Electric lamp and discharge devices – With gas or vapor – Three or more electrode discharge device
Reexamination Certificate
2001-02-23
2004-11-16
Patel, Ashok (Department: 2879)
Electric lamp and discharge devices
With gas or vapor
Three or more electrode discharge device
C313S585000
Reexamination Certificate
active
06819046
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The invention relates to a plasma display panel, more specifically, to a plasma display panel having an improved plane electrode structure.
2. Related Art
The plasma display panel (“PDP”) is well known as a thin flat image display device having a large display screen and displaying a mass information. In the plasma display panel, electrons are accelerated by means of an electric field to cause them to collide with a discharged gas to excite it and convert ultraviolet light irradiated through a relaxation process of the exited gas into visible light to display images. Among various types, the alternating current (“AC”) PDP is superior than the direct current (“DC”) PDP in terms of luminance, luminous efficiency and operating life.
An example of this type of AC type PDP is disclosed in Japanese Unexamined Patent Publication No. 149873 of 1999. FIG.
1
and
FIG. 2
are both plan views of a unit cell (single color illuminating cell) portion of said PDP disclosed by said publication and correspond with FIG.
7
and
FIG. 8
of said publication respectively. The constitution of the prior art will be describe below using FIG.
1
and FIG.
2
.
On a back substrate
51
, a plurality of metal data electrodes
52
are formed at a specified interval in the column direction, on top of which a white dielectric material layer
53
is formed. On the white dielectric material layer
53
, located between the data electrodes
52
, stripe partition walls
54
are formed at a specified interval in the column direction. Containing the side faces of said partition walls and on the white dielectric layer
53
, a plurality of fluorescent material layers
55
, each of which consists of a set of fluorescent material layers
55
r
,
55
g
and
55
b
, each of which generates visible red (r), green (g) and blue (b) light respectively, are formed repeatedly in the column direction.
On the other hand, beneath a front substrate
56
, a plurality of stripe plane electrodes
57
a
are formed in pairs in the row direction at a specified interval forming a pair, below which a plurality of metallic bus electrodes
58
are formed at a specific interval in the row direction. Beneath the stripe plane electrodes
57
a
and the bus electrode
58
, a transparent dielectric layer
61
is formed, under which is formed a protection layer
62
. The stripe plane electrode
57
a
and the bus electrode
58
form a pair of sustaining electrodes consisting of a scan electrode
59
and a common electrode
60
.
Said back substrate
51
and said front substrate
56
are put together sandwiching their constituents inside and are sealed air tight with a sealing part provided on the periphery of the substrate. A discharged gas consisting of gaseous atoms and gaseous molecules for generating ultraviolet light is encapsulated in the inside of the above.
Next, let us describe the operating principle of the prior art. Writing discharge is created by causing an opposing discharge between a data electrode
52
, to which signal voltage pulses are applied independently by each line, and a scan electrode
59
, to which write voltage pulses are applied due to line sequential scanning, in order to generate wall electric charges and priming particles (electrons and ions) to perform a cell selecting operation. The selected cell generates a sustaining discharge by means of a plane discharge between the scanning electrode
59
, to which a sustaining voltage is applied following the writing voltage pulses, and the common electrode
60
, in order to cause visible light luminescence of the fluorescent material layers
55
to operate the cell to display.
In the conventional structure shown in FIG.
1
and
FIG. 2
, since the stripe plane electrode
57
a
is formed in a wide range over a plurality of cells, there was a problem in that the sustaining current (current that runs in accordance with the sustaining discharge), which runs in proportion to the sustaining electrode area, is too large causing large power consumption. When the power consumption is large, it creates not only a large load on the drive circuit, but also an increase in heat generation of the panel, thus resulting in the problem of reliability.
Furthermore, the conventional structure shown in FIG.
1
and
FIG. 2
tends to cause a spread of plasma into adjacent cells in vertical and horizontal directions as a result of discharge, thus creating a problem of incorrect light turn on and turn off due to discharge interferences between adjacent cells.
A countermeasure normally taken to cause a selected cell to perform a luminescence display uniformly over the entire panel surface is to generate a strong discharge by increasing the writing voltage (potential difference that can cause writing discharge between a data electrode
52
and a scan electrode
59
) and the sustaining voltage (potential difference that can cause sustaining discharge between a scan electrode
59
and a common electrode
60
) to high levels, thus generating more wall charges and priming particles so that the capability of transition from writing operations to sustaining operations can be improved. However, if discharge interferences can easily occur between adjacent cells, it is impossible to increase the writing voltage and the sustaining voltage because incorrect light turn on and turn off discharges occur at unselected cells adjacent to the selected cell and cause the unselected cells to turn on and turn off incorrectly when high discharges are caused by increasing the writing voltage and the sustaining voltage to high levels. As a result, the PDP's display image quality seriously deteriorates.
On the other hand, lowering of the writing voltage and the sustaining voltage in order to suppress the discharge interferences between adjacent cells deteriorates the capability making a transition from the writing operation to the sustaining operation and makes it impossible to perform a normal luminescence display, hence also deteriorating the PDP's display image quality. In other words, it was impossible to expand the operating margin and improve the display image quality with the conventional structure shown in FIG.
1
and FIG.
2
.
In order to solve the above problem, a PDP with the structure disclosed by the Japanese Unexamined Patent Publication No. 22772 of 1996 was proposed. FIG.
3
and
FIG. 4
are both the plan views of a unit cell portion of said PDP disclosed by said publication and correspond with the constitutions shown in FIG.
7
(
b
) and FIG.
7
(
a
) of said publication respectively.
In the conventional structure shown in
FIG. 3
, plane electrodes
57
b
are formed by means of rectangular transparent electrodes disposed in each unit cell and these rectangular plane electrodes
57
b
are connected by bus electrodes
58
provided on the side of non-discharging gaps
64
in the row direction to form a pair of sustaining electrodes (scan electrode
59
and common electrode
60
). On the other hand, in the conventional structure shown in
FIG. 4
, plane electrodes
57
c
are formed by means of T-shaped transparent electrodes disposed in each unit cell and these T-shaped plane electrodes
57
c
are connected by bus electrodes
58
provided on the side of non-discharging gaps
64
in the row direction to form a pair of sustaining electrodes (scan electrode
59
and common electrode
60
). As to the bus electrodes
58
, there is no mention of them in FIG.
7
(
b
) and FIG.
7
(
a
) of the Japanese Unexamined Patent Publication No. 22772 of 1996, but it was described in the above assuming that the bus electrodes
58
exist as in the structure of the conventional PDP.
In the conventional structures shown in FIG.
3
and
FIG. 4
, the sustaining current is reduced by reducing the sustaining electrode area compared to that of the conventional structure shown in
FIG. 2
by means of providing the plane electrodes
57
b
and
57
c
independently in each unit cell. Furthermore, by optimizing the length of the plane electrodes (forming the discha
Colón German
Hayes & Soloway P.C.
Patel Ashok
Pioneer Corporation
LandOfFree
Plasma display panel having an improved plane electrode... 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 an improved plane electrode..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Plasma display panel having an improved plane electrode... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3346604