Patent GB-1467905-A (GB)
Title: Recording and or reproducing apparatus
IPC: G11B25/04
Filed: 1974-06-25
Abstract: 1467905 Recording on flexible sheets SONY CORP 25 June 1974 [11 July 1973] 28219/74 Heading G5R Recording and/or playback apparatus utilizes as a record medium a sheet assembly 201, Fig. 8A, including at least two flexibly resilient sheets normally disposed in closely adjacent, confronting relation and at least one of which is adapted to have information recorded thereon, and the apparatus includes separator means 215, Figs. 9, 11, 12, for receiving the sheet assembly and separating substantial portions of the sheets from each other, guiding means 222, Fig. 11, associated with a guide drum D 202 , to receive the separated portion of said one sheet and wrap it around drum D 202 , rotary signal transducing means H 202 , H<SP>1</SP> 202  rotatable in a circular path substantially coinciding with the circumference of drum D 202 , and means for moving the sheet assembly and rotary signal transducing means relative to each other in a direction transverse to the circular path of the transducing means so that the latter scan successive parallel tracks on the separated portion of said one sheet wrapped around drum D 202 . The record medium sheet assembly may comprise an audio record sheet (3), or (103), Figs. 1, 6 (not shown), which is less flexible and longer or wider than a video record sheet (2) or (102), with the sheets being connected together at one end with record surfaces of the sheets facing one another. An alternative assembly 201, Fig. 8A, has a non-recordable leader sheet 205 which is less flexible than both of an audio record sheet 203 and a video record sheet 202, sheet 205 being longer than sheets 202, 203 and sheet 202 being narrower than sheets 203, 205; such an assembly may have an audio sheet and a video sheet superimposed on one another at one side of the leader and a further audio sheet and a further video sheet at the other side of the leader, Figs. 13A, 13B (not shown), the record sheets on the one side or the other side of the leader being guided to operative positions in dependence on which way the sheet assembly is inserted into the sheet separator. The signals may be recorded as grooves, as capacitance variations, electrooptically as variations in light reflection or transmission, or, as shown, magnetically. Record/playback apparatus, Figs. 9, 11, 12, for the sheet assembly 201 of Fig. 8A, has a separator 215, Fig. 9, comprising side members 206a, 206b spaced apart by the width of sheet 202. On insertion of the sheet assembly, side edges of sheets 203, 205 run in channels 208 and the leading end of sheet 205 is guided by triangular diverters 209 into branches 208b, sheet 205 causing diverters 209 to then pivot into a position to guide sheet 203 into branches 208c, whilst sheet 202, unaffected by channels 208 and diverters 209, passes into channels 207f, the sheets assuming the positions in Fig. 11 on full insertion. A motor rotates drum D 202  and video heads H 202 , H<SP>1</SP> 202  thereon and via belts B 1 , B 2 , and clutch C 2 , Fig. 12, rotates drum D 203  and audio heads H 203 , H<SP>1</SP> 203  at a slower speed whereby the audio track pitch is larger than the video track pitch. The audio heads have a transducing gap width less than the audio track pitch, but the video heads have a gap width greater than the video track pitch whereby the video tracks overlap. With clutch C 2  engaged, the sheet separator 215, sheet assembly 201 and guides 222, 223, 225 are driven as a unit axially of drums D 202 , D 203  via a lead screw 247 for normal record/playback. On disengaging clutch C 2  and engaging clutch C 1  said unit is moved in reverse for backspacing or reverse playback. With both clutches disengaged, stop motion playback is produced, or slow motion playback may be effected on manually moving said unit by rotating shaft 236. The audio heads are exactly 180 degrees apart, but the spacing of the video heads deviates from 180 degrees by an angle corresponding to half a horizontal line period whereby the positions of the recorded horizontal sync. pulses in the successive video tracks are arranged along straight lines, Fig. 14A (not shown). The video signals may be recorded as an FM carrier or, preferably, as a phase modulated carrier with the phases of the carrier to be modulated in the successive tracks being aligned in directions parallel to the head gaps whereby during playback of track T n  no beat interference is produced by tracks T n-1 , T n+1 , scanned at the same time as track T n  due to the video head gap width being greater than the video track pitch; a tracking servo is not required with such phase modulation recording.