摘要 |
<p>1,152,420. Magnetic recording and playback. NATIONAL CASH REGISTER CO. 8 Nov., 1967 [1 Dec., 1966], No. 50833/67. Heading G5R. [Also in Division H1] A magnetic recording apparatus comprises a plurality of recording discs 12 mounted on rotating spindle 13 and separate head assemblies 15 for the top and bottom surfaces of each disc. Heads 15a are mounted in support 15b which provides for radial and rotational movement, and an air film of 50-100 micro-inches is maintained between the record surfaces and the heads. The discs are provided on both surfaces with overlayers of synthetic polymer and wax (see Division H1).</p> |