KR20060126196A - Electron emission display and driving method thereof - Google Patents

Abstract

An electron emission display and a driving method thereof are provided to simply regulate the white level by uniformly increasing the voltage level of a scan signal and controlling the time for applying a data signal. An electron emission display includes a pixel unit(100) displaying an image by receiving a data signal and a scan signal; a data driving unit(200) generating and transmitting the data signal to the pixel unit; a scan driving unit(300) generating and transmitting the scan signal with the voltage level changed in an emission period, to the pixel unit; a timing control unit(400) transmitting a driving signal for driving the data driving unit and the scan driving unit; and a regulating unit(500) adjusting the white level by regulating the luminance of red, green, and blue pixels(101). The regulating unit controls the white level by adjusting the luminance of the red, green, and blue pixels by controlling the timing that the data signal is transmitted in an emission period.

Description

Electronic emission display and driving method thereof

1 is a structural diagram showing an electron emission display device according to the prior art.

2 is a structural diagram showing a structure of an electron emission display device according to the present invention.

3 is a perspective view illustrating a pixel unit employed in the electron emission display device illustrated in FIG. 2.

4 is a cross-sectional view illustrating a cross section of a pixel unit employed in the electron emission display device illustrated in FIG. 2.

5 is a waveform diagram showing waveforms of a scan signal and a data signal.

6 is a structural diagram illustrating a data driver employed in the electron emission display shown in FIG. 2.

*** Explanation of symbols on main parts of drawings ***

100: pixel portion 101: pixel

200: data driver 300: scan driver

400: timing controller 500: controller

600: power supply

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron emission display device and a driving method thereof. More specifically, the electron emission display device and its driving method for adjusting white balance by varying the voltage difference between the gate and the cathode for each line of the electron emission display device are described. It is about a method.

BACKGROUND ART A thin, lightweight flat panel display is used as a display device of a portable information terminal such as a personal computer, a cellular phone, a PDA, or a monitor of various information devices. Such flat panel displays include LCDs using liquid crystal panels, organic light emitting displays using organic light emitting diodes, and PDPs using plasma panels.

The flat panel display can be classified into a memory driving method and a non-memory driving method in terms of structurally divided into an active matrix and a passive matrix, and a light emission principle. In general, the active matrix method has meaning with the memory driving method, and the passive matrix method has meaning with the non-memory driving method. The active matrix method and the memory driving method emit light at a period of a frame unit. The passive matrix method and the non-memory driving method emit a light at a period of a line unit.

As for the medium- and large-sized flat panel displays that are currently commercialized, TFT-LCD (Thin Film Transistor Liquid Crystal Display) is an active matrix method, and OLED, which is being developed as a new display device, is also an active method. On the other hand, as a new display device, an electron emission display device is a passive matrix method, and unlike other flat panel devices, a non-memory driving method selects horizontal lines sequentially and emits light only when a selected line is selected among the horizontal lines. Apply the scan method. That is, the driving method has a constant duty ratio.

1 is a structural diagram showing an electron emission display device according to the prior art. Referring to FIG. 1, the electron emission display device includes a pixel unit 10, a data driver 20, a scan driver 30, a controller 40, and a power supply unit 50.

In the pixel portion 10, the pixel 11 is formed at a portion where the cathode electrodes C1, C2... Cn and the gate electrodes G1, G2 .. Gn intersect, and electrons emitted from the cathode are transferred to the anode. Gradation is displayed by colliding and phosphor emitting light. The gray level of the displayed image is changed according to the value of the input digital image signal. In order to adjust the gray level represented according to the value of the digital video signal, a pulse width modulation method or a pulse amplitude modulation method may be generally used.

The data driver 20 is connected to the cathode electrodes C1, C2 ... Cn to generate a data signal and transmit the data signal to the pixel unit so that the pixel unit emits light corresponding to the data signal.

The scan driver 30 is connected to the gate electrodes G1, G2... Gn, generates a scan signal, and transmits the scan signal to the pixel unit 10 so that the pixel unit 10 is line-scanned in a horizontal line unit. By emitting light sequentially, the entire screen can be displayed while being driven while reducing circuit cost and power consumption.

The timing controller 40 transfers the data driver control signal and the scan driver control signal to the data driver 20 and the scan driver 30 to control the operations of the data driver 20 and the scan driver 30.

The power supply unit 50 supplies power to the pixel unit 10, the data driver 20, the scan driver 30, and the timing controller 40 so as to perform additional operations.

In order to match the white balance, the electron emission display device configured as described above adjusts the white balance by adjusting voltage levels between gates and cathodes of each of red, green, and blue pixels.

Accordingly, the present invention has been made to solve the problems of the prior art, and an object of the present invention relates to an electron emission display device and a driving method thereof to adjust a white level by adjusting an input time of a data signal.

In order to achieve the above object, a first aspect of the present invention provides a pixel unit for receiving a data signal and a scan signal to display an image, a data driver for generating the data signal, and transmitting the data signal to the pixel unit. A scan driver which generates a variable scan signal and transmits it to the pixel unit, a timing controller which transmits a drive signal to drive the data driver and the scan driver, and adjusts the luminance of the red, green, and blue pixels to adjust the white balance. It includes a control unit for adjusting, wherein the control unit is provided to the electronic emission display device for adjusting the white balance by adjusting the brightness of the red, green and blue pixels by adjusting the time point at which the data signal is transmitted in the light emitting period. .

According to a second aspect of the present invention, an electron emission method includes adjusting a white balance by adjusting a voltage level of a light emission section of a scan signal and adjusting an application point of a data signal transmitted to the light emission section of the scan signal. It is to provide a method of driving a display device.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

2 is a structural diagram showing a structure of an electron emission display device according to the present invention. Referring to FIG. 2, the electron emission display device includes a pixel unit 100, a data driver 200, a scan driver 300, a timing controller 400, an adjuster 500, and a power supply 600. do.

In the pixel unit 100, a plurality of cathode electrodes C1, C2... Cn are arranged in a column direction, and a plurality of gate electrodes G1, G2... Gn are arranged in a row direction, and a cathode electrode C1. Electron emission sources are provided at portions where C2..Cn and the gate electrodes G1, G2..Gn intersect to form the pixel 110. In addition, the gate electrodes G1, G2 .... Gn may be arranged in the column direction, and the cathode electrodes C1, C2 .... Cn may be arranged in the row direction. In the following description, it is assumed that the cathode electrodes C1, C2 .... Cn are arranged in the column direction and the gate electrodes G1, G2 .... Gn are arranged in the row direction.

The data driver 200 is connected to the cathode electrodes C1, C2... Cn and transmits a data signal to the cathode electrodes C1, C2... Cn. The data driver 200 may turn on / off the pixel 110 formed at a portion where selected cathode electrodes C1, C2 .... Cn and gate electrodes G1, G2 .... Gn intersect. To generate an electrode signal. In addition, the data driver 200 includes a red data driver for transmitting a red data signal, a green data driver for transmitting a green data signal, and a blue data driver for transmitting a blue data signal.

The scan driver 300 is connected to the gate electrodes G1, G2 ... Gn, and selects one gate electrode G1, G2 ... Gn from among the plurality of gate electrodes arranged in the row direction. The data signal is transmitted to the pixel 110 connected to the electrodes G1, G2... Gn. The scan signal output from the scan driver 300 causes the voltage level to rise in the emission period.

The timing controller 400 receives an image signal, generates a control signal for driving the data driver 200 and the scan driver 300, and transmits the control signal to the data driver 200 and the scan driver 300. In more detail, the timing controller 400 generates a control signal for sequentially selecting the control signal for driving the data driver 200 and the horizontal line for driving the scan driver 300.

The adjusting unit 500 is a means for adjusting the output timing of the data signal output from the red, green, and blue data driver to adjust the white balance. The control unit 500 adjusts the output timing of the output signal of the data signal output from the data driver 200. The difference between the gate voltage and the cathode voltage is adjusted by adjusting the difference so that the data signal is transmitted to the gate electrode or the cathode electrode at a predetermined time point of the scan signal having the rising voltage level.

The power supply unit 600 is a part for supplying power required in each part, and transmits an anode voltage to the pixel unit 100, and supplies driving power to the data driver 200, the scan driver 300, and the timing controller 400. To pass.

3 is a perspective view illustrating a pixel unit employed in the electron emission display device illustrated in FIG. 2, and FIG. 4 is a cross-sectional view illustrating a cross section of the pixel unit. Referring to FIG. 4, the electron emission display device includes a lower substrate 110, an upper substrate 190, and a spacer 180, and includes a cathode electrode 120 and an insulating layer 130 on the lower substrate 110. ), The electron emission unit 140 and the gate electrode 150 are formed, and the upper substrate 190 has a front substrate, an anode electrode, and a fluorescent film.

At least one cathode electrode 120 is formed on the lower substrate 110 in a stripe shape, and a plurality of first grooves 131 are formed on the cathode electrode 120 to expose a portion of the cathode electrode 120. The insulating layer 130 is formed. The gate electrode 150 is formed on the insulating layer 130. A plurality of second grooves 151 having a predetermined size are formed in the gate electrode 150, and the second grooves 151 are formed on the first groove 131. The electron emission unit 140 is positioned in an area where the first groove 131 and the second groove 151 coincide with each other on the cathode electrode 120.

The lower substrate 110 uses a glass or silicon substrate, and the electron emitting unit 140 is preferably a transparent substrate such as a glass substrate when forming the same by back exposure using a paste.

The cathode electrode 120 supplies each data signal or scan signal applied from the data driver (not shown) or the scan driver (not shown) to the electron emission unit 140. Indium tin oxide (ITO) is used for the cathode electrode 120.

The insulating layer 130 is formed on the lower substrate 110 and the cathode electrode 120 to electrically insulate the cathode electrode 120 and the gate electrode 150.

The gate electrode 150 is disposed on the insulating layer 130 in a predetermined shape, for example, in a direction crossing the cathode electrode 120 on a stripe, and is applied from the data driver 200 or the scan driver 300. Is supplied to each pixel. The gate electrode 150 is made of at least one conductive metal material selected from a metal having good conductivity, such as gold (Au), silver (Ag), platinum (Pt), aluminum (Al), chromium (Cr), and alloys thereof. .

The electron emission units 140 are electrically connected to the cathode electrodes 120 exposed by the first openings 131 of the insulating layer 130, respectively, and are disposed of materials that emit electrons when an electric field is applied. Carbon based materials or nanometer (nm) size materials, carbon nanotubes, graphite, graphite nanofibers, diamond-like carbon, C ₆₀ , silicon nanowires and combinations thereof are preferred.

The upper substrate 190 includes a fluorescent film to emit light when electrons collide with the fluorescent film, and an anode electrode so that the electrons emitted from the electron emitting part may collide with the upper substrate.

The spacer 180 maintains a constant distance between the lower substrate 110 and the upper substrate 190.

5 is a waveform diagram showing waveforms of a scan signal and a data signal. Referring to FIG. 5, the scan signal S in which the waveform of the light emitting section is increased and the first and second data signals D1 and D2 having different starting points of pulses in the light emitting section are shown.

The pulse of the first data signal D1 starts at a point where the voltage level of the light emission section of the scan signal S is low, and the pulse of the second data signal D2 increases when the voltage level of the light emission section of the scan signal S increases. Begins at the point.

Accordingly, the voltage difference between the cathode electrode and the gate electrode when the first data signal D1 is applied and the voltage difference between the cathode electrode and the gate electrode when the second data signal D2 is applied are formed differently. The electron emission display device in which the amount of electrons emitted from the electron emission unit is determined by the difference between the voltages of the electrode and the gate electrode is the number of electrons emitted from the electron emission unit and the second when the first data signal D1 is transmitted. When the data signal D2 is transmitted, the number of electrons emitted from the electron emission unit is different, so that the brightness is different.

That is, the luminance can be adjusted by adjusting the time point at which the data signal is applied, so that the white balance can be adjusted by adjusting the luminance of red, green, and blue.

6 is a structural diagram illustrating a data driver employed in the electron emission display shown in FIG. 2. Referring to FIG. 6, the data driver 200 includes a shift register 210, a sampling latch 220, a holding latch 230, and a D / A converter 240.

The shift register 210 receives the start pulse CSI and the clock CLK and outputs a shift signal obtained by shifting the start pulse CSI by the clock CLK, and the shift signals are generated at predetermined time intervals. After the shift signal is continuously shifted, the last shift signal CIO signal is output to the output terminal.

The sampling latch 220 receives a video data signal input in series corresponding to the shift signal to output in parallel.

The holding latch 230 includes a latch unit 231 and a counter 232, and the counter 232 receives a load counter signal to determine a time point at which the load counter signal is input, and provides a control signal to the latch unit 231. The latch unit 231 outputs the input video data signal corresponding to the control signal of the counter 232. Therefore, the output time of the video data signal is adjusted by the input time of the load counter signal. In this case, the white balance can be adjusted by differentiating the output timing of the red data driver generating the red data signal, the green data driving unit generating the green data signal, and the blue data driving unit generating the blue data signal. .

In addition, the counter 232 includes a blank signal input terminal, and when the blank signal Blank is input, the counter 232 resets the holding latch 230 to prevent the signal from being output from the holding latch 230, thereby providing data to the data line. This prevents the signal from being output.

The D / A converter 240 converts the video data signal output from the holding latch 230 into an analog data signal and outputs the converted data signal to the pixel unit 100.

While preferred embodiments of the present invention have been described using specific terms, such descriptions are for illustrative purposes only and it is understood that various changes and modifications may be made without departing from the spirit and scope of the following claims. You must lose.

According to the electron emission display device and the driving method thereof according to the present invention, the white balance can be easily adjusted by adjusting the time point at which the data signal is applied and adjusting the white balance by constantly increasing the voltage level of the scan signal. .

Claims (8)

A pixel unit which receives a data signal and a scan signal and displays an image; A data driver which generates the data signal and transmits the data signal to the pixel unit; A scan driver for generating a scan signal of which the voltage level of the light emission period is changed and transferring the scan signal to the pixel unit; A timing controller transferring a driving signal for driving the data driver and the scan driver; And It includes a control unit for adjusting the white balance by adjusting the luminance of the red, green and blue pixels, And the adjusting unit adjusts a time point at which the data signal is transmitted in the light emitting section to adjust white balance by adjusting luminance of the red, green, and blue pixels. The method of claim 1, The data driver includes a red data driver for transmitting a data signal to a red pixel, a green data driver for transmitting a data signal to a green pixel, and a blue data driver for transmitting a data signal to a blue pixel. And the control unit adjusts an output time point of a data signal output from the red data driver, the green data driver, and the blue data driver. The method of claim 1, The data driver A sampling latch for outputting digital data signals input in series; A holding latch for receiving a signal from the controller and changing an output time point of the digital data signal; And And a D / A converter for converting the digital data signal into an analog data signal. The method of claim 1, And the holding latch receives the digital data signal and the counter signal and outputs the digital data signal when the counter signal is input. The method of claim 1, And a voltage level of the scan signal increases. Causing the voltage level of the light emission section of the scan signal to change; And And adjusting white balance by adjusting an application time point of the data signal transmitted to the light emitting section of the scan signal. The method of claim 6, The voltage level of the light emitting section is increased driving method of an electron emission display device. The method of claim 6, And the white balance is adjusted by separately adjusting the red data signal, the green data signal, and the blue data signal at the time point of applying the data signal.

Images