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Plasma Panel Optical Cell by Cell Tester

IP.com Disclosure Number: IPCOM000085673D
Original Publication Date: 1976-May-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Criscimanga, TN: AUTHOR [+4]

Abstract

Upon fabrication of a plasma display panel (PDP), it is desirable to test the "on-off" state of the cells in the panel while the panel is displaying an arbitrary image such as a test pattern, to ensure that the panel operates within the prescribed margins. Such a test can be performed on the panel alone or the panel and its associated drive circuitry. With this testing device, the operating margins of the panel under static as well as dynamic conditions can be determined, if desired, on a cell-by-cell basis.

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Plasma Panel Optical Cell by Cell Tester

Upon fabrication of a plasma display panel (PDP), it is desirable to test the "on-off" state of the cells in the panel while the panel is displaying an arbitrary image such as a test pattern, to ensure that the panel operates within the prescribed margins. Such a test can be performed on the panel alone or the panel and its associated drive circuitry. With this testing device, the operating margins of the panel under static as well as dynamic conditions can be determined, if desired, on a cell-by-cell basis.

The tester interrogates each cell by selectively erasing it, causing the lighted cells to emit light at a moment when the other cells on the PDP are in a static state, and a photomultiplier is gated or strobed to detect the light emitted from the selective erase. If a cell is "on" it emits light when being erased, while an "off" cell does not. By lowering the sustain voltage and testing the on cells, the lower margin of the cells can be tested, while by raising the sustain voltage, and testing the off cells, the upper margin of the panel can be tested. Both tests are performed by the erase technique described above.

Referring to the drawings, the plasma display panel 21 with associated drive circuitry 22 and a photomultiplier tube (PMT) 30 are packaged in a light-tight enclosure 34. PMT 30 is biased and switched by bias and switching circuit 31. Digital controller 40 issues write and erase commands to the panel driver circuits 22...