is connected with one end of the third resistor, and the other end of the first capacitor is connected with the second end of the first switch element; the other end of the first resistor is used as the output end of the signal conversion unit and is connected with the variable resistor unit.
5. The display device according to claim 4, wherein the signal conversion unit further comprises: a fourth resistor and a fifth resistor, wherein the first resistor is connected to the first resistor,
one end of the fourth resistor receives the dimming signal, and the other end of the fourth resistor is connected with the control end of the first switch element;
one end of the fifth resistor is connected to the control end of the first switching element, and the other end of the fifth resistor is connected to the second end of the first switching element.
6. The display device according to claim 3, wherein the variable resistance unit comprises: the first three-terminal regulator and the optical coupling element;
a reference electrode of the first three-terminal regulator receives the direct-current level signal; the negative electrode of the first three-terminal regulator is connected with the primary side output end of the optocoupler, and the positive electrode of the first three-terminal regulator is grounded;
and a primary side input end of the optical coupling element receives a second reference voltage, a secondary side input end of the optical coupling element is connected with the RT pin of the processing unit, and a secondary side output end of the optical coupling element is grounded.
7. The display device according to claim 6, wherein the variable resistance unit further comprises: a sixth resistor and a seventh resistor;
one end of the sixth resistor is connected with the RT pin of the processing unit, the other end of the sixth resistor is connected with the secondary side input end of the optical coupling element,
one end of the seventh resistor is connected with the RT pin of the processing unit, and the other end of the seventh resistor is grounded.
8. The display device according to claim 7, wherein the variable resistance unit further comprises: a first voltage dividing resistor and a second voltage dividing resistor;
one end of the first voltage-dividing resistor receives the direct-current level signal, and the other end of the first voltage-dividing resistor is connected with a reference electrode of the first three-terminal regulator;
one end of the second voltage-dividing resistor is connected with the other end of the first voltage-dividing resistor, and the other end of the second voltage-dividing resistor is connected with the anode of the first three-terminal regulator.
9. The display device according to claim 6, wherein the variable resistance unit further comprises: one end of the eighth resistor is connected with the primary side input end of the optical coupler element, and the other end of the eighth resistor is connected with the primary side output end of the optical coupler element.
10. The display device according to claim 8, wherein the variable resistance unit further comprises: a second capacitor, a ninth resistor and a tenth resistor;
one end of the second capacitor is connected with the other end of the first divider resistor, and the other end of the second capacitor is connected with one end of the ninth resistor; the other end of the ninth resistor is connected with the primary side output end of the optical coupling element;
one end of the tenth resistor is connected with one end of the first voltage-dividing resistor, and the other end of the tenth resistor is connected with the primary side output end of the optical coupler element.
11. The display device according to claim 4, wherein the control module further comprises a reference power supply unit,
the input end of the reference power supply unit receives an input voltage signal, the output end of the reference power supply unit is connected with one end of the first resistor, and the reference power supply unit is used for generating the first reference voltage based on the input voltage signal.
12. The display device according to claim 11, wherein the reference power supply unit comprises a second three-terminal regulator, a third voltage dividing resistor, a fourth voltage dividing resistor, and a fifth voltage dividing resistor;
one end of the third voltage-dividing resistor receives the input voltage signal, and the other end of the third voltage-dividing resistor is connected with one end of the fourth voltage-dividing resistor;
the other end of the fourth voltage-dividing resistor is connected with one end of the fifth voltage-dividing resistor;
the other end of the fifth voltage-dividing resistor is grounded;
the reference electrode of the second three-terminal regulator is connected with the other end of the fourth voltage-dividing resistor, the negative electrode of the second three-terminal regulator is connected with the other end of the third voltage-dividing resistor, and the positive electrode of the second three-terminal regulator is grounded;
and the other end of the third voltage-dividing resistor is used as the output end of the reference power supply unit.
13. The display device according to claim 12, wherein the reference power supply unit further comprises a third capacitor, a fourth capacitor;
one end of the third capacitor receives the input voltage signal, and the other end of the third capacitor is connected with the other end of the fifth voltage-dividing resistor;
one end of the fourth capacitor is connected with the other end of the third voltage-dividing resistor, and the other end of the fourth capacitor is connected with the other end of the fifth voltage-dividing resistor.
CN202211202708.6A 2022-09-29 2022-09-29 Display device Pending CN115588396A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211202708.6A CN115588396A (en) 2022-09-29 2022-09-29 Display device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211202708.6A CN115588396A (en) 2022-09-29 2022-09-29 Display device

Publications (1)

Publication Number Publication Date
CN115588396A true CN115588396A (en) 2023-01-10

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211202708.6A Pending CN115588396A (en) 2022-09-29 2022-09-29 Display device

Country Status (1)

Country Link
CN (1) CN115588396A (en)

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