Browse Prior Art Database

Plasma Controlled Electroluminescent Matrix Addressed Display Panel

IP.com Disclosure Number: IPCOM000086998D
Original Publication Date: 1976-Nov-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 3 page(s) / 38K

Publishing Venue

IBM

Related People

Chang, IF: AUTHOR [+2]

Abstract

This display device utilizes the AC plasma display technology and thin film technology. By introducing an electroluminescent (EL) layer and a semiconducting (SC) layer, the device can provide high resolution, high brightness and multicolor while retaining the memory and charge transfer features of an AC plasma panel. The device requires no additional metallurgy in its fabrication.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 51% of the total text.

Page 1 of 3

Plasma Controlled Electroluminescent Matrix Addressed Display Panel

This display device utilizes the AC plasma display technology and thin film technology. By introducing an electroluminescent (EL) layer and a semiconducting (SC) layer, the device can provide high resolution, high brightness and multicolor while retaining the memory and charge transfer features of an AC plasma panel. The device requires no additional metallurgy in its fabrication.

The AC plasma or gas discharge panel has been found to be an attractive matrix addressed display. However, there are still several needed improvements in the area of high resolution, high brightness and color choice. The AC plasma display is low in efficiency (< .2l/W), thus having limited brightness. The color for the Ne-Ar mixture is in the red and other colors with reasonable efficiency are not easy to achieve. The panel resolution is dictated by three factors. One factor is lithography of defining long narrow electrodes which may be cured with some development work in etching or depositing long narrow electrodes. Another factor is the paschen characteristics which define a set of optimum parameters - gas pressure, electrode gap spacings and firing voltage. The cell-to-cell interaction, such as charge spreading, is another limiting factor.

The following describes an arrangement which adopts the basic AC plasma panel technology with the addition of two steps of thin-film deposition. The thin- film technology has been successfully adopted to advanced plasma panel technology for the panel insulators, thus the added thin-film deposition is quite compatible with the basic plasma panel technology.

Fig. 1 shows a cross-section of the device. As shown, an EL layer 1 (e.g., ZnS(Mn)) and an SC layer 3 (e.g., ZnS or CdS) are introduced in a regular AC plasma panel. Although EL layer 1 is shown deposited directly on electrode 5, it may likewise be deposited upon an interposing insulating layer deposited directly on electrode 5. Layers 7 and 9 are plate glass substrates upon which is conventionally deposited orthogonal sets of parallel electrodes 5 and 11, respectively. Electrodes 11 are covered with a dielectric layer 13 which is, in turn, covered with high secondary-emission layer 15, such as MgO. Likewise, SC layer 3 is covered with layers of dielectric and high secondary-emission material 17 and 19, respectively. A typical cell in such a panel arrangement is shown by 21.

The basic operating principle is illustrated in Fig. 2. A charge pattern is established on the surface of an "on" cell which is fired and sustained in a normal AC plasma panel operation. The sustaining wave-form is interrupted for a short period of time during which an AC signal (at a frequency, or pulse rate, and magnitude desirable for efficient maximum EL output) is applied to the twin electrodes X(A) and X(B)

The voltage V(AB) causes the EL layer or film 1 to emit light only when the cell had been in the "on" state, i.e.,...