WO2013180500A1 - Dispositif d'affichage comprenant un rétroéclairage à del, et appareil d'alimentation et procédé d'alimentation de ce dispositif - Google Patents

Dispositif d'affichage comprenant un rétroéclairage à del, et appareil d'alimentation et procédé d'alimentation de ce dispositif Download PDF

Info

Publication number
WO2013180500A1
WO2013180500A1 PCT/KR2013/004782 KR2013004782W WO2013180500A1 WO 2013180500 A1 WO2013180500 A1 WO 2013180500A1 KR 2013004782 W KR2013004782 W KR 2013004782W WO 2013180500 A1 WO2013180500 A1 WO 2013180500A1
Authority
WO
WIPO (PCT)
Prior art keywords
power
voltage
power factor
factor correction
backlight
Prior art date
Application number
PCT/KR2013/004782
Other languages
English (en)
Korean (ko)
Inventor
류승렬
이정훈
성유창
이용희
Original Assignee
서울반도체 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from KR1020120140237A external-priority patent/KR20130135718A/ko
Application filed by 서울반도체 주식회사 filed Critical 서울반도체 주식회사
Publication of WO2013180500A1 publication Critical patent/WO2013180500A1/fr

Links

Images

Classifications

    • 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
    • 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
    • H05B45/37—Converter circuits
    • H05B45/3725—Switched mode power supply [SMPS]
    • H05B45/385—Switched mode power supply [SMPS] using flyback topology
    • 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]
    • H05B45/40—Details of LED load circuits
    • H05B45/44—Details of LED load circuits with an active control inside an LED matrix
    • H05B45/46—Details of LED load circuits with an active control inside an LED matrix having LEDs disposed in parallel lines
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
    • G09G2330/02—Details of power systems and of start or stop of display operation
    • 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
    • H05B45/37—Converter circuits
    • H05B45/3725—Switched mode power supply [SMPS]
    • H05B45/375—Switched mode power supply [SMPS] using buck topology

Definitions

  • the present invention relates to a display device having a LED (Light Emitting Diode) backlight and a power supply and method thereof. More particularly, the present invention provides a power factor correction voltage directly to the backlight unit and a compensation circuit for ripple of the driving voltage.
  • Display device having an LED backlight that can increase the efficiency and lower the manufacturing cost by eliminating some power conversion process in the Switching Mode Power Supply (SMPS) and the resulting power loss by using the included backlight driver; It relates to a power supply and a method thereof.
  • SMPS Switching Mode Power Supply
  • LED Light Emitting Diode
  • LCD Liquid Crystal Display
  • LED backlights for LCD TVs there are at least tens to hundreds of light emitting diodes (LEDs), depending on the size and resolution of LCD TVs and the application model. Therefore, it is not easy to standardize in providing power for each backlight model.
  • the conventional LED backlight has a variety of models, such as the LED array using a power supply voltage of 24V band to a model using a voltage of about 120V or more, and thus provide the driving power of each LED backlight for each model To do this, it is common to receive the input AC power from the LCD TV power supply circuit and supply the required DC driving voltage through the DC-DC converter of several stages.
  • the power consumption of the LED backlight in the LCD TV is about 70% of the total system, it is essential to reduce the power consumption of the LED backlight to implement a low-power LCD TV.
  • the power circuit of the conventional LCD TV has a disadvantage in that there are many power conversion steps, such as generating a DC 24V power supply and boosting the DC 24V power supply with a backlight driving power supply or stepping down with a panel driving power supply.
  • power conversion steps such as generating a DC 24V power supply and boosting the DC 24V power supply with a backlight driving power supply or stepping down with a panel driving power supply.
  • PMIC power management integrated circuit
  • the various levels of power used in the display panel 3 can include the timing controller power, the source driver power, the gate driver power, the gamma voltage, or the common buffer. Power supply (Vcom Buffer), etc.
  • the SMPS 2 typically includes a filter 2a, a bridge diode 2b, a power factor correction circuit 2c, and an intermediate stage DC-DC converter 2d, which are commercially input from 85V to 256V by the bridge diode 2b.
  • a power factor correction voltage of up to about 385 V is generated by a power factor correction circuit (2c), and a 24 V DC power supply, a 12 V DC power supply, and an intermediate DC-DC converter (2d).
  • Output 5V or 3V DC power that is, in the conventional SMPS 2, the power factor correction voltage of the power factor correction circuit 2c is first stepped down by the intermediate stage DC-DC converter 2d, and then, by the load stage DC-DC converter 3a.
  • step-up or step-down outputs a load voltage suitable for each load (backlight unit, etc.).
  • the 24V DC power is supplied to the backlight unit 3b and the LED driving circuit 3c through the load stage DC-DC converter 3a of the LED backlight 3, and the 12V DC power is supplied to each LCD panel through the PMIC. It is supplied to the driving circuit, and 5V or 3V DC power is supplied for TV set top box or video input.
  • the LED driving circuit 3c controls the DC-DC converter 3a to generate several hundred volts of driving voltage from the 24V driving voltage from the intermediate stage DC-DC converter 2d. Since power is supplied to the backlight unit 3b, power loss is large when converting the power, and a large current capacity is required. Therefore, an expensive component must be used to obtain the reliability required for the product, thereby increasing the cost for the SMPS 2. .
  • most of the SMPS 2 used in the above-described conventional LED TV substantially AC-DC converts the input AC voltage, and primarily converts the AC-DC converted rectified voltage in the intermediate stage DC-DC converter 2d. After conversion to, since the output terminal is finally converted to a voltage suitable for each load in the DC-DC converter (3a, etc.), there is a disadvantage that the efficiency is not good due to the power loss consumed in the three-stage power conversion.
  • the LED driving circuit 3c for driving the backlight unit 3b made of the LED array since the 24V DC voltage is normally boosted again to suit the forward voltage of the LED array, the LED backlight 3 There is a disadvantage in that the overall system efficiency becomes worse due to the power loss in the fourth stage consumed in the DC voltage boosting.
  • the present invention is to solve the above problems, the display device having a LED (Light Emitting Diode) backlight according to the present invention and its power supply device and method, the power factor correction voltage while supplying the power factor compensation voltage directly to the backlight unit.
  • a backlight driver including a compensation circuit for ripples of several tens of volts an object of the present invention is to eliminate multi-stage power conversion and to eliminate power loss.
  • Display device having a LED backlight according to an embodiment of the present invention and its power supply and method is coupled to the power factor correction circuit while supplying a direct current driving voltage having a ripple of several tens of volts directly to the backlight unit having an LED array
  • Another object of the present invention is to use a backlight driver to significantly reduce power consumption of a display device or a power supply thereof and to increase efficiency of the device.
  • a display device having a LED backlight, a power supply device, and a method thereof include a high voltage driving LED having a forward voltage of at least 10 V, thereby efficiently using a power factor correction power source having a high voltage value.
  • a high voltage driving LED having a forward voltage of at least 10 V
  • a power factor correction power source having a high voltage value.
  • a display apparatus for displaying an image according to the input image signal;
  • a backlight unit having at least one LED array and providing illumination to the display panel;
  • a power supply device configured to receive an input AC power and supply power of a DC component to the display panel and the backlight unit, wherein the power supply includes full-voltage rectification of the input AC power to at least a high forward voltage value of the LED array.
  • An AC-DC converter for generating a power factor correction power supply having a value; Bypass wiring for supplying the power factor correction power to the backlight unit as the backlight driving power; And a DC-DC electrically connected to a rear end of an AC-DC converter to generate a display driving power having a low voltage value for driving the display panel by stepping down the backlight driving power and supplying the generated display driving power to the display panel. It characterized in that it comprises a converter.
  • the low voltage value corresponds to the DC power required by the driving circuit of the display panel or the system board of the display device except the DC power required by the LED backlight.
  • the AC-DC converter the input terminal for receiving an input AC power;
  • a full-wave rectifier electrically connected to the input terminal and generating a rectified power by full-wave rectifying the input AC power;
  • a power factor correction unit electrically connected to the full-wave rectifier and generating a power factor correction power source having a median greater than the maximum voltage of the input AC power and a ripple smaller than the voltage fluctuation range of the input AC power by compensating the power factor. Characterized in that.
  • a display device may further include a backlight driver configured to constant current drive at least one LED array.
  • the backlight driver includes: a drive switch having a first terminal connected to an output terminal of at least one LED array; A resistor connected between the second terminal of the drive switch and the reference potential; And a controller connected to the control terminal of the driving switch and PWM controlling the operation of the driving switch based on the feedback voltage and the reference voltage across the resistor.
  • the backlight driver includes a plurality of constant current drivers connected to output terminals of the plurality of LED arrays in which a plurality of LED arrays are formed in a plurality of channels and connected in parallel, respectively, each constant current.
  • the driver is formed of an integrated circuit having a reference voltage generator, and one of the plurality of constant current drivers is set as a master and the other is set as a slave, whereby the plurality of constant current drivers are set as a master.
  • a constant current is driven based on the reference voltage of the constant current driver.
  • the comparator provided in each constant current driving unit alternates the positive input terminal and the negative input terminal of the comparator with the output polarity in the comparator over time, thereby changing the input error of the comparator over time. It is characterized in that the error compensation comparator of the chopping (Chopping) method to cancel accordingly.
  • the backlight driver includes a plurality of constant current drivers connected to output terminals of the plurality of LED arrays in which a plurality of LED arrays form a plurality of channels and connected in parallel.
  • Each constant current driver senses a switch voltage at the first terminal of the drive switch or at least one of a voltage detector and a current detector, and senses a feedback voltage according to a current flowing through a resistor. And providing a power factor compensation feedback signal to the power factor correction unit.
  • the AC input voltage has a voltage corresponding to a root mean square value (RMS value) of 85 V to 240 V DC
  • the AC-DC converter corresponds to a high voltage value.
  • RMS value root mean square value
  • the DC-DC converter generates a display driving power source of DC 3V to 50V corresponding to a low voltage value.
  • the display device may further include an electromagnetic interference (EMI) filter connected to an input terminal of the AC-DC converter.
  • EMI electromagnetic interference
  • the power supply device of the display device is supplied with a direct current to the backlight unit having at least one LED (Light Emitting Diode) array and the display panel to which the backlight unit is coupled to receive the input AC power
  • a power supply for a display device comprising: an AC-DC converter for full-wave rectifying an input AC power to generate a backlight driving power having a high voltage value equal to or greater than a total forward voltage value of at least one LED array; A bypass wiring for supplying backlight driving power to the backlight unit; And a DC-DC converter electrically connected to a rear end of the AC-DC converter and generating a display driving power having a low voltage value for driving the display panel by stepping down the backlight driving power.
  • the AC-DC converter the input terminal for receiving an input AC power;
  • a full-wave rectifier electrically connected to the input terminal and generating a rectified power by full-wave rectifying the input AC power;
  • a power factor correction unit electrically connected to the full-wave rectifier and generating a power factor correction power source having a median greater than the maximum voltage of the input AC power and a ripple smaller than the voltage fluctuation range of the input AC power by compensating the power factor. Characterized in that.
  • the power factor correction unit an inductor connected in series with the output terminal of the full-wave rectifier; A diode to which an anode is connected to the inverter; A first terminal, a second terminal and a control terminal, the first terminal is commonly connected to one end of the inductor and the anode of the diode, the second terminal is connected to the reference potential side, the control terminal is PFC ( A power transistor connected to a power factor correction controller; And a capacitor connected between the cathode of the diode and the reference potential.
  • the PFC control unit receives a monitoring voltage obtained by dividing the voltage of the power factor correction power source into a predetermined magnitude from a voltage divider of a plurality of resistors connected in parallel to the cathode of the diode.
  • the PWM control signal may be applied to the control terminal of the transistor according to a result of comparing the preset reference voltage with the monitoring voltage.
  • the PFC controller is characterized in that for receiving the feedback signal for adjusting the power factor correction voltage from the backlight driver.
  • the AC input voltage has a voltage corresponding to the root mean square value (RMS value) of DC 85V to 240V, AC-DC converter, A backlight driving power source having a medium value of DC 200 V to 400 V corresponding to a high voltage value and a ripple of 50 V or less is generated, and the DC-DC converter generates a display driving power source of DC 3 V to 50 V corresponding to a low voltage value. It is done.
  • RMS value root mean square value
  • the DC-DC converter step-down the power factor correction voltage to generate a first step-down voltage, and supplies the first step-down voltage to the display panel 1 DC-DC converter; And a second DC-DC converter for stepping down the power factor correction voltage to generate a second step-down voltage lower than the first step-down voltage and supplying the generated second step-down voltage to the display panel.
  • the first DC-DC converter is a power supplied to the PMIC of the display panel
  • the second DC-DC converter is also called a standby DC-DC converter
  • the power is initially turned on is characterized in that the power is separated from the first DC-DC converter to operate only the minimum power.
  • the AC-DC converter is a sum of the total forward voltage of the LED array of the backlight unit and the ripple voltage of the power factor correction voltage and the minimum operating voltage of the drive switch of the LED array.
  • the power factor correction voltage having a voltage magnitude greater than or equal to the voltage may be output.
  • the LED array is characterized in that it comprises a high voltage driving LED having a forward voltage of 10V or more.
  • the input AC power is applied to supply a DC component power to a backlight unit having at least one LED (Light Emitting Diode) array and a display panel to which the backlight unit is coupled.
  • a backlight unit having at least one LED (Light Emitting Diode) array and a display panel to which the backlight unit is coupled.
  • a power supply method for a display device comprising: a first step of generating a rectified power by full-wave rectifying an input AC power; A second step of generating a power factor correction voltage by compensating the power factor of the rectified power source; Supplying a power factor compensation voltage to the backlight unit through a bypass path, wherein the power factor compensation voltage is a backlight driving voltage having a high voltage value equal to or greater than a total forward voltage value of at least one LED array; A fourth step of generating a display driving power source having a low voltage value for driving the display panel by stepping down the power factor correction voltage; And a fifth step of supplying display driving power to the display panel.
  • the second step, the power factor correction of the rectified power supply has an intermediate value greater than the voltage maximum value of the input AC power supply, the ripple voltage smaller than the voltage fluctuation range of the input AC power supply It characterized in that to generate a power factor correction voltage having a.
  • the second step the sum of the total forward voltage of the at least one LED array and the ripple voltage of the power factor correction voltage and the minimum operating voltage of the drive switch of the LED array.
  • the power factor correction voltage having the above magnitude is generated.
  • the first step the input AC power having a root mean square value (RMS value) of 85V to 240V DC
  • the second step A power factor correction voltage having an intermediate value of DC 200V to 400V and a ripple of 50V or less is generated
  • the fourth step is to step down the power factor correction voltage to generate a display driving power having 3 to 50V DC.
  • RMS value root mean square value
  • the power factor correction unit for generating the power factor correction voltage receives a feedback signal for adjusting the power factor correction voltage from the backlight driver for constant current driving the at least one LED array. It further comprises a step.
  • the LED (Light Emitting Diode) backlight includes a power factor correction unit for outputting a power factor correction voltage by compensating a power factor of an input AC power source as an LED backlight for a display device; A backlight unit including a plurality of light emitting diodes and driving according to the provided power factor correction voltage; And a backlight driver controlling a current flowing through the plurality of light emitting diodes to a predetermined size and controlling brightness of the backlight unit.
  • the backlight driver is characterized in that to adjust the magnitude of the current according to the result of comparing the voltage and the reference voltage corresponding to the output current of the backlight unit.
  • the power factor correction unit may compensate for the difference in the voltage level of the commercial AC power supply, and the power factor correction voltage having a magnitude equal to or greater than the sum of the reference voltages for driving the plurality of light emitting diodes. It characterized in that the output.
  • the LED backlight according to another embodiment of the present invention may further include a ripple removing unit for removing the AC component included in the power factor compensation voltage to provide the power factor compensation voltage from which the AC component is removed to the backlight unit.
  • LCD liquid crystal display
  • FIG. 2 is a schematic configuration diagram of a display device having an LED backlight according to the present invention.
  • FIG. 3 is a schematic circuit diagram of another embodiment of the backlight driver of FIG. 2;
  • FIG. 4 is a schematic circuit diagram of another embodiment of the backlight driver of FIG. 2;
  • FIG. 5 is a schematic circuit diagram of another embodiment of the backlight driver of FIG. 2; FIG.
  • FIG. 6 is a circuit diagram illustrating a power supply device of a display device according to an embodiment of the present invention.
  • FIG. 7 is a waveform diagram of an input AC power supply of the display device of FIG. 6.
  • FIG. 8 is a partial circuit diagram illustrating a power supply device of a display device according to another embodiment of the present invention.
  • FIG. 9 is a flowchart illustrating a power supply method of a display apparatus according to the present invention.
  • FIG. 2 is a schematic configuration diagram of a display device having an LED backlight according to the present invention.
  • the display device includes a display panel 10, a backlight unit 20, and a power supply device 30.
  • the display panel 10 displays an image according to the input image signal.
  • the display panel 10 may include a power management integrated circuit 11.
  • the power management integrated circuit 11 is a power semiconductor device that integrally controls and manages various powers required for driving a display panel. For example, a power supply of a timing controller, a source driver power, and a gate driver Gate driver power, gamma voltage, or common buffer power (Vcom Buffer) can be controlled and managed.
  • the power management integrated circuit 11 may be replaced with an existing power management unit that performs a corresponding function.
  • the display panel 10 may correspond to the remaining portion of the existing liquid crystal display type display device except for a backlight and a switching mode power supply (SMPS).
  • SMPS switching mode power supply
  • the backlight includes a backlight unit and a backlight driver.
  • the backlight unit 20 includes at least one array of light emitting diodes (LEDs) and provides lighting to the display panel 10.
  • LEDs light emitting diodes
  • the backlight unit 20 may simply be referred to as an LED array.
  • the LED array may include at least one LED group in which a plurality of light emitting diode elements are connected in series, or may include a plurality of LED groups.
  • the backlight unit 20 may include a high voltage driving LED having a forward voltage of at least 10V.
  • the backlight unit effectively provides a power factor correction power supply having a high voltage value.
  • the input voltage is unstable in the case of the general low voltage / high current driving LED of about 3 ⁇ 5V, there is a problem that the brightness change seriously occurs.
  • the high voltage / low current driving LED the change of the luminance even when the input voltage changes As a result, the display device has an effect of providing a stable screen.
  • the high voltage driving LED has a high brightness, when combined with a wide-angle lens, the manufacturing cost is reduced by reducing the number of LEDs constituting the backlight unit.
  • the power supply device 30 includes an AC-DC converter 31, a bypass wiring 32, a backlight driver 33, and a DC-DC converter 34.
  • the power supply device 30 according to the present exemplary embodiment may correspond to a switching mode power supply in which the backlight driver 33 is mounted on a single substrate together with the AC-DC converter 31 and the DC-DC converter 34.
  • the AC-DC converter 31 is a converter having a power factor correction function.
  • the AC-DC converter 31 performs full-wave rectification of the input AC power to generate a power factor correction voltage (V PFC ) having a high voltage value equal to or greater than the total forward voltage value of the LED array and bypass wiring. Supply to the backlight unit 20 through 34.
  • V PFC power factor correction voltage
  • the AC-DC converter 31 rectifies 85 V to 265 V of input DC power and performs power factor correction using a control IC or a MOSFET switch.
  • the AC-DC converter 31 outputs a power factor correction voltage having a ripple of several tens of volts at several volts. That is, the high voltage value equal to or greater than the total forward voltage value of the LED array described above may be a direct current voltage (385V, etc.) having a ripple of about 10V or more.
  • the power factor correction voltage is supplied to the backlight unit 20 as the backlight driving power.
  • the bypass wire 32 directly connects the output terminal of the AC-DC converter 31 and the input terminal of the backlight unit 20.
  • the power factor correction voltage V PFC output from the AC-DC converter 31 by the bypass wiring 32 is directly supplied to the backlight unit 20 without passing through the DC-DC converter 34.
  • the bypass wiring 32 has been described as being included in the AC-DC converter 31, but the present invention is not limited to such a configuration, and the display device or the power supply device does not bypass the bypass wiring 32. It includes having as an independent component.
  • the backlight driver 33 drives a constant current of at least one LED array of the backlight unit 20.
  • the backlight driver 33 supplies the backlight unit 20 as a backlight driving power and drives the backlight unit 20 using a power factor correction voltage having a ripple of several to several tens of volts.
  • the backlight driver 33 may transmit a feedback signal V PC to the power factor correction unit provided in the AC-DC converter 31.
  • the DC-DC converter 34 is electrically connected to the rear end of the AC-DC converter 31 and has a low voltage value for driving the display panel 10 by stepping down the power factor correction voltage (corresponding to the backlight driving voltage).
  • the driving power is generated, and the generated display driving power is supplied to the display panel 10.
  • the low voltage value refers to a voltage of 24V or less used in the display panel 10.
  • FIG. 3 is a schematic circuit diagram of another embodiment of the backlight driver of FIG. 2.
  • the backlight driver 33a includes a first constant current driver 331 coupled to a first LED array 21 of a first channel, and a second LED array 22 of a second channel. ) Is provided with a second constant current driver 332.
  • the first constant current driver 331 includes a first driving switch Q1, a first resistor R, a first controller 3311, a first comparator 3312, and a first reference voltage generator 3313.
  • the second constant current driver 332 includes a second driving switch Q3, a second resistor R, a second controller 3321, a second comparator 3322, and a second reference voltage generator 3323. Each constant current driver may be formed of an IC chip.
  • the first driving switch Q1 includes a first terminal, a second terminal, and a control terminal, and the first terminal is connected to an output terminal of the first LED array 21.
  • the first resistor R is connected between the second terminal of the first driving switch Q1 and the reference potential.
  • the voltage (feedback voltage) across the first resistor R detected at the second terminal of the first driving switch Q1 is input to the negative input terminal of the first comparator 3312, and is supplied from the first control unit 3311.
  • the reference voltage is input to the positive input terminal of the first comparator 3312.
  • the first comparator 3312 applies a PWM control signal according to the feedback voltage and the reference voltage to the control terminal of the first driving switch Q1.
  • the first reference voltage generator 3313 inputs the first reference voltage to the first controller 3311.
  • the connection relationship between the components of the second constant current driver 332 is substantially the same as that of the first constant current driver 331 described above.
  • the backlight driver 33a receives the current I LED flowing through the LED arrays 21 and 22 of each channel according to a result of comparing the feedback voltage applied to both ends of the resistor R of each channel with the reference voltage from each controller. Constant current control.
  • the backlight driver 33a may set each constant current driver to reduce the LED current deviation between channels according to the deviation of the reference voltage because the reference voltage is different for each constant current driver of each channel.
  • the backlight driver 33a is configured to set the reference voltage of the constant current driver of the remaining channels based on the reference voltage provided to the constant current driver of any one channel among the reference voltages provided to the constant current driver of each channel.
  • each constant current driver of the first and second channels is referred to as IC1 and IC2, and if there is a reference voltage generator for each IC chip, it flows in each channel according to the voltage distribution of the reference voltage generator of each channel.
  • IC2 is also operated with the reference voltage of IC1 in order to reduce the difference in LED current and thereby reduce the luminance deviation of each channel.
  • the backlight driver 33a sets IC1 as a master and IC2 as a slave. According to this setting, IC2 can be driven with the reference voltage of IC1.
  • FIG. 4 is a schematic circuit diagram of another embodiment of the backlight driver of FIG. 2.
  • the backlight driver 33b includes a first constant current driver 331 and a second constant current driver 332, and the first constant current driver 331 includes a first drive switch Q1. ), A first resistor R, a first controller 3311, a first error correction comparator 3312a, and a first reference voltage compensator 3313.
  • the second constant current driver 332 includes a second drive switch Q3, a second resistor R, a second controller 3321, a second error compensating comparator 3322, and a second reference voltage compensator 3323. do.
  • Each constant current driver may be formed of an IC chip.
  • the backlight driver 33b may have the same components as those of the backlight driver 33b described above with reference to FIG. 3. Since they are substantially the same, detailed descriptions thereof will be omitted in order to avoid duplication of description.
  • the first and second error correction comparators 3312a and 3322a are a chopping comparator without a capacitor.
  • the first and second error compensating comparators 3322a and 3322a alternately output the positive and negative input terminals of the comparator with the output polarity in the comparator over time. It can be implemented to cancel the input error over time.
  • the LED current deviation according to the input offset voltage deviation of the comparator may be reduced, thereby reducing the luminance variation of the LED array in each channel.
  • FIG. 5 is a schematic circuit diagram of another embodiment of the backlight driver of FIG. 2.
  • the backlight driver 33c includes a driving switch Q1, a resistor R, a controller 3311, a comparator 3312, a voltage detector 3314, and a current detector ( 3315), and the power factor correction voltage control signal generator 3316.
  • the power factor correction voltage (V PFC ) can compensate for the difference in voltage magnitude of the commercial input AC power supply, and has a magnitude greater than or equal to the driving voltage (forward voltage) for driving the LED array 20. .
  • the backlight driver 33c senses the voltage at the first terminal of the driving switch Q or the voltage according to the output current flowing through the driving switch Q, and the detected feedback voltage is the LED array ( If the voltage 20 is higher or lower than the rated voltage required to drive the constant current, the feedback signal V PC capable of adjusting the power factor correction voltage V PFC may include an AC-DC converter including a power factor correction unit or a power factor correction unit (see FIG. 2). Reference numeral 31).
  • the magnitude of the power factor correction voltage V PFC may be determined by a voltage fed back to the power factor correction unit according to a resistance ratio of a series circuit of a plurality of resistors connected in parallel to the output terminal of the power factor correction unit.
  • the backlight driver 33c according to the present exemplary embodiment detects a first voltage expected to fall by the forward voltage of the LED array 20 from the power factor correction voltage V PFC , and detects the first voltage.
  • the power factor correction voltage control signal corresponds to the feedback signal V PC as the power factor compensation voltage control feedback signal, and when the power factor compensation voltage control signal is used, the backlight driving efficiency is improved, and the backlight unit having the LED array is used. Can reduce fever.
  • the backlight driver 33c transmits the power factor correction voltage control signal to the power factor compensation voltage control signal generator 3316 when the current detection result of the current detection unit 3315 is less than the reference current. Is applied to increase the power factor compensation voltage, and when the detected current is equal to or greater than the reference current, the power factor compensation voltage control signal generator 3316 operates to maintain the current power factor compensation voltage (do not output the power factor compensation voltage control signal). Etc.).
  • adjusting the power factor correction voltage may be performed using at least one of the voltage detector 3314 and the current detector 3315, depending on the implementation.
  • FIG. 6 is a circuit diagram illustrating a power supply device of a display device according to an embodiment of the present invention.
  • the display device includes a filter 310, a bridge diode 311, a power factor correction unit 312, a bypass wiring 32, a backlight unit 20, and a backlight driver 33. ), A first DC-DC converter 341 and a second DC-DC converter 342.
  • the bridge diode 311, the bypass wire 32, the backlight unit 20, and the backlight driver 33 are substantially the same as the corresponding components described above with reference to FIG. 2.
  • the backlight driver 33 may be referred to as an AC-LED driver circuit in that the backlight unit 33 drives the backlight unit 20 by a power factor correction voltage having a ripple of several volts to several tens of volts. .
  • the filter 310 includes an electromagnetic interference (EMI) filter.
  • EMI filters are designed to reduce noise signals on commercial input AC power during normal operation and to reduce the magnitude of surge pulses during abnormal operation.
  • Common mode chokes can reduce noise on both power lines of input AC power. Mode Choke), and two capacitors connected across the common mode choke.
  • the filter 310 may include a protection circuit installed at the input terminal of the EMI filter.
  • the protection circuit is to keep the input AC voltage below a certain voltage by cutting off the overvoltage at the input AC power supply and attenuating the overvoltage or surge voltage.
  • the protection circuit fuse and metal oxide varistor (MOV) It may be implemented as a Transient Voltage Suppression (TVS) device.
  • TVS Transient Voltage Suppression
  • the power factor correction unit 312 includes an inductor L, a diode D, a switch Q P , a capacitor C P , and a PFC controller 3121.
  • the inductor L is connected in series to the output terminal of the bridge diode 311, and the anode of the diode D is connected to the inductor L.
  • the switch (MOSFET switch, etc.) has a first terminal, a second terminal and a control terminal, the first terminal is commonly connected to the anode of the inductor L and the diode D, and the second terminal connects the resistor R0.
  • the control terminal is connected to the output terminal of the PFC controller 3121.
  • the capacitor C P has a first terminal and a second terminal, the first terminal is connected to the cathode of the diode D, and the second terminal is connected to the reference potential.
  • a series circuit of the first resistor R1 and the second resistor R2 may be connected between the cathode of the diode D and the reference potential.
  • the PFC controller 3121 of the power factor correction unit 312 When operating in the discontinuous current mode (DCM), the PFC controller 3121 of the power factor correction unit 312 is turned on when the current flowing in the inductor L is zero, and the resistor R0 Switch Q P to be turned off when the voltage applied to both terminals as the reference voltage applied to the predetermined input terminal CS and the current flowing through the inductor L are equal to the inductor voltage applied to the predetermined input terminal ZCD. Control the operation of By repeating this process, the power factor correction unit 312 can substantially bring the power factor closer to 1 by causing the waveform of the input current (average waveform) to follow the input voltage waveform.
  • DCM discontinuous current mode
  • a ripple removing unit may be installed at the input terminal of the backlight unit 20 according to the implementation.
  • the ripple removing unit may be included in some components of the backlight driver or in some components of the LED backlight including the backlight driver and the backlight unit.
  • the ripple removing unit removes at least a portion of an AC component included in the power factor correction voltage V PFC provided from the power factor correction unit 312, and then provides the power factor compensation voltage to which the AC component is partially removed to the backlight unit 20.
  • the ripple removing unit if the magnitude of the AC component included in the power factor correction voltage is too large, the amount of the ripple component may be reduced to reduce power consumed by the ripple component, and the driving of the backlight unit 20 may be easily performed. This can further increase power efficiency.
  • the first DC-DC converter 341 has a form of a flyback converter, and direct current 12V from the power factor correction power applied to the transformer primary side by controlling the transformer connected to the two switches by a resonant controller.
  • the display driving power is operated to be output.
  • the second DC-DC converter 342 has a form of a multi-stage flyback converter coupled to the first DC-DC converter 341, and by controlling a transformer connected to the switch by a PWM controller, the transformer primary side It operates to output DC 3.5V driving power to the transformer secondary side from power factor correction power applied to.
  • the first DC-DC converter 341 corresponds to a converter for supplying panel driving power to the PMIC of the display panel
  • the second DC-DC converter 342 is a standby DC-DC converter depending on the implementation.
  • the display device may correspond to a converter supplying standby power separated from the first DC-DC converter 342 to operate only the minimum standby power.
  • the first DC-DC converter 341 and the second DC-DC converter 342 may be a form in which the first and second DC-DC converters 341 and 342 are integrated into one DC-DC converter according to an implementation. It may be provided.
  • FIG. 7 is a waveform diagram of an input AC power supply of the display apparatus of FIG. 6.
  • the display apparatus greatly improves the power factor by the operations of the power factor compensator 312 and the backlight driver 33. Looking at the power factor of the display device on the input commercial power supply side, the period of the input AC voltage and the period of the input AC current coincide, and the reactive power is greatly reduced.
  • the display device greatly reduces the effective power by directly supplying the power factor correction power output from the power factor correction unit 312 to the backlight unit.
  • the display device used in the comparative example is an LCD TV having an LED backlight of the edge method
  • the display device used in the present embodiment is an LCD improved according to the above-described configuration of the present invention (see FIG. 10). TV.
  • the display device of this embodiment exhibits a power factor of 0.91 by 35.6 [W] of active power and 39.2 [VA] of apparent power, and a display device of Comparative Example of 44.2 [W] and 51.9 [VA of apparent power of Comparative Example. ] Represents a power factor of 0.86.
  • the display device according to the present invention may satisfy a power factor of more than 0.9.
  • the display device according to the present invention mainly exhibits an efficiency of about 95.22% in the power supply, which is about 20% improved compared to 75.05% of the comparative example.
  • the main reason for this is that it does not use a multi-stage DC-DC converter, which consumes a significant amount of power to drive the backlight unit.
  • the display device or the power supply device according to the present invention can provide a large efficiency increase by eliminating power conversion processes of various stages for driving the LED backlight to prevent power loss.
  • FIG. 8 is a partial circuit diagram of a power supply of a display device according to another embodiment of the present invention.
  • the power supply of the display apparatus includes a fuse 310a for power distribution, a bridge diode 311, an input capacitor C V , an inductor L, a diode D, and a power factor.
  • a compensation switch Q P , an output capacitor C P , a drive switch Q LED , a current setting resistor R SET , and a power factor drive control unit 330 are provided.
  • the power supply device is configured to generate a power factor correction voltage by full-wave rectifying and power factor correcting the input AC power V AC , and directly supply the generated power factor compensation voltage to the backlight unit 20.
  • the power factor correction voltage is supplied to a DC-DC converter at a later stage to supply driving power to the display panel of the display device.
  • the fuse 310a for power distribution corresponds to a part of the protection circuit provided at the input terminal of the filter described above.
  • the input capacitor C V has a capacity to stabilize the input voltage, that is, the rectified voltage full-wave rectified by the bridge diode 311 according to the peak current demand of the SMPS.
  • the inductor (L), diode (D), power factor correction switch (Q P ) and output capacitor (C P ) are power converter compensators in the form of boost converters and are substantially the same as corresponding components described above with reference to FIG. Therefore, detailed description thereof will be omitted to avoid duplication.
  • the conventional power factor correction circuit in order to minimize the ripple of the output voltage, it is common to consider the specification of the output capacitor (low ESR capacitor, etc.), but in this embodiment, since the reverse flow compensation voltage having the ripple of a predetermined size is used as it is. Compared with the conventional power factor correction circuit, a wider selection range for the output capacitor of the power factor correction unit can increase design freedom.
  • the current setting resistor R SET is for setting a current flowing in the LED array of the backlight unit 20, and may be integrally integrated with the power factor driving controller 330 according to the implementation. Since the current setting resistor R SET is substantially the same as the resistor R provided in the constant current driving units of the above-described embodiments, detailed description thereof will be omitted to avoid duplication.
  • the power factor drive controller 330 is a PFC controller and a constant current driver of the backlight driver of the AC-DC converter formed of a single integrated circuit.
  • the power factor drive controller 330 performs the functions of the PFC controller 3121 and the backlight driver 33 described above with reference to FIG. 6.
  • the power factor drive controller of a single integrated circuit can reduce the cost of the power supply and drive the LED backlight with high efficiency.
  • FIG. 9 is a flowchart illustrating a power supply method of a display apparatus according to the present invention.
  • the rectifier power is generated by full-wave rectifying the input AC power in the power supply device (S91).
  • the rectifying unit such as a bridge diode provided in the AC-DC converter receives an input AC power source having a root mean square value (RMS value) of 85 V to 240 V DC, and receives the input AC power at any time. It can rectify and output rectified power supply.
  • RMS value root mean square value
  • the power factor correction voltage is generated by compensating the power factor of the rectified power source (S92).
  • the power factor correction unit provided in the AC-DC converter compensates for the rectified power supply and has a median value larger than the maximum voltage of the input AC power supply and has a ripple voltage smaller than the voltage fluctuation range of the input AC power supply. Generate a voltage.
  • the power factor correction unit is a sum of the total forward voltage of the at least one LED array provided in the backlight unit, the ripple voltage of the power factor correction voltage and the minimum operating voltage of the driving switch connected to the output terminal of the LED array.
  • the power factor correction voltage having the above magnitude is generated.
  • the power factor correction unit compensates for the rectified power source to generate a power factor correction voltage having a median value of DC 200V to 400V and a predetermined ripple.
  • the PFC controller of the power factor correction unit may receive a feedback signal for adjusting the power factor compensation voltage from the backlight driver for driving the at least one LED array.
  • the power factor correction unit may drive control the power supply device at an optimum efficiency according to the load (LED array).
  • the countercurrent compensation unit corresponds to the power factor correction control unit.
  • the power factor correction voltage is supplied to the backlight unit through the bypass path (S93).
  • the backlight driver drives the backlight unit by using a power factor correction voltage corresponding to the backlight driving voltage for driving the backlight unit and having a high voltage value equal to or greater than a total forward voltage value of at least one LED array included in the backlight unit. .
  • the backlight driver may be implemented by the backlight driver circuit described above with reference to FIGS. 3 to 5.
  • the power supply device step-down the power factor correction voltage to generate a display driving power having a low voltage value for driving the display panel. (S94). Then, the display driving power is supplied to the display panel (S95).
  • the DC-DC converter electrically connected to the output terminal of the AC-DC converter to step down the power factor correction voltage to generate a display drive power having a direct current 3V to 50V, and to generate the display drive power It can be supplied to the power management integrated circuit of the display panel.
  • the power factor correction voltage having a ripple of several volts to several tens of volts can be directly used in the backlight unit, thereby providing high efficiency, low cost, low power consumption, and high power factor in the display device and its power supply and method. Can be provided.
  • a high voltage driving LED may be used for the backlight unit instead of the existing low voltage driving LED.
  • the number of LEDs used in the backlight unit can be reduced to 1/10, for example, so that the number of LED packages required can be reduced, thereby reducing the manufacturing cost, and the probability of failure of the backlight unit can be lowered as the number of parts is reduced.
  • backlight units using existing low-voltage LEDs require wire bonding between LED chips to mount multiple LED chips in one package.
  • wire bonding due to the wire bonding, it is difficult to combine the wide-angle lens for dispersing the light source on the LED package, and defects frequently occur due to wire bonding disconnection.
  • the backlight unit using the high voltage LED according to the embodiment of the present invention has an advantage that wire bonding is unnecessary by using a single high voltage LED chip having high brightness. This makes it easy to combine the LED package and the wide-angle lens, so that the backlight unit can be configured with a smaller number of LED packages, and the defects due to wire bonding disconnection do not occur.
  • a display device having an LED backlight according to the present invention, a power supply device, and a power supply method include a compensation circuit for a ripple of several tens of volts of the power factor compensation voltage while directly supplying the power factor compensation voltage to the backlight unit.
  • the power conversion process for supplying the driving power of the backlight unit is omitted and thus the power loss is eliminated.
  • a display device including an LED backlight, a power supply device, and a power supply method include a backlight driving unit coupled to a power factor correction circuit while directly supplying a power factor correction voltage having a ripple of several tens of volts to the backlight unit.
  • a display device having a LED backlight, a power supply device, and a method thereof include a high voltage driving LED having a forward voltage of at least 10 V, thereby efficiently using a power factor correction power source having a high voltage value.
  • a change in luminance of the backlight unit is minimized, and the number of LEDs constituting the backlight unit is reduced, thereby providing an effect of lowering manufacturing cost and failure rate.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Circuit Arrangement For Electric Light Sources In General (AREA)
  • Liquid Crystal (AREA)

Abstract

La présente invention concerne un dispositif d'affichage comprenant un rétroéclairage à DEL, une tension de correction de facteur de puissance étant directement appliquée à l'unité de rétroéclairage et un circuit de commande de DEL à courant alternatif comprenant un circuit de correction des ondulations de dizaines de volts de la tension de commande étant utilisé, éliminant ainsi un processus de conversion partielle de la puissance et la perte de puissance résultante dans une alimentation à découpage (SMPS) du dispositif d'affichage, pour améliorer de ce fait la productivité et réduire les coûts de fabrication. La présente invention concerne également un appareil d'alimentation et un procédé d'alimentation de cet appareil. Le dispositif d'affichage comprend : un panneau d'affichage pour afficher une image conformément à un signal d'image entré ; une unité de rétroéclairage comportant au moins un réseau de DEL et éclairant le panneau d'affichage ; et un appareil d'alimentation pour recevoir la puissance alternative entrée et fournir une puissance à composante continue au panneau d'affichage et à l'unité de rétroéclairage. L'appareil d'alimentation comprend : un convertisseur alternatif-continu pour le redressement double alternance de la puissance alternative entrée de manière à générer une puissance à correction de facteur de puissance ayant une valeur de tension élevée qui est supérieure à la valeur de tension directe totale d'un réseau de DEL ; un fil de dérivation pour fournir, en tant que puissance de commande de rétroéclairage, la puissance à correction de facteur de puissance à l'unité de rétroéclairage ; et un convertisseur continu-continu, qui est connecté électriquement à l'extrémité arrière du convertisseur alternatif-continu, et qui abaisse la puissance de commande de rétroéclairage de manière à générer une puissance de commande d'affichage ayant une valeur de tension faible pour commander le panneau d'affichage, et qui délivre la puissance de commande d'affichage générée au panneau d'affichage.
PCT/KR2013/004782 2012-06-01 2013-05-31 Dispositif d'affichage comprenant un rétroéclairage à del, et appareil d'alimentation et procédé d'alimentation de ce dispositif WO2013180500A1 (fr)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
KR10-2012-0059397 2012-06-01
KR20120059397 2012-06-01
KR1020120140237A KR20130135718A (ko) 2012-06-01 2012-12-05 Ｌｅｄ 백라이트를 구비하는 디스플레이 장치와 그 전원 공급 장치 및 방법
KR10-2012-0140237 2012-12-05
KR10-2013-0046737 2013-04-26
KR1020130046737A KR20130135744A (ko) 2012-06-01 2013-04-26 Ｌｅｄ 백라이트를 구비하는 디스플레이 장치와 그 전원 공급 장치 및 방법

Publications (1)

Publication Number Publication Date
WO2013180500A1 true WO2013180500A1 (fr) 2013-12-05

Family

ID=49673626

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2013/004782 WO2013180500A1 (fr) 2012-06-01 2013-05-31 Dispositif d'affichage comprenant un rétroéclairage à del, et appareil d'alimentation et procédé d'alimentation de ce dispositif

Country Status (1)

Country Link
WO (1) WO2013180500A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016093486A1 (fr) * 2014-12-11 2016-06-16 류태하 Pilote de del ca universel
CN107969054A (zh) * 2017-12-30 2018-04-27 欧普照明股份有限公司 Led驱动电源、电源输出电压的控制方法及led灯具
CN111429835A (zh) * 2020-03-05 2020-07-17 广东尚研电子科技有限公司 一种波浪动态显示式充电显示结构及驱动方法
EP3813489A1 (fr) * 2019-10-26 2021-04-28 Graphene Lighting PLC Circuit de commande de del à trajets multiples
CN117953814A (zh) * 2024-03-27 2024-04-30 杭州视芯科技股份有限公司 Led显示系统、led显示系统的控制方法、计算机设备及存储介质

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003092195A (ja) * 2001-09-18 2003-03-28 Toritsu Tsushin Kogyo Kk Ｌｅｄ表示装置
KR20080080272A (ko) * 2001-07-03 2008-09-03 삼성전자주식회사 액정 표시 장치
US20100309188A1 (en) * 2008-01-28 2010-12-09 Osram Gesellschaft Mit Beschraenkter Haftung Driver for a projection system
JP2011041465A (ja) * 2003-06-06 2011-02-24 Sony Corp 電源装置
JP2011082204A (ja) * 2009-10-02 2011-04-21 Fdk Corp 多直列ｌｅｄ駆動回路

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20080080272A (ko) * 2001-07-03 2008-09-03 삼성전자주식회사 액정 표시 장치
JP2003092195A (ja) * 2001-09-18 2003-03-28 Toritsu Tsushin Kogyo Kk Ｌｅｄ表示装置
JP2011041465A (ja) * 2003-06-06 2011-02-24 Sony Corp 電源装置
US20100309188A1 (en) * 2008-01-28 2010-12-09 Osram Gesellschaft Mit Beschraenkter Haftung Driver for a projection system
JP2011082204A (ja) * 2009-10-02 2011-04-21 Fdk Corp 多直列ｌｅｄ駆動回路

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016093486A1 (fr) * 2014-12-11 2016-06-16 류태하 Pilote de del ca universel
CN107969054A (zh) * 2017-12-30 2018-04-27 欧普照明股份有限公司 Led驱动电源、电源输出电压的控制方法及led灯具
EP3813489A1 (fr) * 2019-10-26 2021-04-28 Graphene Lighting PLC Circuit de commande de del à trajets multiples
CN111429835A (zh) * 2020-03-05 2020-07-17 广东尚研电子科技有限公司 一种波浪动态显示式充电显示结构及驱动方法
CN117953814A (zh) * 2024-03-27 2024-04-30 杭州视芯科技股份有限公司 Led显示系统、led显示系统的控制方法、计算机设备及存储介质

Similar Documents

Publication Publication Date Title
TWI474753B (zh) 發光元件驅動系統，驅動控制電路及驅動方法
US20200344438A1 (en) Television power supply driving device and television
WO2014148767A1 (fr) Circuit de pilotage de del utilisant des diodes en double pont et dispositif d'éclairage à del le comprenant
CN101605416B (zh) 发光二极管驱动电路及其控制器
WO2013089506A1 (fr) Dispositif d'attaque de diode électroluminescente (del)
WO2013180500A1 (fr) Dispositif d'affichage comprenant un rétroéclairage à del, et appareil d'alimentation et procédé d'alimentation de ce dispositif
WO2018045696A1 (fr) Alimentation électrique à découpage et téléviseur
US20090295776A1 (en) Light emitting diode driving circuit and controller thereof
WO2012115323A1 (fr) Appareil de régulation de courant
CN103763830B (zh) 发光元件驱动系统、驱动控制电路及驱动方法
US20150154917A1 (en) Backlight module, method for driving same and display device using same
WO2014196702A1 (fr) Appareil d'éclairage à del comprenant un circuit d'entraînement de del haute puissance
WO2014126392A1 (fr) Circuit d'alimentation électrique permettant de modifier la fréquence de scintillement d'une diode électroluminescente
US20230419916A1 (en) Display apparatus and display control method
US11825577B2 (en) Display apparatus and step power circuit
WO2010058923A2 (fr) Dispositif lumineux à courant alternatif, son dispositif d'attaque et procédé d'attaque associé
KR20130135744A (ko) Ｌｅｄ 백라이트를 구비하는 디스플레이 장치와 그 전원 공급 장치 및 방법
WO2022108339A1 (fr) Convertisseur intelligent pour dispositif de commande d'éclairage, convertisseur intelligent à thd et emi améliorés, et dispositif de commande d'éclairage le comprenant
WO2023078157A1 (fr) Circuit d'alimentation électrique et écran d'affichage
WO2019172625A1 (fr) Dispositif d'affichage comprenant un circuit de commande d'affichage à chute de tension de sortie
WO2013095055A1 (fr) Module de rétroéclairage, procédé de commande de ce dernier et dispositif d'affichage qui utilise ce dernier
WO2022108107A1 (fr) Dispositif d'affichage
WO2015008878A1 (fr) Circuit intégré pour un éclairage et procédé permettant de commander un éclairage
CN109410848A (zh) Led背光驱动双控制器级联的系统和方法
CN110769173B (zh) 一种电视电源系统及电视机

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13797671

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13797671

Country of ref document: EP

Kind code of ref document: A1