Electric lamp and discharge devices – With luminescent solid or liquid material – Vacuum-type tube
Reexamination Certificate
1999-02-26
2001-05-22
Patel, Nimeshkumar D. (Department: 2879)
Electric lamp and discharge devices
With luminescent solid or liquid material
Vacuum-type tube
C313S292000, C313S496000, C313S497000, C313S422000
Reexamination Certificate
active
06236157
ABSTRACT:
TECHNICAL FIELD
The present claimed invention relates to the field of flat panel displays. More specifically, the present claimed invention relates to a coating material for a spacer structure of a flat panel display.
BACKGROUND ART
In some flat panel displays, a backplate is commonly separated from a faceplate using a spacer structure. In high voltage applications, for example, the backplate and the faceplate are separated by spacer structures having a height of approximately 1-2 millimeters. For purposes of the present application, high voltage refers to an anode to cathode potential greater than 1 kilovolt. In one embodiment, the spacer structure is comprised of several strips or individual wall structures each having a width of about 50 microns. The strips are arranged in parallel horizontal rows with each strip extending across the width of the flat panel display. The spacing of the rows of strips depends upon the strength of the backplate and the faceplate and the strips. Because of this, it is desirable that the strips be extremely strong. The spacer structure must meet a number of intense physical requirements. A detailed description of spacer structures is found in commonly-owned co-pending U.S. patent application Ser. No. 08/683,789 by Spindt et al. entitled “Spacer Structure for Flat Panel Display and Method for Operating Same”. The Spindt et al. application was filed Jul. 18, 1996, and is incorporated herein by reference as background material.
In a typical flat panel display, the spacer structure must comply with a long list of characteristics and properties. More specifically, the spacer structure must be strong enough to withstand the atmospheric forces which compress the backplate and faceplate towards each other. Additionally, each of the rows of strips in the spacer structure must be equal in height, so that the rows of strips accurately fit between respective rows of pixels. Furthermore, each of the rows of strips in the spacer structure must be very flat to insure that the spacer structure provides uniform support across the interior surfaces of the backplate and the faceplate.
The spacer structure must also have good stability. More specifically, the spacer structure should not degrade severely when subjected to electron bombardment. As yet another requirement, a spacer structure should not significantly contribute to contamination of the vacuum environment of the flat panel display or be susceptible to contamination that may evolve within the tube.
In some conventional prior art spacer structures, a spacer wall is completely covered with a coating. However, in such prior art spacer structures, the coating material is not tailored for the variation in energy of the electrons which may potentially strike the spacer structure. That is, electrons impinging on the spacer structure near the cathode have an energy which is typically much less than the energy of electrons which strike the spacer structure near the anode. As a result of the variation in energy of impinging electrons, the secondary emission coefficient function of the wall will also vary significantly from the portion of the spacer structure near the cathode to the portion of the spacer structure near the anode.
Thus, need exists for a spacer structure which is at least partially coated with a material tailored for the variation in energy of the electrons which may potentially strike the spacer structure. A further need exists for a spacer structure which meets the above need and which does not degrade severely when subjected to electron bombardment. Still another need exists for a spacer structure which does not significantly contribute to contamination of the vacuum environment of the flat panel display or be susceptible to contamination that may evolve within the tube.
DISCLOSURE OF THE INVENTION
The present invention provides a spacer structure which is at least partially coated with a material tailored for the variation in energy of the electrons which may potentially strike the spacer structure. The present invention further provides a spacer structure which accomplishes the above achievement and which does not degrade severely when subjected to electron bombardment. The present invention further provides a spacer structure which accomplishes both of the above-listed achievements and which does not significantly contribute to contamination of the vacuum environment of the flat panel display or be susceptible to contamination that may evolve within the tube.
In one embodiment, the present invention is comprised of a spacer wall which has a specific secondary electron emission coefficient function associated therewith. In the present embodiment, a coating material is then applied to at least a portion of the spacer wall. In this embodiment, the coating material has a secondary electron emission coefficient function which is different than the secondary electron emission coefficient function of the spacer wall. In so doing, the present embodiment provides a spacer assembly having a plurality of secondary electron emission coefficient functions associated therewith.
In another embodiment, the present invention include the features of the above-described embodiment and further recites applying a second coating material applied to at least a first portion of the spacer assembly. In this embodiment, the second coating material has a secondary electron emission coefficient function which is different than the secondary electron emission coefficient function of the spacer wall and which is also different than the secondary electron emission coefficient function of the first coating material.
These and other objects and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiments which are illustrated in the various drawing figures.
REFERENCES:
patent: 5614781 (1997-03-01), Spindt et al.
patent: 5675212 (1997-10-01), Schmid et al.
patent: 5709577 (1998-01-01), Jin et al.
patent: 5726529 (1998-03-01), Dean et al.
patent: 5772485 (1998-06-01), Jeng et al.
patent: 5776540 (1998-07-01), Chadha et al.
patent: 5811927 (1998-09-01), Anderson et al.
patent: 5821911 (1998-10-01), Jachimowicz
patent: 5831384 (1998-11-01), Potter
patent: 5844824 (1998-12-01), Newman et al.
patent: 5847515 (1998-12-01), Lee et al.
patent: 5850123 (1998-12-01), Potter
patent: 5867795 (1999-02-01), Novis et al.
patent: 5872424 (1999-02-01), Spindt et al.
patent: 5945972 (1999-08-01), Okumura et al.
patent: 5956611 (1999-10-01), Cathey, Jr. et al.
Pan Lawrence S.
Schropp, Jr. Donald R.
Candescent Technologies Corporation
Haynes Mack
Patel Nimeshkumar D.
Wagner , Murabito & Hao LLP
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