Plasma display panel

A DC type plasma display panel wherein a plurality of barriers of a predetermined height are formed parallel to each other within the interval of a predetermined space between the front and rear substrate having one anode embedded in the middle of each barrier and cathodes are arranged on the inner surface of the rear substrate crossing the anodes at right angles avoiding the loss of discharged light due to anode abstraction and realizing higher screen luminance.

FIELD OF THE INVENTION 
This invention relates to a plasma display panel and more particularly to a 
DC type plasma display panel of improved structure wherein discharge light 
effectively works for image display. 
BACKGROUND OF THE INVENTION 
The basic structure of a conventional DC type plasma display panel is 
illustrated in FIG. 1. 
A plurality of barriers 30 of a certain height are arranged parallel to 
each other at a predetermined interval between the rear substrate 20 and 
front substrate 10. 
A group of transparent anodes 40 parallel to the barriers 30 are formed on 
the inner surface of the front substrate 10 between barriers 30 while a 
plurality of cathodes 50 are arranged in stripes on the inner surface of 
the rear substrate 20 and crossing the anodes 40 at right-angles thereto. 
In the conventional plasma display panel, discharge light produced within 
the intervals between transparent anodes 40 and the cathodes 50, is viewed 
at the front substrate 10 and through transparent anodes 40. Subsequently, 
much of the discharge light is absorbed by the transparent anodes 40, 
degrading the luminance of the viewed picture. In addition, the 
conventional plasma display panel does not have constant luminance 
throughout the screen because the anodes 40 are made of a highly resistive 
material, for example, indium tin oxide. 
In order to alleviate the foregoing shortcomings, a plasma display panel as 
illustrated in FIGS. 2 and 3 has been introduced. This plasma display 
panel was designed to directly pass the discharged light produced in the 
space between the anodes and the cathodes to the front substrate without 
interference from the anodes. To accomplish this, the plasma display panel 
has a plurality of barriers 30' of a predetermined height arranged as 
parallel stripes and used as spacers to maintain a predetermined distance 
between a front substrate 10 and rear substrate 20, while anodes 40', 
parallel to barriers 30', are embedded in one flank of every barrier 30' 
on the inner surface of the front substrate 10. A plurality of striped 
cathodes 50 are formed on the inner surface of the rear substrate 20 
crossing the anodes 40' at right angles thereto. 
The plasma display panel with the above structure is characterized in that 
only a portion of each anode 40' is embedded in the flanks of the 
barriers. 
In the structure of the above plasma display panel the placement of anodes 
is different from FIG. 1 so that the discharge light produced in the space 
between anodes 40' and cathodes 50 does not pass through the anodes 40'. 
Therefore, unlike the prior art plasma display panels, the anode 40' can 
be made of a more conductive material, for example, metallic paste. 
This plasma display panel, however, still has an inevitable shortcoming 
whereby discharge light is partially cut-off by the portion of anodes 40' 
projecting from the barriers 30'. Moreover, directive luminance that is 
the luminance of discharged light as viewed from the front, alters its 
subject according to the direction of the viewer, for example as in FIG. 
3, direction a or direction b. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a plasma display panel 
having constant luminance. This and other objects can be realized by a 
front and rear substrate having a predetermined distance between each 
other, a plurality of parallel barriers formed between the front and rear 
substrates, a plurality of anodes arranged as stripes and embedded in one 
side of the middle of each barrier and off the inner surfaces of both 
front and rear substrates and a plurality of cathodes arranged as stripes 
on the inner surface of the rear substrate and crossing the anodes at 
right-angles thereto. 
In one embodiment of the present invention, an anode is embedded in the 
middle of individual barriers as an independent unit layer, with only its 
edge surface exposed to the discharging space. Another embodiment of this 
invention removes a portion of the barrier adjacent to the inner surface 
of the front substrate to form a longitudinal cutaway portion of 
predetermined depth along the barrier and open to the discharging space so 
that the anode can be located on the bottom of the cutaway portion, 
opposite the inner surface of the front substrate. As the result, the 
whole surface of one side of the anode is exposed to a discharging space.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As shown in FIGS. 4 and 5, a plasma display panel of the present invention 
comprises components common to general plasma display panels. 
A plurality of barriers 300 of a predetermined height are formed parallel 
to each other functioning as spacers between the front and rear substrates 
100 and 200 which are placed at a predetermined distance from each other. 
An anode 400, in parallel with other anodes is embedded along one side of 
the middle of each barrier 300, with only its edge surface exposed to the 
discharging space. A group of cathodes 500 arranged as stripes are formed 
on the inner surface of the rear substrate 200, crossing anodes 400 at 
right-angles thereto. 
The anode 400 embedded in the middle of each barrier 300 is formed during 
the course of forming the barrier 300 by a screen printing method. For the 
first step, a roughly processed barrier is formed by accumulating a 
plurality of unit layers on the inner surface of the front substrate 100 
via a screen printing method. After which an anode 400 of conductive 
nickel paste is formed on the roughly processed isolating rib. Here, the 
anode 400 is flush with or somewhat projected from one flank of the 
roughly processed barrier. Thereafter, isolating rib 300 is completed by 
successively accumulating a plurality of unit layers over the anode 400. 
A group of cathodes 500 on the rear substrate 200 are formed, also of 
conductive nickel paste, by a screen printing method (which is also used 
for barriers 300 and anodes 400). 
A plasma display panel according to this invention is characterized in that 
the anode 400 which provides gas charge interacting with the cathode 500, 
is segregated from the front substrate 100 at a predetermined distance by 
being placed in the middle of each barrier 300 which are installed to 
avoid crosstalk. Accordingly, all the discharged light produced in the 
space between the anode 400 and the cathode 500 can be projected between 
the barrier and through the light-transmitting area of the front substrate 
100 because the discharge light is emitted without anode interference, 
unlike conventional plasma display panels. 
As the result, no loss of light occurs due a anodes and image luminance 
viewed from the front of front substrate 100 improves. Of particular note 
is the uniform luminance, regardless of from where the display panel is 
viewed. 
Another type of plasma display panel is illustrated in FIGS. 6 and 7. This 
type of plasma display has the same basic structure as the aforementioned 
plasma display panel. 
That is, a plurality of isolating ribs 300 of a predetermined height are 
formed parallel to each other functioning as spacers between the front and 
rear substrates 100 and 200 which are placed at a predetermined distance 
from each other. 
An anode 400, in parallel with other anodes, is embedded along one side of 
the middle of each barrier 300 while a group of cathodes 500 arranged as 
stripes are formed on the inner surface of the rear substrate 200, 
crossing anodes 400 at right-angles thereto. 
In a plasma display panel of this type, an anode 400 is located on the 
bottom wall of the groove 310 to be conformed to the body of the barrier 
300. Therefore, the anode 400 faces the inner surface of the front surface 
100 from a predetermined distance exposing the whole surface of one side 
of the anode 400 to the discharging space. 
The groove 310 is formed by walls provided by a first barrier 320 which is 
the upper part of the barrier 300 and a second isolating rib 330, the 
lower part. 
The first barrier 320 is arranged on the inner surface of the front 
substrate 100, being narrower and shorter than the second barrier 330, 
aligns one flank to that of the second isolating rib 330. 
The firs and the second barriers 320 and 330 are respectively formed on the 
front substrate 100 and the rear substrate 200 by multiple screen printing 
method, and the anode 400 on the second barrier 330, conforming to the 
bottom wall of the groove 310, is also formed by a screen printing method. 
Since this plasma display panel has the whole surface of one side of the 
anode 400 exposed to the discharging space, discharges more powerful than 
the prior embodiment, are possible while having all the general functions 
of the prior one. 
As described above, the plasma display panel according to the present 
invention is directed to make the most of the discharged light in the most 
effective way and is also applicable to other embodiments different from 
the aforesaid embodiments. It will be apparent that plasma display panels 
having anode separated from a front substrate in the middle of the 
isolating rib between an front and rear substrate for better transmission 
of discharged light are within the spirit and scope of this invention.