Claims
- 1. An apparatus for uniformly depositing phosphor particles onto a display surface comprising:
- a) a spray chamber having an open side and an apertured metal plate positioned and arranged opposite to said open side,
- b) a display window comprising said display surface opposing said metal plate and positioned to close said open side,
- c) an electrostatic spray gun, for spraying a mixture of air and ionized phosphor particles towards said display surface, positioned and arranged through said aperture and directed towards said display surface, said electrostatic gun comprising at least one outlet means positioned and arranged within said chamber and parallel to said display surface and said metal plate,
- d) inlet means provided in said gun for passing a supply of air and phosphor particles into said gun for providing a mixture of air and phosphor particles in said gun,
- e) ionizing means, located within said electrostatic spray gun for ionizing said mixture of air and phosphor particles to thereby provide a mixture of ionized air and ionized phosphor particles in said gun,
- f) means, contacting said spray chamber, for electrically charging inner surfaces of said spray chamber to provide a potential difference between the display surface and said metal plate, said metal plate being at a voltage sufficient to form a uniform repulsive field to said ionized phosphor particles,
- g) means for passing said mixture of ionized air and ionized phosphor particles through said at least one outlet into said chamber in a direction parallel to said metal plate and said display surface at a voltage sufficient to fill said chamber below said display window, and
- h) rotating means contacting said means for passing said mixture through said at least one outlet for rotating said means for passing said mixture about the axis of said spray gun from a first stop position to a second stop position.
- 2. An apparatus according to claim 1, wherein said metal plate has a potential of -20 to -40 kV, and wherein said display window is at ground potential.
- 3. An apparatus according to claim 1, wherein said charge phosphor particles are both electrostatically attracted to said display window and pneumatically moved to said display window to uniformly coat said display window.
- 4. An apparatus according to claim 1, wherein said means for passing charged phosphor particles includes a high voltage electrode provided in said gun in the vicinity of said at least one outlet means.
- 5. An apparatus according to claim 4, wherein said high voltage on said electrode is about 80 kV.
Parent Case Info
This is a division of application Ser. No. 08/580,408, filed Dec. 28, 1995 now U.S. Pat. No. 5,637,357.
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DEX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
580408 |
Dec 1995 |
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