KR20070060359A - Apparatus for supplying power source, display apparatus including the same, and method of driving the display apparatus - Google Patents

Abstract

A power supply device, a display apparatus and a driving method including the same are provided to display required images on a light emitting device by synchronizing a drain-source voltage with a timing signal. A power supply device includes a boosting unit(402) and a boosting voltage detector(404). The boosting unit includes a switch(SW) and boosts up a battery voltage from a battery according to a duty ratio of the switch. The boosting voltage detector, which is connected to the boosting unit, detects the boosted battery voltage. The switch is switched in synchronization with one of timing signals, which are supplied to a light emitting device. The light emitting device includes data lines and scan lines, which are formed to cross the data lines. The switch is switched in synchronization with a horizontal synchronous signal to synchronize scan signals, which are supplied to the scan lines, among the timing signals.

Description

Power supply, display device and driving method including same {APPARATUS FOR SUPPLYING POWER SOURCE, DISPLAY APPARATUS INCLUDING THE SAME, AND METHOD OF DRIVING THE DISPLAY APPARATUS}

1 is a block diagram illustrating a conventional display device.

Figure 2a is a circuit diagram showing a conventional power supply.

2B is a timing diagram illustrating an operation process of the power supply device.

2C is a timing diagram illustrating a process of driving the display apparatus.

3 is a block diagram illustrating a display apparatus according to an exemplary embodiment of the present invention.

4 is a circuit diagram illustrating a power supply apparatus according to an exemplary embodiment of the present invention.

5A is a timing diagram illustrating a process of driving the display apparatus according to an exemplary embodiment of the present invention.

5B is a timing diagram illustrating a process of driving the display apparatus according to another exemplary embodiment of the present invention.

The present invention relates to a display device and a method of driving the same, and more particularly, to a display device and a method of driving the same that can display a desired image regardless of the operation of the power supply.

The display apparatus is a device for displaying a predetermined image.

1 is a block diagram illustrating a conventional display device.

Referring to FIG. 1, a conventional display device includes a light emitting device, a power supply 104, and a timing controller 106.

The light emitting device, for example, an organic electroluminescent device, includes a panel 100 and a driver 102.

The power supply 104 applies a predetermined voltage V _CC to the light emitting device. Detailed description thereof will be described below with reference to the accompanying drawings.

The timing controller 106 transmits timing signals, such as display data and a horizontal synchronization signal, to the driving controller 108.

The panel 100 includes a plurality of pixels E11 to E66 formed in light emitting regions where the data lines D1 to D6 and the scan lines S1 to S6 cross each other.

The driver 102 includes a drive controller 108, a scan driver 110, and a data driver 112.

The driving controller 108 receives the display data and the horizontal synchronization signal from the timing controller 106 and controls the scan driver 110 and the data driver 112 according to the received display data and the horizontal synchronization signal.

The scan driver 110 transmits scan signals to the scan lines S1 to S6 under the control of the drive controller 108. As a result, the scan lines S1 to S6 are in turn connected to ground. Here, the scan signals are synchronized with the horizontal synchronization signal.

The data driver 112 applies a data current corresponding to the display data to the data lines D1 to D6 under the control of the drive controller 108. As a result, pixels corresponding to the scan line connected to the ground emit light.

Figure 2a is a circuit diagram showing a conventional power supply. FIG. 2B is a timing diagram illustrating an operation process of the power supply device, and FIG. 2C is a timing diagram illustrating a process of driving the display device.

Referring to FIG. 2A, the power supply 104 includes a boosting unit 202 and a boosted voltage detector 204.

The boosting unit 202 includes an inductor ID connected to the battery 200 and a boosting integrated circuit chip 206 connected to both ends of the inductor ID.

The boosting integrated circuit chip 206 includes a switch SW and boosts the battery voltage provided from the battery 200 by switching the switch SW. Here, since the boosting integrated circuit chip 206 is generally used as a boosting element, description of components other than the switch SW is omitted.

The boosted voltage detector 204 includes resistors R1 and R2 connected in series.

Hereinafter, the display device driving process of the present invention will be described in detail.

First, a process in which power is supplied from the power supply device 104 to the driver 102 will be described in detail.

The switch SW is turned off, so that the battery voltage is stored in the inductor ID.

Subsequently, the switch SW is turned on. In this case, the charge charged in the inductor ID is output to the second node.

The switch SW is then turned off, so that the battery voltage is stored in the inductor ID.

That is, the switch SW repeats the turn-on / off operation, so that the battery voltage is boosted. As a result, the second node has the boosted battery voltage. Here, the turn-on / off ratio of the switch SW means a duty rate. However, when the switch SW is a MOS transistor, the drain-source voltage V _DS has a ripple as shown in FIG. 2B at the start of turn-off of the switch SW.

Subsequently, when the boosted battery voltage is greater than or equal to the threshold voltage of the diode D, the current output from the inductor ID passes through the diode D. As a result, a third node has the boosted battery voltage.

Subsequently, the boosted voltage detector 204 detects the boosted battery voltage, that is, the voltage of the third node.

Hereinafter, it is assumed that the power supply 104 is preset to boost the battery voltage (eg, 3.7V) provided from the battery 200 to 18V. In this case, it is assumed that the voltage of the fourth node is detected as 9V.

For example, when the battery voltage boosted by the boosting unit 202 is 16V, the boosted voltage detector 204 detects that the voltage of the fourth node is 8V.

Subsequently, the boosted voltage detector 204 provides information about the detected voltage of the fourth node to the FB terminal of the boosting integrated circuit chip 206. In this case, the boosting integrated circuit chip 206 determines that the battery voltage has not been boosted to the desired voltage 18V through the provided information. Accordingly, the boosting integrated circuit chip 206 adjusts the duty ratio of the switch SW such that the boosted battery voltage is 18V.

The power supply 104 boosts the battery voltage to a desired voltage through the above process, and provides the boosted battery voltage to the driver 102. That is, when the third node has a desired voltage, the power supply 104 provides the driver 102 with the voltage of the third node. However, since the voltage of the third node is affected by the turn-on / off operation of the switch SW, the voltage of the third node corresponds to the drain-source voltage V _DS as shown in FIG. 2B. Has ripple.

Hereinafter, the driving process of the display apparatus will be described in detail.

The timing controller 106 transmits the display data and the horizontal synchronization signal to the drive controller 108 as shown in FIG. 2C.

The scan driver 110 transmits scan signals to the scan lines S1 to S6 under the control of the drive controller 108. Here, the scan signals are synchronized with the horizontal synchronizing signal as shown in FIG. 2C. That is, the scan signals have low logic from a low logic end point of the horizontal sync signal. However, FIG. 2C illustrates only some of the scan signals SP1 to SP3.

The data driver 112 transmits a data current corresponding to the display data to the data lines D1 to D6 under the control of the drive controller 108. As a result, pixels E11 to E66 emit light during the low logic of the scan signals.

However, the data current corresponding to the display data is affected by the ripple of the voltage of the third node. For example, when the ripple of the third node voltage affects the red data current corresponding to the red display data among the data currents, the pixels flowing through the red data current may emit light with a desired color or luminance. Could not.

It is a first object of the present invention to provide a power supply that operates in synchronization with a timing signal.

It is a second object of the present invention to provide a display device that is not affected by the ripple of a voltage output from a power supply and the same.

In order to achieve the object as described above, the power supply device for supplying power to the light emitting device according to an embodiment of the present invention includes a boosting unit and a boosted voltage detector. The boosting unit has a switch and boosts the battery voltage provided from the battery according to the duty ratio of the switch. The boosted voltage detector is connected to the boosting unit and detects the boosted battery voltage. Here, the switch is switched in synchronization with a predetermined signal among timing signals provided to the light emitting element.

The display device according to an exemplary embodiment of the present invention includes a light emitting device, a timing controller, and a power supply device. The light emitting device includes a panel and a driver for driving the panel. The timing controller provides timing signals to the driver. The power supply device supplies a predetermined voltage to the light emitting device. Here, the voltage supplied to the light emitting element is synchronized with a predetermined signal among the timing signals.

A method of driving a display device including a light emitting device according to an exemplary embodiment of the present invention includes transmitting timing signals to the light emitting device; And supplying a voltage synchronized with a predetermined signal among the timing signals to the light emitting device. Here, a predetermined image is displayed on the light emitting element according to the transmitted timing signals and the supplied voltage.

In the display device including the power supply device and the method for driving the same according to the present invention, since the drain-source voltage V _DS is synchronized with some of the timing signals, a desired image can be displayed on the light emitting device.

Hereinafter, exemplary embodiments of a display apparatus and a method of driving the same according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a block diagram illustrating a display apparatus according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the display device of the present invention includes a light emitting device, a power supply device 304, and a timing controller 306.

The light emitting device includes a panel 300 and a driver 302. The light emitting device according to an embodiment of the present invention is an organic electroluminescent device.

The timing controller 306 transmits timing signals, such as display data and a horizontal synchronization signal, to the driving controller 308. In addition, the timing controller 306 transmits a predetermined signal of the timing signals, for example, the horizontal synchronization signal, to the power supply device 304 as shown in FIG. 3. Of course, the timing controller 306 may provide a vertical synchronization signal among the timing signals to the power supply device 304 as described later.

Hereinafter, it is assumed that a horizontal synchronization signal of the timing signals is transmitted to the power supply 304.

The power supply 304 applies a power source, that is, a predetermined voltage V _CC , to the light emitting device according to the horizontal synchronization signal transmitted from the timing controller 306. Here, the voltage V _CC is synchronized with the horizontal synchronizing signal. Detailed description thereof will be described below with reference to the accompanying drawings.

The panel 300 includes a plurality of pixels E11 to E66 formed in light emitting regions where the data lines D1 to D6 and the scan lines S1 to S6 cross each other. For example, when the light emitting device is an organic electroluminescent device, at least one pixel includes an anode electrode layer, an organic material layer, and a cathode electrode layer sequentially formed on a substrate.

The driver 302 includes a drive controller 308, a scan driver 310, and a data driver 312.

The driving controller 308 receives display data and timing signals from the timing controller 306, and controls the scan driver 310 and the data driver 312 according to the received display data and timing signals.

The scan driver 310 transmits scan signals to the scan lines S1 to S6 under the control of the drive controller 308. As a result, the scan lines S1 to S6 are in turn connected to ground. Here, the scan signals are synchronized with the horizontal synchronization signal.

The data driver 312 applies a data current corresponding to the display data to the data lines D1 to D6 under the control of the drive controller 308. As a result, pixels corresponding to the scan line connected to the ground emit light.

4 is a circuit diagram illustrating a power supply apparatus according to an exemplary embodiment of the present invention. FIG. 5A is a timing diagram illustrating a process of driving the display apparatus according to an exemplary embodiment of the present invention, and FIG. 5B is a timing diagram illustrating a process of driving the display apparatus according to another exemplary embodiment of the present invention. to be.

Referring to FIG. 4, the power supply device 304 includes a boosting unit 402 and a boosted voltage detector 404.

The boosting unit 402 includes an inductor ID connected to the battery 400 and a boosting integrated circuit chip 406 connected to both ends of the inductor ID.

The boosting integrated circuit chip 406 includes a switch SW and boosts the battery voltage provided from the battery 400 by switching the switch SW. Here, since the boosting integrated circuit chip 406 is generally used as a boosting element, description of components other than the switch SW is omitted.

The boosted voltage detector 404 includes resistors R1 and R2 connected in series.

Hereinafter, the display driving process of the present invention will be described in detail.

First, a process in which power is supplied from the power supply device 304 to the driver 302 will be described in detail.

The horizontal synchronization signal is input from the timing controller 306 to the power supply 304.

The switch SW is then turned off, so that the battery voltage is stored in the inductor ID.

Subsequently, the switch SW is turned on. In this case, the charge charged in the inductor ID is output to the second node.

The switch SW is then turned off, so that the battery voltage is stored in the inductor ID.

That is, the switch SW repeats the turn-on / off operation in synchronization with the horizontal synchronizing signal, so that the battery voltage is boosted. As a result, the second node has the boosted battery voltage. Here, the turn-on / off ratio of the switch SW means a duty rate.

The turn-off start time of the switch SW according to an embodiment of the present invention is synchronized with the horizontal synchronization signal. Therefore, when the switch SW is a MOS transistor, the drain-source voltage V _DS is changed corresponding to the horizontal synchronization signal as shown in FIG. 5A. However, the drain-source voltage V _DS has a ripple as shown in FIG. 5A at the start of turn-off of the switch SW.

Subsequently, when the boosted battery voltage is greater than or equal to the threshold voltage of the diode D, the boosted battery voltage passes through the diode D. As a result, a third node has the boosted battery voltage.

Subsequently, the boosted voltage detector 404 detects the boosted battery voltage, that is, the voltage of the third node.

Hereinafter, assume that the power supply 304 is preset to boost the battery voltage (eg, 3.7V) provided from the battery 400 to 18V. In this case, it is assumed that the voltage of the fourth node is detected as 9V.

For example, when the battery voltage boosted by the boosting unit 402 is 16V, the boosted voltage detector 404 detects that the voltage of the fourth node is 8V.

Subsequently, the boosted voltage detector 404 provides the FB terminal of the boosting integrated circuit chip 406 with information about the detected voltage of the fourth node. In this case, the boosting integrated circuit chip 406 determines that the battery voltage has not been boosted to the desired voltage 18V through the provided information. Accordingly, the boosting integrated circuit chip 406 adjusts the duty ratio of the switch SW such that the boosted battery voltage is 18V.

The power supply device 304 boosts the battery voltage to a desired voltage through the above process, and provides the boosted battery voltage to the driver 302.

Hereinafter, the driving process of the display apparatus will be described in detail.

The timing controller 306 transmits the display data and the horizontal synchronizing signal to the driving controller 308 as shown in FIG. 5A.

The scan driver 310 transmits scan signals to the scan lines S1 to S6 under the control of the drive controller 308. Here, the scan signals are synchronized with the horizontal synchronization signal as shown in FIG. 5A. That is, the scan signals have low logic from the low logic end point of the horizontal synchronization signal.

However, FIG. 5A illustrates only some of the scan signals SP1 to SP3.

The data driver 312 transmits a data current corresponding to the display data to the data lines D1 to D6 under the control of the drive controller 308. As a result, pixels E11 to E66 emit light during the low logic of the scan signals.

In short, in the display device driving method of the present invention, the drain-source voltage V _DS and the scan signals are synchronized with the horizontal synchronization signal. Therefore, the ripple generated at the turn-off start point of the switch SW does not affect the display data (ie, the data current corresponding to the display data) as shown in FIG. 5A. Therefore, in the display device driving method of the present invention, unlike in the conventional display device driving method, a predetermined image is displayed on the light emitting element without error.

In the display device driving method according to another exemplary embodiment of the present invention, the drain-source voltage V _DS may be synchronized with the vertical synchronization signal among the timing signals. Here, the vertical synchronization signal synchronizes the scan lines S1 to S6 in units of screens, unlike the horizontal synchronization signal that synchronizes the scan lines S1 to S6, respectively.

In the method of driving the display device according to another embodiment of the present invention, the time ST1 corresponding to the turn-off of the switch SW among the drain-source voltage V _DS is horizontally synchronized as shown in FIG. 5B. It can be larger or smaller than the signal's low logic time. However, the ripple generated from the drain-source voltage V _DS is in a low logic range among the horizontal synchronization signals. Thus, the ripple does not affect the data current corresponding to the display data, so that the light emitting element can accurately display the desired image.

Preferred embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art having various ordinary knowledge of the present invention may make various modifications, changes, and additions within the spirit and scope of the present invention. Additions should be considered to be within the scope of the following claims.

As described above, in the display device including the power supply device and the method of driving the same, the drain-source voltage V _DS is synchronized with some of the timing signals, so that a desired image is displayed on the light emitting device. There is an advantage that can be.

Claims (11)

In the power supply for supplying power to the light emitting device, A boosting unit having a switch and boosting a battery voltage provided from a battery according to a duty ratio of the switch; And A boosted voltage detector connected to the boosting unit and detecting the boosted battery voltage; And the switch is switched in synchronization with a predetermined signal among timing signals provided to the light emitting element. The method of claim 1, wherein the light emitting element, Data lines and scan lines crossing the data lines; And the switch is switched in synchronization with a horizontal synchronizing signal for synchronizing the scan signals provided to the scan lines among the timing signals. The method of claim 1, wherein the light emitting element, Data lines and scan lines crossing the data lines; And the switch is switched in synchronization with a vertical synchronizing signal for synchronizing the scan signals provided to the scan lines among the timing signals on a screen basis. A light emitting device comprising a panel and a driver for driving the panel; A timing controller providing timing signals to the driver; And Including a power supply for supplying a predetermined voltage to the light emitting device, And a voltage supplied to the light emitting element is synchronized with a predetermined one of the timing signals. The method of claim 4, wherein the light emitting element, Data lines and scan lines crossing the data lines; And a voltage supplied to the light emitting element is synchronized with a horizontal synchronizing signal for synchronizing scan signals provided to the scan lines among the timing signals. The method of claim 4, wherein the light emitting element, Data lines and scan lines crossing the data lines; And a voltage supplied to the light emitting device is synchronized to a vertical synchronizing signal for synchronizing scan signals provided to the scan lines among the timing signals on a screen basis. The display apparatus according to claim 4, wherein the light emitting element is an organic electroluminescent element. In the method for driving a display device comprising a light emitting element, Transmitting timing signals to the light emitting device; And Supplying a voltage synchronized with a predetermined one of the timing signals to the light emitting device, And a predetermined image is displayed on the light emitting element according to the transmitted timing signals and the supplied voltage. The method of claim 8, wherein the voltage supplied to the light emitting device is synchronized with a horizontal synchronizing signal among the timing signals. The method of claim 8, wherein the voltage supplied to the light emitting element is synchronized with a vertical synchronizing signal among the timing signals. The method of claim 8, wherein the light emitting element, Pixels formed in the light emitting regions where the data lines and the scan lines cross each other; The display device driving method, Providing data signals to the data lines in accordance with the transmitted timing signals; And And providing scan signals to the scan lines according to the transmitted timing signals.

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