Electric lamp and discharge devices – With gas or vapor – Three or more electrode discharge device
Reissue Patent
1999-07-01
2003-12-23
Patel, Nimeshkumar D. (Department: 2879)
Electric lamp and discharge devices
With gas or vapor
Three or more electrode discharge device
C313S485000, C313S584000, C313S585000, C313S586000, C313S587000
Reissue Patent
active
RE038357
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a plasma display panel (also referred to hereinafter as a “PDP”) used in a plasma display apparatus, and particularly to a structure of a surface discharge AC type plasma display panel.
2. Description of the Related Art
The PDPs are generally classified into the DC type (or direct discharge type) in which the discharging electrodes are exposed in the discharge space and into the AC type (or indirect discharge type) in which the discharging electrodes are covered with a dielectric layer. The AC type PDPs are also classified into two types, one is a facing surfaces discharge type in which the discharging electrodes are provide onto two substrates of back and front sides respectively and, the other is a surface discharge type in which the discharging electrodes are provide onto only one of two substrates of back and front sides. The AC type PDP is driven by a voltage application method such as the refreshing method, the matrix addressing method, the self-shifting method and so on.
FIG. 1
, for example, shows a surface discharge AC type PDP with a matrix addressing method which comprises a front side substrate
1
and a back side substrate
2
facing and parallel to each other, and a discharge gas space
4
defined by these substrates and barrier ribs of an insulative material (not shown). The barrier rib partitions pixel cells to prevent the adjacent cells from leaking ultraviolet rays produced by the electrical discharge.
In the front side substrate
1
, a plurality of pairs of sustaining electrodes are formed parallel to each other on the inside as row electrodes per one pixel cell. Each sustaining electrode comprises a transparent thin electrode body “S” and a metallic bus electrode “Sa” overlapped on the “S”. A dielectric layer
23
is uniformly formed on and over the sustaining electrodes at a predetermined thickness “t” by using a screen printing method or the like. A MgO layer
24
is formed on this dielectric layer
23
.
In the back side substrate
2
, address electrodes “W” are formed parallel to each other on the inside as column electrodes in such a manner that each address electrode crosses the sustaining electrode. Fluorescent layers
11
are formed on the internal surface of the back side substrate so as to correspond to unit pixel cells respectively. The front side substrate
1
and the back side substrate
2
are assembled after aligned in a way that each address electrode and each sustaining electrode intersect apart from each other at an intersection space
4
for a discharge-oriented emission corresponding one pixel cells, and then the discharge space
4
is filled with a rare gas mixture. In this way, a surface discharge type PDP is manufactured.
This PDP is operated as follows: When a predetermined voltage is applied across each pair of the address electrodes W and the sustaining electrodes “S” embedded in the dielectric layer, a discharging region appears above the dielectric layer
23
at the crossover point of each pair of electrodes in the gaseous space
4
. Ultraviolet rays emitted from the discharging region stimulate the fluorescent layer
11
to emit light radiating through the front side substrate
1
as an emission region. This discharged emission is maintained by a sustaining voltage applied between the sustaining electrodes, but canceled by an erase pulse applied between the address electrodes “W”.
In the ordinary surface discharge AC type PDP, a pair of transparent thin electrode bodies “S” of the sustaining electrode have strip-shapes extending parallel to one another (to a normal line direction in FIG.
1
), on and along the opposite edges of which a pair of the metallic bus electrodes “Sa” are overlapped respectively. The barrier ribs are formed on the back side substrate
2
to be placed and extended between the address electrodes W for crossing vertically apart from the sustaining electrodes to define discharge cells for light emissions. Therefore, there is a tendency of occurrence of a rib space between the barrier rib and the MgO layer
24
of the front side substrate
1
due to unevenness of top surface of the barrier ribs and the convex MgO layer caused by the bus electrode (several micrometers thickness) put on the transparent electrode body.
As shown in
FIG. 1
, the surface discharge in the gaseous space
4
is initiated on and between the facing edges of the transparent electrodes “S” spaced at a discharge gap “G” and then expands outward along the transparent electrodes to the bus electrodes Sa. Since the rib space between the barrier rib and the front side substrate
1
exists over the transparent electrodes, the surface discharge expands and leaks from the rib space to the adjacent cell in the gaseous space
4
. Therefore, upon application of a pulse signal to a predetermined address electrodes W, there is a probability of light emission in the adjacent cell other than the predetermined discharge cell. To prevent the unwanted light emission, it is necessary to flatten the surfaces of the dielectric layer and the like and the top surface of the barrier ribs.
Furthermore, as shown in
FIG. 1
, the expansion of the surface discharge over the bus electrodes (both side curved dot arrows) increases the discharge current. However, light emissions over the bus electrodes (single side dot arrows) are useless, since the metallic bus electrodes “Sa” interrupts such light emissions to output, so that the emission efficiency of the PDP is reduced.
SUMMARY OF THE INVENTION
Thus, the present invention has been made to solve such a problem in view of the forgoing status. An object of the invention is to provide a surface discharge AC type plasma display panel that are capable of emitting light at a high emission efficiency.
A surface discharge type plasma display panel according to the present invention comprises;
a pair of first and second substrates spaced parallel to each other and sandwiching a discharge gas space;
a plurality of pairs of row electrodes extending horizontally and arranged on an internal surface of said first substrate each pair including; a pair of transparent electrodes disposed apart from each other by a discharge gap and arranged in an extending direction of said row electrodes respectively; and a pair of bus electrodes formed on far ends of said transparent electrodes from said discharge gap respectively and each having an area smaller than that of the transparent electrode;
a dielectric layer formed on the internal surface of said first substrate and said row electrodes; a
plurality of column electrodes extending vertically and arranged on an internal surface of said second substrates; and
a plurality of barrier ribs extending vertically and formed at least between said column electrodes on the internal surface of said second substrate to define a plurality of emission regions in said discharge gas space;
characterized in that said dielectric layer comprises protruding portions each disposed on said bus electrode overlapped on said transparent electrode and each having a thickness larger than that on said transparent electrode.
In an embodiment of the surface discharge type plasma display panel according to the present invention, each of said transparent electrodes has expanded portions vertically extending from said bus electrodes.
In another embodiment of the surface discharge type plasma display panel according to the present invention, each of said transparent electrodes is a row of individual island-shaped electrodes connected to said bus electrode.
In another embodiment of the surface discharge type plasma display panel according to the present invention, said dielectric layer further comprises protruding portions disposed and extending in at least one of regions each facing a top of a corresponding one of said barrier ribs, and between adjacent bus electrodes of said emission regions arranged in the vertical direction.
In another embodiment of the surface discharge type plasma display panel according to the present invention, s
Amemiya Kimio
Tanaka Yukio
Teshirogi Hitoshi
Patel Nimeshkumar D.
Pioneer Corporation
Santiago Mariceli
Sughrue & Mion, PLLC
LandOfFree
Surface discharge type plasma display panel does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Surface discharge type plasma display panel, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Surface discharge type plasma display panel will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3107454