×

Optical read-write system with electronically variable image size

  • US 4,233,636 A
  • Filed: 07/03/1978
  • Issued: 11/11/1980
  • Est. Priority Date: 07/03/1978
  • Status: Expired due to Term
First Claim
Patent Images

1. An optical read-write system for scanning an object and reproducing an image which may vary in size from said object comprising:

  • first laser means for linearly scanning an object at a scan rate and a photo multiplier tube for generating an electrical image signal for each scan,means for generating a read clock signal having a read frequency and generating a write clock signal having a write frequency, said means for generating a read clock signal and a write clock signal includinga source of a reference signal,a phase comparator for receiving said reference signal and a feedback signal and producing a control voltage based on a comparison of said reference signal and said feedback signal,a voltage controlled oscillator having a control terminal, means connecting said control voltage from said phase comparator to said control terminal whereby said oscillator generates a pulse signal at a frequency dependent on said control voltage,pulse removal means connected to receive said oscillator signal and controllable to produce an output signal in which a variable number of pulses of said oscillator signal may be removed,frequency divider means connected to receive said output signal from said pulse removal means and produce a divider output signal at a frequency lower than said oscillator signal frequency,means for applying said divider output signal to said phase comparator as said feedback signal, said write clock signal being derived from said oscillator signal and said read clock signal being derived from said output signal produced by said pulse removal means,means for storing said electrical image signal at said read frequency in synchronization with the scan of said means for optically scanning, andsecond laser means for receiving said stored electrical image signal and linearly scanning at said scan rate for displaying an image at said write frequency.

View all claims
  • 3 Assignments
Timeline View
Assignment View
    ×
    ×