KR20080030865A - Light emitting device and method of driving the same - Google Patents

Abstract

A light emitting device and a method for driving the same are provided to prevent the loss of commands by executing a separate operation without synchronization between a driving voltage signal and a clock signal. A light emitting device includes a panel(100), an IC(Integrated Circuit) chip(102), and a driving voltage supply unit(124). The panel includes plural pixels formed at cross sections where data and scan lines(112,114,116) are crossed with each other. The IC chip generates a clock signal according to an oscillation command, generates a driving voltage signal according to a DC/DC command, and drives the pixels by supplying a driving signal synchronized with the clock signal to the panel. The driving voltage supply unit generates a panel driving voltage according to the driving voltage signal and supplies the generated panel driving voltage to the panel through the IC chip. The driving voltage signal and the clock signal are asynchronous.

Description

LIGHT EMITTING DEVICE AND METHOD OF DRIVING THE SAME}

1 is a view showing a light emitting device according to an embodiment of the present invention.

FIG. 2A illustrates the panel of FIG. 1 in accordance with one preferred embodiment of the present invention. FIG.

FIG. 2B is a cross-sectional view illustrating the pixel of FIG. 2A.

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

4 is a diagram illustrating a driving voltage providing unit of FIG. 1 according to an exemplary embodiment of the present invention.

5 is a view showing a panel according to another preferred embodiment of the present invention.

The present invention relates to a light emitting device and a method of driving the same, and more particularly to a light emitting device and a method of driving the same that does not occur side effects.

The light emitting device is a device for generating light having a predetermined wavelength when a predetermined voltage or current is provided, in particular the organic electroluminescent device is a self-light emitting device.

Such a light emitting device generally includes a panel including a plurality of pixels, an integrated circuit chip for driving the pixels, and a driving voltage providing unit for generating a driving voltage which is a reference voltage of the panel.

The integrated circuit chip outputs various signals for operating the panel according to an input of an integrated circuit chip driving voltage, and synchronizes the signals with a clock signal composed of clocks of a predetermined period. Among these synchronized signals, a driving voltage signal is provided to the driving voltage providing unit.

The driving voltage providing unit generates a panel driving voltage according to a driving voltage signal provided from the integrated circuit chip, and provides the generated panel driving voltage to the panel. The driving voltage signal is a signal synchronized with the clock signal and is generated after the integrated circuit chip driving voltage is input to the integrated circuit chip.

In the light emitting device having such a structure, the driving voltage signal should be generated after the integrated circuit chip driving voltage is input to the integrated circuit chip, but the integrated circuit chip may be generated by the clock signal even before the integrated circuit chip driving voltage is input. In some cases, the driving voltage was incorrectly recognized as being input and was instantaneously generated. As a result, the panel drive voltage was instantaneously provided to the panel, so that the pixels at the top of the panel emitted light, causing streaks at the top of the panel. This effect is called a side effect.

An object of the present invention is to provide a light emitting device that does not generate a side effect and a method of driving the same.

In order to achieve the above object, a light emitting device according to an embodiment of the present invention includes a panel, an integrated circuit chip and a driving voltage providing unit. The panel includes a plurality of pixels formed in regions where data lines and scan lines intersect. The integrated circuit chip generates a clock signal CLK according to an oscillator command OSC cmd, generates a driving voltage signal according to a DC / DC command, and the clock signal CLK to the panel. The pixels are driven by providing a driving signal synchronized with the. The driving voltage providing unit generates a panel driving voltage according to the driving voltage signal, and provides the generated panel driving voltage to the panel through the integrated circuit chip. Here, the driving voltage signal is asynchronous to the clock signal CLK.

An integrated circuit chip connected to a panel including a plurality of pixels and a driving voltage providing unit according to an exemplary embodiment of the present invention includes input electrodes, a controller, and an oscillator. The input electrodes are input passages of an oscillator command OSC cmd and a DC / DC command. The controller generates an oscillator signal according to an oscillator command (OSC cmd) input through the input electrodes, and drives the driving voltage providing unit according to a DC / DC command (DC / DC cmd) input through the input electrodes. Provide a voltage signal. The oscillator generates a clock signal CLK according to the generated oscillator signal. Here, the driving voltage signal is out of synchronization with the clock signal CLK.

According to a preferred embodiment of the present invention, a method of driving a light emitting device including a panel having a plurality of pixels may include generating a driving voltage signal according to a DC / DC command; Providing a panel driving voltage to the panel according to the generated driving voltage signal; Generating a clock signal CLK according to an oscillator command OSC cmd; And driving the pixels by providing a driving signal synchronized with the clock signal CLK to the panel. Here, the driving voltage signal is asynchronous with the clock signal CLK.

In the light emitting device and the method for driving the same according to the present invention, since the driving voltage signal for generating the panel driving voltage is not synchronized with the clock signal but also operates separately, no side effect is generated in the panel. As a result, waste of commands is also prevented.

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

1 is a view showing a light emitting device according to an embodiment of the present invention. FIG. 2A illustrates the panel of FIG. 1 in accordance with one preferred embodiment of the present invention, and FIG. 2B is a cross-sectional view illustrating the pixel of FIG. 2A.

Referring to FIG. 1, the light emitting device of the present invention includes a panel 100, an integrated circuit chip 102, data lines 112, first scan lines 114, second scan lines 116, and driving. The voltage provider 124 is included.

The light emitting device according to the preferred embodiment of the present invention is a device for displaying a predetermined image, and includes an organic electroluminescent device (PDP), a plasma dispaly panel (PDP), a liquid crystal display (LCD), and the like.

The panel 100 includes a plurality of pixels 204 formed in regions where the first electrode layers 200 and the second electrode layers 202 intersect as shown in FIG. 2A.

When the light emitting device is an organic electroluminescent device, at least one pixel includes a first electrode layer 200, an organic material layer 210, and a second electrode layer 202 sequentially stacked as illustrated in FIG. 2B.

When predetermined voltages are applied to the electrode layers 200 and 202, holes and electrons generated from the electrode layers 200 and 202 combine in the light emitting layer included in the organic layer 210 to form excitons. As the excitons are decomposed, light having a predetermined wavelength is emitted from the light emitting layer.

According to an embodiment of the present invention, the first electrode layer 200 is made of indium tin oxide as a positive electrode, and the second electrode layer 202 is made of metal, for example, aluminum (eg, a negative electrode). Al).

The data lines 112 are connected to the first electrode layers 200.

The first scan lines 114 are connected to some of the second electrode layers 202, and the second scan lines 116 are connected to the remaining second electrode layers.

The ends of these lines 112, 114, and 116 are coupled to output electrodes arranged in the output electrode portion 108 of the integrated circuit chip 102 as shown in FIG. 1.

The integrated circuit chip 102 includes a driver 104, an input electrode unit 106 in which various input commands 110 are input, and an output electrode unit 108 in which the output electrodes are arranged. It includes.

The driver 104 includes a controller 118, an oscillator 120 and an OSC, and a driver 122.

The controller 118 outputs the oscillator signal to the oscillator 120 according to the oscillator command OSC cmd input through the input electrodes 110, and the DC / DC command DC input through the input electrodes 110. A driving voltage signal is output to the driving voltage provider 124 according to / DC cmd. In addition, the controller 118 outputs a driving data signal to the driver 122 according to the data input through the input electrodes 110.

The oscillator 120 generates a clock signal CLK including clocks of a predetermined period according to the oscillator signal output from the controller 118.

The driver 122 provides the driving signal, for example, data signals and scan signals, to the panel 100 through the lines 112, 114, and 116 according to the driving data signal output from the controller 118. The driving data signal is synchronized with the clock signal CLK generated from the oscillator 120. In detail, the driver 122 provides data signals to the first electrode layers 200 through the data lines 112 and scan signals to the second electrode layers 202 through the scan lines 114 and 116. To provide. As a result, the pixels 204 emit light.

The driving voltage providing unit 124 generates a panel driving voltage according to the driving voltage signal output from the controller 118. The panel driving voltage generated as the voltage corresponding to the maximum luminance of the pixels is the input electrodes 110. ) Is provided to the panel 100 via the driver 104. Here, the driving voltage signal is not synchronized with the clock signal CLK. Detailed description thereof will be described below with reference to the accompanying drawings.

The integrated circuit chip driving voltage Vdd is a reference voltage for driving the integrated circuit chip 102 and is input through the input electrodes 110. However, since the integrated circuit chip driving voltage Vdd drives the integrated circuit chip 102, a small voltage, for example, 2.8V, may be required, whereas the panel driving voltage should be sufficient to drive the panel 100. Therefore, it has a large voltage, for example 18V.

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

Referring to FIG. 3, the controller 118 includes a register 300, a first latch 302, a second latch 304, a third latch 306, a fourth latch 308, and a first latch 308. 5 latch 310 and flipflop 312.

Hereinafter, a process of driving the light emitting device will be described in detail.

The first latch 302 outputs a first latch signal according to a DC / DC command (DC / DC cmd) input through the input electrodes 110. Here, the first latch signal is a signal output from the first latch 302, and the first latch signal is operated separately from the clock signal CLK, that is, is not synchronized to the clock signal CLK.

Subsequently, the register 300 outputs the first register signal to the second latch 304 in accordance with the first latch signal output from the first latch 302.

According to an embodiment of the present invention, the register 300 may include a multiplexer, a shift register, and the like.

Subsequently, the second latch 304 outputs a driving voltage signal to the driving voltage providing unit 124 according to the first register signal output from the register 300. In this case, the driving voltage providing unit 124 generates the panel driving voltage according to the driving voltage signal.

Next, the third latch 306 outputs the second latch signal to the register 300 according to the oscillator command OSC cmd input through the input electrodes 110.

Thereafter, the register 300 outputs the second register signal to the fourth latch 308 according to the second latch signal output from the third latch 306.

Subsequently, the fourth latch 308 outputs the oscillator signal to the oscillator 120 according to the second latch signal output from the register 300. In this case, the oscillator 120 generates a clock signal CLK according to the oscillator signal.

Subsequently, the fifth latch 310 outputs the third latch signal to the register 300 according to the data input through the input electrodes 110.

Thereafter, the register 300 outputs the third register signal to the flipflop 312 according to the third latch signal output from the fifth latch 310.

Subsequently, the flip-flop 312 outputs a driving data signal to the driver 122 according to the third register signal output from the register 300. Here, the driving data signal is synchronized with the clock signal CLK. In this case, the driver 122 outputs the data signals and the scan signals according to the drive data signal.

The R / S pin is a pin that determines whether a series of values input through the input electrodes 110 are a command or data.

In the operation of the controller 118 as described above, the process of generating the panel driving voltage is performed separately from the process of generating the clock signal CLK. That is, the panel driving voltage is generated regardless of the clock signal CLK, and preferably, the panel driving voltage is generated before the clock signal CLK is generated. That is, in the light emitting device of the present invention, unlike the conventional light emitting device, since the panel driving voltage is not affected by the clock signal CLK, before the integrated circuit chip driving voltage Vdd is input to the integrated circuit chip 102. The panel driving voltage is not provided to the panel 100. Therefore, side effects do not occur in the light emitting device of the present invention. In addition, since no error occurs due to such side effects, there is no waste of commands.

4 is a diagram illustrating a driving voltage providing unit of FIG. 1 according to an exemplary embodiment of the present invention.

Referring to FIG. 4, the driving voltage providing unit 124 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, an operation process of the driving voltage provider 124 will be described in detail.

The switch SW is turned off, so that the battery voltage output from the battery 400 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.

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, it is assumed that the driving voltage providing unit 124 is preset to boost the battery voltage (for example, 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 driving voltage providing unit 124 boosts the battery voltage to a desired voltage through the above process, and outputs the boosted battery voltage, that is, the panel driving voltage V _CC .

5 is a view showing a panel according to another preferred embodiment of the present invention.

As shown in FIG. 5, the scan lines 500 are arranged in one direction of the panel 100, unlike the scan lines 114 and 116 of FIG. 2A.

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 light emitting device and the method of driving the same according to the present invention, since the driving voltage signal for generating the panel driving voltage is synchronized with the clock signal and operates separately, the side effect does not occur in the panel. There is this. As a result, waste of commands is also prevented.

Claims (11)

A panel including a plurality of pixels formed in regions where the data lines and the scan lines cross each other; A clock signal CLK is generated according to an oscillator command OSC cmd, a driving voltage signal is generated according to a DC / DC command DC / DC cmd, and a driving signal synchronized with the clock signal CLK to the panel. An integrated circuit chip for driving the pixels; And A driving voltage providing unit generating a panel driving voltage according to the generated driving voltage signal and providing the generated panel driving voltage to the panel through the integrated circuit chip; And the driving voltage signal is asynchronous to the clock signal (CLK). The method of claim 1, wherein the integrated circuit chip, Output electrodes connected to the panel; Input electrodes that are input passages of the DC / DC command and the oscillator command OSC cmd; And And a driver for receiving the commands through the input electrodes and generating an oscillator signal corresponding to the oscillator command and the driving voltage signal. The method of claim 2, wherein the driver, A control unit generating the oscillator signal and providing the driving voltage signal to the driving voltage providing unit; An oscillator for generating the clock signal CLK according to an oscillator signal generated from the controller; And And a driving unit for providing the driving signal to the panel. The method of claim 3, wherein the control unit, A first latch configured to output a first latch signal corresponding to the DC / DC command input through the input electrodes; A register for outputting a first register signal in accordance with the first latch signal output from the first latch; And And a second latch configured to provide the driving voltage signal to the driving voltage providing unit according to the first register signal output from the register. The method of claim 4, wherein the control unit, A third latch providing a second latch signal to the register corresponding to the oscillator command input through the input electrodes; And And a fourth latch configured to provide the oscillator signal to the oscillator in accordance with a second register signal output from the register in accordance with the third latch signal. The method of claim 4, wherein the control unit, A fifth latch providing a third latch signal to the register corresponding to data input through the input electrodes; And A flip-flop for receiving a third register signal output from the register according to the third latch signal and outputting a driving data signal according to the received third register signal, And the driver generates the drive signal according to a drive data signal output from the flip-flop. The light emitting device of claim 1, wherein the driving voltage providing unit is a DC-DC circuit. The light emitting device of claim 1, wherein the at least one pixel includes a light emitting layer made of an organic material. An integrated circuit chip connected to a panel and a driving voltage providing unit including a plurality of pixels, Input electrodes which are input passages of an oscillator command OSC cmd and a DC / DC command; An oscillator signal is generated according to an oscillator command OSC cmd input through the input electrodes, and a driving voltage signal is provided to the driving voltage providing unit according to a DC / DC command input through the input electrodes. Providing a control unit; And Including an oscillator for generating a clock signal (CLK) in accordance with the generated oscillator signal, And the driving voltage signal is asynchronous to the clock signal (CLK). The method of claim 9, wherein the integrated circuit chip, And a driver configured to provide a driving signal to the panel to drive the pixels according to the data input through the input electrodes. In the method of driving a light emitting device comprising a panel having a plurality of pixels, Generating a driving voltage signal according to a DC / DC command (DC / DC cmd); Providing a panel driving voltage to the panel according to the generated driving voltage signal; Generating a clock signal CLK according to an oscillator command OSC cmd; And Driving the pixels by providing a driving signal synchronized with the clock signal CLK to the panel, And the driving voltage signal is asynchronous to the clock signal (CLK).

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