Gas discharge (plasma) displays

• US 5,793,158 A
• Filed: 05/29/1997
• Issued: 08/11/1998
• Est. Priority Date: 08/21/1992
• Status: Expired due to Term

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Photonic Systems Inc. (Photonics Systems Holding GmbH)
• Inventors: Wedding, Donald K. Sr.
• Primary Examiner(s): O'Shea, Sandra L.
• Assistant Examiner(s): Patel, Vip
• Application Number:
  US08/864,896
• Time in Patent Office: 439 Days
• Field of Search: 313/493, 313/489, 313/484, 313/587, 313/485
• US Class Current: 313/493
• CPC Class Codes: H01J 11/12 with main electrodes provided on both sides of the discharge space
• CPC Class Codes: H01J 11/42 Fluorescent layers

Abstract

A gas discharge display panel incorporating phosphor protected by undercoats and overcoats. The device is comprised of a pair of substrates, each of which has an electrode array thereon with the dielectric coating on at least one of the electrode arrays. An array of channels having sidewalls is formed in the dielectric layer with an array of channels corresponding to and aligned with one of the electrode arrays. The channels have sidewalls and lands between channels with a protective undercoat on the channel sidewalls and a photoluminescent phosphor on the protective undercoat. Due to the sloping nature of the sidewalls and the photoluminescent phosphors being sandwiched between the protective undercoat and overcoat and the channel walls in which the phosphor is placed outside the path of charged particles produced on discharge but close or near the site of the UV production, the arrangement significantly enhances the light output because the phosphor surfaces are greater in extent area wise and are closer to the UV sources in the discharge and are not in the path of the discharge products. Since the light is produced in two spaced areas of phosphor by the UV produced on discharge, more light is produced and electrodes have less attenuating effect on visible light emission from each side.

Claims

1. A gas discharge matrix display device comprising:

a first substrate and a first electrode array on a first surface of said first substrate, a first dielectric layer on said first surface and said first electrode array,

a second substrate having a second surface and a second electrode array on said second surface, a second dielectric layer on said second surface of said second substrate and said second electrode array,

an array of channels formed in one of said dielectric layers, said array of channels corresponding to and aligned with one of said electrode arrays, each channel having channel sidewalls, lands between each channel, respectively, a protective undercoat on said channel sidewalls, a photoluminescent phosphor on said protective undercoat on said channel sidewalls and a protective overcoat on said photoluminescent phosphor such that said phosphor is sandwiched between said undercoat and said overcoat, said channel sidewalls on which said phosphor is placed being outside the path of charged particles produced on discharge and near the site of UV production thereby,

a seal region on each of said substrates, respectively,

means joining said substrates together at said seal regions with said electrode arrays orthogonally related, said lands maintaining a uniform spacing between said electrode arrays and optically isolating said channels from each other, and

a gaseous discharge medium filling said channels.

4. The invention defined in claim 1 or claim 2 wherein the phosphor on one channel sidewall emits light of a different color than its next adjacent neighboring channel, respectively.

5. The invention defined in claim 1 wherein the electrodes in said one of said electrode arrays is aligned with said channels are reflective electrodes.

2. A gas discharge matrix display panel comprising:

a first substrate having a flat surface and a first linear electrode array on aid flat surface, with each electrode in said first linear array having a longitudinal axis, a dielectric layer on said first linear electrode array, means forming an array of channels in said dielectric layer, each channel having a base and a pair of facing sidewalls, each sidewall making an angle to said flat surface, the base of each channel being positioned over and having a longitudinal axis which is aligned with the longitudinal axis of said electrodes in said first linear electrode array, respectively, a thin protective undercoat layer on at least one of said facing sidewalls and the base of said channels, a photoluminescent phosphor layer on said thin protective undercoat on at least one of said facing sidewalls in each said channel, respectively, one or more protective overcoat layers on each said photoluminescent phosphor layer in each said channel,

a second substrate and a second linear electrode array on a surface of said second substrate and transverse to said first linear electrode array, dielectric coating means on said second electrode array, a protective overcoat layer on said dielectric coating means,

a seal region on each of said substrates, respectively,

seal means joining said first substrate to said second substrate at said seal regions, and

a gaseous discharge medium filling said channels.

3. The invention defined in claim 2 wherein each phosphor on said channel sidewalls is a continuous strip.

6. The invention defined in claim 2 wherein said protective overcoat layer is transparent and thin and essentially UV transparent.

7. In a gas discharge display panel in which row and column electrode arrays are insulated from the gas by at least one dielectric layer, and a UV responsive phosphor layer is on the said at least one dielectric layer and at least one protective overcoat layer is on the UV responsive phosphor layer, the improvement comprising a protective undercoat layer between said UV responsive phosphor layer and said dielectric layer whereby said UV responsive phosphor layer is sandwiched between said protective undercoat and said protective overcoat.

8. The invention defined in claim 7 including channels having channel sidewalls formed in said at least one dielectric layer and wherein said phosphor is on said channel sidewalls.

9. The invention defined in claim 7 wherein said protective overcoat layer is transparent and thin and essentially UV transparent.

10. The invention defined in claim 8 wherein each phosphor on said channel sidewalls is a continuous strip.