Multiple zone multiple disk video recording system

A video disk recording system for video signals including synchronization pulses defining fields, said signals being formed into a parallel digitized data stream N bits wide comprising

• a plurality M of recording disks mounted for coordinate movement,
• a servo disk,
• spindle means for mounting said disks for rotation in common about a single axis, said recording disks and servo disk having a plurality of data impressionable surfaces thereon,
• said servo disk carrying a set of once-around reference pulses for establishing a position synchronizing signal to which all said data tracks are physically and electrically synchronized,
• motor means for rotating the spindle at a speed for synchronizing the video pulses with the once-around reference pulses,
• means forming a plurality of read/write heads and a servo reading head associated with said recording surfaces respectively,
• actuator means for mounting said plurality of heads and including arm means for carrying said heads over each respective disk surface,
• whereby video recording proceeds as each video field is recorded one of a series of single cylinders defined collectively by a set of tracks on the recording disk surfaces taken together,
• means for incrementally adjusting the speed of said motor means until the video sync pulses coincide with servo disk reference pulses,
• means for locking up the motor speed when coincidence occurs, said disk memory thereby forming a parallel stack which accepts M bit words,
• and means forming a word formatter for accepting data in N bit parallel words and for converting the same into M bit parallel words continually in real time of said video signal whereby an N bit wide parallel data stream is connected into and recorded as an M bit parallel data stream.

A video disk recording system for video signals including synchronization pulses defining fields, said signals being formed into a parallel digitized data stream comprising

• a plurality of recording disks mounted for coordinate movement,
• a servo disk,
• spindle means for mounting said disks for rotation in common about a single axis, said recording disks and servo disk having a plurality of data impressionable surfaces thereon,
• said servo disk carrying a set of once-around reference pulses for establishing a position synchronizing signal to which all said data tracks are physically and electronically synchronized,
• means for rotating the spindle at a speed for synchronizing the video pulses with the once-around reference pulses,
• means forming a plurality of read/write heads and a servo reading head associated with said recording surfaces respectively,
• actuator means for mounting said plurality of heads and including arm means for carrying said heads over each respective disk surface whereby video recording proceeds as each video field is recorded on one of a series of single cylinders defined collectively by a set of tracks on the recording disk surfaces taken together, each of said read/write heads including read/write amplifiers each of which comprises a magnetic head circuit mounted on an actuator in recording relation to a respective disk, a write circuit for providing a current source in response to write signals, a read circuit for providing a low noise preamplifier,
• solid state switching means for selectively interconnecting said read circuit or said write circuit to said head and for switching very rapidly between read and write circuit functions, said switching means being under control of an electrical signal,
• said read circuit, write circuit, solid state switching means being constructed as a discrete hybrid circuit, means for mounting each circuit on the end of an actuator arm with said respective read/write head.

A video disk recording system for video signals including synchronization pulses defining fields, said signals being formed into a parallel digitized data stream comprising

• a plurality M of recording disks mounted for coordinate movement,
• a servo disk,
• spindle means for mounting said disks for rotation in common about a single axis, said recording disks and servo disk having a plurality of data impressionable surfaces thereon,
• said servo disk carrying a set of once-around reference pulses for establishing a position synchronizing signal to which all said data tracks are physically and electrically synchronized,
• motor means for rotating the spindle at a speed for synchronizing the video pulses with the once-around reference pulses,
• means forming a first plurality (A) of read/write heads and a servo reading head associated with said recording surfaces respectively,
• actuator means (A) for mounting said first plurality of heads and including arm means for carrying said heads over each respective disk surface in a first zone (A),
• means forming second plurality (B) of read/write heads and a servo head associated with said recording surfaces respectively,
• actuator means (B) independent of said first actuator means for mounting said second plurality of heads, and including second arm means for carrying said heads over each respective recording surface in a second zone (B) independently of said first zone (A),
• means for recording alternate fields of video data on said first and second zones respectively, the actuator means of one zone performing track search functions while the actuator and heads of the other zone are reading or writing,
• a computer and a flaw map memory, means for programming said computer for comparing a flaw memory location with an incoming track request and for computing a next non-flawed track in a real time segment short enough for the seeking actuator to complete finding the next non-flawed track.