KR100658339B1 - Field emission display device and driving method thereof - Google Patents

Abstract

The present invention relates to a field emission display device capable of removing charges accumulated in a spacer.

The field emission display device of the present invention includes a spacer driver for applying an erase pulse to the spacer to remove charges accumulated in the spacer.

According to the present invention, an erase pulse having a predetermined level can be applied to the spacer to remove charges accumulated in the spacer.

Description

Field emission display device and driving method thereof {Field Emission Display and Method of Driving the same}             

1 is a perspective view showing a conventional field emission display device.

FIG. 2 is a cross-sectional view of the field emission display device shown in FIG. 1. FIG.

3 is a view showing a driving device of a conventional field emission display device.

4 is a plan view showing the arrangement of the spacer shown in FIG. 1;

FIG. 5 is a cross-sectional view showing that charge is accumulated in the spacer shown in FIG. 4; FIG.

FIG. 6 is a cross-sectional view illustrating an electrode formed on the spacer illustrated in FIG. 4. FIG.

7 is a view showing a driving device of the field emission display device of the present invention.

Fig. 8 is a waveform diagram showing driving waveforms of the field emission display device according to the first embodiment of the present invention.

9 is a waveform diagram showing driving waveforms of a field emission display device according to a second embodiment of the present invention;

<Description of Symbols for Main Parts of Drawings>

2: upper glass substrate 4: anode electrode                 

6: phosphor 8: lower glass substrate

10 cathode electrode 12 resistive layer

14 gate insulating layer 16 gate electrode

22 emitter electrode 30 electron beam

32: field emission array 40, 44: spacer

42: charge 46: electrode

48: pixel 50A, 60A: first cathode driver

50B, 60B: second cathode driver 52, 62: gate driver

64: spacer drive part

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field emission display device and a driving method thereof, and more particularly, to a field emission display device and a driving method thereof capable of removing charges accumulated in a spacer.

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 "LCD"), field emission displays (hereinafter referred to as "FED"), and plasma display panels (hereinafter referred to as "PDP"). And electroluminescence (hereinafter referred to as "EL"). In order to improve the display quality, research and development have been actively conducted to increase the brightness, contrast and color purity of flat panel displays.

The FED concentrates a high field on a sharp cathode (emitter), emits electrons by a quantum mechanical tunnel effect, and displays an image by exciting the phosphor using the emitted electrons.

1 and 2, an FED having an upper glass substrate 2 on which an anode electrode 4 and a phosphor 6 are stacked, and a field emission array 32 formed on the lower glass substrate 8. Is shown. The field emission array 32 includes the cathode electrode 10 and the resistive layer 12 formed on the lower glass substrate 8, and the gate insulating layer 14 and the emitter 22 formed on the resistive layer 12. ) And a gate electrode 16 formed on the gate insulating layer 14. The cathode electrode 10 supplies a current to the emitter 22, and the resistive layer 12 limits the overcurrent applied from the cathode electrode 10 toward the emitter 22, thereby making it uniform to the emitter 22. It serves to supply current. The gate insulating layer 14 insulates between the cathode electrode 10 and the gate electrode 16. The gate electrode 16 is used as an extraction electrode for drawing electrons. A spacer 40 is installed between the upper glass substrate 2 and the lower glass substrate 8. The spacer 40 supports the upper glass substrate 2 and the lower glass substrate 8 so as to maintain a high vacuum state between the upper glass substrate 2 and the lower glass substrate 8.

3 is a view showing a driving device of a conventional field emission display device.                         

Referring to FIG. 3, a conventional driving device of a field emission display device includes a gate driver 52 connected to m gate electrode lines R to sequentially enable respective gate electrode lines R; A first cathode driver 50A which is connected to the odd-numbered cathode electrode lines C and sequentially supplies the image data to the gate electrode lines R during the period in which the gate electrode lines R are enabled; The second cathode driver 50B is connected to the first cathode electrode lines C to sequentially supply image data to the gate electrode lines R during the period in which the gate electrode lines R are enabled. Pixels 48 formed in a matrix form are positioned at the intersections of the gate electrode lines R and the cathode electrode lines C. FIG. The gate driver 52 sequentially supplies scan pulses to the first to m th gate electrodes R1 to Rm. The cathode driver 50 is enabled when scan pulses are supplied to the gate electrodes R to supply image data to the first to nth cathode electrode lines C.

In order to display an image, a negative (-) cathode voltage is applied to the cathode electrode 10 and a positive (+) anode voltage is applied to the anode electrode 4. The gate voltage of positive polarity (+) is applied to the gate electrode 16. Then, the electron beam 30 emitted from the emitter 22 is accelerated toward the anode electrode 4. The electron beam 30 collides with the red, green, and blue phosphors 6 to excite the phosphors 6. At this time, visible light of any one of red, green, and blue colors is generated according to the phosphor 6. The spacer 40 is formed in parallel with the gate electrode 16 as shown in FIG. 4. For this reason, when the electron beam 30 generated in any one subpixel or pixel is accelerated toward the phosphor 6, the charge 42 is accumulated in the spacer 40 by the electron beam 30 diffusion. The charge thus accumulated causes cross talk and discharge irregularity between adjacent pixel cells. In other words, the charges 42 accumulated in the spacer 40 lower the uniformity of the pixel cells or cause unevenness of the discharge, thereby degrading the image quality of the FED.

In order to prevent the charge 42 from accumulating in the spacer 40, a predetermined number of electrodes 46 are formed in the spacer 44 as shown in FIG. 6 in US Pat. No. 5,532,548. A predetermined voltage is applied to the electrode 46 formed in the spacer 44 to prevent charges from accumulating in the spacer 44. However, it is difficult to form an electrode in the spacer 44 of a predetermined size or less, and a considerable process time is consumed for forming the electrode, thereby decreasing productivity.

Accordingly, an object of the present invention is to provide a field emission display device and a driving method thereof capable of removing charges accumulated in a spacer.

In order to achieve the above object, the field emission display device of the present invention includes a spacer driver for applying an erase pulse to the spacer to remove charges accumulated in the spacer.

The driving method of the field emission display device of the present invention includes the step of sequentially applying an erase pulse to the spacer to remove the charge accumulated in the spacer.

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. 7 to 9.

7 is a view showing a driving device of a field emission display device according to an embodiment of the present invention.

Referring to FIG. 7, a driving device of a field emission display device according to an exemplary embodiment of the present invention is connected to m gate electrode lines R to gates for sequentially enabling respective gate electrode lines R. FIG. A first cathode connected to the driver 62 and the odd-numbered cathode electrode lines C to sequentially supply image data to the gate electrode lines R during the period in which the gate electrode lines R are enabled. The second cathode driver connected to the driver 60A and the even-numbered cathode electrode lines C to sequentially supply image data to the gate electrode lines R during the period in which the gate electrode lines R are enabled. 60B and a spacer driver 64 connected to the k spacer electrode lines S to enable the spacer electrode lines S, respectively. Pixels 66 disposed in a matrix form are positioned at the intersections of the gate electrode lines R and the cathode electrode lines C. FIG. The spacer 68 is formed in parallel with the gate electrode lines R and is formed every three gate electrode lines R. As shown in FIG. The number of such spacers 68 may be determined to match the structure of the pixel cell, the influence between the spacers, and the state of the panel. The gate driver 62 sequentially supplies scan pulses to the first to m th gate electrode lines R1 to Rm. The cathode driver 60 is enabled when scan pulses are supplied to the gate electrode lines R to supply image data to the first to nth cathode electrode lines C1 to Cn. After the scan pulse is supplied to the third gate electrode line R3, the spacer driver 64 supplies an erase pulse having a predetermined level to the first spacer S1 to remove charges accumulated in the first spacer S1. That is, the spacer driver 64 supplies the erase pulse of a predetermined level to the spacer after the scan pulse is supplied to the gate electrode line R formed at the front end of the spacer 68.

8, the scan pulse Vg is first supplied from the gate driver 62 to the first gate electrode line R1. When the scan pulse Vg is supplied to the first gate electrode line R1, the image data is supplied to the first to nth cathode electrode lines C1 to Cn. When image data is supplied to the cathode electrode lines C, electrons corresponding to the image data are emitted from the pixels 66. Thereafter, the scan pulses Vg are sequentially supplied to the second and third gate electrode lines R2 and R3. After the scan pulse is supplied to the third gate electrode line R3, the negative erase pulse (-Vs) is supplied from the spacer driver 64 to the first spacer electrode line S1. When the negative erase pulse (-Vs) is supplied to the spacer 68, the charges accumulated in the spacer 68 are released into the vacuum space. Electrons released into the vacuum space are reused at the next electron emission. In addition, in the present invention, an erase pulse of positive polarity may be supplied to the spacer electrode line S from the spacer driver 64. When a bipolar (+) erase pulse is supplied to the spacer 68, the charges accumulated in the spacer 68 are removed through recombination. That is, in the present invention, an erase pulse of positive or negative polarity is applied to the gate electrode lines R to remove the charges accumulated in the spacer 68. In addition, in the present invention, as shown in FIG. 9, the reset pulse is applied to all the spacers 68 before the scan pulse Vg is applied to the gate electrode lines R, thereby accumulating in the previous field or frame. The charged particles can be removed. The reset pulse applied to the spacer 68 is a bipolar or negative polarity pulse of a predetermined level.

As described above, according to the field emission display device and the driving method thereof according to the present invention, an erase pulse having a predetermined level can be applied to the spacer to remove the charge accumulated in the spacer. Therefore, cross talk between the pixel cells and discharge unevenness can be minimized.

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 (8)

In a field emission display device having pixel cells arranged in a matrix at an intersection of a gate electrode line and a cathode electrode line, and having at least one spacer formed in parallel with the gate electrode line. And a spacer driver for applying an erase pulse to the spacer to remove charges accumulated in the spacer. The method of claim 1, And the erasing pulse is any one of a positive voltage and a negative voltage. The method of claim 1, And the erase pulses are sequentially applied to the spacers. The method of claim 3, wherein And the erase pulse is applied to the spacer after the scan pulse is applied to the gate electrode line formed at the front end of the spacer. And a gate electrode line to which an erase pulse is applied, a cathode electrode line to which image data is supplied in synchronization with the erase pulse, and at least one spacer disposed in parallel with the gate electrode line. In And erasing pulses sequentially applied to the spacers to remove charges accumulated in the spacers. The method of claim 5, And the erase pulse is applied to the spacer after the erase pulse is applied to the gate electrode line formed at the front end of the spacer. The method of claim 5, And applying a reset pulse to the spacer before the erase pulse is applied. The method of claim 7, wherein And the reset pulse is simultaneously applied to all spacers.

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