Abstract: An arrangement is provided for computing the magnitude value of the vector sum of two quadrature-related component signals I and Q with a minimal of hardware. To this end, the magnitude values of the orthogonal I and Q signals are applied to a ROM as address codes to produce the Log.sub.B .vertline.I.vertline. and Log.sub.B .vertline.Q.vertline. values to the logarithmic base B. The smaller of the Log.sub.B .vertline.I.vertline. and Log.sub.B .vertline.Q.vertline. logarithmic values is subtracted from the larger of the logarithmic values to produce the absolute value .vertline.D.vertline. of the difference between the respective logarithmic values. The difference value D is applied to a ROM as an address code which is programmed to generate a correction value F=0.5 Log.sub.B (1+B.sup.-2.vertline.D.vertline.).

Abstract: A 7 bit digital signal is dithered by adding a low-level digital dithering signal comprised of alternating 1's and 0's, and by truncating the product to 6 bits. To dedither, an EXCLUSIVE-OR gate compares the previous and the current values of the least significant bit of the 6 bit dithered signal. If they are dissimilar, it outputs a "1". Otherwise, it outputs a "0". The output of the EXCLUSIVE-OR gate is ANDed with the dithering signal. If the dithering signal and the output of the EXCLUSIVE-OR gate are both one, then the 6 bit dithered signal is decremented. Otherwise, the 6 bit dithered signal is passed unchanged. The decremented-or-not 6 bit dithered signal is combined with the bit generated by the EXCLUSIVE-OR gate to produce the final 7 bit reconstituted signal.

Abstract: Apparatus for the manufacture of a video disc caddy sleeve comprising folding platens, an intermediate spacer plate with indentations on the leading edge, and a selective heating means. Spacer plate causes plastic sheet to bend in the middle while folding platens close to a folded up position. Indentations on the leading edge act to keep label, already adhered to plastic sheet, from tearing while sheet is being bent into a U-shaped enclosure.

Abstract: The player is provided with a pair of spaced apart spine latching members which hook up with an inner record retaining spine as a caddy is inserted into the player so that when the outer jacket is withdrawn, the record/spine assembly is retained inside the player. A caddy overtravel mechanism prevents a selected one of the latching members from latching up the spine until the other latching member is also in position to capture the spine. A rigid coupling member interconnecting the latching members precludes the other latching member from capturing the spine until both latching members are ready to latch up the spine to assure simultaneous latching of the spine.

Abstract: A video disc player has a record extraction mechanism to facilitate record loading and unloading while the record remains enclosed in its caddy. The caddy comprises a record retaining spine releasably secured to an outer sleeve by means of a pair of spine locking fingers extending from the opposite edges thereof. A pair of spine releasing members engage and deflect the spine locking fingers to release the spine from its sleeve when a caddy is inserted into the player. Simultaneously, a pair of spine latching members hookingly engage the spine to hold it in place so that the record/spine assembly is retained inside the player when the sleeve is withdrawn. When the sleeve is reinserted into the player to recapture the record/spine assembly, it engages and drives the spine releasing members against the spine latching members in a manner freeing the spine. The caddy is then extracted.

Abstract: The stylus cleaner includes a stylus wiping pad holder mounted for motion along a path which is angularly disposed with respect to the carriage path. The location of the holder path is such that the stylus arm carriage engages the holder to drive it away from the record, against the force of a spring, as the carriage is driven toward an off-record rest position. The holder, carrying a stylus wiping pad, follows the carriage as it heads toward the record for playback. A stylus lifting/lowering apparatus located in the carriage is momentarily activated to cause engagement between the stylus with the wiping pad at points beyond the periphery of the record to effect stylus cleaning as the carriage is heading away from the off-record rest position.

Abstract: A caddy-type player has a pair of spring-loaded lockout members disposed at the opposite ends of the caddy input slot. The lockout members are positioned inside and outside the caddy insertion path, respectively, in response to the presence of and the absence of a record/spine assembly inside the player. The lockout members have square edges and sloping edges which are, respectively, disposed perpendicularly and non-perpendicularly to the caddy insertion path when the lockout members are positioned in the caddy insertion path. When an empty caddy sleeve is inserted into the player to retrieve a retained record/spine assembly, its leading edges engage the respective sloping edges of the lockout members to position the lockout members outside the caddy insertion path. If a full caddy is inserted into the player, while it already has another record/spine assembly inside, the square edges of the lockout members engage the leading edge of the full caddy to prevent it from going in.

Abstract: The stylus arm carriage is provided with a slidably-mounted plunger. When the carriage is driven to an off-record home position, a portion of the front wall of the player engages a protruding end of the plunger to drive it in. The other end of the plunger engages a carriage-mounted stylus cleaner mechanism to lock it in place while the carriage is disposed at the home position to prevent the possibility of accidental contact between a pickup stylus and the cleaner mechanism.

Abstract: A record handling mechanism in a disc record playback system includes a record lifting finger which rises through a slot in the turntable to lift a record against a pair of stops located above a set of record receiving pads. The record receiving pads are then retracted out of the way, and the record lifting finger is lowered to a position below the turntable to transfer the record to the turntable. The operating sequence is reversed to restore the record back on the receiving pads.

Abstract: The player has a record handling mechanism which consists of a sequencing cam for coordinating the operations of a record lifting finger and a set of record receiving pads. To transfer a record from the record receiving pads to a turntable for playback, the record lifting finger is raised through a slot in the turntable to lift the record to a position above the receiving pads, the receiving pads are retracted out of the way, and then the record lifting finger is withdrawn to a location beneath the turntable to deposit the record on the turntable. To transfer the record back to the record receiving pads for retrieval, the sequence of operations is basically reversed. It is desirable to hold the registration between the turntable slot and the record lifting finger when the player is turned off. To this end a shutoff switch actuating mechanism is provided. When the player is turned off, the sequencing cam is driven in a direction that raises the record lifting finger through the turntable slot.

Abstract: A turntable secured to a bearing member is freely rotatable about a support post. The bearing member has radial slots through which the fingers of a segmented spindle protrude. The spindle is axially slidable on the post. A spring is disposed about the post for urging the spindle upward for engagement with the record center hole as a record is placed on the turntable.

Abstract: A stylus arm assembly is formed by heating the stylus to about 250.degree. F., and then inserting it into a section of heat shrink tubing. The subsequent heating of the joint causes the portions of the heat shrink tubing surrounding the stylus to shrink to fixedly hold the stylus in place.

Abstract: A stylus cleaner arm is pushed back to a retracted position when a record-bearing caddy is inserted into the player to load an enclosed record therein. The cleaner arm is held in the retracted position by a record retaining spine upon subsequent jacket withdrawal. The cleaner arm follows the caddy as it is withdrawn from the player after record playback. The cleaner arm engages a switch which actuates a stylus lowering device to lower a pickup stylus onto a cleaning pad disposed on the cleaner arm. The cleaning pad wipes the stylus as the cleaner arm swings back. A timing device deenergizes the stylus lowering device after a preselected time interval to lift the stylus away from the cleaning pad.