JP2013140356A - Power supplying apparatus, power supplying method, organic light-emitting diode display apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display apparatus including an organic light-emitting diode (OLED) and a power supplying method therefor.SOLUTION: A power supplying apparatus, a power supplying method, an organic light-emitting diode (OLED) display apparatus are provided. The OLED display apparatus includes: a plurality of components which are to perform an operation of the OLED display apparatus; a power supplying unit; a rectifier which rectifies an input voltage supplied from the power supplying unit; and a voltage level converter which converts a level of the input voltage rectified by the rectifier and supplies it commonly to the plurality of components.

Description

  The present invention relates to a power supply device, a power supply method, and an OLED display device, and more particularly to a display device including an OLED (Organic Light Emitting Diode) and a power supply method thereof.

  With the development of electronic technology, various electronic products have been developed and spread. In particular, various display devices such as a TV, a mobile phone, a personal computer, a notebook personal computer, and a PDA are used in many general homes.

  Conventional display devices have displayed various images using liquid crystal display devices. Since such a conventional liquid crystal display device is not a self-luminous display device, a backlight unit is used as a light source.

  In general, the display device rectifies a 110 [V] or 200 [V] service voltage applied from the outside and supplies the rectified voltage to each power consuming component provided in the display device. On the other hand, since the backlight unit requires a higher driving voltage than other power consuming components, the display device supplies power to the main DC / DC converter and other components for supplying power to the backlight unit. The sub DC / DC converter must be provided separately.

  As a result, the conventional liquid crystal display device has a problem that it is more expensive and is limited in reducing the thickness and weight of the display device. Furthermore, since the conventional liquid crystal display device requires a backlight, it is disadvantageous in that it is not only heavy but thick and has a slow response speed.

  On the other hand, recently, an organic light emitting display (OLED) has been developed as a next-generation video display device for dealing with liquid crystal display devices. Such an organic light emitting display device displays an image using an organic light emitting diode (OLED) that emits light by recombination of electrons and holes.

  Here, an organic light emitting diode (OLED) used in an organic light emitting display includes an anode and a cathode and a light emitting layer formed between the anode and the cathode. When light flows, light is emitted in the light emitting layer, and the luminance is expressed so that the amount of light varies according to the change in the amount of current.

  Organic electroluminescent display devices using organic light emitting diodes (OLEDs) described above can be used in PDAs, MP3 players, etc. in addition to applications for mobile phones due to various advantages such as excellent color reproducibility and thinness. The market is expanding greatly.

  A driving method for such an organic light emitting display using an OLED is largely classified into a passive matrix method and an active matrix method. First, the passive matrix method is a method in which a positive electrode and a negative electrode are formed so as to be orthogonal to each other, and a current is applied to a selected negative electrode line and a positive electrode line for driving. The active matrix method is a driving method in which a thin transistor (TFT) and a capacitor are integrated in each pixel to hold a voltage according to the capacitor capacity.

  Hereinafter, a driving process of driving an organic light emitting display device including a normal OLED unit pixel using an active matrix method will be described with reference to FIG.

  FIG. 1 is a circuit diagram for driving a conventional organic light emitting display device through an active matrix method.

  As shown in FIG. 1, the conventional organic light emitting display device is configured such that a scan line (SL) and a data line (DL) intersect, a gate is connected to the scan line (SL), and a source is a data line. A switching transistor (T1) connected to the wiring (DL), a driving transistor (T2) whose gate is connected to the drain of the switching transistor (T1), and whose source is connected to the first power supply (ELVDD); The capacitor (C) configured between the source and gate of T2), the drain and anode of the driving transistor (T2) are connected, and the cathode is configured with an OLED connected to the second power source (ELVSS).

  In the circuit operation, when the switching transistor (T1) is turned on, a data voltage is applied to the gate electrode of the driving transistor (T2), and a current flows through the driving transistor (T2) according to the data voltage to emit light. The data voltage applied to the gate electrode for a certain time is held by the capacitor (C).

  Since such an OLED has low voltage and high current characteristics, high power efficiency cannot be achieved if a conventional general power supply unit (for example, SMPS (Switch Mode Power Supply)) is applied as it is. There was a problem.

Korean Laid-Open Patent Publication No. 2005-0104611 Korean Patent Registration No. 10-0894606

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a display device that applies a voltage of the same level to a display panel including an OLED and other power consuming components, and the display device. It is to provide a power supply method.

  Still another object of the present invention is to provide a power supply device, a power supply method, and a display device that improve power efficiency by controlling ON / OFF of the PFC unit in the data voltage charging period and the light emission period. is there.

  In order to achieve the above object, an OLED (Organic Light Emitting Diode) display device according to an embodiment of the present invention includes a plurality of components for operating the display device, a power supply unit, and a power supply unit. A rectifier configured to rectify the supplied input voltage; and a voltage level converter configured to convert the level of the input voltage rectified by the rectifier and provide the same to the plurality of components.

  The rectifying unit may include a power factor correction (PFC) unit that compensates a power factor of the input voltage.

  The voltage level conversion unit may convert the level of the output DC voltage of the PFC unit into a voltage level for driving a display panel and provide the same for the plurality of components.

  The display panel may be composed of a plurality of pixels including the OLED.

  Note that a control unit for controlling on / off of the PFC unit may be further included in accordance with the operation states of the plurality of components.

  The control unit may turn off the PFC unit while the display panel performs a data voltage charging operation, and may turn on the PFC unit while the display panel performs a light emission operation.

  The controller detects the level of the DC voltage provided to the display panel, and determines that the data voltage charging operation is performed when the detected level of the DC voltage is the first voltage level. When the PFC unit is turned off and the detected DC voltage level is the second voltage level, it is determined that the light emission operation is performed, and the PFC unit may be turned on.

  The control unit may turn on the PFC unit before a preset time with reference to a time point when the data voltage charging period ends.

  The control unit determines that the preset time has been reached when the output voltage of the PFC unit is equal to or lower than a preset level with the PFC unit turned off, and the PFC unit is reached. May be turned on.

  The image display apparatus may further include a scan driver that provides a scan signal to the plurality of pixels, a data driver that provides a data signal to the plurality of pixels, and a voltage driver that supplies a drive voltage to the display panel. .

  The plurality of components may include at least one of a display panel, an audio amplifier, a communication interface module, and a sub microcomputer.

  On the other hand, in the power supply device for supplying power to a display panel including a plurality of pixels configured with an OLED (Organic Light Emitting Diode) according to an embodiment of the present invention for achieving the above-described object, The supply device includes a PFC (Power Factor Correction) unit that compensates a power factor of an input voltage, a DC / DV converter that converts the magnitude of an output DC voltage of the PFC unit and provides the display panel, and the display panel And a control unit that controls on / off of the PFC unit in accordance with the operation state of the PFC unit.

  The control unit may turn off the PFC unit while the display panel performs a data voltage charging operation, and may turn on the PFC unit while the display panel performs a light emission operation.

  The controller detects the level of the DC voltage provided to the display panel, and determines that the data voltage charging operation is performed when the detected level of the DC voltage is the first voltage level. When the PFC unit is turned off and the detected DC voltage level is the second voltage level, it is determined that the light emission operation is performed, and the PFC unit may be turned on.

  The control unit may turn on the PFC unit before a preset time with reference to a time point when the data voltage charging period ends.

  The control unit determines that the preset time has been reached when the output voltage of the PFC unit is equal to or lower than a preset level with the PFC unit turned off, and the PFC unit is reached. May be turned on.

  Meanwhile, a method for supplying power to a display panel including a plurality of pixels composed of an OLED (Organic Light Emitting Diode) according to an embodiment of the present invention for achieving the above-described object, Compensating the power factor of the input voltage using the PFC unit, converting the magnitude of the DC voltage output by the compensation and providing it to the display panel, and depending on the operating state of the display panel, Controlling on / off of the PFC unit.

  The controlling step includes turning off the PFC unit while the display panel performs a data voltage charging operation, and turning on the PFC unit while the display panel performs a light emitting operation. It's okay.

  The controlling step further includes a step of detecting a level of a DC voltage provided to the display panel. When the detected level of the DC voltage is a first voltage level, a data voltage charging operation is performed. If it is determined to be performed, the PFC unit is turned off, and if the detected DC voltage level is the second voltage level, it may be determined that the light emission operation is performed, and the PFC unit may be turned on.

  The controlling step may turn on the PFC unit before a preset time from the end of the data voltage charging period.

  The controlling step determines that the preset time has been reached when the output voltage of the PFC unit is equal to or lower than a preset level in a state where the PFC unit is turned off. The part may be turned on.

  As described above, according to the present invention, the same level voltage is applied to the display panel including the organic light emitting diode and other power consuming components using one DC / DC converter, and the display device is provided. Each module can be driven. Furthermore, through the present invention, power efficiency can be improved by performing ON / OFF control of a PFC (Power Factor Correction) unit in a data voltage charging period and a light emission period.

It is a circuit diagram for driving a conventional organic light emitting display device through an active matrix method. 1 is a block diagram of an OLED display device according to an embodiment of the present invention. It is a timing diagram which shows the operating characteristic of the PFC part which concerns on one Embodiment of this invention. It is a block diagram which shows the detailed structure of the display apparatus which concerns on one Embodiment of this invention. It is a circuit block diagram of the RGB pixel of the display panel which concerns on one Embodiment of this invention. 1 is a block diagram of a power supply device that supplies power to a display panel including a plurality of RGB pixels configured by OLEDs according to an embodiment of the present invention. 3 is a flowchart of a method for supplying power from a power supply device according to an embodiment of the present invention to a display device including a display panel including a plurality of pixels configured by OLEDs. 3 is a detailed flowchart illustrating a method for supplying power from a power supply apparatus to a display apparatus according to an exemplary embodiment of the present invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 2 is a block diagram of an OLED display device according to an embodiment of the present invention.

  2, the OLED display device includes a power supply unit 210, a rectification unit 220, a voltage level conversion unit 230, a plurality of components 240-1, 2,..., N, and a control unit 250. Such an OLED display device is realized by various devices including a display unit such as a television, a mobile phone, a PDA, a notebook computer, a monitor, a tablet personal computer, an electronic book, a digital photo frame, and a computer kiosk. Good.

  The power supply unit 210 supplies a voltage for driving the display device. The power supply unit 210 can supply power to the components 240-1, 2,..., N constituting the display device using an AC voltage input from the outside.

  The rectifying unit 220 rectifies the input voltage supplied from the power supply unit 210. Specifically, the rectification unit 220 rectifies the AC voltage input from the power supply unit 210 into a DC voltage and transmits the DC voltage to the voltage level conversion unit 230. The rectifying unit 220 may include a rectifying circuit (not shown) and a PFC (Power Factor Correction) unit 221. That is, the rectifying unit 220 compensates for the power factor of the input voltage that is an AC voltage input from the power supply unit 210 via the rectifying circuit (not shown) and the PFC unit 221. Specifically, when an AC voltage is input from the power supply unit 210, a rectifier circuit (not shown) rectifies the input AC voltage into a DC voltage. Thereafter, the PFC unit 221 can compensate the power factor of the rectified DC voltage and output it to the voltage level conversion unit 230, and the output of the PFC unit 221 may be about 400V normally.

  Further, the PFC unit 221 is supplied with a power saving circuit added to improve the efficiency of the power supplied to the display device, and is supplied to a configuration such as a transformer or a ballast that may cause instantaneous power leakage. The power can be adjusted. That is, the PFC unit 221 can improve the power efficiency by reducing the power consumption and blocking the temperature from rising due to the current being switched to heat. Specifically, the PFC unit 221 may include an inductor, a diode, a capacitor, and switching means. Here, the inductor and the capacitor may be respectively connected to both ends of the diode, and the switching means may be connected to a contact point of the inductor and the diode. Such switching means may be used as a transistor. Since a specific circuit diagram of the PFC unit 221 is a well-known technique, a detailed description and a circuit diagram are omitted in the present invention. Note that the PFC unit 221 according to the present invention may be a boost topology.

  The voltage level conversion unit 230 converts the input voltage rectified by the rectification unit 220, that is, the level of the DC voltage, and provides the level in common to the plurality of components 240-1, 2,. The voltage level conversion unit 230 may include a DC / DC converter (not shown), and a DC voltage input from the rectification unit 220 through the provided DC / DC converter (not shown). It converts into a DC voltage having a preset level and outputs it.

  Specifically, the voltage level conversion unit 230 converts the DC voltage input from the rectification unit 220 into a voltage level for driving the display panel, and provides the voltage level in common to the plurality of components 240-1, 2,. can do. Here, the display panel may be composed of a plurality of pixels including self-luminous elements. Here, the self-luminous element may be realized by an organic light emitting diode (hereinafter referred to as OLED).

  In general, an organic light emitting display device is a display device using an OLED using light emission of an organic material, and displays an image by driving voltage or current on N * M organic light emitting cells arranged in a matrix form. Can do. Here, since the organic light emitting cell has a diode characteristic, it is also called an OLED and has a structure of an anode, an organic thin film, and a cathode electrode layer. Such an OLED has a feature that it can be driven at a low driving voltage of about 12 to 15V. Therefore, the voltage level for driving the display panel according to the present invention may be a voltage level (12 to 15 V) for driving the OLEDs constituting the pixels of the display panel. That is, the voltage level conversion unit 230 provides a DC voltage having a voltage level for driving the OLED to the components 240-1, 2,.

  The plurality of components 240-1, 2,..., N perform at least one of a display panel, an audio up, an interface module, a communication interface module, and a sub-microcomputer. Good.

  According to an additional aspect of the present invention, the display device may further include a controller 250 that controls the overall operation of each component of the display device. Such a control unit 250 controls on / off of the PFC unit 221 of the rectification unit 220 in accordance with the operating states of the plurality of components 240-1, 2,..., N. Specifically, the controller 250 can turn off the PFC unit 221 while the display panel performs the data voltage charging operation, and can turn on the PFC unit 221 while the display panel performs the light emitting operation. .

  The controller 250 detects the level of the DC voltage provided to the display panel, and determines that the data voltage charging operation is performed when the detected level of the DC voltage is the first voltage level. 221 is turned off. On the other hand, when the detected DC voltage level is the second voltage level, the control unit 250 determines that the light emission operation is performed, and can turn on the PFC unit 221.

  Here, in the data voltage charging period in which the display panel performs the data voltage charging operation, the scan driver 280 of the display device, which is an organic light emitting display device, scans through a plurality of scan lines (S1, S2,..., Sn). The switching transistor T1 is turned on by providing a signal, and the data driver 270 of the display apparatus provides a data signal through the plurality of data lines D1, D2,..., Dm, and includes capacitors included in the plurality of pixels. It may be a section in which (C) is charged. At this time, the capacitor C stores the provided data signal as a data voltage.

  During the data voltage charging period, the ELVDD voltage provided to the plurality of pixels included in the display panel by the voltage level converter 230 may be the first voltage level. In the light emitting section where the display panel emits light, the scan driver 280 of the display device, which is an organic light emitting display device, blocks a scanning signal provided through a plurality of scanning lines (S1, S2,..., Sn). The OLED emits light by providing a voltage of a certain level through ELVDD and generating a driving current corresponding to a data voltage and a threshold voltage stored in the capacitor (C) by the driving transistor (T2). At this time, the OLED emits light corresponding to the drive current.

  Meanwhile, the ELVDD voltage provided to the plurality of pixels included in the display panel by the voltage level converter 230 during the light emission period may be at the second voltage level. That is, the control unit 250 detects the level of the ELVDD voltage output from the voltage level conversion unit 230, and determines that the data voltage charging period is detected when the detected voltage level is the first voltage level. it can. Note that the controller 250 may detect the level of the ELVDD voltage output from the voltage level converter 230, and determine that the light emitting section is in the case where the detected voltage level is the second voltage level.

  As described above, the control unit 250 can turn off the PFC unit 221 when it is determined as the data voltage charging period, and can turn on the PFC unit 221 when it is determined as the light emission period. That is, the control unit 250 can control ON / OFF of the PFC unit 221 by controlling the switching elements included in the PFC unit 221.

  As described above, the control unit 250 can obtain the power consumed by the PFC unit 221 during the data voltage charging period by turning off the PFC unit 221 during the data voltage charging period. As described above, the present invention does not provide current to the OLED during the data voltage charging period, but provides current to the OLED only during the light emission period, so that the PFC unit 221 operates in the data voltage charging period. Thus, it is possible to improve the problems of the conventional display device in which wasteful power loss occurs.

  Meanwhile, according to an additional aspect of the present invention, the control unit 250 may turn on the PFC unit 221 before a preset time with respect to a time point when the data voltage charging period ends. That is, the control unit 250 turns off the PFC unit 221 of the rectifying unit 220 during the data voltage charging period. In this case, since the PFC unit 221 may include the capacitor (C), the voltage charged in the capacitor (C) is provided to the voltage level conversion unit 230, and thus the charging voltage of the PFC unit 221 is increased. The level decreases. Thereafter, when the light emission section is reached, the PFC unit 221 is turned on, and it is possible to know the time required to reach a preset voltage level by the output of the PFC unit 221 provided thereby. Accordingly, the control unit 250 performs the PFC before the preset time from the time when the data voltage charging interval ends (before the time when the preset voltage level can be reached at the start of the light emission interval). The part 221 can be turned on.

  Meanwhile, according to an additional aspect of the present invention, the control unit 250 reaches a preset time when the output voltage of the PFC unit 221 is equal to or lower than a preset level in a state where the PFC unit 221 is turned off. The PFC unit 221 may be turned on. Specifically, during the data voltage charging period, when the output voltage of the PFC unit 221 is equal to or lower than a preset level (Vmin), the power efficiency of the voltage level conversion unit 230 that turns off the PFC unit 221 is PFC unit. The power efficiency passing through the voltage level conversion unit 230 may be lowered in a state in which 221 is turned on. Therefore, when the output voltage of the PFC unit 221 is equal to or lower than a preset level (Vmin), the PFC unit 221 may be switched on according to the control command of the control unit 250.

  So far, each configuration of the display device according to the present invention has been described in detail. Hereinafter, the operation characteristics of the PFC unit 221 described above with reference to FIG. 3 will be described in detail.

  FIG. 3 is a timing diagram showing operating characteristics of the PFC unit according to an embodiment of the present invention.

  Specifically, the timing diagram shown in FIG. 3 may include an ELVDD voltage characteristic (a), an operating characteristic (b) of the PFC unit 221, and an output voltage (c) of the PFC unit 221.

  Referring to the ELVDD voltage characteristic (a), it can be seen that the ELVDD voltage is applied with the second voltage during the light emission period and the first voltage level is applied during the data voltage charging period. It can be seen that the second voltage level applied during the light emission period is higher than the first voltage level applied during the data voltage charging period.

  During the data voltage charging period, the scan driver 280 of the display device, which is an organic light emitting display, provides a scan signal through a plurality of scan lines S1, S2,..., Sn to turn on the switching transistor T1. The data driver 270 of the display apparatus can provide data signals through the plurality of data lines D1, D2,..., Dm and charge the capacitors C included in the plurality of pixels.

  During the light emission period, the scan driver 280 of the display apparatus cuts off a scan signal provided through a plurality of scan lines (S1, S2,..., Sn), provides a constant level voltage through ELVDD, and a drive transistor. In (T2), the OLED can emit light by generating a drive current corresponding to the data voltage and threshold voltage stored in the capacitor (C). At this time, it is desirable that the OLED emits light corresponding to the drive current.

  The PFC unit 221 refers to the operation characteristic (b). The PFC unit 221 is turned off during the data voltage charging period in which the level of the DC voltage provided to the display panel is the first voltage level, and is provided to the display panel. It can be seen that the turned-on DC voltage is turned on during the light emission period in which the level is the second voltage level. Note that the PFC unit 221 is turned on before a preset time from the end of the data voltage charging operation.

  Referring to the output voltage (c) of the PFC unit 221, it can be seen that when the PFC unit 221 is turned on, a constant DC voltage of the PFC unit 221 is provided. When the PFC unit 221 is turned off, since the PFC unit 221 includes the capacitor (C), the voltage charged in the capacitor (C) is provided to the voltage level conversion unit 230, thereby the PFC unit 221. It can be seen that the level of the charging voltage decreases.

  However, here, it is desirable that the output voltage (c) of the PFC unit 221 does not fall below a preset level (Vmin). That is, during the data voltage charging period, when the output voltage of the PFC unit 221 is equal to or lower than a preset level (Vmin), the power efficiency of the voltage level conversion unit 230 that turns off the PFC unit 221 causes the PFC unit 221 to turn off. In the on state, the power efficiency passing through the voltage level conversion unit 230 may fall. Therefore, when the output voltage of the PFC unit 221 is equal to or lower than a preset level (Vmin), the PFC unit 221 is preferably switched on according to the control command of the control unit 250.

  Below, each structure of the display apparatus which is an organic electroluminescent apparatus which concerns on one Embodiment of the above-mentioned this invention is demonstrated in detail with reference to FIG.

  FIG. 4 is a block diagram illustrating a detailed configuration of the display device according to the embodiment of the present invention.

  First, prior to the description of the operation of the detailed configuration of the display apparatus, as shown in FIG. 2, a plurality of components 240-1, 2,..., N may be included, and the component 240-1 may be a display panel. . Therefore, in FIG. 4, the description will be given assuming that the component 240-1 is the display panel 240-1.

  As shown in FIG. 4, the display device includes an interface unit 260, a display panel 240-1, a control unit 250, a data driver 270, a scan driver 280 and a voltage driver 290.

  In general, a display device, which is an organic light emitting display device, may be driven by a passive matrix method or an active matrix method. In the present invention, the description will proceed based on what the display device is driven in an active manner. Alternatively, a display device that is an organic light emitting display device can perform RGB display using any one of an independent pixel method, a color conversion method (CCM), and a color filter method. The present invention will be described based on the display device displaying RGB through the independent pixel method.

  First, the interface unit 260 may include a tuner for receiving broadcast program content from a broadcast station, a DVI connected to a recording medium playback device, an HDMI (High Definition Multimedia Interface) terminal, and the like. A video signal having red, green, and blue components is received from the outside and transmitted to the controller 250. When such a video signal is received, the control unit 250 transmits the received video signal to the data driving unit 270.

  The display panel 240-1 may be composed of a plurality of pixels (hereinafter referred to as RGB pixels) 241-1 including an OLED. The plurality of RGB pixels 241-1 may include a self-luminous element that emits light in response to a current flow, an ELVDD that supplies current to the self-luminous element, and a drive transistor that controls the current supplied to the self-luminous element. Here, the self-light emitting element may be an OLED, and each RGB pixel 241-1 may be a red (Red) OLED, a green (Green) OLED, and a blue (Blue) OLED. That is, as described above, when the display apparatus performs RGB display through the independent pixel method, the display panel 240-1 may be configured by a sequential arrangement of a plurality of pixels including red OLED, green OLED, and blue OLED.

  Alternatively, the display panel 240-1 includes n scan lines (S1, S2,..., Sn) arranged in the row direction and transmitting the scan signal and m data arranged in the column direction and transmitting the data signal. Lines (D1, D2,..., Dm) may be included. The display panel 240-1 is driven by receiving an ELVDD power source as a driving power source and an ELVSS power source as a base power source from the voltage driving unit 290. For example, the display panel 240-1 can supply current to the plurality of RGB pixels 241-1 by a scanning signal, a data signal, an ELVDD power source, and an ELVSS power source. Accordingly, the plurality of RGB pixels 241-1 emit light corresponding to the amount of current.

  The data driver 270 receives the video signal having red, green, and blue components received from the controller 250 and generates a data signal. The data driver 270 applies the data signal generated by being connected to the data lines (D1, D2,..., Dm) of the plurality of RGB pixels 241-1 to the display panel 240-1.

  The scan driver 280 is configured to perform an operation of generating a scan signal, and is connected to the scan lines (S1, S2,..., Sn) and transmits the scan signal to a specific row of the display panel 240-1. Accordingly, the data signal output from the data driver 270 may be transmitted to the plurality of RGB pixels 241-1 to which the scanning signal is transmitted.

  The voltage driving unit 290 may include a rectifying unit 220 including a PFC unit 221 and a voltage level converting unit 230. The driving voltage generated through the rectifying unit 220 and the voltage level converting unit 230 is displayed on the display panel 240-. 1 is transmitted. Specifically, the voltage driver 290 uses the DC voltage generated through the rectifier 220 and the voltage level converter 230 described with reference to FIGS. 2 to 3 to apply the OLED drive voltage to the RGB pixels 241-1. Can be supplied. That is, the voltage driver 290 can supply ELVDD power and ELVSS power corresponding to each of the red OLED, the green OLED, and the blue OLED constituting the plurality of RGB pixels 241-1.

  Specifically, the PFC unit 221 of the rectifying unit 220 can compensate for the power factor of the input voltage and output it to the voltage level conversion unit 230. That is, when an AC voltage is input, the rectifying unit 220 rectifies the input AC voltage to generate a DC voltage. When the DC voltage is generated, the PFC unit 221 can compensate the power factor of the rectified DC voltage and output it to the voltage level conversion unit 230.

  The voltage level conversion unit 230 converts the output DC voltage of the PFC unit 221 into at least one DC voltage. The voltage level converter 230 may provide at least one DC voltage to the display panel 240-1. As described above, the power supply unit 280 that provides the direct-current voltage to the display panel 240-1 through the rectifying unit 220 and the voltage level conversion unit 230 causes the plurality of RGB pixels 241-1 constituting the display panel 240-1 to ELVDD. In addition to supplying power and ELVSS power, power can be supplied to each component of the display device.

  On the other hand, the controller 250 not only receives a video signal input from the outside through the interface 260 but also receives a horizontal synchronization signal (Hsync), a vertical synchronization signal (Vsync), a main clock signal (MCLK), and the like. The video data signal, the scanning control signal, the data control signal, the light emission control signal, and the like may be received and generated and transmitted to the display panel 240-1, the data driving unit 270, the scanning driving unit 280, and the voltage driving unit 290. Since the specific configuration of such a signal is obvious to those skilled in the art, a detailed description thereof will be omitted.

  As described above, the control unit 250 that controls the display device and each component can control the rectifying unit 220 of the voltage driving unit 290 according to the operation state of the display panel 240-1. Specifically, the control unit 250 turns off the PFC unit 221 included in the rectifying unit 220 while the display panel 240-1 performs the data voltage charging operation, and the display panel 240-1 performs the light emitting operation. In the meantime, the PFC unit 221 can be turned on. That is, the controller 250 detects the level of the ELVDD voltage output from the voltage level converter 230. If the detected voltage level is the first voltage level, the controller 250 determines that the data voltage charging period is detected. When the voltage level is the second voltage level, it may be determined that the light emission section.

  As described above, when the data voltage charging period or the light emission period is determined according to the detected voltage level, the control unit 250 controls the switching element included in the PFC unit 221 and turns on the PFC unit 221. Can be turned off.

  The controller 250 turns on the PFC unit 221 before a preset time from the end of the data voltage charging period, and the output voltage of the PFC unit 221 is changed in a state where the PFC unit 221 is turned off. When the level is equal to or lower than a preset level, the PFC unit 221 can be turned on. As described above, the controller 250 is consumed by the PFC unit 221 during the voltage charging period by controlling the switching elements included in the PFC unit 221 to perform the operation of turning the PFC unit 221 on and off. As much as power can be obtained, power efficiency can be improved as compared with the conventional case. Meanwhile, the operation of the controller 250 controlling the switching element included in the PFC unit 221 to turn on / off the PFC unit 221 has been described in detail with reference to FIGS. Omitted.

  On the other hand, the plurality of components 240-1, 2,..., N described above may include an IR receiving module for receiving an IR (Infra Red) signal from the remote control device. The plurality of components 240-1, 2,..., N are driven using the DC voltage input from the voltage level conversion unit 230 included in the voltage driving unit 290. However, each component 240-1, 2,..., N may be driven with a voltage smaller than the OLED driving voltage, such as 1.1V, 1.8V, 3.3V, 5V, and the like. In this case, each of the components 240-1, 2,..., N includes a separate voltage enhancement circuit (not shown) that drops the input DC voltage, and uses the voltage provided from the voltage level converter 230 as the operating voltage. Can be lowered to level.

  Meanwhile, the voltage level converter 230 may further include SMPS (Switching Mode Power Supply). That is, the voltage level conversion unit 230 converts the DC voltage having the OLED driving voltage level into the voltage required from the remaining components 240-2,..., N other than the display panel component 240-1, through SMPS. Can be output. The SMPS may include a voltage device, and when a DC voltage having a level for driving an OLED is applied to the primary coil of the transformer, the DC voltage having various levels may be applied to the secondary coil according to the coil ratio. Can be guided to. Through this process, the SMPS outputs various DC voltages such as 1.1V, 1.8V, 3.3V, 5V, etc., and the remaining components 240-2 including the component 240-1 which is a display panel. ..., can be provided to n.

  According to the embodiment of the present invention as described above, a drive voltage can be applied to each of the components 240-1, 2,..., N constituting the display device more efficiently using one DC / DC converter. it can.

  The OLED is a light emitting element that emits light at a driving voltage of 12 to 15V. Therefore, when the RGB pixel 241-1 of the display device 240-1 is realized by an OLED, the component 240- which is a display panel at a voltage smaller than that when the liquid crystal display device emits light using a backlight unit (for example, 200 to 300 V). 1 drive is possible. On the other hand, the components 240-1, 2,..., N included in the display device are usually driven with a voltage equal to or smaller than the OLED driving voltage. That is, since the OLED drive voltage and the drive voltages of the components 240-1, 2,..., N are similar, the drive voltage constituting the OLED drive voltage can be generated through one DC / DC converter.

  Hereinafter, the circuit configuration of the RGB pixel 241-1 of the display panel 240-1 of the display device according to the present invention will be described in detail.

  FIG. 5 is a circuit configuration diagram of RGB pixels of the display panel according to the embodiment of the present invention.

  As shown in FIG. 5, each RGB pixel 241-1 of the display panel 240-1 includes an OLED and a pixel circuit 241-1 'for supplying current to the OLED.

  The anode electrode of the OLED is connected to the pixel circuit 241-1 ', and the cathode electrode is connected to the second power source (ELVSS). Such an OLED generates light having a predetermined luminance corresponding to the current supplied from the pixel circuit 241-1 '. As illustrated, the pixel circuit 241-1 'included in the RGB pixel 241-1 may include three transistors (M1 to M3) and two capacitors (C1, C2). Here, the gate electrode of the first transistor (M1) is connected to the scanning line (S), the first electrode is connected to the data line (D), and the second electrode of the first transistor (M1) is connected to the first node ( N1).

  That is, the scanning signal (Scan (n)) is input to the gate electrode of the first transistor (M1), and the data signal (Data (t)) is input to the first electrode. The gate power of the second transistor (M2) is connected to the second node (N2), the first electrode is connected to the first power source (ELVDD (t)), and the second power source is the anode electrode of the organic light emitting device. Connected to. Here, the second transistor (M2) serves as a driving transistor.

  The first capacitor (C1) is connected between the first node (N1) and the first electrode of the second transistor (M2), that is, the first power supply (ELVDD (t)), and the first node (N1). The first capacitor C2 is connected between the second node N2 and the second node N2. The gate electrode of the third transistor (M3) is connected to the control line (GC), the first electrode is connected to the gate electrode of the second transistor (M2), and the second electrode is the anode electrode of the organic light emitting device, that is, , Connected to the second electrode of the second transistor (M2).

  Accordingly, when the control signal (GC (t)) is input to the gate electrode of the third transistor (M3) and the third transistor (M3) is turned on, the second transistor (M2) is connected to the diode, The cathode electrode of the organic light emitting device is connected to a second power source (ELVSS (t)).

  Hereinafter, a power supply device that supplies power to a display panel including a plurality of RGB elements constituted by OLEDs according to the present invention will be described in detail.

  FIG. 6 is a block diagram of a power supply device that supplies power to a display panel including a plurality of RGB pixels configured by OLEDs according to an embodiment of the present invention.

  As shown in FIG. 6, the power supply device includes a PFC unit 610, a DC / DC converter 620, and a control unit 630. Here, as shown in FIG. 4, the power supply device may be used for a display device including a display panel 240-1 including a plurality of pixels configured by OLEDs. Here, the display device may be an organic light emitting display device.

  A power supply device that supplies power to the display panel 240-1 of such a display device can supply ELVDD power and ELVSS power. Here, the power supply device can supply not only ELVDD power and ELVSS power but also drive power to all components that constitute the display device and require power.

  The PFC unit 610 can compensate the power factor of the input voltage and output it to the DC / DC converter 620. That is, as shown in FIG. 3 or 4, the PFC unit 610 compensates for the power factor of the rectified DC voltage when the AC voltage input by the rectifying unit 220 is rectified and generated as a DC voltage. It can be output to the DC / DC converter 620. In general, the output of the PFC unit 610 may be about 400V in a display device that is an organic light emitting display device.

  Here, the PFC unit 610 is provided with a power saving circuit in order to improve the power efficiency of the power supply device. As a result, the power supplied to the configuration such as a transformer or a ballast that may cause instantaneous power leakage. Adjust. That is, the PFC unit 610 can improve the power efficiency by reducing the power consumption and blocking the temperature from rising due to the current being switched to heat.

  Specifically, the PFC unit 610 may include an inductor, a diode, a capacitor, and switching means. Here, the inductor and the capacitor may be connected to both ends of the diode, the switching means may be connected to the contact point of the inductor and the diode, and the switching means may be used as a transistor. A specific circuit diagram of the PFC unit 610 will be omitted. The PFC unit 610 may have a boost topology.

  The DC / DC converter 620 converts the magnitude of the output DC voltage of the PFC unit 610. As shown in FIG. 4, the DC / DC converter 620 can provide a direct-current voltage whose magnitude has been converted to the display panel 240-1 of the display device. Here, the DC / DC converter 620 may be configured using a conventional well-known DC / DC converter circuit. The control unit 630 controls the overall operation of the power supply device. Specifically, the control unit 630 can control the PFC unit 610 and the DC / DC converter 620.

  The control unit 630 can perform ON / OFF control of the PFC unit 610 according to the operation state of the display panel 240-1. That is, the control unit 630 turns off the PFC unit 610 while the display panel 240-1 performs the data voltage charging operation, and turns on the PFC unit 610 while the display panel 240-1 performs the light emission operation. You may let me.

  Here, in the data voltage charging period in which the display panel 240-1 performs the data voltage charging, as shown in FIG. 4, the scan driver 280 of the display apparatus has a plurality of scanning lines (S1, S2,..., Sn− 1, Sn provides a scanning signal to turn on the switching transistor T 1, and the data driver 270 of the display apparatus provides the data signal through the plurality of data lines D 1, D 2,..., Dm−1, Dm. In this section, the capacitor (C) included in the plurality of pixels is charged. At this time, the capacitor C stores the provided data signal as a data voltage.

  During the data voltage charging period, the ELVDD voltage provided to the plurality of pixels included in the display panel 240-1 by the DC / DC converter 620 may be at the first voltage level.

  In the light emission period in which the display panel 240-1 emits light, the scan driver 280 of the display apparatus blocks a scanning signal provided through a plurality of scanning lines (S1, S2,..., Sn-1, Sn). The OLED emits light by providing a voltage of a certain level through ELVDD and generating a driving current corresponding to a data voltage and a threshold voltage stored in the capacitor (C) by the driving transistor (T2). At this time, the OLED emits light corresponding to the drive current.

  The ELVDD voltage provided to the plurality of pixels included in the display panel 240-1 by the DC / DC converter 620 during the light emission period may be at the second voltage level. That is, the control unit 630 detects the level of the ELVDD voltage output from the DC / DC converter 620, and determines that the detected voltage level is the first voltage level as a data voltage charging period. it can. Note that the control unit 630 may detect the ELVDD voltage level output from the DC / DC converter 620, and determine that the light emitting section is in the case where the detected voltage level is the second voltage level.

  The control unit 630 can turn off the PFC unit 610 when the data voltage charging period is determined. In addition, the control part 630 can turn ON the PFC part 610, when it is judged as a light emission area. That is, the control unit 630 can control ON / OFF of the PFC unit 610 by controlling the switching elements included in the PFC unit 610.

  As described above, the control unit 630 controls the PFC unit 610 to be turned off during the data voltage charging period, thereby obtaining the power consumed by the PFC unit 610 during the data voltage charging period. it can. That is, when the conventional voltage supply device is applied as it is, the driving characteristics of the display device which is an organic light emitting display device (ie, no current is provided to the OLED during the data voltage charging period, and the current is supplied to the OLED only during the light emission period. Therefore, the PFC unit 610 operates even in the data voltage charging period, thereby causing a loss of useless power. Therefore, the power supply apparatus according to the embodiment of the present invention can improve power efficiency.

  In addition, the control unit 630 can turn on the PFC unit 610 before a preset time from the end of the data voltage charging period. That is, the controller 630 turns off the PFC unit 610 during the data voltage charging period. In this case, since the PFC unit 610 includes a capacitor, the voltage charged in the capacitor is provided to the DC / DC converter 620, thereby reducing the level of the charging voltage of the PFC unit 610. Thereafter, when the light emission section is reached, the PFC unit 610 is turned on, and it takes time until the output of the PFC unit 610 provided thereby reaches a preset voltage level. Accordingly, the control unit 630 may determine a time before the preset time from the end of the data voltage charging period (that is, before a time at which the voltage level reaches a preset level at the start of the light emission period). The PFC unit 610 can be turned on.

  Note that the control unit 630 can control the PFC unit 610 to be turned on when the output voltage of the PFC unit 610 is equal to or lower than a preset level in a state where the PFC unit 610 is turned off. That is, when the output voltage of the PFC unit 610 is equal to or lower than a preset level (Vmin) during the data voltage charging period, the power efficiency of only the DC / DC converter 620 that turns off the PFC unit 610 is In a state where 610 is turned on, the power efficiency passing through the DC / DC converter 620 may be lowered. Therefore, the control unit 630 can control the PFC unit 610 to be turned on when the output voltage of the PFC unit 610 is equal to or lower than a preset level (Vmin).

  So far, each configuration of the display device and the power supply device according to the present invention has been described in detail. Hereinafter, a method for supplying power to a display panel including a plurality of pixels configured by OLEDs of a display apparatus in the power supply apparatus according to the present invention will be described in detail.

  FIG. 7 is a flowchart of a method for supplying power from a power supply apparatus according to an embodiment of the present invention to a display apparatus including a display panel including a plurality of pixels configured by OLEDs.

  As shown in FIG. 7, the power supply device compensates the power factor of the input voltage using the PFC unit (S710). Thereafter, the power supply device compensates the power factor of the input voltage and converts the magnitude of the output DC voltage to provide it to the display panel (S720). Then, the power supply device performs on / off control of the PFC unit according to the operation state of the display panel (S730). Hereinafter, this will be described in more detail with reference to FIG.

  FIG. 8 is a detailed flowchart for a method of supplying power from a power supply apparatus to a display apparatus according to an exemplary embodiment of the present invention.

  As shown in FIG. 8, the power supply device compensates the power factor of the input voltage through the PFC unit (S810). When a DC voltage with respect to the input voltage is output due to the compensation, the power supply apparatus converts the output DC voltage and provides it to the display panel provided in the display apparatus (S820). Thereafter, the power supply device detects the level of the DC voltage provided to the display panel, and checks whether the level of the detected DC voltage is the first level (S830, S840). As a result of the check, if the detected DC voltage level is the first level, the power supply apparatus determines that the display panel performs the data voltage charging operation and turns off the PFC unit (S850). On the other hand, if the level of the detected DC voltage is not the first level as a result of the check, the power supply apparatus determines that the level of the detected DC voltage is the second level. Therefore, the power supply apparatus determines that the display panel performs the light emission operation and turns on the PFC unit (S860).

  As described above, the power supply apparatus that performs the on / off operation of the PFC unit according to the level of the DC voltage provided to the display panel may perform the PFC before the preset time from the end of the data voltage charging period. The part can be turned on. Note that the power supply device may turn on the PFC unit when the output voltage of the PFC unit is equal to or lower than a preset level with the PFC unit turned off.

  Meanwhile, according to various embodiments of the present invention described above, the power supply apparatus turns off the PFC unit during the data voltage charging period, thereby dividing the power consumed in the PFC unit during the data voltage charging period. Can only get. Thereby, power efficiency can be improved. So far, the power supply device, the power supply method, and the OLED display device according to the present invention have been described in detail.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. It is obvious that a person having ordinary knowledge in the technical field to which the present invention belongs can come up with various changes or modifications within the scope of the technical spirit described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

210 Power supply unit 220 Rectification unit 221 PFC unit 230 Voltage level conversion unit 241-1 Component 1
241-2 Component 2
241-n component n
250 Control Unit 260 Interface Unit 270 Data Drive Unit 280 Scan Drive Unit 290 Voltage Drive Unit 610 PFC Unit 620 DC / DC Converter 630 Control Unit

Claims (15)

In an OLED (Organic Light Emitting Diode) display device,
A plurality of components for operating the display device;
A power supply unit;
A rectifying unit that rectifies an input voltage supplied from the power supply unit;
An OLED display device comprising: a voltage level conversion unit that converts a level of an input voltage rectified by the rectification unit and provides the level to the plurality of components in common. The rectifying unit is
The OLED display device according to claim 1, further comprising a power factor correction (PFC) unit that compensates a power factor of the input voltage. The voltage level converter is
3. The OLED display device according to claim 2, wherein the output DC voltage level of the PFC unit is converted into a voltage level for driving a display panel and provided in common to the plurality of components. The display panel is
The OLED display device according to claim 3, comprising a plurality of pixels including the OLED.   The OLED display device according to claim 3, further comprising a control unit that controls on / off of the PFC unit according to an operation state of the plurality of components. The controller is
While the display panel performs the data voltage charging operation, the PFC unit is turned off.
The OLED display device according to claim 4, wherein the PFC unit is turned on while the display panel performs a light emitting operation. The controller is
Detecting the level of the DC voltage provided to the display panel;
If the detected DC voltage level is the first voltage level, it is determined to perform a data voltage charging operation, the PFC unit is turned off,
The OLED display device according to claim 6, wherein when the detected DC voltage level is the second voltage level, it is determined that a light emission operation is performed, and the PFC unit is turned on. The controller is
8. The OLED display device according to claim 7, wherein the PFC unit is turned on before a preset time with reference to a time when the data voltage charging period ends. The controller is
When the output voltage of the PFC unit is equal to or lower than a preset level with the PFC unit turned off, it is determined that the preset time has been reached, and the PFC unit is turned on. The OLED display device according to claim 8. A scan driver for providing a scan signal to the plurality of pixels;
A data driver for providing a data signal to the plurality of pixels;
The OLED display device of claim 4, further comprising: a voltage driver that provides a driving voltage to the display panel. The plurality of components are:
The OLED display device according to claim 1, further comprising at least one of a display panel, an audio amplifier, a communication interface module, and a sub-microcomputer. In a method for supplying power to a display panel including a plurality of pixels composed of OLED (Organic Light Emitting Diode),
Compensating the power factor of the input voltage using the PFC unit;
Converting the magnitude of the DC voltage output by the compensation and providing it to the display panel;
Controlling the on / off of the PFC unit according to the operating state of the display panel. The controlling step includes
Turning off the PFC unit while the display panel performs a data voltage charging operation;
The power supply method according to claim 12, further comprising: turning on the PFC unit while the display panel performs a light emitting operation. The controlling step includes
Detecting a level of a DC voltage provided to the display panel;
If the detected DC voltage level is the first voltage level, it is determined that the data voltage charging operation is performed, the PFC unit is turned off, and the detected DC voltage level is the second voltage level. The power supply method according to claim 13, wherein the power supply operation is determined to be performed and the PFC unit is turned on. The controlling step includes
14. The power supply method according to claim 13, wherein the PFC unit is turned on before a preset time from the end of the data voltage charging period.

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