9. The apparatus according to claim 5 wherein said means for producing an electrical signal are further defined to include a return beam vidicon tube including means for producing an electron beam, and means for deflecting said electron beam in response to said first and second control means.
9. The apparatus according to claim 5 wherein said means for producing an electrical signal are further defined to include a return beam vidicon tube including means for producing an electron beam, and means for deflecting said electron beam in response to said first and second control means. 10. The apparatus according to claim 9 further comprising third control means in the signal path of said electron beam for controlling intensity of said electron beam to scan said storage tracks on said target means.