Display device for generating power signals based on voltages of capacitors

Abstract

A display device according to one embodiment may include a transformer comprising a first inductor, a second inductor mutually coupled to the first inductor, and a third inductor mutually coupled to the first inductor. The display device may include a first voltage changing circuit that charges a first capacitor and a second capacitor using an alternating current voltage induced in the second inductor, and outputs a first DC voltage based on the voltages of the first capacitor and the second capacitor. The display device may include a second voltage changing circuit that charges the second capacitor and the third capacitor using an alternating current voltage induced in the third inductor, and outputs a second DC voltage different from the first DC voltage.

Description

Technology Field

[0001] The following descriptions relate to a display device and method for generating power signals based on the voltages of capacitors. Background Technology

[0003] With the recent advancement of electronic technology, various types of display devices are being developed and distributed, and the demand for large display devices is increasing. As display devices are designed to support more functions, the load circuits included in them can be diversified. These diversified load circuits can be designed to provide power signals with different characteristics. The problem to be solved

[0004] A method may be required for the power circuit of a display device to simultaneously output power signals corresponding to different characteristics of load circuits included in the display device.

[0005] The technical problems to be solved in this document are not limited to those described above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which this invention belongs from the description below. means of solving the problem

[0007] A display device according to one embodiment may include a transformer comprising a first inductor, a second inductor mutually coupled to the first inductor, and a third inductor mutually coupled to the first inductor. The display device may include a first voltage changing circuit that charges a first capacitor and a second capacitor using an alternating voltage induced in the second inductor, and outputs a first DC voltage based on the voltages of the first capacitor and the second capacitor. The display device may include a second voltage changing circuit that charges the second capacitor and the third capacitor using an alternating voltage induced in the third inductor, and outputs a second DC voltage different from the first DC voltage.

[0008] According to one embodiment, a display device may include at least one speaker. The display device may include a processor for controlling the at least one speaker. The display device may include a power circuit that outputs power signals having different DC voltages to the at least one speaker and the processor. The power circuit of the display device may include a first voltage changing circuit that charges each of a plurality of capacitors in different time intervals and transmits a power signal of a first DC voltage corresponding to the combination of the voltages of the charged plurality of capacitors to the processor. The power circuit of the display device may include a second voltage changing circuit that charges a first capacitor among the plurality of capacitors in a second time interval different from the first time interval in which the first capacitor is charged by the first voltage changing circuit among the different time intervals, and obtains a power signal of a second DC voltage that exceeds the first DC voltage and is to be provided to the at least one speaker based on the voltage of the first capacitor.

[0009] According to one embodiment, a power circuit of a display device may include a transformer comprising a first inductor, a second inductor inductively coupled to the first inductor, and a third inductor inductively coupled to the first inductor. A power circuit of a display device may include an inverter circuit that inputs power output from a power factor conversion circuit to the first inductor of the transformer. A power circuit of a display device may include a first voltage changing circuit that charges a first capacitor and a second capacitor based on the second inductor among the second inductor and the third inductor, and outputs a first voltage based on the voltage of the first capacitor and the voltage of the second capacitor based on the series connection of the first capacitor and the second capacitor. The power circuit of the display device may include a second voltage changing circuit that charges the second capacitor and the third capacitor based on the third inductor among the second inductor and the third inductor, and outputs a second voltage based on the voltage of the first capacitor, the voltage of the second capacitor, and the voltage of the third capacitor based on the series connection of the first capacitor, the second capacitor, and the third capacitor. Effects of the invention

[0011] A display device according to one embodiment can generate power signals corresponding to different characteristics of load circuits included in the display device based on relatively low loss using a power circuit.

[0012] The effects obtainable from the present disclosure are not limited to those described above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure pertains from the description below. Brief explanation of the drawing

[0014] FIG. 1 is a block diagram of a display device according to an embodiment. FIG. 2 is a block diagram of a power circuit included in a display device according to one embodiment. FIGS. 3a and 3b are block diagrams of a voltage conversion circuit of a power circuit of a display device according to one embodiment. FIGS. 4a to 4b are circuit diagrams of power circuits including each of the voltage conversion circuits of FIGS. 3a to 3b. FIG. 5 is a graph showing the current and / or voltage of the nodes of the power circuit of a display device according to one embodiment. Specific details for implementing the invention

[0015] Hereinafter, various embodiments of this document will be described with reference to the attached drawings.

[0016] The various embodiments of this document and the terms used therein are not intended to limit the technology described in this document to specific embodiments and should be understood to include various modifications, equivalents, and / or substitutions of such embodiments. In connection with the description of the drawings, similar reference numerals may be used for similar components. A singular expression may include a plural expression unless the context clearly indicates otherwise. In this document, expressions such as "A or B," "at least one of A and / or B," "A, B or C," or "at least one of A, B and / or C" may include all possible combinations of items listed together. Expressions such as "first," "second," "first," or "second" may modify the components, regardless of order or importance, and are used only to distinguish one component from another and do not limit the components. When it is mentioned that a certain (e.g., 1st) component is "(functionally or telecommunicationally) connected" or "connected" to another (e.g., 2nd) component, said certain component may be directly connected to said other component or connected through another component (e.g., 3rd component).

[0017] As used in this document, the term "module" includes a unit composed of hardware, software, or firmware, and may be used interchangeably with terms such as logic, logic block, component, or circuit. A module may be a component formed as a whole, or a minimum unit or part thereof that performs one or more functions. For example, a module may be composed of an application-specific integrated circuit (ASIC).

[0019] FIG. 1 is a block diagram of a display device (101) according to an embodiment. The display device (101) may be an electronic device capable of displaying images. For example, the display device (101) may include a TV (television), a monitor, a computer, a smartphone, a tablet, a portable media player, a wearable device, a video wall, a digital photo frame, etc. For example, the display device (101) may be implemented as various types of devices, such as a video processing device including a set-top box that does not have a display, a home appliance including a refrigerator and a washing machine, or an information processing device including a computer main body. For convenience of explanation, the following description assumes that the display device (101) is implemented as a TV, but the embodiment is not limited thereto.

[0020] Referring to FIG. 1, a display device (101) according to one embodiment may include at least one of a power circuit (110), a display driving circuit (130), a main circuit (140), a display panel (150), or a speaker (160). The power circuit (110), the display driving circuit (130), the main circuit (140), the display panel (150), and the speaker (160) may be electrically and / or operably coupled with each other by electronic components, such as a power line and / or a communication bus. The type and / or number of hardware components included in the display device (101) are not limited to those shown in FIG. 1. For example, the display device (101) may include only some of the hardware components shown in FIG. 1.

[0021] Referring to FIG. 1, a power circuit (110) of a display device (101) according to one embodiment may be electrically connected to a power source (120) provided from a power distribution system. The display device (101) may include a power plug that electrically connects the power circuit (110) and the power source (120). Through the power plug, the power circuit (110) of the display device (101) may receive an alternate current signal (AC signal) from the power source (120). The alternating current signal received by the power circuit (110) is a power signal having a voltage that changes over time, for example, the voltage of the alternating current signal may change according to a sinusoidal wave having a specified frequency (e.g., 60 Hz) and a specified amplitude (e.g., 220 V and / or 110 V).

[0022] A power circuit (110) of a display device (101) according to one embodiment may output a direct current signal (DC signal) having a constant voltage and / or another direct current signal having a period and / or amplitude independent of the alternating current signal, using an alternating current signal received from a power source (120). The direct current signal may correspond to a power signal having a voltage that is maintained independently of changes in time. A power circuit (110) according to one embodiment may simultaneously output a plurality of power signals having different voltages. In the following, multiple outputs of the power circuit (110) may mean that the power circuit (110) outputs a plurality of power signals having different voltages (e.g., DC components of different magnitudes).

[0023] In one embodiment in which the power circuit (110) supports multiple outputs, the different voltages of the power signals output from the power circuit (110) may correspond to voltages designated for driving each of the different circuits (e.g., display driving circuit (130) and main circuit (140)) included in the display device (101). Hereinafter, among the circuits included in the display device (101), at least a portion that is operated by the power signal output from the power circuit (110) may be referred to as a load circuit. For driving each of the different load circuits included in the display device (101), the power circuit (110) may generate power signals having voltages corresponding to each of the load circuits. The operation of the power circuit of the display device (101) according to one embodiment generating power signals having different voltages for driving each of the different circuits will be described later through the description of FIG. 2 and / or FIG. 3a to FIG. 3b.

[0024] A display device (101) according to one embodiment may include a display driving circuit (130) for driving a display panel (150). A display device (101) according to one embodiment may include a display panel (150) that is controlled by the display driving circuit (130) and outputs an image. By using the display panel (150), the display device (101) may output visualized information to a user. The display panel (150) may include a Flat Panel Display (FPD). The FPD may include a Liquid Crystal Display (LCD), a Plasma Display Panel (PDP), and / or one or more Light Emitting Diodes (LEDs). The LED may include an Organic LED (OLED). In one embodiment, the display panel (150) may include electronic paper.

[0025] In one embodiment, the display driving circuit (130) may include a timing controller that generates a timing signal for outputting an image from the display panel (150). In one embodiment, the display driving circuit (130) may include an LED driving circuit for driving one or more LEDs included in the display panel (150). The one or more LEDs may be included in the backlight panel and / or pixels of the display panel (150). The LED driving circuit may adjust the voltage of a power signal to be provided to one or more LEDs in order to control the brightness of one or more LEDs included in the display panel (150). For example, the display driving circuit (130) may control the brightness of one or more LEDs included in the display panel (150). The embodiments are not limited thereto, and the power signal may be provided from the power circuit (110) independently of another power signal to be supplied to another circuit that is distinguished from the display driving circuit (130) among the multiple outputs of the power circuit (110).

[0026] Referring to FIG. 1, a display device (101) according to one embodiment may include a main circuit (140) distinct from a display driving circuit (130) for driving a display panel (150). For example, the main circuit (140) may perform other functions distinct from the functions of the display driving circuit (130) (e.g., the function of adjusting the voltage of a power signal to be provided to an LED). The main circuit (140) may include a processor and / or memory for executing one or more functions of the display device (101). The main circuit (140) may generate a signal representing an image to be displayed on the display panel (150) by the display driving circuit (130). The main circuit (140) may transmit the generated signal to the display driving circuit (130). The display driving circuit (130) may control the display panel (150) based on the signal transmitted from the main circuit (140). As the display driving circuit (130) controls the display panel (150), an image corresponding to a signal generated by the main circuit (140) can be displayed on the display panel (150). Hereinafter, the main circuit (140) may be referred to as a main board and / or main circuit.

[0027] In one embodiment, the main circuit (140) may be electrically connected to one or more switches for acquiring user input. The one or more switches may be exposed outside at least partially through the housing of the display device (101). In one embodiment, the main circuit (140) may include a communication circuit for communicating with an external electronic device for acquiring user input, such as a remote control. A display device (101) according to one embodiment may identify user input associated with the one or more switches and / or the remote control using the main circuit (140). The communication circuit may communicate with the external electronic device based on a wireless communication protocol such as infrared communication, Bluetooth and / or Wi-Fi. The main circuit (140) may include a Printed Circuit Board (PCB) comprising at least one of a chipset, a processor, memory, electronic components, or wiring for executing one or more functions. In one embodiment, the main circuit (140) may take the form of a System-on-Chip (SoC).

[0028] In one embodiment, the display driving circuit (130) can control one or more pixels included in the display panel (150) based on a signal received from the main circuit (140). For example, the display panel (150) may include a plurality of pixels arranged in a two-dimensional matrix form. In the above example, the display driving circuit (130) can control at least one pixel included in a corresponding row or column among the plurality of pixels based on the signal. The control of at least one pixel by the display driving circuit (130) may include an operation to adjust the luminance, brightness, and / or color of at least one pixel.

[0029] Referring to FIG. 1, according to one embodiment, a display device (101) may include a speaker (160) for outputting an acoustic signal, which is operated by a power signal provided from a power circuit (110). In one embodiment of FIG. 1, one speaker (160) is shown, but the embodiment is not limited thereto, and the display device (101) may include one or more additional speakers. The main circuit (140) of the display device (101) may obtain an audio signal to be played by the speaker (160). For example, the main circuit (140) of the display device (101) may obtain an audio signal representing audio by the speaker (160) and a video signal representing an image to be displayed through the display panel (150), based on a data signal broadcast from an external electronic device. The main circuit (140) can transmit the acquired audio signal and the acquired video signal, respectively, to the speaker (160) and the display panel (150).

[0030] Referring to FIG. 1, a display device (101) according to one embodiment may include a power circuit (110) that provides power to a load such as a display driving circuit (130), a main circuit (140), a display panel (150), and a speaker (160). The power circuit (110) may output power signals having different DC voltages required by each of the display driving circuit (130), the main circuit (140), the display panel (150), and the speaker (160) based on multiple outputs. For example, the power circuit (110) may output a power signal having a relatively large voltage for driving the backlight of the display panel (150), and at the same time output a power signal having a relatively small voltage for driving the main circuit (140).

[0031] According to one embodiment, the power circuit (110) of the display device (101) can output power signals based on the power characteristics of each of the load circuits. For example, to stably drive the main circuit (140), the power circuit (110) can output a power signal of DC voltage having relatively little ripple to the main circuit (140). For example, the power consumption of the speaker (160) may have a relatively large deviation in the time domain depending on the volume of the audio output from the speaker (160). According to one embodiment, the power circuit (110) can stabilize the power signal transmitted to the speaker (160) despite a sudden change in the power consumption of the speaker (160). For example, the power circuit (110) can generate a power signal to be transmitted to the speaker (160) based on relatively high efficiency.

[0032] Hereinafter, with reference to FIG. 2, the structure of a power circuit (110) of a display device (101) according to one embodiment is described.

[0034] FIG. 2 is a block diagram of a power circuit (110) included in a display device (101) according to one embodiment. The display device (101) of FIG. 2 may be an example of the display device (101) of FIG. 1. For example, the power circuit (110) and power source (120) of FIG. 2 may be examples of the power circuit (110) and power source (120) of FIG. 1, respectively. The hardware components included in the power circuit (110) are not limited to the example of FIG. 2, and although not shown, the power circuit (110) may further include circuits such as a lightning protection circuit, a varistor, and a surge arrester.

[0035] Referring to FIG. 2, a power circuit (110) according to one embodiment may include an electromagnetic interference (EMI) filter (210). The EMI filter (210) of the power circuit (110) according to one embodiment may remove or reduce noise included in the AC signal of the power source (120). For example, the EMI filter (210) may reduce noise included in the AC signal based on a line filter. The noise may include voltage ripple caused by other frequency components that differ from the frequency components of the AC signal intended by the producer generating the AC signal.

[0036] Referring to FIG. 2, according to one embodiment, a power circuit (110) may include a rectifier circuit (220). The rectifier circuit (220) may receive an alternating current signal having noise reduced by the EMI filter (210) from an EMI filter (210). According to one embodiment, the rectifier circuit (220) may rectify an alternating current signal from a power source (120) and output a rectified alternating current signal. To rectify the alternating current signal, the rectifier circuit (220) may include one or more diodes. For example, the rectifier circuit (220) may include a bridge diode circuit that performs full-wave rectification on the alternating current signal of the power source (120). For example, the power source (120) may perform half-wave rectification on the alternating current signal. The circuit included in the rectifier circuit (220) is not limited to the bridge diode and may include a non-bridge type circuit.

[0037] Referring to FIG. 2, according to one embodiment, a power circuit (110) may include a power-factor correction circuit (230) connected to a rectifier circuit (220) to generate a current flow based on the phase and period of the voltage of an AC signal rectified by the rectifier circuit (220). For example, the current flow generated between the power-factor correction circuit (230) and the rectifier circuit (220) may have a phase that matches the voltage of the AC signal rectified by the rectifier circuit (220) and / or the AC signal of the power source (120). As the power-factor correction circuit (230) receives current from the rectifier circuit (220) based on a phase that matches the voltage of the AC signal rectified by the rectifier circuit (220), the power factor of the display device (101) including the power-factor correction circuit (230) may be improved.

[0038] Referring to FIG. 2, according to one embodiment, a power circuit (110) may include a capacitor (235) that is charged by a power factor conversion circuit (230). The power factor conversion circuit (230) may charge the capacitor (235) based on an alternating current signal received from a rectifier circuit (220). In one embodiment, the capacitor (235) may be a circuit element that stores electrical energy based on an electric field. For example, the capacitor (235) may include an electrolytic capacitor, a tantalum capacitor, a ceramic capacitor, and / or a film capacitor. As the capacitor (235) is charged by the power factor conversion circuit (230), the voltage between the two ends (240-1, 240-2) of the capacitor (235) may be smoothed. For example, the capacitor (235) may be referred to as a bulk capacitor having a relatively large capacitance.

[0039] Referring to FIG. 2, according to one embodiment, a power circuit (110) may include an inverter circuit (240) that receives power output from a power factor conversion circuit (230) by being connected to both ends (240-1, 240-2) of a capacitor (235) that is charged by a power factor conversion circuit (230). According to one embodiment, the power circuit (110) may include a transformer (250) that includes a first inductor electrically connected to the inverter circuit (240). The first inductor may be a primary coil of the transformer (250). In one embodiment, the transformer (250) may include a second inductor and a third inductor, which are secondary coils mutually coupled to the primary coil. For example, the first inductor and the second inductor of the transformer (250) may be mutually coupled to each other. For example, the first inductor and the third inductor of the transformer (250) can be inductively coupled to each other.

[0040] In one embodiment, the first inductor, the second inductor, and the third inductor included in the transformer (250) may be electrically isolated from each other. Due to the electrical isolation of the transformer (250), the load circuit connected to the power source (120) and the power circuit (110) may be electrically isolated. The inverter circuit (240) may input power output from the power factor conversion circuit (230) (e.g., power charged in the capacitor (235)) to the inductor corresponding to the primary coil of the transformer (250). For example, the inverter circuit (240) may induce voltage and / or current in the secondary coil of the transformer (250) by controlling the flow of current from the capacitor (235) to the primary coil of the transformer (250).

[0041] Referring to FIG. 2, according to one embodiment, a power circuit (110) may include a voltage conversion circuit (260) connected to secondary coils (e.g., the second inductor and the third inductor) of a transformer (250) to generate one or more power signals based on voltage and / or current induced in the secondary coils. The voltage conversion circuit (260) may output power signals having different DC voltages required by each of the load circuits to each of the different load circuits. For example, to a terminal (260-1) connected to the main circuit (140), the voltage conversion circuit (260) may apply a first designated level of DC voltage required by the main circuit (140). For example, at a terminal (260-2) connected to a linear rectifier circuit (170) for providing power to a speaker (160), the voltage conversion circuit (260) may apply a DC voltage of a second designated level required by the linear rectifier circuit (170). In the above example, the first designated level may be less than the second designated level. In the above example, only the speaker (160) and the main circuit (140) are illustrated, but the embodiment is not limited thereto. For example, the voltage conversion circuit (260) may output one or more power signals to be provided to other load circuits included in the display device (101) (e.g., the display driving circuit (130) of FIG. 1, and / or the display panel (150)).

[0042] According to one embodiment, the power circuit (110) may include a controller (265) that controls the inverter circuit (240) based on a power signal output through a terminal (260-1) of the voltage conversion circuit (260). The controller (265) may change the power signal of the terminal (260-1) by means other than electrical means in order to maintain electrical isolation by the transformer (250). Referring to FIG. 2, an example is shown in which the controller (265) receives a power signal output from the power circuit (110) to the main circuit (140), but the embodiment is not limited thereto. According to one embodiment, the structure of the controller (265) and the inverter circuit (240) controlled by the controller (265) will be described later with reference to FIGS. 4a and 4b.

[0043] According to one embodiment, the display device (101) may further include a linear rectifier circuit (270) that generates a power signal for driving a speaker (160) based on a power signal output through a terminal (260-2) of a voltage conversion circuit (260). In one embodiment, the linear rectifier circuit (270) may be included as part of a power circuit (110). The linear rectifier circuit (270) may require a DC voltage of a level exceeding the second designated level in order to output a DC voltage of the second designated level for driving the speaker (160). The voltage conversion circuit (260) may output a power signal having a DC voltage of a level exceeding the second designated level to the linear rectifier circuit (270) through the terminal (260-2). Referring to FIG. 2, according to one embodiment, the display device (101) may further include a capacitor (280) for storing power output from a linear rectifier circuit (270). Referring to the equivalent circuit of the speaker (160) of the display device (101) illustrated based on resistance, the speaker (160) is connected to both ends of the capacitor (280) and can be activated based on the power stored in the capacitor (280). For example, between the two ends of the capacitor (280), the voltage of the second designated level may be applied.

[0044] Referring to FIG. 2, power loss may occur in the linear rectifier circuit (270) while generating a DC voltage of the second designated level based on a voltage drop from a power signal received through the terminal (260-2). The power loss in the linear rectifier circuit (270) may be proportional to the difference between the voltage of the power signal received through the terminal (260-2) and the voltage of the power signal output to the speaker (160) (e.g., the second designated level). According to one embodiment, the voltage conversion circuit (260) of the power circuit (110) can generate a power signal for stable operation of the speaker (160) in which instantaneous changes in power consumption occur, while reducing the difference between the voltages. As the difference between the voltages is reduced, the loss in the linear rectifier circuit (270) may be reduced.

[0045] According to one embodiment, a voltage conversion circuit (260) of a power circuit (110) can generate power signals to be output to stages (260-1, 260-2) by at least partially stacking the voltages of a plurality of capacitors charged based on the secondary coils of a transformer (250). The voltage conversion circuit (260) can charge at least one of the plurality of capacitors using all of the secondary coils of the transformer (250). As the voltage conversion circuit (260) generates the power signals by stacking the voltages of the plurality of capacitors, the winding ratios between the primary coil and the secondary coil of the transformer (250) can be designed independently of the level of DC voltage required by load circuits (e.g., main circuit (140), and speaker (160)). For example, the winding ratios can be designed to reduce the winding loss of the transformer (250) independently of the level of the DC voltage. The voltage level of the power signal output to the linear rectifier circuit (270) associated with the speaker (160) may approximate the voltage level required by the speaker (160) as it is generated by the combination of at least one of the voltages of the plurality of capacitors.

[0046] Hereinafter, with reference to FIGS. 3a and 3b, the structure of a voltage conversion circuit (260) of a power circuit (110) according to one embodiment is described in detail.

[0048] FIGS. 3a and 3b are block diagrams of a voltage conversion circuit (260) of a power circuit of a display device according to one embodiment. The display device and power circuit of FIGS. 3a and 3b may be examples of the display device (101) and power circuit (110) of FIGS. 1 and 2. For example, the voltage conversion circuit (260) of FIGS. 3a and 3b may be examples of the voltage conversion circuit (260) of FIG. 2.

[0049] Referring to FIGS. 3a and 3b, the voltage conversion circuit (260) may be electrically connected to a second inductor (342) and / or a third inductor (344), which are secondary coils of a transformer of a power circuit (e.g., the transformer (250) of FIG. 1 and / or FIG. 2). Each of the terminals (260-1, 260-2) of the voltage conversion circuit (260) may be matched to the terminals (260-1, 260-2) of FIG. 2. For example, the voltage conversion circuit (260) may output a power signal for driving a main board (e.g., the main circuit (140) of FIG. 1 and / or FIG. 2) among the load circuits of a display device through terminal (260-1). For example, the voltage conversion circuit (260) can output a power signal for driving a speaker of a display device (e.g., speaker (160) of FIG. 1 and / or FIG. 2) through a terminal (260-2). Based on different levels of DC voltages required by different load circuits, the voltage conversion circuit (260) according to one embodiment can output power signals based on different combinations of a plurality of capacitors (332, 334, 336). Referring to FIG. 3a and 3b, different connection relationships of a plurality of capacitors (332, 334, 336) included in the voltage conversion circuit (260) according to one embodiment are illustrated. The embodiment is not limited thereto.

[0050] Referring to FIG. 3a, a voltage conversion circuit (260) according to one embodiment may include a first voltage multiplying circuit (310) for outputting a power signal having a first level voltage to a terminal (260-1). Hereinafter, the voltage multiplying circuit may be referred to as a voltage changing circuit. For example, the first voltage multiplying circuit (310) may apply a first DC voltage to the terminal (260-1). According to one embodiment, a voltage conversion circuit (260) may include a second voltage multiplying circuit (320) for outputting a power signal having a second level voltage exceeding the first level to a terminal (260-2). For example, the second voltage multiplying circuit (320) may apply a second DC voltage exceeding the first DC voltage to the terminal (260-2). The voltages applied to each of the terminals (260-1, 260-2) may be potential differences between each of the terminals (260-1, 260-2) and the ground node (305).

[0051] Referring to FIG. 3a, a voltage conversion circuit (260) according to one embodiment may include a first capacitor (332), a second capacitor (334), and a third capacitor (336) connected in series between a ground node (305) and a terminal (260-2), which is a node of the second voltage doubling circuit (320). For example, the first capacitor (332) may include one end connected to the ground node (305) and the other end. For example, the second capacitor (334) may include one end connected to the other end of the first capacitor (332) and the other end. For example, the third capacitor (336) may include one end connected to the other end of the second capacitor (334) and the other end connected to terminal (260-2). Referring to FIG. 3a, at node (374), the other end of the first capacitor (332) and one end of the second capacitor (334) can be electrically connected. At the node corresponding to terminal (260-1) of the voltage conversion circuit (260), the other end of the second capacitor (334) and one end of the third capacitor (336) can be electrically connected.

[0052] Referring to FIG. 3a, according to one embodiment, a first voltage doubling circuit (310) of a voltage conversion circuit (260) may include nodes (372, 374) connected to each of the two ends of a second inductor (342) of a transformer (e.g., the transformer (250) of FIG. 1 and / or FIG. 2) electrically connected to the voltage conversion circuit (260). The first voltage doubling circuit (310) may include a first diode (352) having a cathode connected to a node (372) at one end of the second inductor (372) and an anode connected to a ground node (305). The first voltage doubling circuit (310) may include a second diode (354) having an anode connected to a node (372) at one end of the second inductor (372) and a cathode at a terminal (260-1) at which the first DC voltage is applied. The first voltage doubling circuit (310) can be connected to the other end of the first capacitor (332) and one end of the second capacitor (334) through the node (374), which is the other end of the second inductor (372). Referring to FIG. 3a, according to one embodiment, the voltage conversion circuit (260) may include a fourth capacitor (360) having one end connected to the terminal (260-1), which is the node to which the first DC voltage is applied, and the other end connected to the ground node (305).

[0053] Referring to FIG. 3a, according to one embodiment, the second voltage doubling circuit (320) of the voltage conversion circuit (260) may include a node (376) corresponding to one end of the third inductor (344) of the transformer. The second voltage doubling circuit (320) may include a third diode (356) including a cathode connected to the node (376) which is one end of the third inductor (344), and an anode connected to the node (374) which is the other end of the second inductor (342). The second voltage doubling circuit (320) may include a fourth diode (358) including an anode connected to the node (376) which is one end of the third inductor (344), and a cathode connected to the terminal (260-2) which is the node to which the second DC voltage is applied. Referring to FIG. 3a, in the third inductor (344), the other end, which is different from the one end connected to the node (376), can be connected to the other end of the second capacitor (334) and the one end of the third capacitor (336) in the voltage conversion circuit (260), which is the node (260-1). For example, the first voltage doubling circuit (310) and the second voltage doubling circuit (320) may share the second capacitor (334) based on the end (260-1) and the node (374). Sharing the second capacitor (334) may mean that the second capacitor (334) is used to drive both the first voltage doubling circuit (310) and the second voltage doubling circuit (320).

[0054] In one embodiment, the first capacitor (332), the second capacitor (334), and the third capacitor (336) may be charged by at least one of the first voltage doubling circuit (310) or the second voltage doubling circuit (320). As voltage is applied in the primary coil of a transformer (e.g., the transformer (250) of FIG. 1 and / or FIG. 2) comprising the secondary coils, the second inductor (342) and the third inductor (344), an induced current may be generated by inductive coupling of the transformer in the second inductor (342) and the third inductor (344). The induced current may selectively charge at least one of the first capacitor (332) to the third capacitor (336) by means of the first diode (352) to the fourth diode (358). As the above-mentioned induced current is generated, the voltages between the two ends of the second inductor (342) and the third inductor (344) can be changed by the above-mentioned induced current.

[0055] Referring to FIG. 3a, when a current is induced from node (374) to node (372) in the second inductor (342), the induced current may flow from node (372) to the second diode (354) connected to node (372) through the anode, among the first diode (352) and the second diode (354). In this case, as the current passes through the second diode (354) and is delivered to the second capacitor (334), the second capacitor (334) may be charged among the first capacitor (332) and the second capacitor (334). For example, when a current is induced from node (372) to node (374) in the second inductor (342), the induced current may be output from node (374) and flow to node (372) after passing through the first capacitor (332) and the first diode (352). In this case, as the current output from the node (374) is transferred to the first capacitor (332), the first capacitor (332) can be charged among the first capacitor (332) and the second capacitor (334).

[0056] In one embodiment, the first voltage doubling circuit (310) may selectively charge either the first capacitor (332) and the second capacitor (334) based on the direction of the current (or the sign of the voltage) induced in the second inductor (342). Each of the first capacitor (332) and the second capacitor (334) may be charged by the first voltage doubling circuit (310) at different time intervals. The first voltage doubling circuit (310) may sequentially transmit the current induced in the second inductor (342) to the first capacitor (332) and the second capacitor (334). For example, the first voltage doubling circuit (310) may sequentially transmit the current to the first capacitor (332) and the second capacitor (334) based on the direction of the current induced in the second inductor (342).

[0057] Referring to FIG. 3a, as the first voltage doubling circuit (310) charges the first capacitor (332) and the second capacitor (334), a combination of the voltage of the charged first capacitor (332) and the voltage of the charged second capacitor (334) can be applied to terminal (260-1). A fourth capacitor (360) connected to terminal (260-1) can be charged by the combination of the voltages output from terminal (260-1). As the first voltage doubling circuit (310) stores the current induced in the second inductor (342) in the first capacitor (332) and the second capacitor (334), respectively, the first voltage doubling circuit (310) can output a DC voltage that exceeds the peak (or amplitude) of the voltage induced in the second inductor (342) through terminal (260-1). For example, the first voltage doubling circuit (310) can apply a DC voltage to the terminal (260-1) that is twice the peak of the voltage induced in the second inductor (342).

[0058] In one embodiment, since terminal (260-1) is connected to the main circuit of the display device (e.g., the main circuit (140) of FIG. 1 and / or FIG. 2), the first voltage doubling circuit (310) can output a power signal of a first DC voltage corresponding to the combination of the voltages of the first capacitor (332) and the second capacitor (334) to the main circuit. The first capacitor (332) and the second capacitor (334) have the same voltage V C When charged as such, the first DC voltage is 2 x V c The main circuit of the display device may include a controller and / or a processor for controlling the speaker of the display device (e.g., the speaker (160) of FIG. 1 and / or FIG. 2). For example, the power signal of the first DC voltage output by the first voltage doubling circuit (310) may be provided to the controller and / or processor for controlling the speaker of the display device.

[0059] Referring to FIG. 3a, as the induced voltage is applied to the third inductor (344), when the voltage of node (376) exceeds the voltage of terminal (260-1), the current output from the third inductor (344) through node (376) can be transmitted to the third capacitor (336) by passing through the fourth diode (358) among the third diode (356) and the fourth diode (358). In the above state, the current output from the third inductor (344) can be used to charge the third capacitor (336). As the induced voltage applied to the third inductor (344) changes, in a different state where the voltage of terminal (260-1) exceeds the voltage of node (376), the current induced in the third inductor (344) can be output from the third inductor (344) through terminal (260-1), pass through the second capacitor (334) and the third diode (356), and then flow to node (376). In the other state, the current induced in the third inductor (344) can be used to charge the second capacitor (334).

[0060] Referring to FIG. 3a, as the second voltage doubling circuit (320) charges the second capacitor (334) and the third capacitor (336), a combination of the voltage applied to terminal (260-1) and the voltage of the third capacitor (336) can be applied to terminal (260-2) of the voltage conversion circuit (260) corresponding to the other terminal of the third capacitor (336). As the first capacitor (332), the second capacitor (334), and the third capacitor (336) are connected in series between the terminal (260-2) of the voltage conversion circuit (260) and the ground node (305), the voltage applied to the terminal (260-2) of the voltage conversion circuit (260) may correspond to a combination of the voltages of the first capacitor (332), the second capacitor (334), and the third capacitor (336), which are charged by the first voltage doubling circuit (310) and the second voltage doubling circuit (320). For example, the second voltage doubling circuit (320) may output a power signal through the terminal (260-2) having a second DC voltage that exceeds the first DC voltage output from the terminal (260-1) connected to the first voltage doubling circuit (310).

[0061] In one embodiment, since terminal (260-2) is connected to a linear rectifier circuit (e.g., linear rectifier circuit (270) of FIG. 2) for driving a speaker of a display device (e.g., speaker (160) of FIG. 1 and / or FIG. 2), the second voltage doubling circuit (320) can output a power signal of a second DC voltage to the linear rectifier circuit, wherein the third capacitor (336) is stacked on the first DC voltage. The first capacitor (332), the second capacitor (334), and the third capacitor (336) all have the same voltage V C When charged, the second DC voltage is 3 x V C It may be. In one embodiment, V CThe magnitude (or peak value) of the alternating voltage induced in the second inductor (342) and the third inductor (344), which are the secondary coils of the transformer, may be the magnitude (or peak value). For example, the voltage conversion circuit (260) may transmit a power signal of a second DC voltage exceeding the first DC voltage input to the main circuit to the speaker of the display device and / or a linear rectifier circuit.

[0062] Referring to FIG. 3a, the polarities of the second inductor (342) and the third inductor (344), which are the secondary coils of the transformer, are exemplarily shown based on dot convention. Based on the polarities of the second inductor (342) and the third inductor (344) in FIG. 3a, while a current is induced in the second inductor (342) from node (372) to node (374), a current can be induced in the third inductor (344) from node (376) to terminal (260-1). Referring to the above example, the time interval during which the first capacitor (332) is charged by the first voltage doubling circuit (310) and the time interval during which the second capacitor (334) is charged by the second voltage doubling circuit (320) may coincide with each other. Meanwhile, the time interval during which the second capacitor (334) is charged by the first voltage doubling circuit (310) and the time interval during which the third capacitor (336) is charged by the second voltage doubling circuit (320) may coincide with each other. For example, the first voltage doubling circuit (310) and the second voltage doubling circuit (320) may alternately charge the second capacitor (334). However, the embodiment is not limited thereto, and the time intervals during which the first voltage doubling circuit (310) and the second voltage doubling circuit (320) each charge the second capacitor (334) may overlap at least partially.

[0063] Referring to FIG. 3b, a voltage conversion circuit (260) including a third capacitor (336) having a different connection relationship from that of FIG. 3a is shown. In the following description, any description that overlaps with FIG. 3a may be omitted. The third capacitor (336) of FIG. 3b may include one end connected to a terminal (260-2) of the voltage conversion circuit (260) and the other end connected to a ground node (305). The third capacitor (335) of FIG. 3b may be charged based on a voltage greater than any one of the first capacitor (332), the second capacitor (334), and the third capacitor (336) of FIG. 3a.

[0064] In one embodiment of FIG. 3a, the first capacitor (332), the second capacitor (334), and the third capacitor (336), which are charged based on a relatively small voltage, may be implemented based on film capacitors. For example, the third capacitor (336) of FIG. 3b, which is charged based on a relatively large voltage, may be implemented based on an electrolytic capacitor, for example, a material different from that of the film capacitor. As the other end of the third capacitor (336) of FIG. 3b is connected to the ground node (305), the third capacitor (336) may operate relatively stably even though it is implemented based on an electrolytic capacitor. In one embodiment of FIG. 3b, the first voltage doubling circuit (310) and the second voltage doubling circuit (320) of the voltage conversion circuit (260) may operate similarly to the embodiment of FIG. 3a.

[0065] As described above, according to one embodiment, the voltage conversion circuit (260) may have a structure in which the first voltage doubling circuit (310) and the second voltage doubling circuit (320) are at least partially superimposed. The first voltage doubling circuit (310) and the second voltage doubling circuit (320) may charge capacitors (e.g., first capacitor (332) to third capacitor (336)) included in the voltage conversion circuit (260) based on timing synchronized by the secondary coils (e.g., second inductor (342) and third inductor (344)) of a single transformer (e.g., transformer (250) of FIG. 2). Each of the first capacitor (332) and the second capacitor (334) may be charged to a voltage that is half of the first DC voltage by a first voltage doubling circuit (310) which generates a power signal of the first DC voltage for driving the main circuit of the display device (e.g., the main circuit (140) of FIG. 1 and / or FIG. 2). In one embodiment of FIG. 3a, each of the second capacitor (334) and the third capacitor (336) may be charged to a voltage that is half of the first DC voltage by a second voltage doubling circuit (320) which generates a power signal of the second DC voltage required for driving the speaker of the display device.

[0066] In one embodiment of FIG. 3a, when the number of turns of the second inductor (342) and the third inductor (344) match each other and the first DC voltage is 13 V, each of the first capacitor (332) to the third capacitor (336) can be charged to the same voltage of 13 V × 0.5 = 6.5 V. In the above example, the second DC voltage may be 19.5 V, which is 1.5 times the first DC voltage. In the above example, as the power signal of the second DC voltage of 19.5 V is transmitted from the voltage conversion circuit (260) to the linear rectifier circuit (e.g., the linear rectifier circuit (270) of FIG. 2), the linear rectifier circuit can output to the speaker a power signal of the third DC voltage (e.g., 18 V) required to drive the speaker (e.g., the speaker (160) of FIG. 1 and / or FIG. 2). The loss generated in the linear rectifier circuit may be proportional to the voltage drop between the second DC voltage and the third DC voltage. Compared to another example in which a DC voltage relatively larger than the second DC voltage (e.g., 20 V to 22 V) is applied to the linear rectifier circuit due to variations in the power consumption of the speaker, the loss generated in the linear rectifier circuit may be relatively small in an embodiment in which a power signal of the second DC voltage of 19.5 V is transmitted to the linear rectifier circuit.

[0067] According to one embodiment, a power circuit (e.g., power circuit (110) of FIG. 1 and / or FIG. 2) including a voltage conversion circuit (260) can regulate the flow of current input to the primary coil of a transformer (e.g., transformer (250) of FIG. 2) including a second inductor (342) and a third inductor (344), which are secondary coils, based on the first DC voltage output to the main circuit through a terminal (260-1). As the power circuit regulates the flow of current based on the first DC voltage, the first DC voltage output from the terminal (260-1) of the voltage conversion circuit (260) can be maintained stably. As the first DC voltage is maintained stably, the second DC voltage output from the terminal (260-2) of the voltage conversion circuit (260) based on the first DC voltage can also be maintained stably despite changes in power consumption in the load circuit (e.g., speaker) receiving the power signal of the second DC voltage.

[0068] As described above, as the second DC voltage output from the terminal (260-2) of the voltage conversion circuit (260) is maintained stably, the second DC voltage can be robust against voltage drop caused by the load circuit. If the load circuit is a speaker and a linear rectifier circuit for providing a voltage of a level designated by the speaker, the voltage conversion circuit (260) can be designed to output the second DC voltage approximated by the designated level in order to reduce losses of the linear rectifier circuit despite voltage drop caused by the speaker. In one embodiment, as the power circuit including the voltage conversion circuit (260) is designed independently of the voltage drop caused by the speaker, the winding ratio of the transformer included in the power circuit (e.g., the transformer (250) of FIG. 2) can be designed independently of the voltage drop caused by the speaker. As the above winding ratio is designed independently of the voltage drop caused by the speaker, the number of turns of the primary coil and secondary coils (e.g., second inductor (342), and third inductor (344)) included in the transformer can be designed to increase the DC bias current or / or decrease winding losses. For example, the number of turns of the secondary coils, the second inductor (342) and the third inductor (344), can be designed to match each other. If the number of turns of the second inductor (342) and the third inductor (344) are designed to match each other, the first capacitor (332) to the third capacitor (336) can be charged to the same voltage.

[0069] In another example, if the number of turns of the second inductor (342) and the third inductor (344) are different, a DC offset current may be generated by the transformer. This DC offset current may increase the current of the magnetizing inductor of the transformer. For example, if the ratio between the number of turns of the second inductor (342) and the number of turns of the third inductor (344) is 1:2 and the first DC voltage output through terminal (260-1) is 13 V, the voltage of the third capacitor (336) may be 13 × 2 / 2 = 13 V. In the above example, the voltage of the second capacitor (334) may be (13 × 2 / 2 + 13 / 2) / 2 = 9.75 V. In the above example, the voltage of the first capacitor (332) may be 13 - 9.75 = 3.25 V.

[0070] Hereinafter, with reference to FIGS. 4a and 4b, a power circuit including an embodiment of the voltage conversion circuit (260) of FIGS. 3a and 3b is described to generate a flow of current for charging capacitors included in the voltage conversion circuit (260).

[0072] FIGS. 4a and 4b are circuit diagrams of a power circuit (110) including each of the voltage conversion circuits of FIGS. 3a and 3b. The power circuit (110) of FIGS. 4a and 4b may be an example of the power circuit (110) of FIGS. 1 and 2. For example, the terminals (240-1, 240-2) of FIGS. 4a and 4b may be matched to each of the terminals (240-1, 240-2) of a capacitor (235) placed between the power factor conversion circuit (230) and the inverter circuit (240) of FIG. 2. Referring to FIGS. 4a and 4b, a portion of the power circuit (110) including each of the voltage conversion circuits (260) of FIGS. 3a and 3b is shown. In the following, descriptions that overlap with the descriptions of the power circuit (110) of FIGS. 1 and 2 and the voltage conversion circuit (260) of FIGS. 3a and 3b may be omitted.

[0073] Referring to FIG. 4a, a portion of a power circuit (110) including the voltage conversion circuit (260) of FIG. 3a is shown. For example, the first voltage doubling circuit (310) and the second voltage doubling circuit (320) of FIG. 4a can be matched to the first voltage doubling circuit (310) and the second voltage doubling circuit (320) of the voltage conversion circuit (260) of FIG. 3a. Referring to FIG. 4a, an equivalent circuit of a main circuit (140) connected through terminal (260-1) of the power circuit (110) according to one embodiment, and an equivalent circuit of a linear rectifier circuit (270), a capacitor (280), and a speaker (160) connected through terminal (260-2) of the power circuit (110) are shown.

[0074] As described above in FIG. 3a, according to one embodiment, a power circuit (110) can generate a first DC voltage to be applied to a terminal (260-1) connected to a main circuit (140) based on the combination of the voltage of a first capacitor (332) charged by a first voltage doubling circuit (310) and the voltage of a second capacitor (334) charged by the first voltage doubling circuit (310) and the second voltage doubling circuit (320). The power circuit (110) can generate a second DC voltage to be applied to a terminal (260-2) connected to a linear rectifier circuit (270) by combining the voltage of a third capacitor (336) charged by the second voltage doubling circuit (320) with the first DC voltage applied to the terminal (260-1).

[0075] Referring to FIG. 4a, an equivalent circuit of a first inductor (460), which is the primary coil of a transformer (e.g., the transformer (250) of FIG. 2), is shown. An inverter circuit (240) electrically connected to the first inductor (460) may include an inductor (470) connected to one end of the first inductor (460) and a capacitor (480) connected to the other end of the first inductor (460). Referring to FIG. 4a, an LLC resonant converter may be formed based on the magnetizing inductance formed in the equivalent circuit of the first inductor (460) based on the transformer, the inductor (470) of the inverter circuit (240), and the capacitor (480).

[0076] Referring to FIG. 4a, according to one embodiment, the inverter circuit (240) of the power circuit (110) may include switches (440, 450) connected to a node (490), which is the other end of an inductor (470), including one end connected to one end of a first inductor (460). Switches (440, 450) implemented with P-channel MOSFETs (Metal Oxide Field Effect Transistors) are shown, but the embodiment is not limited thereto. For example, switches (440, 450) may be implemented based on N-channel MOSFETs, MISFETs (Metal Insulator Semiconductor FETs), and / or BJTs (Bi-Junction Transistors). Referring to FIG. 4a, each of the switches (440, 450) can control the electrical connection between the terminal (240-1) and the node (490), and the electrical connection between the terminal (240-2) and the node (490).

[0077] According to one embodiment, the power circuit (110) may include a controller (265) for controlling switches (440, 450) included in the inverter circuit (240) based on the voltage of any one of the power signals output from the voltage conversion circuit. Referring to FIG. 4a, the controller (265) may include one or more circuit elements for identifying a first DC voltage (e.g., a voltage applied to terminal (260-1)) of a power signal provided from the first voltage doubling circuit (310) of the voltage conversion circuit to the main circuit (140). For example, the controller (265) may include an inverting input to which the first DC voltage is applied, a reference voltage (V ref It may include an operational amplifier (410) that includes a non-inverting input to which ) is applied.

[0078] According to one embodiment, the controller (265) may include an optical coupler (420) that generates an optical signal based on the first DC voltage. For example, the optical coupler (420) is obtained based on an operational amplifier (410) and a reference voltage (V ref A light signal representing the result of comparing the first DC voltage and the light signal can be generated. The light signal can be generated by an LED (Light Emitting diode) included in the light coupler (420). The light signal can be transmitted to a control signal generator (430) included in the controller (265) based on a photodiode included in the light coupler (420). The light coupler (420) may be included in the controller (265) to maintain electrical isolation between the primary coil (e.g., first inductor (460)) and secondary coils (e.g., second inductor (342), and third inductor (344)) of the transformer.

[0079] According to one embodiment, the control signal generator (430) of the controller (265) can generate control signals to be transmitted to the switches (440, 450) based on Pulse Frequency Modulation (PFM) and / or Pulse Width Modulation (PWM). In one embodiment of FIG. 4a in which the switches (440, 450) are implemented based on transistors, the control signals generated by the control signal generator (430) of the controller (265) can be applied to the source of each of the switches (440, 450). For example, the switches (440, 450) of the inverter circuit (240) can be controlled by the controller (265) to stably maintain a first DC voltage applied to the main circuit (140) through the terminal (260-1). For example, the controller (265) can control the switches (440, 450) of the inverter circuit (240) based on the voltage of the power signal provided to the main circuit (140) (e.g., the first DC voltage).

[0080] In one embodiment, as switches (440, 450) are controlled by a controller (265), a current based on the voltage between terminals (240-1, 240-2) may be generated in the first inductor (460). For example, an inverter circuit (240) may generate an alternating voltage applied to the first inductor (460) from the voltage between terminals (240-1, 240-2) (e.g., a voltage applied by the power factor conversion circuit (230) of FIG. 2). The current generated in the first inductor (460) may cause the generation of voltage and / or current in the second inductor (342) based on inductive coupling between the first inductor (460) and the second inductor (342). Similarly, the current generated in the first inductor (460) may cause the generation of voltage and / or current in the third inductor (344) based on the inductive coupling between the first inductor (460) and the third inductor (344). The voltage and / or current generated in the second inductor (342) and the third inductor (344) may be used to charge the first capacitor (332) to the third capacitor (336) by the first voltage doubling circuit (310) and the second voltage doubling circuit (320), as described above in FIGS. 3a and 3b.

[0081] Referring to FIG. 4b, a portion of a power circuit (110) including the voltage conversion circuit (260) of FIG. 3b is shown. As described above in FIG. 4a, the controller (265) of the power circuit (110) can obtain the voltage of a power signal transmitted to a main circuit (140) including a processor for controlling a speaker through a terminal (260-1). Based on the obtained voltage, the controller (265) can control the switches (440, 450) of the inverter circuit (240). The change in the magnetic field generated in the first inductor (460) by the switches (440, 450) can cause the generation of current in the second inductor (342) and the third inductor (344) inductively coupled to the first inductor (460). Each of the first voltage doubling circuit (310) and the second voltage doubling circuit (320) can control the charging of at least one of the first capacitor (332) to the third capacitor (336) connected in series based on the current induced in the second inductor (342) and the third inductor (344). The voltages of the first capacitor (332) to the third capacitor (336) can be at least partially combined and used to generate power signals to be provided to each of the main circuit (140) and / or linear rectifier circuit (270). The power signal provided to the main circuit (140) can be fed back to the inverter circuit (240) by the controller (265).

[0082] As described above, in a power circuit (110) according to one embodiment, a voltage conversion circuit for supporting multiple outputs can be implemented based on passive components at a relatively low production cost. The power circuit (110) can provide a power signal robust to the voltage drop, which causes a voltage drop as power is consumed instantaneously, such as with a speaker (160).

[0083] Hereinafter, with reference to FIG. 5, the operation of a power circuit (110) including a voltage conversion circuit according to one embodiment, which generates a power signal robust to changes in power consumption of a load circuit, is described.

[0085] FIG. 5 is a graph illustrating the current and / or voltage at the nodes of a power circuit of a display device according to one embodiment. The display device and power circuit of FIG. 5 may be an example of the display device (101) and power circuit (110) of FIG. 1 and / or FIG. 2. Referring to FIG. 5, changes in the current and / or voltage at different nodes of the power circuit (110) of FIG. 4a and / or FIG. 4b are illustrated according to an exemplary change in the power consumption of the load circuit of the display device.

[0086] The graphs (510, 520, 530, 540, 550, 560) of FIG. 5 show the current and / or voltage of different nodes of the display device along a synchronized time axis. Graph (510) of FIG. 5 shows the current (i) flowing through the inductor (470) of the inverter circuit (240) of FIG. 4a and / or FIG. 4b. Lr It indicates the change of ). Referring to FIGS. 4a and 4b, the current (i) flowing through the inductor (470) Lr ) can be matched with the current input to the first inductor (460) of the transformer. Graphs (520, 530, 540) of FIG. 5 represent changes in the voltages of the first capacitor (332), the second capacitor (334), and the third capacitor (336), respectively, of FIG. 4a and / or FIG. 4b. Graph (550) of FIG. 5 represents changes in the voltage (e.g., the second DC voltage) applied to terminal (260-2) of FIG. 4a and / or FIG. 4b. Graph (560) of FIG. 5 represents the current (i) flowing from the linear rectifier circuit (270) and / or capacitor (280) of FIG. 4a and / or FIG. 4b to the speaker (160). O2 It represents the change of ).

[0087] In the following, it is assumed that the speaker of the display device plays audio starting from time t0. Referring to the graph (560) in FIG. 5, as the speaker plays audio starting from time t0, the magnitude of the current (i) flowing to the speaker O2 ) can be increased from time t0. As described above, the power circuit of the display device according to one embodiment can generate a power signal having a voltage robust to changes in current shown by the graph (560), based on the voltage conversion circuit (260) of FIG. 2 and / or FIG. 3a to FIG. 3b.

[0088] Referring to graph (550) in FIG. 5, the voltage of the power signal provided to the linear rectifier circuit connected to the speaker can change based on a relatively small deviation despite the change in the speaker's current at time t0. Similarly, the voltage and / or current in the power circuit, as indicated by graphs (520, 530, 540), can change based on a relatively small deviation before and after time t0. For example, despite the change in the speaker's current, the power circuit can prevent a voltage drop of the power signal transmitted to the linear rectifier circuit connected to the speaker. As the voltage drop is prevented, the power circuit can be designed independently of an increase in the voltage of the power signal to compensate for the voltage drop, in order to minimize losses in the linear rectifier circuit.

[0090] As described above, a display device according to one embodiment may include a power circuit that provides a DC voltage robust to changes in power consumption in a load circuit. The power circuit of the display device may generate the DC voltage by accumulating the voltages of a plurality of capacitors charged by an induced current in a transformer. The power circuit of the display device may include a plurality of voltage doubling circuits that charge the plurality of capacitors based on the induced current. Within the power circuit, the plurality of voltage doubling circuits may share at least one of the plurality of capacitors.

[0092] A display device according to one embodiment as described above may include a transformer comprising a first inductor, a second inductor mutually coupled to the first inductor, and a third inductor mutually coupled to the first inductor. The display device may include a first voltage changing circuit that charges a first capacitor and a second capacitor using an alternating current voltage induced in the second inductor, and outputs a first DC voltage based on the voltages of the first capacitor and the second capacitor. The display device may include a second voltage changing circuit that charges the second capacitor and the third capacitor using an alternating current voltage induced in the third inductor, and outputs a second DC voltage different from the first DC voltage.

[0093] For example, the first voltage changing circuit may include a first diode comprising a cathode connected to one end of the second inductor and an anode connected to a ground node. For example, the first voltage changing circuit may include a second diode comprising an anode connected to one end of the second inductor and a cathode connected to a first node to which the first DC voltage is applied.

[0094] For example, the first capacitor may include one end connected to the other end of the second inductor and the other end connected to the ground node. The first capacitor may be charged by a current passing through the first diode during a first time interval in which the magnitude of the alternating voltage of the second inductor falls within a specified range.

[0095] For example, the second capacitor may include one end connected to the other end of the second inductor and the other end connected to the first node. The second capacitor may be charged by a current passing through the second diode in a second time interval distinct from the first time interval.

[0096] For example, the display device may include a fourth capacitor comprising one end connected to the first node and the other end connected to the ground node. The fourth capacitor may be charged by the first DC voltage output from the first voltage changing circuit.

[0097] For example, the second voltage changing circuit may include a third diode comprising an anode connected to the other end of the second inductor and a cathode connected to the other end of the third inductor that is different from the one end and connected to the first node. For example, the second voltage changing circuit may include a fourth diode comprising an anode connected to the other end of the third inductor and a cathode connected to the second node to which the second DC voltage is applied.

[0098] For example, the second capacitor may include one end connected to the other end of the second inductor and the other end connected to one end of the third inductor. The second capacitor may be charged by a current passing through the third diode during a first time interval in which the magnitude of the alternating voltage of the third inductor falls within a specified range.

[0099] For example, the third capacitor may include one end connected to the second node and the other end connected to one end of the third inductor. The third capacitor may be charged to a voltage matching the voltage of the first capacitor and the voltage of the second capacitor by a current passing through the fourth diode in a second time interval different from the first time interval.

[0100] For example, the third capacitor may include one end connected to the second node and the other end connected to the ground node. The third capacitor may be charged to the summation of the voltage of the first capacitor and the voltage of the second capacitor by the current passing through the fourth diode in a second time interval different from the first time interval.

[0101] For example, the first capacitor, the second capacitor, and the third capacitor may be connected in series between a ground node and a node of the second voltage changing circuit where the second DC voltage is output.

[0102] For example, the first voltage changing circuit can charge the second capacitor using an alternating voltage induced in the second inductor in a second time interval different from the first time interval in which the second capacitor is charged by the second voltage changing circuit.

[0103] For example, the display device may include an inverter circuit that obtains an AC voltage applied to the first inductor of the transformer from a third DC voltage output from a power factor conversion circuit. For example, the display device may include a controller that controls switches included in the inverter circuit based on the first DC voltage of the first voltage change circuit.

[0104] For example, the controller may include an optical coupler that generates an optical signal based on the first DC voltage.

[0105] For example, the display device may include a linear rectifier circuit that outputs a third DC voltage that is less than the second DC voltage and exceeds the first DC voltage from the second DC voltage output from the second voltage changing circuit. The display device may include a speaker that receives the third DC voltage output from the linear rectifier circuit.

[0106] For example, the display device may further include a processor that generates an audio signal to be transmitted to the speaker based on the first DC voltage output from the first voltage changing circuit.

[0108] A display device according to one embodiment as described above may include at least one speaker. The display device may include a processor for controlling the at least one speaker. The display device may include a power circuit that outputs power signals having different DC voltages to the at least one speaker and the processor. The power circuit of the display device may include a first voltage changing circuit that charges each of a plurality of capacitors in different time intervals and transmits a power signal of a first DC voltage corresponding to the combination of the voltages of the charged plurality of capacitors to the processor. The power circuit of the display device may include a second voltage changing circuit that charges a first capacitor among the plurality of capacitors in a second time interval different from the first time interval in which the first capacitor is charged by the first voltage changing circuit among the different time intervals, and obtains a power signal of a second DC voltage that exceeds the first DC voltage and is to be provided to the at least one speaker based on the voltage of the first capacitor.

[0109] For example, the power circuit may include a power factor conversion circuit. The power circuit may include an inverter circuit that generates power to charge the first capacitor by means of the first voltage changing circuit and the second voltage changing circuit, using a transformer comprising a first inductor, a second inductor inductively coupled to the first inductor, and a third inductor inductively coupled to the first inductor, from a third DC voltage generated from the power factor conversion circuit. For example, the first voltage changing circuit may charge each of the plurality of capacitors in the different time intervals based on the alternating voltage induced in the second inductor. For example, the second voltage changing circuit may charge the first capacitor in the second time interval based on the alternating voltage induced in the third inductor.

[0110] For example, the power circuit may include a controller for controlling the direction in which the third DC voltage flows to the first inductor in the inverter circuit based on the power signal of the first DC voltage.

[0111] For example, the first DC voltage of the power signal transmitted to the processor by the first voltage changing circuit may be twice the magnitude of the AC voltage induced in the second inductor. For example, the second DC voltage of the power signal provided to the at least one speaker by the second voltage changing circuit may be three times the magnitude of the AC voltage induced in the second inductor.

[0112] For example, the power circuit may further include a linear rectifier circuit disposed between the second voltage changing circuit and the at least one speaker, which outputs a third DC voltage that exceeds the first DC voltage and is less than the second DC voltage from a power signal of the second DC voltage.

[0114] A power circuit of a display device according to one embodiment as described above may include a transformer comprising a first inductor, a second inductor inductively coupled to the first inductor, and a third inductor inductively coupled to the first inductor. A power circuit of a display device may include an inverter circuit that inputs power output from a power factor conversion circuit to the first inductor of the transformer. A power circuit of a display device may include a first voltage changing circuit that charges a first capacitor and a second capacitor based on the second inductor among the second inductor and the third inductor, and outputs a first voltage based on the voltage of the first capacitor and the voltage of the second capacitor based on the series connection of the first capacitor and the second capacitor. The power circuit of the display device may include a second voltage changing circuit that charges the second capacitor and the third capacitor based on the third inductor among the second inductor and the third inductor, and outputs a second voltage based on the voltage of the first capacitor, the voltage of the second capacitor, and the voltage of the third capacitor based on the series connection of the first capacitor, the second capacitor, and the third capacitor.

[0115] For example, the second capacitor may be charged by a current transmitted from the first voltage changing circuit to the second capacitor and induced in the second inductor during a first time interval. The second capacitor may be charged by a different current transmitted from the second voltage changing circuit to the second capacitor and induced in the third inductor during a second time interval different from the first time interval.

[0117] The device described above may be implemented as a hardware component, a software component, and / or a combination of a hardware component and a software component. For example, the device and components described in the embodiments may be implemented using one or more general-purpose or special-purpose computers, such as a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing unit may execute an operating system (OS) and one or more software applications executed on said operating system. Additionally, the processing unit may access, store, manipulate, process, and generate data in response to the execution of the software. For ease of understanding, the processing unit may be described as being used as a single unit, but those skilled in the art will understand that the processing unit may include multiple processing elements and / or multiple types of processing elements. For example, the processing unit may include multiple processors or one processor and one controller. In addition, other processing configurations, such as parallel processors, are also possible.

[0118] Software may include computer programs, code, instructions, or a combination of one or more of these, and may configure a processing unit to operate as desired or instruct the processing unit independently or collectively. Software and / or data may be embodied in any type of machine, component, physical device, computer storage medium, or device so as to be interpreted by the processing unit or to provide instructions or data to the processing unit. Software may be distributed over networked computer systems and may be stored or executed in a distributed manner. Software and data may be stored on one or more computer-readable recording media.

[0119] The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. In this case, the medium may continuously store a program executable by a computer, or temporarily store it for execution or download. Additionally, the medium may be various recording or storage means in the form of a single or several hardware combined, and may not be limited to a medium directly connected to a computer system but may exist distributed over a network. Examples of media may include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical recording media such as CD-ROMs and DVDs; magneto-optical media such as floptical disks; and media configured to store program instructions, including ROM, RAM, and flash memory. Additionally, other examples of media may include recording or storage media managed by app stores that distribute applications or sites and servers that supply or distribute various other software.

[0120] Although the embodiments have been described above with reference to limited examples and drawings, those skilled in the art can make various modifications and variations from the description above. For example, suitable results can be achieved even if the described techniques are performed in a different order than described, and / or the components of the described system, structure, device, circuit, etc. are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents.

[0121] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims set forth below.

Claims

Claim 1 A display device comprises: a transformer including a first inductor, a second inductor mutually coupled to the first inductor, and a third inductor mutually coupled to the first inductor; a first voltage changing circuit that charges a first capacitor and a second capacitor using an alternating current voltage induced in the second inductor and outputs a first DC voltage based on the voltages of the first capacitor and the second capacitor; and a second voltage changing circuit that charges the second capacitor and the third capacitor using an alternating current voltage induced in the third inductor and outputs a second DC voltage different from the first DC voltage, wherein the first voltage changing circuit comprises a first diode including a cathode connected to one end of the second inductor and an anode connected to a ground node; A display device comprising a second diode including an anode connected to one end of the second inductor and a cathode connected to a first node to which the first DC voltage is applied. Claim 2 delete Claim 3 A display device according to claim 1, wherein the first capacitor, comprising one end connected to the other end of the second inductor and the other end connected to the ground node, is charged by a current passing through the first diode during a first time interval in which the magnitude of the alternating voltage of the second inductor is included in a specified range. Claim 4 A display device according to paragraph 3, wherein the second capacitor, comprising one end connected to the other end of the second inductor and the other end connected to the first node, is charged by a current passing through the second diode in a second time interval distinguished from the first time interval. Claim 5 A display device according to claim 1, further comprising a fourth capacitor having one end connected to the first node and the other end connected to the ground node, and charged by the first DC voltage output from the first voltage changing circuit. Claim 6 A display device according to claim 1, wherein the second voltage changing circuit comprises: a third diode having an anode connected to the other end of the second inductor and a cathode connected to the other end different from one end, which is connected to the first node in the third inductor; and a fourth diode having an anode connected to the other end of the third inductor and a cathode connected to the second node to which the second DC voltage is applied. Claim 7 A display device according to claim 6, wherein the second capacitor, comprising one end connected to the other end of the second inductor and the other end connected to one end of the third inductor, is charged by a current passing through the third diode during a first time interval in which the magnitude of the alternating voltage of the third inductor is included in a specified range. Claim 8 A display device according to claim 7, wherein the third capacitor, comprising one end connected to the second node and the other end connected to one end of the third inductor, is charged to a voltage matching the voltage of the first capacitor and the voltage of the second capacitor by a current passing through the fourth diode in a second time interval different from the first time interval. Claim 9 A display device according to claim 7, wherein the third capacitor, comprising one end connected to the second node and the other end connected to the ground node, is charged by the summation of the voltage of the first capacitor and the voltage of the second capacitor by a current passing through the fourth diode in a second time interval different from the first time interval. Claim 10 A display device comprising: a transformer including a first inductor, a second inductor mutually coupled to the first inductor, and a third inductor mutually coupled to the first inductor; a first voltage changing circuit that charges a first capacitor and a second capacitor using an alternating voltage induced in the second inductor and outputs a first DC voltage based on the voltages of the first capacitor and the second capacitor; and a second voltage changing circuit that charges the second capacitor and a third capacitor using an alternating voltage induced in the third inductor and outputs a second DC voltage different from the first DC voltage, wherein the first capacitor, the second capacitor, and the third capacitor are connected in series between a ground node and a node of the second voltage changing circuit where the second DC voltage is output. Claim 11 delete Claim 12 delete Claim 13 delete Claim 14 delete Claim 15 delete Claim 16 delete Claim 17 delete Claim 18 delete Claim 19 delete Claim 20 delete

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