System for recording and reading back data on a recording media

• US 4,122,501 A
• Filed: 12/13/1976
• Issued: 10/24/1978
• Est. Priority Date: 12/13/1976
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sperry Rand Corporation
• Inventors: Cloke, Robert L., Sordello, Frank J.
• Primary Examiner(s): Canney, Vincent P.
• Application Number:
  US05/750,204
• Time in Patent Office: 680 Days
• Field of Search: 360/51
• US Class Current: 360/51
• CPC Class Codes: G11B 20/16 using non self-clocking codes, i.e. the clock signals are either recorded in a separate clocking track or in a combination of several information tracks

Abstract

A system for detecting data from and recording data on a recording media whereby a single clocking signal generator is utilized for generating the clocking signal both during the recording of data on and the reading of data from the recording media.

Claims

1. A system for reading data from a recording media, comprising in combination:

data readback means for reading data from the recording media;

clocking signal generating means for generating a clocking signal for data read from the recording media, said clocking signal having a frequency responsive to an input signal supplied to the generating means;

means to regulate the input signal responsive to the frequency of the data recorded on the recording media;

means to momentarily stop the clocking signal generating means when said data readback means is energized to read data from the media and when data is detected from the media by the readback means; and

means to start the clocking signal generating means with the phase of the clocking signal corresponding to the phase of the data signal whereby the clocking signal will be set at a frequency corresponding to that of the data signal with the setting of the input signal as previously determined.

2. A system for reading data from and recording data on a recording media, said recording media being capable of generating a media signal responsive to the velocity of the recording media;

data recording means to write data on the recording media;

data readback means to read data from the recording media;

a clocking signal generator for generating a clocking signal for the data having a frequency responsive to an input signal;

means to adjust said input signal responsive to changes in velocity in the recording media, thereby to maintain the clocking signal frequency at a level responsive to the velocity of the media;

means to supply the clocking signal to the data recording means while writing data on the recording media;

means to stop the clocking signal generator when the data readback means is energized to detect data from the recording media; and

means to start said clocking signal generator when said readback means detects data from the recording media, said starting being accomplished at a time responsive to the data thereby to correlate the phase of the clocking signal with the data.