KR20030008692A - Apparatus and Method for Driving of Metal Insulator Metal Field Emission Display - Google Patents

Abstract

PURPOSE: A device for driving a flat field emission display and a method for the same are provided to uniformly maintain the overall illumination of screen by compensating a voltage drop caused by a difference of resistance in response to the position of a scan line by converting the value of data differently supplied or inputted the driving voltage and the pulse width of the driving voltage in response to the position of the data line. CONSTITUTION: A device for driving a flat field emission display includes a scan driving block(14) for driving a plurality of scan lines(S1-Sm), an upper and a lower data driving blocks(10,12) for driving a plurality of data lines(D1-Dn) and a first to a third connectors(16,18,20) formed on the lower substrate(28), wherein the upper data driving block(10) includes n number of driving integrated circuits(ICs)(4) and the lower data driving block(12) includes n number of driving ICs. The scan driving block(14) sequentially supplies a scan pulse each of the scan lines(S1-Sm).

Description

Apparatus and Method for Driving of Metal Insulator Metal Field Emission Display}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to planar field emission display devices, and more particularly, to an apparatus and method for driving a planar field emission display device to improve the uniformity of pixel cells.

Recently, various flat panel displays have been developed to reduce weight and volume, which are disadvantages of cathode ray tubes (CRTs). Such flat panel displays include liquid crystal displays (hereinafter referred to as "LCDs"), field emission displays (hereinafter referred to as "FEDs"), plasma display panels, and electroluminescence. Sense (Electro-Luminescence: "EL"). In order to improve the display quality, research and development for increasing the brightness, contrast and color purity of flat panel displays have been actively conducted.

The dual FED is a tip type FED that concentrates a high field on a sharp cathode (emitter) and emits electrons by a quantum mechanical tunnel effect, and a quantum mechanical tunnel by focusing a high field on a metal having a predetermined area. It is divided into planar (Metal Insulator Metal: MIM) FED which emits electrons by Tunnel effect.

1 is a view illustrating a pixel cell of a MIN type field emission display device of a conventional FED.

Referring to FIG. 1, a pixel cell 100 of a conventional MIN type field emission display device is formed on an upper substrate 42 on which an anode electrode 44 and a phosphor 46 are stacked, and a lower substrate 48. And a field emission array 56.

The field emission array 56 includes a scan electrode 50, an insulating layer 52, and a data electrode 54 formed on the lower substrate 48. The insulating layer 52 is formed of a thin film so that electrons from the scan electrode 50 can tunnel.

In order to display an image, a negative scan pulse is applied to the scan electrode 50 and a positive data pulse is applied to the data electrode 54. Then, a positive anode voltage is applied to the anode electrode 44. Then, electrons are tunneled from the scan electrode 50 to the data electrode 54 and accelerated toward the anode electrode 44.

These electrons collide with the red, green and blue phosphors 46 to excite the phosphors 46. At this time, visible light of any one of red, green, and blue colors is generated according to the phosphor 46.

The MIN type FED is capable of driving a lower voltage than the tip type FED because the scan electrode 50 and the data electrode 54 are installed to face each other with a predetermined area. That is, a voltage of several to 10V is applied to the scan electrode 50 and the data electrode 54 of the MIN type FED. In addition, in the MIN type FED, since the scan electrode 50 and the data electrode 54 emitting electrons have a predetermined area, the scan electrode 50 and the data electrode 54 can be manufactured in a simpler manufacturing process than the tip type FED. have.

On the other hand, in the MIN type FED, since the insulating layer 52 is formed as a thin film, the capacitance component becomes very large. In other words, the capacitance component becomes very large because the thickness of the dielectric constant is thin in the formula C = ε × s / d (where ε is the dielectric constant, d is the dielectric constant thickness, and s is the cell area). Therefore, a high current is applied to the pixel cell 100 of the MIN type FED.

2 is a view showing a driving unit of a conventional MIN type field emission display device.

Referring to FIG. 2, the conventional MIN type FED includes a scan driver 84 for driving the scan lines S1 to Sm, and upper and lower data drivers 80 and 82 for driving the data lines D1 to Dn. ) And first to third connectors 86, 88, and 90 formed on the lower substrate 48.

The scan driver 84 sequentially supplies scan pulses to the scan lines S1 to Sm.

The upper and lower data drivers 80 and 82 supply data pulses to the data lines D1 to Dn depending on whether data is supplied or not. At this time, the odd data lines Dn + 1 (n is a positive integer greater than or equal to 0) receive data pulses from the upper data driver 80, and the even data lines Dn + 2 from the lower data driver 82. The data pulse is supplied.

The first connector 86 is electrically connected to the odd data line Dn + 1. The first connector 84 is electrically connected to the upper data driver 80. That is, the first connector 86 supplies the data pulses applied from the upper data driver 80 to the odd data line Dn + 1. The second connector 88 is electrically connected to the even data line Dn + 2. The second connector 88 is electrically connected to the lower data driver 82. That is, the second connector 88 supplies the data pulses applied from the lower data driver 82 to the even data line Dn + 2.

The third connector 90 is electrically connected to the scan lines S1 to Sm. This third connector 90 is electrically connected to the scan driver 84. That is, the third connector 90 supplies a driving signal applied from the scan driver 84 to the scan lines S1 to Sm.

3 is a waveform diagram showing a driving waveform applied to a conventional MIN type FED.

3 and 4, negative scan pulses SP are sequentially supplied to the scan lines S1 to Sm of the conventional MIN type FED, and negative scan pulses are supplied to the data lines D1 to Dn. The positive data pulse DP synchronized with SP is supplied. In the pixel cells supplied with the scan pulse SP and the data pulse DP, electrons are emitted by the voltage difference between the scan pulse SP and the data pulse DP.

For example, when -5V scan pulse SP is applied to the first scan line S1 and 5V data pulse DP is applied to the data line D, the scan pulse SP is formed on the first scan line S1. A voltage difference of 10V is generated in the first pixel cells P1. Therefore, electrons are emitted from the first pixel cells P1 supplied with the data pulse DP.

Meanwhile, electrons are not emitted because only 5V, that is, the data pulse DP is applied to the second to mth pixel cells P2 to Pm formed in the second to mth scan lines S2 to Sm.

Thereafter, the process is repeated to sequentially apply the scan pulse SP and the data pulse DP to the m th scan line Sm to drive the first to m th pixel cells P1 to Pm to display an image. do. After the image is displayed, a positive reset pulse RP is applied to the first to m th scan lines S1 to Sm. When the reset pulse RP is applied to the first to mth scan lines S1 to Sm, the charges charged in the first to mth pixel cells P1 to Pm are removed.

However, the voltage values of the scan pulse SP applied to the first position 70, the second position 72, and the third position 74 in the conventional MIN type FED are different. In other words, the scan lines S1 to Sm of the conventional MIN type FED have a high resistance value, and a voltage drop is generated by the high resistance value, and thus have different voltage values for each position of the scan lines S1 to Sm. Scan pulse SP is applied. At this time, the data pulses DP applied to the data lines D1 to Dn from the upper and lower data drivers 80 and 82 are the same regardless of the positions 70, 72 and 74 of the scan lines S1 to Sm. Voltage / pulse width. For example, in the case of the conventional 5.3-inch MIN type FED, each of the scan lines S1 to Sm has a resistance value of about 100 to 150 mV.

As such, the upper and lower data drivers 80 and 82 of the conventional MIN type FED include a plurality of data driver drivers for supplying data pulses to the data lines D1 to Dn blocked in predetermined units. Since the driving voltage supplied to the data driver has the same voltage / pulse width, the data applied due to the different resistance values for the positions 70, 72, and 74 of the scan line S has different brightness depending on the position of the screen. The image is represented. In other words, the conventional MIN-type FED did not represent a uniform image due to the voltage drop.

In particular, such a voltage drop phenomenon occurs more and more MIN-type FED in a large area. Therefore, it is currently difficult to manufacture MIN type FED in large area.

Accordingly, an object of the present invention is to provide a driving device and method for a flat field emission display device capable of improving the uniformity of pixel cells.

1 is a cross-sectional view showing a conventional flat field emission display device.

FIG. 2 is a view illustrating a driving unit of the planar field emission display device illustrated in FIG. 1.

3 is a waveform diagram showing a driving waveform applied to the planar field emission display device shown in FIG. 1;

4 is a diagram illustrating an arrangement of pixel cells of the field emission display device illustrated in FIG. 1.

5 is a view showing a driving unit of the planar field emission display device of the present invention.

FIG. 6 is a waveform diagram showing driving voltage levels supplied to upper and lower data drivers shown in FIG. 5 as a first embodiment of the present invention; FIG.

FIG. 7 is a waveform diagram illustrating pulse widths of driving voltages supplied to upper and lower data driving units shown in FIG. 5 according to a second exemplary embodiment of the present invention; FIG.

FIG. 8 is a block diagram showing data conversion supplied to the upper and lower data driving units shown in FIG. 5 as a third embodiment of the present invention. FIG.

FIG. 9 is a block diagram of a data converter for converting data shown in FIG. 8; FIG.

10 to 11b are driving waveform diagrams supplied to the scan and data electrodes shown in FIG.

<Explanation of symbols for main parts of drawing>

4: data driver 10, 80: upper data driver

12, 82: lower data driver 14, 84: scan driver

16,18,20,86,88,90: Connector 42: Upper board

30: scan driver timing controller 32: data processing unit

34: line or frame memory 36: analog-to-digital converter

44 anode electrode 46 phosphor

50 scanning electrode 52 insulating layer

56 field emission array 54 data electrode

In order to achieve the above object, the method of driving the planar field emission display device according to the present invention comprises the steps of sequentially supplying a scan pulse to a plurality of scan lines, and a data line intersecting the scan line selected by the scan pulse And differently supplying any one of a driving voltage and a pulse width of the driving voltage supplied to each of the plurality of divided data driving drivers for supplying data to the plurality of data driving drivers.

The driving device of the flat field emission display device according to the present invention includes an analog-to-digital converter for converting an analog image signal supplied from the outside into a digital image signal, and converts the value of the digital image signal into a data value corresponding to the position of the data line. And a data processor for converting the data, the storage unit for storing the converted data for each line or frame, and a data driving driver for receiving data for each line or frame from the storage unit and supplying the data to a plurality of data lines.

Other objects and features of the present invention in addition to the above objects will become apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 5 through 11B.

Referring to FIG. 5, the planar field emission display device of the present invention includes a scan driver 14 for driving the scan lines S1 to Sm, and upper and lower data drivers for driving the data lines D1 to Dn. 10 and 12, and first to third connectors 16, 18, and 20 formed on the lower substrate 28.

The scan driver 14 sequentially supplies scan pulses to the scan lines S1 to Sm.

The upper and lower data drivers 10 and 12 supply data pulses to the data lines D1 to Dn depending on whether data is supplied or not. To this end, the upper and lower data drivers 10 and 12 include a plurality of integrated circuits 4 (hereinafter, referred to as “ICs”) according to the number of pixel cells.

Accordingly, the odd data lines Dn + 1 (n is a positive integer greater than or equal to 0) receive data pulses from the data driver ICs 4 embedded in the upper data driver 10, respectively, and the even data lines Dn. The data pulse is received from the lower data driver 12.

The first connector 16 is electrically connected to the odd data line Dn + 1. The first connector 14 is electrically connected to the upper data driver 10. That is, the first connector 16 supplies the data pulses applied from the upper data driver 10 to the odd data line Dn + 1. The second connector 18 is electrically connected to the even data line Dn. This second connector 18 is electrically connected to the lower data driver 12. That is, the second connector 18 supplies the data pulses applied from the lower data driver 12 to the even data line Dn.

The third connector 20 is electrically connected to the scan lines S1 to Sm. This third connector 20 is electrically connected to the scan driver 14. That is, the third connector 20 supplies a driving signal applied from the scan driver 14 to the scan lines S1 to Sm.

At this time, since the scan lines Sm-x to Sm far from the scan driver 14 have a large resistance and a large current, a voltage drop occurs when a voltage is applied, and thus the left and right brightness of the screen are different.

In order to solve this problem, in the driving method according to the first embodiment of the present invention, referring to FIG. 6, a driving power source applied to drive the data driving ICs IC1 to ICn embedded in the data driving unit 10. The voltage is applied to have a voltage difference for each of the data driving ICs IC1 to ICn. For example, if the pixel cell is VGA resolution, the upper and lower data drivers 10 and 12 are connected to 960 data lines, respectively. Each data driver 10, 12 requires ten data driver ICs 4 having at least 100 outputs. The driving power supply voltage applied to the second data driving IC IC2 is higher than that of the first data driving IC IC1. That is, the driving power supply voltage is gradually applied toward the nth data driving IC ICn.

In other words, since the data lines connected to the first data driver IC IC1 are located at a close distance from the scan driver 14, a relatively low driving power supply voltage is applied because the line resistance is very small. On the other hand, since the data lines connected to the n-th data driver IC ICn are located at a long distance from the scan driver 14, the line resistance value is very large, so that a high driving power supply voltage is applied to compensate for the resistance value. At this time, the driving power supply voltage applied to each data driving IC is determined in consideration of the current flowing through the scan lines S1 to Sm and the voltage drop.

In addition, the driving power supply voltage may be applied in a linearly increasing form from the first data driving IC IC1 to the n th data driving IC ICn. As such, the driving power voltage applied linearly is compensated according to the difference in the resistance value in the distance of the scan lines S1 to Sm.

Accordingly, since the resistance of the scan lines S1 to Sm is large and the current is large, the voltage drop due to the resistance of the scan lines S1 to Sm is prevented according to the position of the screen when voltage is applied, so that the brightness of all pixel cells is uniform Done.

FIG. 7 shows a pulse width of a driving voltage supplied to each of the data driving ICs IC1 to ICn embedded in the upper and lower data driving units 10 and 12 in the driving method according to the second embodiment of the present invention. Differently supplied by PWM (Pulse Width Modulation).

The second data driving IC IC2 is applied with a driving voltage having a larger pulse width than the first data driving IC IC1. That is, a driving voltage having a larger pulse width is applied toward the n-th data driving IC ICn. At this time, the driving power supply voltage supplied to the data driving ICs IC1 to ICn is fixed at one voltage level.

In other words, since the data lines connected to the first data driver IC IC1 are located at a close distance from the scan driver 14, the line resistance is very small, and thus has a relatively small pulse width (70%). Since the data lines connected to the n data driver IC ICn are located at a long distance from the scan driver 14, the line resistance values are very large and have a large pulse width (100%) compensated for by the resistance values. At this time, the pulse width applied to each of the data driving ICs IC1 to ICn is set to a pulse width that gradually increases for each position after determining the difference between the positions of the scan lines S1 to Sm and the screen.

As such, the pulse width of the driving voltage supplied to the data driving ICs IC1 to ICn is supplied differently according to the distance from the scan driver 14 to compensate for the voltage drop according to the position of the screen to uniformly adjust the brightness of the screen left and right can do.

Referring to FIG. 8, in the driving method according to the third exemplary embodiment of the present invention, the input image signals R, G, and B are applied to the data converter 90 in response to a voltage drop at a distance from the scan driver 14. A uniform image can be obtained by compensating the data information and supplying it to the screen.

Such compensation of data information converts the video signals R, G and B inputted from a video card (not shown) into digital, and converts the changed digital video signals R, G and B in the data processor 32 again. The information of the image signals R, G, and B according to the position of the screen is compensated by subtraction or addition. The compensated image signals R, G, and B are supplied to the data driving ICs IC1 to ICn corresponding to the respective positions to compensate for the substantial voltage drop according to the distance from the scan driver 14. A detailed description with reference to FIG. 9 is as follows.

The data converter 90 according to the present invention includes an analog-to-digital converter 36 for converting input image signals R, G, and B into digital image signals DR, DG, and DB, and an analog-digital converter. Data information of the digital video signals DR, DG, and DB supplied from the 36 is supplied from the data processor 32 and the data processor 32 to compensate for the voltage drop according to each position of the MIM panel 100. A line or frame memory 34 for temporarily storing data information to be stored, and data driving ICs IC1 to ICn for supplying data processed data information supplied from the line or frame memory 34 to respective data lines. do.

The analog-to-digital converter 36 receives the red, green, and blue video signals R, G, and B and the vertical and horizontal synchronous signals V and H from an image signal supply unit (not shown). The analog video signals R, G, and B are converted into digital video signals DR, DG, and DB, and are supplied to the data processor 32. In addition, it serves to supply a drive control signal to the scan drive timing controller 30 provided between the analog-digital converter 36 and the scan driver 14. The scan drive timing controller 30 generates various control signals of the scan driver 14 and supplies them to the scan driver 14. The scan driver 14 supplies a scanning signal generated by a control signal of the scan drive timing controller 30 to a scan line (not shown) of the MIM panel 100.

The data processor 32 is programmed as a kind of EEPROM and compensates by adding or subtracting the data information according to a preset data value, that is, a look up table. At this time, the lookup table value includes values for digital voltage signals DR, DG, and DB supplied from the analog-to-digital converter 36 to compensate for voltage drops according to positions from the scan driver 14. . That is, the data processor 32 adds or subtracts the values of the digital image signals DR, DG, and DB according to the position of the MIM panel 100.

Accordingly. The digital video signals DR, DG, and DB are compensated by the data processor 32 and converted into values of data information corresponding to positions in the MIM panel 100.

The line or frame memory 34 temporarily stores the digital image signals DR, DG, and DB changed from the data processing unit 32 and supplies them to the driving ICs IC1 to ICn for each line or frame.

The driving ICs IC1 to ICn compensate for the voltage drop according to the position of the MIM panel 100 with respect to the digital image signals DR, DG, and DB supplied from the line or frame memory 34.

As described above, the voltage drop according to the position of the screen may be compensated by adding or subtracting the data value according to the distance from the scan driver 14 to make the left and right brightness of the screen uniform.

Fig. 10 is a waveform diagram showing driving waveforms applied to the present invention MIN type FED.

Referring to FIG. 10, negative scan pulses SP are sequentially supplied to the scan lines S1 to Sm of the MIN type FED of the present invention, and the data electrodes D are synchronized with the negative scan pulses SP. The positive data pulse DP is supplied. Here, the data pulse DP is converted and supplied by different voltages, pulse widths, and data conversions as in the first to third embodiments of the present invention described above.

Electrons are emitted by the voltage difference between the scan pulse SP and the data pulse DP in the pixel cell supplied with the data pulse DP whose data value is compensated according to the position of the scan pulse SP and the screen.

For example, when -5V scan pulse SP is applied to the first scan line S1 and 5V data pulse DP is applied to the data electrode D, the scan pulse S is formed on the first scan line S1. A voltage difference of 10V is generated in the first pixel cells P1. Therefore, electrons are emitted from the first pixel cells P1 supplied with the data pulse DP.

Thereafter, this process is repeated to sequentially apply the scan pulse SP and the data pulse DP to the nth scan line Sm to display an image. After the image is displayed, the charges charged in the pixel cell are removed by applying the positive reset pulse RP to the first to nth scan lines S1 to Sm.

In the reset pulse RP for removing charged charges, as shown in FIG. 11A, a negative scan pulse SP is supplied to the scan line S, and then a positive reset pulse RP is supplied to the scan line S. The reset pulse RP is supplied between the scan pulse SP supplied to one of the scan lines Si and the scan pulse SP supplied to the next scan line Si + 1. In other words, the reset pulse RP is supplied at a predetermined time (blanking period) between the scan pulses SP.

For example, after the scan pulse SP is supplied to the first scan line S1, the reset pulse RP is supplied to the first scan line S1. In this case, the scan pulse SP supplied to the first scan line S1 is supplied before the scan pulse SP is supplied to the second scan line S2.

In addition, the reset pulse RP for removing the charged charges is at least 2 to the scan electrodes (S1 to Sm) after the scan pulse (SP) is sequentially supplied to all the scan electrodes (S) as shown in Figure 11b More than one reset pulse RP is supplied.

As such, when at least two reset pulses RP are supplied to the scan electrodes S1 to Sm, all charged charges may be removed by driving the scan electrodes S1 to Sm, thereby improving cell uniformity. You can.

As described above, the driving device and the driving method of the planar field emission display device according to the present invention supply the driving voltage and the pulse width of the driving voltage supplied to the data driving driver differently depending on the position of the data line or input data values. By compensating for the voltage drop due to the resistance difference according to the position of the scan line, the overall brightness of the screen can be maintained uniformly.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (6)

Sequentially supplying scan pulses to a plurality of scan lines; And differently supplying any one of a driving voltage and a pulse width of the driving voltage supplied to each of the plurality of divided data driving drivers for supplying data to the data lines crossing the scan lines selected by the scan pulses. A method of driving a flat field emission display device. The method of claim 1, And the driving voltage supplied to the data driving driver increases gradually away from the scan driving unit supplying the scan pulse. The method of claim 1, And a pulse width of the driving voltage supplied to the data driving driver becomes larger as the pulse width of the driving voltage is increased from the scan driving unit supplying the scan pulse. The method of claim 1, And the data is converted into a value corresponding to a position of the data line and supplied to the data driving driver. An analog-digital converter for converting an analog video signal supplied from the outside into a digital video signal; A data processor for converting a value of the digital video signal into a data value corresponding to a position of a data line; Storage means for storing the converted data for each line or frame; And a data driver for receiving data from the storage means for each line or frame and supplying the data to a plurality of data lines. The method of claim 5, And the data processor converts the data values into data values corresponding to the positions of the plurality of data lines.