US 6,473,139 B1Granted

Data error recovery for digital beam landing error correction arrangement

AssigneeThomson Licensing

InventorJohn Barrett George

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Abstract

In a video display, correction data for a digital convergence arrangement are stored in a first non-volatile memory. During power turn on procedure, the correction data are read out of and stored in a volatile memory. During each deflection cycle, the data stored in the volatile memory are successively read out and applied to an auxiliary convergence winding. When a parity error is detected in the read out data, the data stored in a second non-volatile memory are automatically read out and transferred to the volatile memory and to the first non-volatile memory. The second non-volatile memory contains a duplicate of the correction data stored in the first non-volatile memory, during factory set up. The data in the second non-volatile memory are maintained parity error free. Thereby the parity error containing data stored in the first non-volatile memory are substituted with the data that are free of parity error, provided by the second, non-volatile memory.

Claims5

Dependent claims

A video display deflection apparatus, comprising:

means for generating a deflection field in a cathode ray tube to vary a beam landing location of an electron beam of said cathode ray tube;
a first memory space containing beam landing error correction data that are read out of said first memory space, during a given deflection cycle, and applied to said deflection field generating means for varying said deflection field by a variable amount that varies in accordance with said varying beam landing location;
a second memory space containing beam landing error correction data that are read out from said second memory space and stored in said first memory space, during a mode set up procedure;
a third memory space containing beam landing error correction data;
a bit error detector for detecting data bit error in the data stored in one of
said first and second memory spaces;
and
a controller for reading out said beam landing error correction data of said third memory space and for storing said read out data of said third memory space in one of said first and second memory spaces to replace said data bit error containing data, after said data bit error has been detected.

5 more elements

Dependencies are inferred from the claim text.