Patent GB-1462827-A (GB)
Title: Apparatus for magnetically recording and reproducing video signals and which has a still motion reproducing mode of operation
IPC: H04N/
Filed: 1974-11-11
Abstract: 1462827 Helical-scan video tape recorder SONY CORP 11 Nov 1974 [15 Nov 1973] 48744/74 Heading G5R A helical-scan video magnetic tape recording and playback apparatus has a still motion reproduction mode of operation in which a tape drive capstan 26 and pinch roller 35, Fig. 1, are inoperative and a brake 82, Fig. 2, holds a tape supply reel support 21 against rotation by driving means of a tape take-up reel support 22, and means 108 normally spaced from support 21 are manually actuatable during said still motion mode to engage and rotate support 21 to thereby adjust the longitudinal position of the tape relative to rotary scanning assembly 11, 13, Fig. 1, to achieve the best still picture. The apparatus may be of the open-reel or cassette type. In the still motion mode, drive to the take-up reel support 22 is maintained via an idler (23) and slipping clutch (24), Fig. 3 (not shown), but the tape is held stationary by a brake pad 82, Fig. 2, located on a spring 84 biased brake lever 80, pivoted on a spring 76 biased pivoted arm 74, and acting on supply reel support 21. To move the tape longitudinally to achieve the best still picture with least annoying guard band noise, a knob 103 is manually oscillated whereby, via a link 96, an arm 93 pivoted about the spindle 94 of support 21 is oscillated in directions a, a<SP>1</SP>. Each time arm 93 is pivoted in direction a, a drive member 108 pivoted on arm 93 has a wedge-like engagement with a cylindrical surface 109 of support 21 which is thereby incrementally driven clockwise to unwind the tape slightly for take-up by the reel 17. Member 108 slides on surface 109 without turning support 21 when arm 93 pivots in direction a<SP>1</SP>. A spring 107 biases arm 93 in direction a<SP>1</SP> to a normal inoperative position in which cam follower pin 117 on drive member 108 engages a raised part 116 of a cam 115, 116 to maintain a separation d between surface 109 and member 108. A blocking member 120 on a pivoted arm 118 is drawn by link 123 and spring- biased arm 67 to a position maintaining such separation d, even if knob 103 is inadvertently operated, whenever a pin 66 on a support ring 31, Fig. 1, of a tape loading/unloading device 30 is not engaged with arm 67, e.g. during fast wind/rewind. The brake 82 is engaged and disengaged via links 85, 87, 89 when pinch roller actuating solenoid 47 is de-energized and energized, respectively. Tape loading and unloading from a cassette 15, Fig. 1, is effected by a rotary ring 31 and swinging arms 54, 55. In the loading start position, pins 60, 61 on auxiliary rings 58, 59 are at 60<SP>1</SP>, 61<SP>1</SP> within cassette 15 and pinch roller 35 and pin 34, both on ring 31, are at 35<SP>11</SP>, 34<SP>11</SP> in cassette 15. When load push-button 70a is pushed ring 31 is first rotated clockwise through about 60 degrees to a "stop" position whereat pin 34 and roller 35 are at 34<SP>111</SP> and 35<SP>111</SP> and guide pins 52, 53 on arms 54, 55 have been swung from their starting positions 52<SP>1</SP>, 53<SP>1</SP> to the full-line positions and the tape extends along run L1 for fast wind/rewind. To fully load the tape for normal record/playback and still motion playback, play button 70c is then pressed whereby ring 31 is further rotated clockwise from the "stop" position. Auxiliary rings 58, 59 initially-continue to turn with ring 31 until ring 59 is stopped by a projection 63 thereon engaging a stop 65 and then ring 58 is stopped by a projection 62 thereon engaging stop 64, ring 31 continuing to rotate until the pin 66 thereon moves the arm 67 to operate microswitch 69 and de-energize the drive roller 33 of ring 31, and to also push the blocking member 120 to an inoperative position, the tape then being along run L2. To unload the tape to the fast wind/rewind position or fully back into cassette 15 the ring 31 is driven anti-clockwise. During full unloading, rings 58, 59 initially turn with ring but are stopped when pins 60, 61 are at 60<SP>1</SP>, 61<SP>1</SP>, and arms 54, 55 swing back to positions 54<SP>1</SP>, 55<SP>1</SP> or ring 31 rotates from its "stop" position to the starting position. Tape tension may be controlled by a brake band (not shown) acting on reel support 21 and controlled by means of arm 54 and by a brake (not shown) acting on reel support 22 and controlled by a pivoted tape tension sensing arm 72.