Random access memory system employing a phonograph disk

Claim 2

A memory system for storing digital information comprising, a disk having a multi-turn spiral groove therein, said information being stored within said groove; address entry means for entering an address indicative of a specific portion of said groove to be accessed; a readout head mounted for substantially radial movement across said spiral groove and for tracking movement within said groove upon rotation of said disk; means for rotating said disk; means responsive to the entry of an address into said address entry means for moving said readout head radially across said disk in contact with said disk such that said readout head produces output signals for each turn of said spiral traversed; means coupled to said address entry means and to said readout head for stopping the traversing movement of said readout head in a radial position in said groove determined by a comparison between said entered address and the readout head signals produced during the traversing motion, said means for rotating thereafter rotating said disk to produce tracking movement of said readout head within said groove, and output means producing output signals indicative of the information stored at said addressed position within said groove.

Claim 3

A memory system in accordance with claim 1 wherein said rotating means operates to rotate said disk only after the traversing motion of said readout head has been stopped.

Claim 4

A memory system in accordance with claim 2 wherein said rotating means commences rotation of said disk at a predetermined time delay after the traversing motion of said readout head has stopped.

Claim 5

A memory system in accordance with claim 1 wherein said stored digital information is stored in the form of undulations within said spiral groove and said readout head includes a phonograph stylus.

Claim 6

A memory system in accordance with claim 4 wherein said readout head has a normal home position near the center of said disk and wherein said spiral commences at a point further out on said disk than said home position, the traversing motion of said readout head being from the home position outwardly across said disk.

Claim 7

A memory system in accordance with claim 5 wherein said means for stopping the traversing movement of said readout head includes a comparator means for comparing the entered address to the number of signals produced by the readout head upon traversing the turns of said groove, said stopping means acting in response to said comparator means only to stop said traversing movement when said stylus has traversed a specific number of turns beyond the radial position corresponding to the entered address.

Claim 8

A memory system for storing digital information comprising, a disk having a multi-turn spiral groove therein, said digital information being stored as a series of undulations within said groove, address entry means for entering an address indicative of a specific portion of said groove to be accessed; a transducer including a phonograph stylus; an arm pivotally mounted on a pivot positioned beyond the edge of said disk, said arm carrying said transducer for radial motion of said transducer transversely across the turns of said groove and for tracking movement within the groove upon rotation of said disk; means for rotating said disk; means responsive to the entry of an address into said address entry means for moving said arm radially across said disk, maintaining said stylus in contact with said disk such that said transducer produces an electrical output signal for each turn of said spiral as it is traversed; means responsive to the entered address and to the signals from said transducer for stopping the traversing radial motion of said arm when said stylus is positioned in a turn in said groove further out on said disk than the specific portion corresponding to the entered address, said rotating means thereafter rotating said disk to produce tracking movement of said transducer within said groove, and output means coupled to said transducer for producing output signals indicative of the information stored at said addressed position.

Claim 9

A memory system for storing digital information comprising, a disk having a multi-turn spiral groove therein, said digital information being stored as a series of undulations within said groove, address entry means for entering an address indicative of a specific portion of said groove to be accessed; a transducer including a phonograph stylus; an arm pivotally mounted on a pivot positioned beyond the edge of said disk, said arm carrying said transducer for radial motion of said transducer transversely across the turns of said groove and for tracking movement within the groove upon rotation of said disk; means for rotating said disk; means responsive to the entry of an address into said address entry means for moving said arm radially across said disk, maintaining said stylus in contact with said disk such that said transducer produces an electrical output signal for each turn of said spiral as it is traversed; means responsive to the entered address and to the signals from said transducer for stopping the traversing radial motion of said arm when said stylus is positioned in a turn in said groove further out on said disk than the specific portion corresponding to the entered address, said rotating means thereafter rotating said disk to produce tracking movement of said transducer within said groove, and output means coupled to said transducer for producing output signals indicative of the information stored at said addressed position.

Claim 10

A memory system in accordance with claim 7 wherein said transducer has a normal home position near the center of said disk and wherein said radial traversing motion of said transducer is outwardly from said home position across the turns of said groove.

Claim 11

A memory system in accordance with claim 8 and further including means operative after the information stored at said address position has been ascertained for disengaging said stylus from contact with said disk and returning said transducer to its home position.

Claim 12

A memory system in accordance with claim 8 wherein said means for stopping the traversing movement of said arm includes a comparator means for comparing the output signals from said transducer with said entered address and for actuating said stopping means to stop the traversing motion only when the signals from said transducer indicate that said stylus is positioned in a portion of said groove several turns beyond that portion of the groove corresponding to the entered address.

Claim 13

A memory system in accordance with claim 7 wherein said means for moving said arm radially across said disk includes a motor and a mechanical linkage for coupling said motor to said arm such that rotation of said motor produces said radial traversing motion of said arm.

Claim 14

A memory system in accordance with claim 11, wherein said mechanical linkage includes an energizable electromagnetic element, said electromagnetic element being energized for traversing motion of said arm, said means for stopping the motion of said arm acting to deenergize said electromagnetic element to decouple said arm from said motor to stop the traversing radial motion of said arm.

Claim 15

A memory system in accordance with claim 11 wherein said mechanical linkage includes a belt havinG means for mechanically linking a specific section of said belt to said arm and wherein said motor is a bi-directional stepping motor which is operated in a first direction to move said arm radially across said disk in an outward direction, while said stylus is in contact with said disk and to operate in the opposite direction to move said arm inwardly to a rest position near the center of said disk after said output means has produced the output signals indicative of the stored information.

Claim 16

A memory system in accordance with claim 13 wherein said means for linking said arm to said belt includes an energizable electromagnetic element which is energized for moving said arm radially across said disk and wherein said means for stopping radial motion of said arm includes means for deenergizing said electromagnetic element to stop the traversing radial motion to said arm.

Claim 17

A memory system in accordance with claim 14 and further including first and second limit switches, said first limit switch being positioned near said belt to be actuated by said electromagnetic element at a position corresponding to the arm having moved radially to a position at the outer edge of said disk, the second limit switch being positioned to be actuated by the electromagnetic element on said belt at a position corresponding to the arm being positioned near the center of said disk in a home position, said first and second limit switches, upon actuation, acting to deenergize said motor.

Claim 18

A memory system in accordance with claim 11 wherein said mechanical linkage includes a cam having at least one cam surface and wherein said motor is a uni-directional motor, said mechanical linkage being such that it includes means for reversing the direction of motion of said arm after said linkage has traveled a predetermined distance in a first direction, whereby said arm may be moved from an initial position near the center of said record outwardly across the turns in said spiral groove and thereafter move from an outer position at the periphery of said disk back inwardly across said turns in said groove to said initial position.

Claim 19

A memory system in accordance with claim 16 wherein said cam includes a second cam surface positioned to raise said arm to disengage the stylus from physical contact with said disk surface when said arm is moving in the opposite direction to return to its rest position.

Claim 20

A memory system in accordance with claim 16 wherein said mechanical linkage includes an energizable electromagnetic element coupling said arm to said motor, said electromagnetic element being initially energized to provide for moving said arm in a radial traversing motion across said spiral turns, said stopping means including means for deenergizing said electromagnetic element to stop the traversing radial motion of said arm.

Claim 21

A memory system in accordance with claim 18 and further including first and second limit switches positioned to be actuated by said cam surface when said electromagnetic element is in a position such that if said electromagnetic element is energized, said arm is positioned at the extreme outer edge of disk, the actuation of said first limit switch acting to stop the action of said motor, said second limit switch being positioned to be actuated by said cam surface when said arm is positioned at a home position near the center of said disk, said second limit switch, when actuated stopping the action of said motor.

Claim 22

Apparatus for positioning a memory system readout transducer at a radial position on a disk having a multi-turn spiral groove inscribed thereon, the radial position being designated by an address entered into an entry means in said system, said apparatus comprising, means mounting said readout transducer for substantially radial movement across said spiral groove and for tracking movement within said groove upon rotation of said disk; means responsive to the entry of an address into said address entry means for moving said readout transducer radIally across said disk in contact with said disk such that said readout transducer produces output signals for each turn of said spiral traversed; means responsive to said entered address for stopping the traversing movement of said readout transducer in a radial position in said groove determined by a comparison between said entered address and the readout transducer signals produced during the traversing motion.

Claim 23

Apparatus for positioning a memory system readout transducer at a radial position on a disk having a multi-turn spiral groove inscribed thereon, the radial position being designated by an address entered into an entry means in said system, said apparatus comprising, means mounting said readout transducer for substantially radial movement across said spiral groove and for tracking movement within said groove upon rotation of said disk; means responsive to the entry of an address into said address entry means for moving said readout transducer radIally across said disk in contact with said disk such that said readout transducer produces output signals for each turn of said spiral traversed; means responsive to said entered address for stopping the traversing movement of said readout transducer in a radial position in said groove determined by a comparison between said entered address and the readout transducer signals produced during the traversing motion.

Claim 24

Apparatus in accordance with claim 20 wherein said transducer includes a phonograph stylus.

Claim 25

Apparatus in accordance with claim 21 wherein said readout transducer has a normal home position near the center of said disk and further in than the point at which said spiral groove commences, the traversing motion of said readout transducer being from the home position outwardly across said disk.

Claim 26

Apparatus in accordance with claim 22 wherein said means for stopping the traversing movement of said readout transducer includes a comparator means for comparing the entered address to the number of signals produced by the readout transducer upon traversing the turns of said groove, said stopping means acting in response to said comparator means only to stop said traversing movement when said stylus has traversed a specific number of turns beyond the radial position corresponding to the entered address.

Claim 27

Apparatus for positioning a memory system readout transducer including a phonograph stylus at a radial position on a multi-turn spiral groove inscribed on a memory disk, the radial position being designated by an address entered into an entry means in said system, said apparatus comprising; an arm pivotally mounted on a pivot positioned beyond the edge of said disk, said arm carrying said transducer for radial motion of said transducer transversely across the turns of said groove and for tracking movement within the groove upon rotation of said disk; means responsive to the entry of an address into said address entry means for moving said arm radially across said disk, maintaining said stylus in contact with said disk such that said transducer produces an electrical output signal for each turn of said spiral as it is traversed; means responsive to the entered address and to the signals from said transducer for stopping the traversing radial motion of said arm when said stylus is positioned in a turn in said groove farther out on said disk than the specific portion designated by the entered address.

Claim 28

Apparatus for positioning a memory system readout transducer including a phonograph stylus at a radial position on a multi-turn spiral groove inscribed on a memory disk, the radial position being designated by an address entered into an entry means in said system, said apparatus comprising; an arm pivotally mounted on a pivot positioned beyond the edge of said disk, said arm carrying said transducer for radial motion of said transducer transversely across the turns of said groove and for tracking movement within the groove upon rotation of said disk; means responsive to the entry of an address into said address entry means for moving said arm radially across said disk, maintaining said stylus in contact with said disk such that said transducer produces an electrical output signal for each turn of said spiral as it is traversed; means responsive to the entered address and to the signals from said transducer for stopping the traversing radial motion of said arm when said stylus is positioned in a turn in said groove farther out on said disk than the specific portion designated by the entered address.

Claim 29

Apparatus in accordance with claim 24 wherein said transducer has a normal home position near the center of said disk and wherein said radial traversing motion of said transducer is outwardly from said home position across the turns of said groove.

Claim 30

Apparatus in accordance with claim 25 and further including means operative after the information stored at said address position has been ascertained for disengaging said stylus from contact with said disk and returning said transducer to its home position.

Claim 31

Apparatus in accordance with claim 25 wherein said means for stopping the traversing movement of said arm includes a comparator means for comparing the output signals from said transducer with said entered address and for actuating said stopping means to stop the traversing motion only when the signals from said transducer indicate that said stylus is positioned in a portion of said groove several turns beyond that portion of the groove corresponding to the entered address.

Claim 32

Apparatus in accordance with claim 24 wherein said means for moving said arm radially across said disk includes a motor and a mechanical linkage for coupling said motor to said arm such that rotation of said motor produces said radial traversing motion of said arm.

Claim 33

Apparatus in accordance with claim 28 wherein said mechanical linkage includes an energizable electromagnetic element, said electromagnetic element being energized for traversing motion of said arm, said means for stopping the motion of said arm acting to deenergize said elecTromagnetic element to decouple said arm from said motor to stop the traversing radial motion of said arm.

Claim 34

Apparatus in accordance with claim 28 wherein said mechanical linkage includes a belt having means for mechanically linking a specific section of said belt to said arm and wherein said motor is a bi-directional stepping motor which is operated in a first direction to move said arm radially across said disk in an outward direction, while said stylus is in contact with said disk and to operate in the opposite direction to move said arm inwardly to a rest position near the center of said disk after said output means has produced the output signals indicative of the stored information.

Claim 35

Apparatus in accordance with claim 30 wherein said means for linking said arm to said belt includes an energizable electromagnetic element which is energized for moving said arm radially across said disk and wherein said means for stopping radial motion of said arm includes means for deenergizing said electromagnetic element to stop the traversing radial motion to said arm.

Claim 36

Apparatus in accordance with claim 31 and further including first and second limit switches, said first limit switch being positioned near said belt to be actuated by said electromagnetic element at a position corresponding to the arm having moved radially to a position at the outer edge of said disk, the second limit switch being positioned to be actuated by the electromagnetic element on said belt at a position corresponding to the arm being positioned near the center of said disk in a home position, said first and second limit switches, upon actuation, acting to deenergize said motor.

Claim 37

Apparatus in accordance with claim 28 wherein said mechanical linkage includes a cam having at least one cam surface and wherein said motor is a uni-directional motor, said mechanical linkage being such that it includes means for reversing the direction of motion of said arm after said linkage has traveled a predetermined distance in a first direction, whereby said arm may be moved from an initial position near the center of said record outwardly across the turns in said spiral groove and thereafter move from an outer position at the periphery of said disk back inwardly across said turns in said groove to said initial position.

Claim 38

Apparatus in accordance with claim 33 wherein said cam includes a second cam surface positioned to raise said arm to disengage the stylus from physical contact with said disk surface when said arm is moving in the opposite direction to return to its rest position.

Claim 39

Apparatus in accordance with claim 33 wherein said mechanical linkage includes an energizable electromagnetic element coupling said arm to said motor, said electromagnetic element being initially energized to provide for moving said arm in a radial traversing motion across said spiral turns, said stopping means including means for deenergizing said electromagnetic element to stop the traversing radial motion of said arm.

Claim 40

Apparatus in accordance with claim 35 and further including first and second limit switches positioned to be actuated by said cam surface when said electromagnetic element is in a position such that if said electromagnetic element is energized, said arm is positioned at the extreme outer edge of disk, the actuation of said first limit switch acting to stop the action of said motor, said second limit switch being positioned to be actuated by said cam surface when said arm is positioned at a home position near the center of said disk, said second limit switch, when actuated stopping the action of said motor.