Browse Prior Art Database

Long Life CRT Display

IP.com Disclosure Number: IPCOM000094270D
Original Publication Date: 1966-Aug-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 23K

Publishing Venue

IBM

Related People

Marchetti, AA: AUTHOR [+3]

Abstract

In a CRT display system, one consideration involved in providing a substantially flicker-free display is the life of the phosphor utilized in the CRT. Assuming that the various parameters which effect phosphor selection are invariant, a system for extending the life of the phosphor functions as follows. In the conventional CRT, character display normally occurs on the same horizontal rows such that wear on the phosphor is concentrated on the display areas. By setting the space between character rows equal to or greater than that used for display and alternating the display between its normal position and the the space areas, the wear on the phosphor is extended over substantially the entire display surface and the tube life is greatly expanded.

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Long Life CRT Display

In a CRT display system, one consideration involved in providing a substantially flicker-free display is the life of the phosphor utilized in the CRT. Assuming that the various parameters which effect phosphor selection are invariant, a system for extending the life of the phosphor functions as follows. In the conventional CRT, character display normally occurs on the same horizontal rows such that wear on the phosphor is concentrated on the display areas. By setting the space between character rows equal to or greater than that used for display and alternating the display between its normal position and the the space areas, the wear on the phosphor is extended over substantially the entire display surface and the tube life is greatly expanded. This is accomplished in a raster scanning CRT display system by varying the timing of the vertical synchronizing signal resulting in shifting the video data in relation to the vertical reference.

The vertical retrace signal is applied from timing and control 11 to latch circuit
13. The complement signal which causes the display vertical displacement is applied from timing and control 11 to latch circuit 15. Output 17 of latch 13 conditions And's 19 and 21. Outputs 23 and 25 from latch 15 provide the second input to And's 19 and 21 respectively. Assume that line 23 is activated during the normal character positioning and line 25 during the space interval and that latch 15 is initially set.

Under this c...