Electric lamp and discharge devices – With gas or vapor – Three or more electrode discharge device
Reexamination Certificate
2001-01-24
2003-08-05
Lee, Susan S. Y. (Department: 2852)
Electric lamp and discharge devices
With gas or vapor
Three or more electrode discharge device
C313S495000, C313S582000
Reexamination Certificate
active
06603265
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a flat panel display device, and more particularly to a plasma display panel that is capable of improving the discharge and light-emission efficiencies and the brightness.
2. Description of the Related Art
Generally, a plasma display panel (PDP) radiates a fluorescent body by an ultraviolet with a wavelength of 147 nm generated during a discharge of He+Xe or Ne+Xe gas to thereby display a picture including characters and graphics. Such a PDP is easy to be made into a thin film and large-dimension type. Moreover, the PDP provides a very improved picture quality owing to a recent technical development. The PDP is largely classified into a direct current (DC) driving system and an alternating current (AC) driving system. The DC-type PDP causes an opposite discharge between an anode and a cathode provided at a front substrate and a rear substrate, respectively to display a picture. On the other hand, the AC-type PDP allows an alternating voltage signal to be applied between electrodes having dielectric layer therebetween to generate a discharge every half-period of the signal, thereby displaying a picture. Since such an AC-type PDP uses a dielectric material which allows a wall charge to be accumulated on the surface thereof upon discharge, it produces a memory effect.
Referring to
FIG. 1
, the AC-type PDP includes a front substrate
10
provided with a sustaining electrode
12
, and a rear substrate
20
provided with an address electrode
22
. The front substrate
10
and the rear substrate
20
are spaced in parallel to each other with having a barrier rib
26
therebetween. A mixture gas, such as Ne—Xe or He—Xe, etc., is injected into a discharge space defined by the front substrate
10
, the rear substrate
20
and a barrier rib
26
. The sustaining electrode
12
makes a pair by two within a single of plasma discharge channel. Any one of the pair of sustaining electrode
12
is used as a scanning/sustaining electrode that responds to a scanning pulse applied in an address interval to cause an opposite discharge along with the address electrode
22
while responding to a sustaining pulse applied in a sustaining interval to cause a surface discharge with the adjacent sustaining electrodes
12
. Also, the remaining one of the sustaining electrode pair
12
is used as a common sustaining electrode to which a sustaining pulse is applied commonly. On the front substrate
10
provided with the sustaining electrode pair
12
, a dielectric layer
24
and a protective layer
18
are disposed. The dielectric layer
24
is responsible for limiting a plasma discharge current as well as accumulating a wall charge during the discharge. The protective film
18
prevents a damage of the dielectric layer
24
caused by the sputtering generated during the plasma discharge and improves the emission efficiency of secondary electrons. This protective film
18
is usually made from MgO. Barrier ribs
26
for dividing the discharge space is extended perpendicularly at the rear substrate
2
. On the surfaces of the rear substrate
20
and the barrier ribs
26
, a fluorescent material
28
excited by a vacuum ultraviolet lay to generate a visible light is provided.
In such an AC-type PDP, one frame consists of a number of sub-fields so as to realize gray levels by a combination of the sub-fields. For instance, when it is intended to realize 256 gray levels, one frame interval is time-divided into 8 sub-fields. Further, each of the 8 sub-fields is again divided into a reset interval, an address interval and a sustaining interval. The entire field is initialized in the reset interval. The discharge pixel cells on which a data is to be displayed are selected by the address discharge in the address interval. The selected cells sustain the discharge in the sustaining interval. The sustaining interval is lengthened by an interval corresponding to 2
n
depending on a weighting value of each sub-field. In other words, the sustaining interval involved in each of first to eighth sub-fields increases at a ratio of 2
0
, 2
1
, 2
3
, 2
4
, 2
5
, 2
6
and 2
7
. To this end, the number of sustaining pulses generated in the sustaining interval also increases into 2
0
, 2
1
, 2
3
, 2
4
, 2
5
, 2
6
and 2
7
depending on the sub-fields. The brightness and the chrominance of a displayed image are determined in accordance with a combination of the sub-fields.
As shown in
FIG. 2
, in the conventional PDP, the sustaining discharge begins at a portion between the sustaining electrode pair
12
to make a surface discharge at the surface of the sustaining electrode pair
12
. Accordingly, the conventional PDP has a problem in that a light-emission area is extremely limited to have low brightness and efficiency. The brightness of such a PDP is proportional to a quantity of a vacuum ultraviolet ray generated during the discharge. In order to increase a generated quantity of a vacuum ultraviolet ray, there has been suggested a method of lengthening a distance between the sustaining electrode pair
12
to prolong a discharge path or a method of widening an electrode width of the sustaining electrode pair
12
to enlarge a discharge intensity. However, when a distance between the sustaining electrode pair
12
is large, a discharge length is prolonged to increase a generated quantity of a ultraviolet ray, but a discharge initiation voltage rises suddenly at more than a certain distance to cause a difficulty in a real application. When a width of the discharge-sustaining electrode is large, a generated quantity of an ultraviolet ray is increased in accordance with an increase of the discharge intensity. But, because a discharge current is increased in proportion to an electrode width, a wasted amount of the discharge current is increased to cause a disadvantage in respect of the efficiency.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a plasma display panel that is capable of improving the discharge and light-emission efficiency as well as the brightness.
In order to achieve these and other objects of the invention, a plasma display panel according to an embodiment of the present invention includes a sustaining electrode pair formed on an upper substrate in such a manner to be positioned at the edges of a discharge cell; a trigger electrode pair, being positioned between the sustaining electrode pair, to cause a trigger discharge for deriving a sustaining discharge; and dielectric layers formed on the sustaining electrode pair and the trigger electrode pair to have a different thickness.
A plasma display panel according to another embodiment of the present invention includes a sustaining electrode pair formed at a first distance on an upper substrate in such a manner to be positioned at the edges of a discharge cell; a first dielectric layer formed to entirely cover the sustaining electrode pair; a trigger electrode pair formed at a second distance larger than the first distance on the first dielectric layer; and a second dielectric layer formed to entirely cover the first dielectric layer and the trigger electrode pair.
A plasma display panel according to still another embodiment of the present invention includes a trigger electrode pair formed at a first distance on an upper substrate in such a manner to be positioned at the edges of a discharge cell; a first dielectric layer formed to entirely cover the trigger electrode pair; a sustaining electrode pair formed at a second distance larger than the first distance on the first dielectric layer; and a second dielectric layer formed on the first dielectric layer to entirely cover the sustaining electrode pair.
A plasma display panel according to still another embodiment of the present invention includes a sustaining electrode pair formed on an upper substrate in such a manner to be positioned at the edges of a discharge cell; a trigger electrode pair formed on the upper substrate in such a manner to be positioned between the sustaining electrode
Ahn Sung Yong
Lee Eun Cheol
Park Young Chan
Fleshner & Kim LLP
Lee Susan S. Y.
LG Electronics Inc.
LandOfFree
Plasma display panel having trigger electrodes does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Plasma display panel having trigger electrodes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Plasma display panel having trigger electrodes will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3077168