Patent GB-1522528-A (GB)
Title: Video disc player
IPC: G11B19/16
Filed: 1976-01-13
Abstract: 1522528 Video disc playback SANYO ELECTRIC CO Ltd 13 Jan 1976 [14 Jan 1975 (2) 17 Jan 1975 20 Jan 1975 17 July 1975] 1268/76 Heading G5R In a video disc playback device, each disc in its envelope is manually entered into a receiving chamber where the disc is held whilst the envelope is withdrawn and after playback the disc is removed by entering the envelope into the chamber and withdrawing it loaded with the disc. A disc VD is disposed in envelope J with part of the disc exposed at the envelope edge which lesds during entry of the envelope with face 1 uppermost into the playback device. Cut-out 1C on the envelope co-operates with a keyway in the device to ensure correct orientation. With a control knob 53 in its off position and the lid PL of the device open the envelope with disc is entered via porch 10 into the receiving chamber. When fully inserted a gripper formed of a resilient covered fixed member 22 and movable member 17 grip the exposed part of the record retaining it whilst the envelope is removed from the chamber. The lid PL is now lowered and movement is coupled to a slider 32 carrying pins 34, 32c whereby the movable member 17 of the gripper is pivoted away from fixed member 22 and a disc raising member 29 (to be referred to later) is pivoted below the surface of platform 5 forming the base of the receiving chamber. As a result the record drops on to the platform where it is centred by conical projection 44a of disc holder 44 mounted on an arm 45 movable with the lid. The holder engages disc mount 43 and the disc is secured between holder and mount which are held engaged by a permanent magnet part of the mount. The control knob is now moved from the off position to a start position. At the first part of this movement a locking device is actuated which locks the lid in the closed position. The rotation of the knob is also transmitted via gear 55 and small gear 63 to a drive reel 62 driving a cord extending over guides 66a, 66b and secured to a carriage 57. The cord drives the carriage in the direction of its length such that when the knob is in its start position a pick up stylus of pick up assembly P mounted on the carriage is over the start groove of the record. On operation of the play button 68 a motor M driving the record is energized so that the record rotates supported on an air cushion above the platform 5 and a slide member 72, Fig. 16 is moved to the right and latched in position so that a worm gear 83 driven by shaft 82 and worm gear 81 from the record drive shaft, is moved into engagement with a large gear 64 also coupled to the drive reel 62 so that the pick up mechanism carriage is driven in synchronism with rotation of the record. In addition the pick up mechanism carriage is tilted to move the stylus into engagement with the record. The record is now played back during which time the gear 55 and the knob are also rotated. The system is arranged such that at the end of the record a release pin on gear 55 acts on the latch of slide member 72 so that this is returned to its original position with the worm gear 83 uncoupled from the carriage drive gear 64. At the same time the play button is released, the pick up arm carriage is tilted to raise the pick up stylus and the motor M is de-energized. To remove the played back disc the control knob 53 is rotated back to its off position, this movement returning the pick up assembly carriage to its original position and the final part of the movement unlocking the lid PL. With the lid lifted the disc is released from engagement with the disc mount and the movement of slider 32 allows movable member 17 of the gripper to move into engagement with fixed member 22 and allows lifting member 29 to pivot raising the edge of the record nearest the porch 10 so that when the envelope is entered the disc is inserted therein. The geometry of the panel region and gripper region of the record receiving chamber and the shape of the leading edge of the envelope assists in the removal and subsequent reinsertion of the disc in the envelope. A grinding wheel 88 is provided for sharpening the stylus after so many records have been played. If during play the stop button is operated this has the effect of unlatching slide member 72 so that the device is stopped as described. If the repeat button is depressed then an arm 77, Fig. 16, moves a second slide member 73, mounted on slide member 73 to the left to a latched position where it is held for a fixed period of time during which with the worm gear 83 disconnected from drive gear 64, the pick up assembly carriage is not driven so that the picture being displayed is repeatedly played back. At the end of the period of time the second slide member is unlatched and the device is returned to normal operation.