which is displayed on a monitor 15 being combined with a television synchronizing signal produced by a synchronizing signal generating circuit 19 below a method for correcting the content of the drop out part on the image memory 8 will be explained according to the sequence number with reference to fig4 in step s1 a counter a doc for generating an address for reading data from the doc address memory 12 is initialized then in step s2 the content of the address a doc of the doc address memory 12 is loaded let the read out data be x as y as hereby x as and y as are the coordinates of the start address on the image memory 8 of the drop out part doc along the directions of row and column respectively then in step s3 1 is added to the address a doc in order to read the next address of the address a doc from the doc address memory 12 then the content of the address a doc is loaded as x ae y ae step s4 x ae and y ae are the last address on the image memory 8 of the drop out part doc in step s5 the upper and lower data a3 a4 and the data along.