Patent GB-1133826-A (GB)
Title: Improvements in or relating to magnetic video tape recording
IPC: G11B5/53
Filed: 1967-05-04
Abstract: 1,133,826. Magnetic video tape recording. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 4 May, 1967 [7 May, 1966; 15 March, 1967], No. 20716/67. Heading G5R. A magnetic apparatus for recording, playing back and/or erasing electric signals on a tape provided with a magnetizable layer, which comprises an exchangeable magazine having a base, a lid and side faces which accommodates winding-up and winding-off spools, driving and guiding members for the tape, and which is provided with mechanical devices which, upon introduction of the magazine into the rest of the magnetic apparatus, are coupled with one or more winding-up and winding-off devices, and with guiding and/or driving members for the tape, arranged so that for recording, playing back and/or erasing video signals, the magazine accommodates a guiding device which comprises two drum halves, whilst the aligned axes of the drum halves are at an acute angle to the axes of the guiding and/or driving members lying in the travelling direction of the tape immediately before and behind the drum halves, and one of these two sets of axes extends parallel to the spool axes, which angle is chosen so that a loop of the tape can be helically wound around the drum halves, in which one or more video-recording, playing back or erasing heads are adapted to rotate. As shown in Figs. 1 to 3, a box 2 has a shaft 4 about which rotates a spool 5, a guide roller 7, an erase head 8, a sound or synchronizing record/ playback head 9 (both with external contacts 27), tape guides 34 and half, 10, of a fixed drum assembly for helical-scan video recording. The lid 3 has a guide roller 13, a shaft 17 about which rotates a take-up spool 18, the other half, 19, of the fixed drum assembly, and tape guides 11. A driving roller 14 and its shaft 15, and a pressure roller 16, are provided in the apparatus with which the magazine is to be used. A video record/playback head 25, Fig. 3, is mounted on a disc 24 to rotate in a gap 20 provided between the drum halves. The disc 24 is driven by a shaft 32 through toothed members 31, 29, which may incorporate slip contacts or a rotating transformer for the head 25. In Figs. 4 to 9 (not shown), the tape spools are concentric, the sound- or synchronizing-head is downstream of the drum assembly and the video-head disc is driven by a disc having camengagement with it. Also, the driving disc in this case incorporates resilient contacts for the video-head, which contacts are urged into contact with further contacts on the head disc only by centrifugal force, so that connection is made only during rotation. In Fig. 10, the drum halves 68, 69, have their axes parallel to the spool shaft 64, all these axes being perpendicular to the box and lid of the magazine, and it is the axes of guide rollers 70 and 71 which in this case are at an angle to the remaining axes, to provide the helical wrap for the tape 67. The spindles of guide rollers 70 and 71 may be angularly adjustable. In all embodiments the spool shafts (or one of them) are driven by the external apparatus; in the case of the second embodiment concentric shafts would be provided.