US3811061A

US3811061A - Plane surface discharge plasma display panel

Info

Publication number: US3811061A
Application number: US00297267A
Authority: US
Inventors: N Nakayama; Y Shirouchi; T Urade
Original assignee: Fujitsu Ltd
Current assignee: Fujitsu Ltd
Priority date: 1971-10-15
Filing date: 1972-10-13
Publication date: 1974-05-14
Anticipated expiration: 1991-05-14
Also published as: DE2248608A1; DE2248608C3; GB1386021A; NL7213988A; NL176321C; NL176321B; DE2265577C2; DE2248608B2

Abstract

Plasma discharge display apparatus is disclosed, comprising an airtight envelope for receiving discharge electrode pairs formed on a common base plate and a dielectric layer formed overlaying the discharge electrode pairs. The discharge characteristics between the discharge electrodes of the respective pairs are made uniform irrespective of the curvature of the base plate and the shape of the airtight envelope.

Description

United States Patent 1191 Nakayama et a1.

1451 May 14,1974

PLANE SURFACE DISCHARGE PLASMA DISPLAY PANEL Inventors: Norihiko Nakayama, Kobe;

Yasunari Shirouchi, Akashi: Toshinori Urade, Kobe, all of .1 apan Assigneez Fujitsu Limited, Kawasaki,1apan Filed: Oct. 13, 1972 Appl. No.: 297,267

Foreign Application Priority Data Oct. 15, 1971 Japan 46-80935 OCL 15. 1971 Japan .l 46-81407 us. (:1. 313/109.5, 313/217 1m..c1 H0lj 7/42, 11011 1/60 Field of Search 313/1095, 188,217,218

References Cited UNlTED STATES PATENTS I 2/1972 Lay 313/1095 3,673,451 6/1972 Tackett 3l3/l09 5 3,675,065 7/1972 Warne 313/1095 3,346,759 10/1967 Hardwick 313/1095 3,327,154 6/1967 Bowerman..... 313/1095 3,652,891 3/1972 Janning 313/1095 Primary ExaminerWilliam F. Lindquist Attorney, Agent, or FirmStaas, Halsey & Gable [57] ABSTRACT 13 Claims, 22 Drawing Figures PATENTEDHAY 14 1974 3.81 1.' 081 SHEU 2 OF 5 7 I .16 FIG Li ffff I20 I4 E x E FIG. '5

Qmwgm a:

FIG. 6A

FIG. 6B

FIG 60 PATENTEDMAY 14 I914 3.811.061

SHEET 5 OF 5 g FIG. 15

PLANE SURFACE DISCHARGE PLASMA DISPLAY A PANEL BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to discharge plasma display apparatus in which discharge electrode pairs are provided on the same base plate while being insulated from each other.

2. Description of the Prior Art 1 In early plasma display panels such, for example, a

' disclosed in the U.S. Pat. No. 3,559,190, a glass plate having bored therein apertures forming discharge cells is interposed between a pair of glass base plates; a mixture gas composed of neon Ne and nitrogen N is sealed within the discharge cells; electrodes are provided on the outside of each glass base plate in directions perpendicular to 'each other; and a discharge is produced to radiate in the discharge cell at the intersecting point of selected electrodes. The conventional plasma display panels are advantageous in that since the cells each forming a discharge region are isolated from one another, no interference occurs between adjacent ones of them and in that since the apertured glass plate interposed between the pair of the glass base plates serves as a spacer of the latter, the opposing electrodes can be maintained at the same distance. On the other hand, however, the prior art display panels are defective in that evacuation and sealing of the discharge gas are difficult. To avoid this difficulty, it is considered possible to leave out the intermediate glass plate having apertures and assemble the glass base plates with a spacer or spacers interposed therebetween only at their periphery. In such a case, however, it is difficult to hold the glass base plates in parallel with each other, so that the distances between the opposing electrodes become non-uniform to introduce dispersion in the characteristics of the respective discharge regions. Further, since the glass base plates are required mechanically strong enough to withstand the pressure difference between the sealed gas pressure and the atmospheric pressure, they are unduly thick. Accordingly, the provision of the electrodes on the outside of each glass base plate leads to an increase in the distance between the opposing electrodes, which results in a defect that a high firing voltage is required. In order to lower the firing voltage, it is considered necessary to provide an electrode inside of the glass base plates and cover it with thin glass or like dielectric layer. Also in this case, however, it is not easy to hold the glass base plates in parallel with each other. The glass base plates themselves are also a little curved, so that the characteristics of the respective discharge regions cannot be made uniform with case. This presents a problem especially in the construction of large display panels.

SUMMARY OF THE INVENTION A gions regardless of curvature of a base plate.

According to this invention, discharge electrode pairs are provided on a glass or like base plate; a solder glass or like dielectric layer isformed overlying'the discharge electrodes; a glass or like cover is mounted on the dielectric layer to provide a discharge gas space therebetween the periphery of the cover being sealed; an ionizable gas such as neon or the like is sealed within the discharge gas space; and a display is provided by a discharge caused between the respective discharge electrode pairs on the dielectric layer.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and advantages of the present invention will become more apparent by referring to the following detailed description and accompanying drawings, in which:

FIG. 1 is a fragmentary perspective view, partly cut away, showning one example of this invention;

FIG. 2 is its cross-sectional view;

FIG. 3 is a fragmentary perspective view, partly cut away, illustrating another example of this invention;

FIG. 4 is a cross-sectional view of the display apparatus shown in FIG. 3;

FIG. 5 is a cross-sectional view illustrating another example of this invention;

FIGS. 6A to 6D, inclusive, are a sequence of steps involved in the manufacture of the plasma display apparatus of the example depicted in FIGS. 1 and 2;

FIGS. 7A to 7D, inclusive, are a sequence of steps involved in the manufacture of the plasma display panel of the example depicted in FIG. 5;

FIGS. 8 and 9 are cross-sectional views showing modified forms of a discharge cell;

FIG. 10 is atop plan view showing the electrode ar- 1 FIG. 14 is a fragmentary perspective view, partly cut I away, illustrating the plasma display panel of the example of this invention for numeral display;

FIG. 15 is a top plan view showing the electrode arrangement of anotherexample of this invention for numeral display; and v FIG. 16 is a cross-sectional view of the embodiment shown in' FIG. 15.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, there is illusrated a fragmentary perspective view, partly cut away, of one example of this invention. On a glass or like base plate 1, parallel X- and Y- direction electrodes 2 and 4 are provided while being insulated by an insulating layer 3 from each other and a solder glass or dielectric layer 5 is formed on the insulating layer 3. At each intersecting point of the electrodes 2 and 4,

discharge portions

2a and 4a are formed on the insulating layer 3 to provide a discharge gap therebetween. The discharge portion 2a is connected to the electrode 2 through a through hole formed in the insulating layer 3 and a cover 6 as of glass is mounted on the dielectric layer 5 to form a discharge gas space 7 therebetween. the cover 6 being sealed at its periphery, and a discharge gas such as neon or the like is like.

An alternating sustain voltage is impressed to all of the electrodes and a write-in voltage is impressed to selected ones of'the X- and Y-direction electrodes. When an electric field of the discharge gap exceeds a firing voltage, a discharge spot P is produced between the

discharge portions

2a and 4a, as depicted in FIG. 2. Then, the dielectric layer 5 holds the charge produced by discharge to provide a memory function and the discharge spot is maintained by the subsequent sustain voltage as is the case with the conventional plasma display panel. The discharge gaps can be accurately formed by printed circuit techniques and are formed on the same base plate, so that even if the base plate 1 is curved, the discharge gaps do not change. Since the cover 6 is only to form the discharge gas space 7, the degree of parallelism of the electrodes with the base plate 1 is not important and the characteristics of the discharge cells formed with the discharge gaps become uniform and the fabrication of the display panel becomes extremely easy.

The electric field in the discharge gas space 7 is related to the thickness of the dielectric layer 5 and the distance between the

discharge portions

2a and 4a, that is, the discharge gap length; but, by selecting the thickness of the dielectric layer 5 less than about one half of the discharge gap length, the discharge spot can completely be produced in the discharge gas space 7. A display of letters or the like can be provided by the combination of the positions of the discharge spots, that is, selected intersecting points of the X- and Y-direction electrodes 2 and 4.

FIG. 3 is a fragmentary perspective view, partly cut away, of another example of this invention and FIG. 4 is its cross-sectional view. In the present example, the intersecting points of X-direction electrodes 12 formed on a baseplate 11 with Y-direction electrodes 14 are formed by cross-over techniques as in the case of multilayer wiring. In FIGS. 3 and 4, reference numeral 16 indicates a cover and 17 a discharge gas space.

More specifically, the X-direction electrodes 12 each include a plurality of raised portions 12a extending through apertures formed in an insulating plate 13. The i raised portionsl2a are disposed in a common plane with the Y-direction electrodes 14 whereby discharge gaps are formed between the raised portions 12a and the adjacent portions of the Y-direction electrodes 14. In FIG. 5, X-direction electrodes 22 are formed on a base plate 21. X-direction electrodes 24 are spaced from the Y-direction electrodes 23 by an insulating layer 23. The insulating layer 23 includes plurality of openings at the intersecting points of the electrodes to expose one portion of each X-direction electrode 22 in such a manner as to form a discharge region in the neighborhood of each intersecting point. A dielectric layer 25 is formed over all of the exposed portions of the X-direction electrodes 22, the insulating layers 23 and the Y-direction electrodes 24. In FIG. 5, reference ing layer all over of them and then form the Y-direction electrodes thereon.

FIGS. 6A to D are a series of steps employed in the fabrication of the display panel exemplified in FIGS. 1 and 2. At first, holes 102 are formed as by punching through a green sheet 101 and the sheet 101 is fired (FIG. 6A). A conductive paste is filled in the holes 102 to form interconnecting portions 1021; within the holes 102. X-direction electrodes 103 coupled with the connecting portions 102!) are formed on one surface of the sheet 101 by means of printed circuit techniques, and Y-direction electrodes 104 and the aforementioned discharge portions 102a are formed on the other surface of the sheet 101 by means of printed circuit techniques. Finally, the assembly is fired (FIG. 68). Then, a dielectric layer 105 is formed by means of printing, precipitation, spattering, vapor deposition or like method on the surface of the sheet 101 on which the Y-direction electrodes have been formed (FIG. 6C). Next a base plate 106 is attached to the surface of the sheet 101 on which the X-direction electrodes 103 and a cover 108 is mounted on the surface of the sheet 101 on the side of the dielectric layer 105 to provide a discharge gas space 107 thereon, the cover 108 being attached at its periphery to the dielectric layer 105. The discharge gas space 107 is evacuated and then a mixture gas composed of neon Ne and nitrogen N is sealed within the discharge gas space 107, thus providing a finished display panel (FIG. 6D).

FIGS. 7A to D illustrate a series of steps involved in the manufacture of the example of FIG. 5. At first, X- direction electrodes 202 are formed on a base plate 201 and an insulating layer 203 is formed at each intersecting point of the X-direction electrode 202 with Y- direction electrodes subsequently formed (FIG. 7A). Then, Y-direction electrodes 204 are provided to lie on the insulating layers 203 (FIG. 7B) and a dielectric layer 205 is formed all over the X- and Y-

direction electrodes

202 and 203, and the insulating layers 203 (FIG. 7C). A cover 206 is mounted to provide a discharge gas space 207 (FIG. 7D).

The electric field between the X- and Y-direction electrodes is established not only in the discharge gas space but also in the dielectric layer and the insulating layers, so that the display panel is desired to be of such a construction that as large an electric field as possible may be established in the discharge gas space so as to insure efficient generation of the discharge spot. To this end, it is desirable to use such electrode structures as shown in FIGS. 8 to 11. Namely, in the example of FIG. 8, V-shaped grooves are formed in a base plate 31, and X- and Y-

direction electrodes

32 and 34 are provided in the side walls of each groove. A dielectric layer 35 is formed on the base plate 31 to cover the

electrodes

32 and 34. In this example, an electric field is confined in the discharge gas space as indicated by broken lines. In the example of FIG. 9, U-shaped grooves are formed in a base plate 41 and

electrodes

42 and 44 are formed in opposing side walls of each groove. Reference numeral 45 designates a dielectric layer. This example is similar to a prior art plasma display panel of the type in which electrodes are formed in opposing relation through a discharge gas space. However, this example is different from the conventional plasma display panel in that the X- and Y-

direction electrodes

42 and 44 are formed on the same base plate 41.

- energized segments.

FIG. is a top plan view of another example of this invention with the dielectric layer being taken away, and FIG. 11 is a cross-sectional view taken along line A-A in FIG. 10. In this example, insulating layers 53 are formed only at the intersecting points of X- and Y-

direction electrodes

52 and 54; the

electrodes

52 and 54 are formed on the same base plate 51; extensions 60 are formed to extend from the electrodes 54 substantially in parallel with the electrodes 52 or askew thereto; depressions 57 are formed in the base plate 51 between the extensions 60 and the electrodes 52; a dielectric layer 55 is formed on the base plate 51 to cover the depressions 57; and depressions 58 are also formed in a cover 56 in opposing relation to depressions 57. Electric fields are established in discharge gas spaces 59 defined by the depressions 57 and 58, as indicated by broken lines, to produce discharge spots in the discharge gas spaces 59.

As has been described in the foregoing, in the plane surface discharge plasma display panel of this invention, the X- and Y-direction electrodes are provided on the same base plate while being insulated from each other at their intersecting points and the discharge gaps defining the discharge regions are. formed at the intersecting points or in the neighborhood thereof. Accordingly, curvature of the base plate does not exert any influence on the discharge characteristic and since the discharge gaps can be uniformly formed as by printed circuit techniques with accuracy, uniform characteristics are obtained. Especially in the case of constructing a large display panel, no influence is exerted by curvature of the base plate and the cover, so that the large display panel can also be produced. Thus, the discharge characteristics of the discharge regions can be made uniform, and accordingly no faulty shift occurs also in a self-shift panel of the type that the discharge spot is sequentially shifted to adjacent discharge regions in response to the changeover of the sustain voltage.

FIG. 12 is a diagrammatic showing of the electrode arrangement of one example of this invention for providing a numeral display by selective lighting of electrode segments and FIG. 13 is its cross-sectional view. One a base plate 61, there are provided pairs of parallel and opposing bar-shaped

discharge electrodes

62 and 64 of seven segments, and a dielectric layer 65 is formed'on the base plate 61 to cover the electrodes. Reference numeral 66 indicates a cover and 67 a discharge gas space. A discharge is caused between the

electrodes

62 and 64 of each segment and numerals 0 to 9 can be displayed by the combination of selectively FIG. 14 is a fragmentary perspective view, partly cut away, of another example of the plasma display panel of this invention for numeral display. In the illustrated example, electrodes 72 and 74 are provided on a base plate 71 and a dielectric layer 75 is formed over them.

The inner electrodes 74 are interconnected with each other and, further, are connected through a lead 77 to a terminal 78, while the outer segment electrodes 72 are connected separately through leads to corresponding terminals 80. In FIG. 14, reference numeral 76 indicates a cover, and 79 spacers for forming a discharge gas space.

FIG. is also a diagrammatic representation of the electrode arrangement of another example of this invention for numeral display, and FIG. 16 is its crosssectional view. On a base plate 81 as of glass, there are and an insulating layer 83 is formed over them.

Barshaped discharge electrodes

82a, 82b and 84 making up each segment are formed on the insulating layer 83 and are connected to the leads 90 to 98 and the connecting

lines

88 and 89 through holes formed in the insulating layer 83. A dielectric layer 85 is forined on 7 these electrodes and a discharge gas space 87 is provided between the dielectric layer 85 and a cover 86.

The

common electrodes

82a and 82b are interconnected through the connecting line 89 and are all connected to the lead 90 through the connecting lines 88. The lead 90 is for digit selection and the leads 91 to 98 are connected to the selecting electrodes 84 of the respective segments for segment selection.

lmpressing a write-in voltage, that is, a voltage highe than a firing voltage through leads, for example, 91, 93, 94, 96, 97 and 98 with an alternating sustain voltage being impressed to all of the leads 90. to 98 (as in the case with usual plasma display panels), a numeral 3" is displayed. This display is continuously maintained only by the impression of the sustain voltage due to the memory action by the wall voltage until an erasing voltage is impressed. In .this example, a discharge is caused between the electrode 84 and the

common electrodes

82a and 82b on both sides thereof in each slected segment and the display area is wide as compared with that in the example of FIG. 12, thereby facilitating a rapid interpretation of the display. Further, the connecting

lines

88 and 89, the

leads

90 and 98 and the

electrodes

82a, 82b and 84 are formed in the same manner as a two-layer wiring, so that the segment selecting electrodes for each digit can be readily connected by the leads and the fabrication of the display panel is easy. The leads 90 to 98 are connected to corresponding terminals provided on the peripheral portion of the base plate as is the case with the example of FIG. 14.

Numerous changes may be made in the abovedescribed apparatus and the different embodimentsof the invention may be made without departing from the spirit thereof; therefore, it is intended that all matter contained in the foregoing description and in the'accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. Discharge plasma display apparatus comprising:

a. a plurality of spaced electrode pairs disposed in a common place on a surface of a common insulating support means, said plurality of electrode pairs being disposed in a configuration to display information;

b. means for impressing an AC sustain voltage to each of said electrode pairs for establishing an alternating electrical field between said electrodes of a pair and a write-in voltage to selected ones of said electrode pairs;

c. a dielectric layer disposed over said plurality of electrode pairs in common contact with each electrode of said electrode pairs; and

d. means for forming an envelope having an ionizable gas therein in cooperation with said common insulating support means, disposed opposite said plurality of electrode pairs so that the alternating elec-' trical field passes through said dielectric layer and said ionizable gas as contained within said envelope means.

2. Discharge plasma display apparatus as claimed in claim 1, wherein said common support means comprises a second dielectric layer which includes first and second opposing surfaces, said plurality of electrode pairs isdisposed on said second surface, and said impressing means comprises a first electrical connector disposed upon said first surface of said second dielectric layer and connected with one electrode of each of said pairs, and a second electrical connector is disposed upon said second surface of said second dielectric layer connected with the other electrode of each of said pairs, said first-mentioned dielectric layer is disposed upon said second surface.

3. Discharge plasma display apparatus as claimed in claim 2, wherein said second dielectric layer includes a plurality of openings therethrough for receiving means for establishing an electrical connection between said one electrode of each of said pairs and said first electrical connector.

4. Discharge plasma display apparatus as claimed in claim 3, wherein said connecting means comprises U- shaped portions formedin said first electrical connector and disposed through said openings within said second dielectric layer.

5. Discharge plasma display apparatus as claimed in claim 2, wherein there is included a first plurality of said first electrical connectors disposed in a first direction and a second set of said second electrical connectors disposed in a second direction substantially perpendicular to the first direction.

6. Discharge plasma display apparatus as claimed in claim 1, wherein one electrode of each of said pairs comprises an electrical connector disposed in a first direction, said other electrode of each of said pairs comprising a second electrical connector disposed in a second direction traverse to said first direction, and there further is included a second dielectric layer for insulating said first electrical connector from said second electrical connector at their point of intersection.

7. Discharge plasma display apparatus as claimed in claim 1, wherein at least one groove is disposed within said surface of said support means, and said electrodes of each of said pairs are disposed in a spaced relationship on a surface of said groove to form a discharge path across the groove between said electrodes.

8. Discharge plasma display apparatus as claimed in claim 1, wherein said plurality of electrode pairs is dia-, posed in a configuration upon said surface for forming a selected one ofa plurality of alphanumeric characters dependent upon which electrode pairs are energized.

9. Discharge plasma display apparatus as claimed in claim 8, wherein said impressing means includes a first electrical connector for making a common electrical connection to one electrode of said electrode pairs, and a plurality of electrical connectors for making separate connections to each of said other electrodes of said electrode pairs.

10. Discharge plasma display apparatus as claimed in claim 9, wherein there is included a second dielectric layer disposed upon said surface of said support means, said plurality of electrode pairs disposed upon a surface of said second dielectric layer remote from said support means, and said first electrical connector and said plurality of said second electrical connectors disposed upon said surface of said support means and connected to said electrode pairs through openings within said second dielectric layer, said first-mentioned dielectric layer is disposed on said remote surface of said second dielectric layer and said plurality of electrode pairs.

1 1. Discharge plasma display apparatus as claimed in .claim 8, wherein there is included a third electrode with each of said plurality of electrode pairs, said third electrode being electrically connected to said one electrode of said electrode pair and said other electrode being disposed intermediate between said one electrode and said third electrode.

12. Discharge plasma display apparatus as claimed in claim 1, wherein said impressing means includes a first set of electrical connectors disposed'in a first direction and electrically connected to one electrode of said electrode pairs, and a second set of electrical connectors disposed in a second direction traverse to the first direction and intersecting said electrical connectors of said first set at a plurality of points, a plurality of insulating layers disposed between said electrical connectors of said first and second sets at their points of intersection, said second set of electrical connectors including a plurality of segments extending therefrom in the first direction to form with an adjacent portion of an electrical connector of said first set an electrode pair for producing a discharge path therebetween.

13. Discharge plasma display apparatus as claimed in claim 12, wherein said first and second sets of electrical connectors are disposed upon said surface of said support means and said support means includes a plurality of recesses each disposed at a discharge path, said dielectric layer disposed over said first and second sets of electrical connectors and said surface, and said envelope means comprising a cover member spaced from said dielectric layer and forming said envelope means therebetween through which passes the discharge paths.

Claims

1. Discharge plasma display apparatus comprising: a. a plurality of spaced electrode pairs disposed in a common place on a surface of a common insulating support means, said plurality of electrode pairs being disposed in a configuration to display information; b. means for impressing an AC sustain voltage to each of said electrode pairs for establishing an alternating electrical field between said electrodes of a pair and a write-in voltage to selected ones of said electrode pairs; c. a dielectric layer disposed over said plurality of electrode pairs in common contact with each electrode of said electrode pairs; and d. means for forming an envelope having an ionizable gas therein in cooperation with said common insulating support means, disposed opposite said plurality of electrode pairs so that the alternating electrical field passes through said dielectric layer and said ionizable gas as contained within said envelope means.

2. Discharge plasma display apparatus as claimed in claim 1, wherein said common support means comprises a second dielectric layer which includes first and second opposing surfaces, said plurality of electrode pairs is disposed on said second surface, and said impressing means comprises a first electrical connector disposed upon said first surface of said second dielectric layer and connected with one electrode of each of said pairs, and a second electrical connector is disposed upon said second surface of said second dielectric layer connected with the other electrode of each of said pairs, said first-mentioned dielectric layer is disposed upon said second surface.

4. Discharge plasma display apparatus as claimed in claim 3, wherein said connecting means comprises U-shaped portions formed in said first electrical connector and disposed through said openings within said second dielectric layer.

8. Discharge plasma display apparatus as claimed in claim 1, wherein said plurality of electrode pairs is diaposed in a configuration upon said surface for forming a selected one of a plurality of alphanumeric characters dependent upon which electrode pairs are energized.

11. Discharge plasma display apparatus as claimed in claim 8, wherein there is included a third electrode with each of said plurality of electrode pairs, said third electrode being electrically connected to said one electrode of said electrode pair and said other electrode being disposed intermediate between said one electrode and said third electrode.

12. Discharge plasma display apparatus as claimed in claim 1, wherein said impressing means includes a first set of electrical connectors disposed in a first direction and electrically connected to one electrode of said electrode pairs, and a second set of electrical connectors disposed in a second direction traverse to the first direction and intersecting said electrical connectors of said first set at a plurality of points, a plurality of insulating layers disposed between said electrical connectors of said first and second sets at their points of intersection, said second set of electrical connectors including a plurality of segments extending therefrom in the first direction to form with an adjacent portion of an electrical connector of said first set an electrode pair for producing a discharge path therebetween.