CRT display with truncated Rho-Theta presentation
AssigneeRCA Corporation
InventorCharles Albert Clark, Jr.
Life of this patent
Estimating the term…
Abstract
In a CRT display exhibiting a Rho-Theta format where certain of the lines would normally extend beyond the edges of the CRT screen, feedback signals from at least a deflection coil are used to terminate display lines at the edge of the screen and to initiate immediate retrace. Compensation is applied to at least a deflection voltage to compensate for display line bunching caused by unequal scan line times.
Claims9
In a cathode ray tube display device which has a viewing screen and which includes a deflectable electron beam and which includes a deflection means for causing said beam to scan from a common origin on said screen across said viewing screen to and beyond the edge of said viewing screen in a succession of scan lines, the improvement comprising:
- first means responsive to an indication that said electron beam has been scanned to said edge of said viewing screen for producing a signal;
- and
- second means responsive to said signal for initiating retrace of said electron beam to said common origin, and a fixed time after initiating said retrace for initiating the deflection by said deflection means of the next scan line of said succession thereof.
A weather radar system which includes a cathode ray tube having a viewing screen, a deflectable beam and deflection means for deflecting said beam radially outward from an origin on said screen normally a fixed radial distance successively at a plurality of angles, said fixed radial distance extending beyond at least an edge of the viewing screen for some of the plurality of scan lines, the improvement comprising:
- means responsive to said beam being scanned to said edge for producing a first signal;
- means responsive to said beam scanned to said fixed radial distance for producing a second signal;
- means responsive to the first occurring of either said first or second signal for initiating retrace of said deflection beam to said origin and a fixed time after initiating said retrace for initiating the deflection by said deflection means at the next angle of said plurality of said angles.
Dependencies are inferred from the claim text.