| 摘要 |
<p>PCT No. PCT/GB87/00922 Sec. 371 Date Aug. 18, 1989 Sec. 102(e) Date Aug. 18, 1989 PCT Filed Dec. 30, 1987 PCT Pub. No. WO88/05245 PCT Pub. Date Jul. 14, 1988.Deterioration of the image as a result of failure of individual memory cells is avoided by storing, together with the data relating to each line of the image field, a code value computed as a function of the value of each data bit in the line and the position of each bit in the line. A picture signal stored in this way may be reproduced by transmitting each line signal to a function generator (15), adder (16) and accumulator (17) to re-compute a code value by the same function utilized during the storage of the signal, and applying the stored code value to a latch (21). The outputs of the accumulator (17) and latch (21) are applied to a subtracting circuit (25), and when the latter produces any output signal other than zero, the value of such signal will indicate both the position of any single faulty bit and the direction in which the stored value is in error.</p> |
